SCIENCE AND POLITICS OF THE US DIET GUIDELINES

It was a comment by Dr. Robert Perlman, a friend and brilliant scientist in the field of evolutionary medicine, that set me off on what I can only call a historical and scientific pilgrimage, a pilgrimage to the beginnings of the modern guidelines. At the end of my most recent article on the guidelines and our present stone fomenting diet, he pointed out that the US diet guidelines are so influential and the new ones so helpful in management of kidney stone disease we all must question who creates them, and how. The guidelines must have, he implies, the kind of elaborate and winding history one expects from a succession of governmental committees which, howsoever well served by volunteer scientific experts, can be subverted – by money, by … Continued

OUR DIET PROMOTES STONES AND BONE DISEASE

I have summarized the scientific evidence that low intakes of diet calcium and potassium and high intakes of refined sugar and sodium and protein raise risk of stones and loss of bone mineral. I have pointed out that the recommended US diet specifically seeks to correct all five of these risks and we should recommend it to all of our stone patients unless contraindicated by some specific problem. But I have not as yet shown to what extent we as a nation eat a diet deficient in calcium and potassium and excessive in refined sugar, sodium, and protein. In other words I have not as yet quantified the extent of the problem that stone forming patients face. Here is evidence from a large body … Continued

THE SCIENCE OF THE KIDNEY STONE DIET

What is the Point of this Article? From 1980 to now the US government has published diet recommendations for the American people. Gradually and over time these have become quantitative and specify amounts of critical nutrients such as calcium, sodium, refined sugar, protein, and potassium – as alkaline anions in mainly fruits and vegetables. The goals are reduction of osteoporosis, hypertension, obesity, and diabetes. Decades of kidney stone research have converged on precisely the same diet though aimed at management of hyperoxaluria, hypocitraturia, and bone disease and stone risk from idiopathic hypercalciuria.The government document recognizes that the DASH diet embodies many of the elements of the current US diet recommendations, and stone researchers have established that ‘DASH – Like’ diets associate with reduced stone … Continued

CASE 4: MEDULLARY SPONGE KIDNEY

Medullary sponge kidney (MSK) is more spoken about than witnessed, and more witnessed than accurately diagnosed. This patient adds to the 12 we have described in our publication, and adds also in having a very long and evolving history with one of us (FLC). We write for a general audience yet hope to include a level of detail that satisfies physicians and scientists. Here, we may fail of clarity to the one audience or of a sufficiency to the other because the disease is complex. But withal, the evolution of diagnosis and care for this person so educates and the surgical anatomy and histopathology so instructs we have chosen to share the experience. What is it we are sharing? MSK is a Unique Disease MSK is remarkably specific in … Continued

HOW TO EAT THE KIDNEY STONE DIET

Recently we presented what we think of as The kidney stone diet, meaning a unitary diet platform suitable for idiopathic calcium stone formers in otherwise good health. The story of that diet and the implications it has for stone prevention deserve perhaps a bit more commentary than we allowed for in the original article. The lovely image – Hendrick van Cleef, The Building of the Tower of Babel hangs in the Kröller-Müller Museum. He (1525 – 1589) is one of a family of famous painters and much admired for his brilliant textures and colors. Babel was to keep us aware we are divine. The Narrow Winding Path Over many decades, kidney stone researchers have gradually recognized what the ideal kidney stone diet might be. They did … Continued

THE KIDNEY STONE DIET

If we put together everything on this site about diet for kidney stone prevention we get a reasonable and consistent image of one basic pattern. It is more or less what is ideal for idiopathic hypercalciuria and for reducing urine oxalate. It is the diet that has been used in the one major trial of diet for stone prevention. It accords with modern recommendations for the health of the American people. More or less, after all is said, there is only one diet plan that meets the needs for kidney stone prevention and we have called it ‘The Kidney Stone Diet.’ Of course, we are speaking of the diet for treatment of idiopathic calcium stones. Stones from systemic diseases, like bowel disease, primary … Continued

Case 3: A Success Story

This is a first for the site, and perhaps it should have been a feature long ago. After all the generalizations and reviews there is something wonderful about a single instance that contains all the elements of a topic in the kind of instructive detail we can get only in life itself. Pat – who has permitted me to use his name and data – forms calcium stones and has idiopathic hypercalciuria and a job that makes hydration a problem. For treatment I wanted to use low sodium diet to lower his urine calcium excretion and if possible avoid thiazide diuretics just because of his job which is outside and in summertime poses serious heat loads. MIchelle, his wife, created a reliable low sodium diet for him as proven by multiple follow up tests and that reduction of sodium lowered urine sodium and stone risk, as one might expect. I asked her to share her experience in doing this, and she responded with this wonderful article. It helps that she is a professional writer! I am indebted to Michelle and Pat for their story, and I hope you like it. 

Does Too Much Protein Increase Stones or Damage Bones?

Some of us overdo things with shakes and powders, some with 2 pound steaks. Others love sweets too much and don’t eat much protein. Like all the diet factors in stone and bone disease, protein intake is complex. Certainly, we all need protein in our diet but how much? Experts debate the best course, and patients wonder what to do. Abraham van Beijeren was, by the way, little recognized in his day but now considered a major painter of ‘luxuries’ like this standing roast. I chose it, as opposed to others more brilliant, because it looks  modern – I have seen something like it on my own dining room table. In preparing this article I have made considerable use of the analyses performed by professor … Continued

TREATMENT OF IDIOPATHIC CALCIUM STONES

Here are all the trials for prevention of idiopathic calcium stones, and my personal approach to using their results in clinical stone prevention. The whole site thus far has been built to support this article, which is the capstone of the enterprise. To highlight its importance I have made it header type larger.

Beside the usual references, I provide spreadsheets that contain all of the trial stone data with links to the original articles and PDF images of the articles. I also provide spreadsheets of stone risk data from the trials that I use in my analysis of the physiological responses to treatment. So this is a definitive as I can make it. I have left the two preceding videos in red because they are the steps up to this article, and perhaps people might want to view them in preparation. The two prior articles on phenotypes that come before the videos are also preparatory to this final presentation.

I say final because with the full presentation of all of the trials we have more or less covered the entirety of idiopathic calcium stone disease and need to move on to other stone types and to the systemic diseases that cause stones.

Video Article: How Stones Form

With considerable trepidation, I unfurl my first and certainly very unpolished video offering. The good part of the articles on this site is their devotion to scientific accuracy and referencing from PubMed. The bad parts are their opacity, length, and difficulty. I have long been a public lecturer and decided that video offerings might be a valuable add on. There is more room, I think I speak better than I write, and it seems to me one video can summarize and complement a group of written articles, so I did this one. It covers crystal formation, how crystals are made, and where in the niches and crevasses of the kidney they actually form. Its message is my usual one: Prevent crystals and you prevent stone disease. This is a beta version. I know it has some errors in it. I also know it lacks refinements I need. But, refinements and corrections will come. Let me know.

IDIOPATHIC CALCIUM OXALATE STONE FORMERS (ICSF)

Here is the most common kind of stone former, described in such detail as one can muster up at this time. They are simple to diagnose: Stones containing a preponderance of calcium oxalate, no uric acid, struvite, cystine, brushite, drugs, or rare organic materials, and exclusion of any systemic disease as a cause of stones. More or less, these patients are stone disease as it is seen in primary care and most urology practices. Of the millions of stone formers most are like this. The trials for prevention of calcium stones have mainly used these patients as a majority of subjects. However common they may be, and easy to define, they are complex in the way that they make stones, and it appears that there may be not one but perhaps two kinds of idiopathic calcium oxalate stone former. Because of modern flexible ureteroscopy the types of idiopathic calcium oxalate stone former will soon be told apart during stone removal surgery, and patients and their physicians confronted with a variety they may not fully expect. This article sums up what is known, as best as I can manage.

CASE 2: A Calcium Oxalate Stone Former

CLINICAL FINDINGS A man in his fifties formed his first stone in the early 2000’s and his last 6 months ago. There was a single passage event a year or two after the first stone at which time he was given hydrochlorothiazide 25 mg daily. A right SWL procedure was performed 1.5 years ago because of a stone attack, and  potassium citrate 10 mEq twice daily was added in treatment. A right sided URS procedure was performed 8 months later but was not completed because of bleeding. A right URS 6 months ago is said to have left his right kidney stone free, but some stones were seen on the left. I did not have images to review when I saw him. He believes that all of … Continued

CASE 1: A stone Former

CASE 1: A Stone Former. As you will see, this is a person with considerable numbers of stone attacks who has certainly produced large stones in the past, but he posed major problems in deciding if stones were active and is therefore a perfect place to start. His many laboratory abnormalities are just wonderful for thinking about stone pathophysiology.

IDIOPATHIC CALCIUM PHOSPHATE STONE FORMERS

The second in this series of stone forming phenotypes, the calcium phosphate stone formers are less numerous than the calcium oxalate stone formers, but perhaps more worrisome, and certainly more complex. There are two types, those whose stones contain any brushite – an unusual form of calcium phosphate in stones, and those whose phosphate is only hydroxyapatite – the mineral found in bones. This latter group is to a large extent composed of young women, for reasons we do not know. Phosphate stones are likely than the calcium oxalate variety to be numerous, and often produce nephrocalcinosis, a mixture of small stones and tissue calcium deposits. Nephrocalcinosis, in turn, is often labelled medullary sponge kidney simply on radiological grounds, even when the distinctive lesions of MSK are not necessarily present. Likewise, phosphate stone patients can appear to have renal tubular acidosis because of nephrocalcinosis and because RTA and phosphate stone patients both produce a more alkaline urine than do normals, or patients with calcium oxalate stones. All in all, this is a complex form of calcium stones, challenging for clinicians and often very trying and concerning for patients with it. The article is long and difficult, so you might want to watch this video by way of an introduction.

Video article: Supersaturation – The calcium crystals

As I see things, all of stone disease concerns the balance between the opposing forces of supersaturation and kinetic retardation of crystallization. The former is better understood and more tractable because easily measured and commercially produced for clinical care. The latter is not fully understood in term of the molecules responsible and not commercially available as a clinical test. So of the two primary forces that control whether crystals can form, we have only supersaturation to use. Being so central, this one measurement, for each of the stone crystals, has unusual importance. These three relatively short videos cover the main elements of supersaturation: What it is, how kidneys produce it, and how it is measured and used in stone prevention. They combine with ‘How Stones Form’ to make what I think is a fine story about stone disease and a fine basis for understanding how stones are best prevented. I have gathered together in the article links to all of the supersaturation articles on the site thus far.

A GREAT SITE FOR KIDNEY STONE PATIENTS

This is a very first for me: Recommending a kidney stone site to those who visit here. Although the internet is vast and even a casual search shows a lot of kidney stone sites, this one stand out because it has all the traits I respect. It is run by a fine and thoughtful urological surgeon with special skills in kidney stone surgery. It has very high academic, intellectual, and scientific standards. It is large and therefore has a lot of material in it whereas many otherwise good sites are small and limited. It has a distinctive tilt toward patients, and a tradition of having patients write articles on it. For people who like this site, kidneystoners.org will feel famiiar yet different enough in its emphasis that to me the sites are highly complementary. Take a look and let me know what you think.

The Idea of Partnership in Treatment and Prevention of Kidney Stones

Partner: ‘a person who takes part in an undertaking with another…‘. Part: ‘a piece or segment of something … which combined with other pieces makes up the whole‘. I am not about trivium in posing this fairly obvious idea. It is not to repeat the obvious. What I am after is clarity about a fact of all medical care – that patients have their part in the matter and that part is at once essential and perhaps not always defined the in best way. The Girl Before a Mirror was painted by Picasso in 1932. I have slightly misaligned it so as to emphasize the faces – her and her images. THE NATURAL DELIMITERS Treatment and Prevention Concern the Body of the … Continued

Web Apps and Smart Bottles

This is an article that can be written only by the readers of this site. We are not product testers nor do we do market surveys. But given how many fluid and diet apps one can find on the web and also given how many people come to this site every month we should be able to get a good idea about which ones seem of value. The benefit of accumulating your experience in comments to this very brief article accrues to all of you who come here. Whether you use an app or not crowd sourcing of a kind can tell us all which ones seem really good, and we can all use that knowledge. There are almost no words in the article, but as the results come in – in other words if you will share – we will count up by app in a table or so, ongoing. As for smart bottles, there are only a few on the market, but we should be able to get an idea about them if you will share. So, here it is: A blank slate for everyone to write on so everyone can benefit. Please share.

Control of Urine Oxalate Excretion

There is no doubt that urine oxalate excretion is an important factor in calcium oxalate kidney stone production, and that excretion is a very complex outcome of transport in the gut and kidney tubules and, of course, diet calcium intake. We have devoted a lot of energy to refining food oxalate lists and making a reasonable diet plan for oxalate. Here, we have taken on the harder task of reviewing the complex movements of oxalate from food into urine. The intestines not only absorb oxalate from food into the blood, they can secrete oxalate back out from blood into the gut lumen from which it is removed in the stool. The kidneys remove the net of diet oxalate absorbed minus that secreted by a process of filtration and subsequent renal cell reabsorption and secretion of that filtered oxalate. It is as though evolution has handled oxalate like a real hot potato: keep control of how much oxalate the kidneys need to remove and keep control of the blood oxalate concentration. This seems prudent – if one dares to speak this way about evolution – as oxalate can crystallize in blood as it does in urine and both processes can be dangerous. The new work on oxalate transport does not now directly translate into new tests or treatments for patients, but surely will. So I and my brilliant colleague Dr Hatim Hassan – who is the real expert here – have written about the future in medicine. Because the article is very complex and may not get a lot of readers – scared off – I have made a tiny movie to introduce it by way of encouragement. 

My Lab Report

This little goodie started with my partner Dr Anna Zisman who to wanted us to have a simpler format for patients to follow in looking at their 24 hour urine lab reports. Answer five easy questions and get back a list of what you have to do with fluids and diet. Try it. Let me know if it works. If not, can you help make it better?

PUTTING IT ALL TOGETHER

Well, here it is, the last pillar in the foundation. My goal is to enable patients to achieve successful stone prevention and I believe this requires a partnership with their physicians, a partnership in which they play a very active individual role. Patients after all are the ones who can manage diet, fluid intake, and life demands, only they can assure that 24 hour urine collections are representative of normal life, and, frankly, only they can decide on a life of long term prevention. Stones being rarely fatal and usually not a cause of progressive kidney disease, patients can elect prevention or not, and their physicians are in a role more like attorneys and accountants than authoritarian directors of events. But as in Eden, one can expect proper choices only if one has provided full knowledge, which I have set out to accomplish. By proper I mean most suitable to patients given full knowledge, for some may not care to exercise themselves so much as I think they must to be successful, whereas others may consider the work of prevention slight indeed compared to the consequences of continued stones. In any event, this article is the end of that cycle of enablement I can manage, and I put it here, as in all writings, as the chef puts out her best effort – to face the indifferent judgement of the gourmet.

HOW TO READ YOUR KIDNEY STONE LAB REPORT – Uric Acid Stones

These two articles cover the main stone types, and this new one on uric acid parallels the prior one on calcium stones. Like the calcium stone article it is meant for patients, although physicians might like some of the nuances. The purpose is not to make patients into their own physicians but to enable them to understand their own stone forming abnormalities. My ruling hypothesis is that patients want prevention, and will embrace and implement the changes needed with more enthusiasm and endurance if they fully understand the goals. LIkewise if they can themselves follow the effects of their efforts on stone risk factors they will believe that what they are doing has real meaning. I know that hypotheses are for disproving, and I know someone may well do a prospective double blind randomized trial, some day, to test mine. Right now, I believe in the idea because of Eden whose resident twosome were not just told about the tree but exactly why they should not eat of its fruit. I know it is an unfortunate comparison, given the outcome, but much effort was expended on education. My source for the details, apart from the Hebrew Bible, is Milton, J: Paradise Lost; Books V – Viii.

HOW TO READ YOUR KIDNEY STONE LAB REPORT – Calcium stones

This site is meant to promote prevention and my current hypothesis is that enabling patients to read their own 24 hour urine tests with a professional eye will help achieve that aim. It is not an easy task. Lab reports, even the best of them, are dazzling arrays of numbers in often mysterious units. Even physicians have some work to do. But numbers are numbers and people can read them if they have the code. Here I have parsed out the main numbers for the calcium stones: Volume, calcium, oxalate, sodium, citrate and pH. Because this is the first article on reading this kind of report I also discuss collection quality, conversion of units – some labs report, as an example, calcium in mg/24 hour, others in mmol/24 hour, even mEq. So I introduce the simple conversions needed to use what I have written for a report with different units. Likewise I introduce how urine creatinine can be used to estimate collection quality. The supersaturation come at the end, as they should, being the final summary of everything. The tone is about that for trainees in nephrology or urology I have often worked with but with jargon elided and a focus on lab results per se. Those interested can follow the links into the thickets of the site which hold enough to satisfy most appetites. The main purpose is to enable patients to cast a cold eye on their own problems and on the results of treatment efforts so that in the event saturations can be effectively reduced and stone recurrence with them.

THIAZIDE DIURETICS FOR STONE PREVENTION

The thiazide type diuretics are able to reduce new stone formation and are an important part of stone prevention regimens. Here is all about these drugs: The trials that show they work; How they work; What they do for bone: Certain precautions in their use. To give a pill to someone is to throw a seed on unprepared ground – it is a sterile and doomed enterprise. All the features of prevention from diet and fluids and lifestyle come first, so that what one can do with them is being done. Then the drug will be most useful. And, you will know by the fall in urine supersaturation achieved. Whatever it was when stones were forming is too high, and real treatment means it has been reduced. After all that can be done without thiazide has been done, there will no doubt be residual supersaturation lowering needed, or one would not use the drug. The marginal benefit of the pill can be assessed by the extra fall in supersaturation it produces. Which supersaturations? Those related to crystals in the stones forming.

Five Steps to Stone Prevention

THE FIVE STEPS TO STONE PREVENTION

Ultimately we want to prevent kidney stones. Trial data, and my own large experience correspond in this one point: Prevention is a reasonable objective that can be successfully accomplished. Here is my own approach, simplified into five steps. They correspond to the overarching theme of this entire site: Stones require crystals; crystals follow the laws of physics; the force that drives crystallization is supersaturation; commercial vendors in the US provide supersaturation measurements in 24 hour urines at a reasonable price. So the steps are indeed simple: Know the stone crystals; measure the urine supersaturations; lower those urine supersaturations for the crystals in the stones being formed; keep them low. If stones persist, lower them more. It takes physicians to initiate this process, and there are complications such as the occasional systemic diseases which must be detected and treated in special ways. But it takes motivated patients to carry out the long term changes in fluids, diet, lifestyle needed, and to take the medications provided. It is time to focus here: Prevention is better than surgery. To help, I wrote a companion article several months ago about how to organize your medical stone prevention visits so as to get the most out of them. 

Control Your Salt for Fewer Stones and Stronger Bones

Two good trials support lower sodium diets as a way of reducing new calcium stone formation and of protecting bones from calcium loss. The physiology behind these trials is detailed in the articles on idiopathic hypercalciuria and salt. In Italy at least, and in men with calcium stones and idiopathic hypercalciuria, a diet low in sodium, moderate in protein, and high in calcium leads to less stones than low calcium diet alone, and in fact to a rather low new stone recurrence rate. Among postmenopausal women, a high calcium low sodium diet brings bone mineral balance into the positive range: Bones add mineral. Neither trial is comprehensive in covering men and women, young and old, US vs. Italian cuisine, but they are the only ones we have of this quality, they are consistent with the science we have, and convincing. To me they are enough to recommend low sodium diet, moderation of diet protein, and high diet calcium for calcium stone formers with idiopathic hypercalciuria, recommend this kind of diet without reservation pending what I hope will be more trials which cover a wider range of patients and of ages. It is this kind of additional trial we really need in the US right now, substantial, bearing on really important diet interventions, and arising out of a sound scientific base.

HOW TO BE A SUCCESSFUL KIDNEY STONE PATIENT

It has always seemed to me that medical practice is a dance. One leads, perhaps, but the other does, too. If physicians know more steps, patients can prepare their parts in advance and organize their large roles in long term treatments so the final result is graceful and ultimately elegant in obtaining the best results with the least extra effort and resources. After all, it is patients who know the past and will determine the future. Here are lists for you, ways to think about time with physicians, and especially a way to think about your treatment over the long years of stone prevention. For it is years, this being a chronic and recurrent disease, years of work by you with only a rare burst of medical guidance here and there. Yet so important as rare needs preparation and curating so what transpires is not lost. What is here is my own ideal of how things should happen, how the dance is conducted – so brief, so important.

IDIOPATHIC HYPERCALCIURIA (IH)

Idiopathic hypercalciuria may well be the most complex and important issue in all of medical management of calcium kidney stones. It arises within the elaborate systems that regulate calcium metabolism and produces both a risk of stone formation and of bone disease with fractures. IH is strongly familial, almost certainly genetic in origin, and present in children as well as adults. Treatments used include high calcium – moderate protein – reduced sodium diet, moderation of dietary sugar loads, and potassium citrate, and thiazide type diuretics, each of which act through different and reasonably well characterized pathways which cannot be understood without a knowledge of how IH works in the first place. Unlike stones themselves, supersaturation, or citrate, each a very large and important topic, IH cannot be presented well – at least by me – in separated linked articles but only in one article that carries its many intersecting physiologies along side by side and uninterrupted. Being a long and comprehensive article, foundational for this site and – to me at least – for comprehension of the whole topic of pathogenesis and treatment of nephrolithiasis, this article is not necessarily meant to be read all at once but rather used as a resource. I will cover the treatments of IH later on, in separate articles.

HYPERCALCIURIA

This is a foundational article for the site. High rates of urine calcium excretion (hypercalciuria) will raise calcium concentration at any given urine flow rate, and therefore raise supersaturation with the calcium stone forming salts. Genetic (‘idiopathic’) hypercalciuria, simply the upper end of the normal range, is greatly over-represented among stone formers, and idiopathic hypercalciuria (IH) is a main focus of treatment for stone prevention. As well, people with IH, stone formers or not, are at risk for bone disease. This article introduces hypercalciuria: IH itself and a few of the less uncommon named diseases that cause hypercalciuria like primary hyperparathyroidism, renal tubular acidosis, and sarcoidosis. It mentions confusing disorders such as normocalcemic primary hyperparathyroidism, secondary hyperparathyroidism, and familial hypocalciuric hypercalcemia. It also offers evidence linking specific levels of urine calcium excretion to risk of stones, a very important matter in deciding what needs to be treated.

WALKING TOUR: SUPERSATURATION

Being so important, the very force that drives crystal and stone formation, supersaturation has enjoyed considerable attention on this site and it seemed time to gather the articles about it into a coherent narrative. The walking tour seems apropos as such tours visit a group of related sites and have, or should have, a guide to put each one into perspective and extract from the entire group some large and generous idea about the world from which they arose. My prior one on stones themselves attempted the same.

THE LOW FLOWS

Given that kidneys supersaturate the urine by conserving water, no treatment can be more immediate and direct than to drink more water than one needs so the kidneys can excrete it and in the process dilute the urine salts – which is to lower supersaturation. Alas, there are many patients who cannot or will not drink enough water, and it is these Joan Parks writes about in this article. Over our 40 years of collaboration very many patients with the problem of persistent low flow have come through our stone program at UC, but Joan and I never wrote a paper about them so much of what we found is buried in their charts. By way of redress, Joan has conjured up a lot of details that we think people will find valuable, even though they have not been shaped into the formal character of a scientific paper.

NEPHROCALCINOSIS

Not a few of you have heard this word and wondered what it meant for your health and management. Here is what it means. On the one hand, crystal deposits in kidney tissue. On the other, the name radiologists use when they see calcified regions overlying your kidneys, regions that are not clearly free stones but could be stones or tissue mineral. They really cannot tell with great precision. They never could. Modern high resolution ureteroscopy can tell, and surgeons everywhere have adopted this wonderful technology into common practice. You need to know this. Those of you who carry the diagnosis of nephrocalcinosis will all benefit from modern surgical visualization as opposed to indirect means of radiology.

A WALKING TOUR ABOUT KIDNEY STONES THEMSELVES

If you want a comprehensive view of what kidney stones are and how they are made, I have put together various of the articles in this by now rather large site to make up a kind of story, or narrative, or, as I like to think of it, a walking tour. Read in the order I suggest, and take a look at the few narrator comments and I promise a nice overview of the topic. More will come if people seem to like this format.

AN EXPERT REBUKES DEFECTIVE ACP GUIDELINES FOR KIDNEY STONE PREVENTION

Dr. David Goldfarb has taken on the American College of Physicians concerning the flawed guidelines they have promulgated for prevention of kidney stones. I have criticised these guidelines  – for fluids and medication use – in two prior articles. My criticisms were about their intellectual failings and naivete concerning medical practice. His are broader because in addition to their intellectual and medical flaws they were published against the advice he gave as a peer reviewer of the articles. Furthermore, as he points out, they do not properly acknowledge the guidelines of the American Urological Association, which represents the main body of physicians who actually take care of stone patients. The AUA guidelines contradict those of the ACP and, in my opinion, and his, properly so. This matters to you as patients. If your doctor has been told something is good and proper, by physicians promoted as experts by the ACP, he or she may act accordingly, and that may not be good for your care. Read what Dr. Goldfarb says, and likewise what I have said about this matter.

SALT

Get ready. We have covered stones, supersaturation, stone risk, potassium citrate, and more, but now we are coming to a central mystery – a pivotal issue in whether or not treatment will work or not. Calcium is the first name of most kidney stones, and the calcium in stones comes mainly from the urine. So the urine calcium is a big deal. Yet it is sodium chloride, humble table salt, that strongly controls how much calcium is in the urine. Genes play a role, protein, too, lots of factors. But salt intake is so modifiable, so amenable to change it has a massive role in treatment. Here is my best on the subject. I hope you like it.

Why 24 Hour Urine: Supersaturation

This is the essential basis for modern kidney stone prevention. I review its limitations, and how much information it provides on the pattern of stone risk factors for a given patient. Also, I show how much variation within a day hides in the 24 hour averaging and what you should do about it, and point out why you need at least two 24 hour urines before treatment. If you have signed up for my emails, read the one for this article because it explains how it is put together and best read.

MARRIAGE OF SCIENCE AND MEDICINE

I have no illusions this will have mass appeal, but the topic is important and many patients may have an interest in how medicine and science work together in general and in this disease as a particular example. Unlike the rest of this site where I am redacting and elaborating well known themes, here I am forced into originality by the general poverty of writing on the subject. For those who like this kind of writing, the Site Logic Page is its natural home. For those who do not – no doubt a vast majority – pass by.

Citrate and the Ostwald Limit

This article will take you for a ride and offer you some surprises.

It is about how urine resists crystallization, a property summed up in the forbidding term ‘Upper Limit of Metastability.’

But don’t be scared off.

The ULM is a powerful concept that will help you understand the real issues in stone prevention.

And, at the end of the article, you will find that quite possibly it is not the mysterious and giant collection of urine proteins which protect us against crystals but perhaps our familiar citrate molecule in league with another small molecule, inorganic pyrophosphate which is a close relative of the bone sparing and common bisphosphonate drugs.

Enjoy.

Potassium Citrate: The Contributions of Dr. Charles Pak

It seems to me important to highlight not only what we can do for stone prevention, but here and there to recognize those people who have given us what we have. Charles Pak’s work was instrumental in getting potassium citrate into the real world as a treatment. He helped to establish it worked, and helped industry make a practical pill form of it. As my tribute to him I have reviewed some his most important papers on the subject. Anyone who uses the drug should care.

HOW POTASSIUM CITRATE PILLS WORK

This article is long and complex but I think patients will want to trouble themselves to read it. It tells the story of how our diet in the US, Europe, and urban Asia imposes an acid load which the kidneys must remove. That demand forces them to conserve citrate which is a natural defense against kidney stones. The pills neutralize the diet acid, and release the kidneys from their lifelong task of compensating for how we eat. That is why the urine citrate can rise. Removing acid is a major task that affects how kidney cells work. The humble potassium citrate pills have massive and probably beneficial effects on those cells. Of course, diet could the same as the pills, but how can one pursue a diet against the tendencies of the culture? Even with a will, most of us could not get it right – the balance of food, a proper nutrition. I could not advise we try.

THE GRAND INHIBITOR

Here is part two: citrate slows and can even stop stone crystals from growing. It does this by binding calcium, not the calcium in the urine but calcium atoms already part of a calcium stone crystal.

By binding to structural calcium atoms, citrate interferes with the orderly arrangement of atoms that is necessary for the crystal to exist, so one can think of inhibition and binding as two aspects of one power.

Like binding itself, this is not easy material to present or read. It is like climbing a tall hill for the view. If you will follow me up, I promise a reward.

CALCIUM BINDING BY CITRATE

The citrate molecule in urine is thought to protect against formation of calcium stones. This thought began as reasoning from chemistry, and culminated in clinical trials which substantiate the idea. As a result manufacturers produce citrate products for medicinal use, and doctors prescribe the medicine. All this is a wonderful success story, a kind of perfection of the paradigm of translational science: From science to a treatment for patients that reduces illness from kidney stone disease. But what, exactly, is the science? Can scientists not enjoy the story of such a success, physicians derive from it a deeper understanding of the drug they so regularly dispense and patients the comfort that a perfected knowledge support the rightness of their prescribed treatment? Citrate The Molecule As … Continued

CITRATE TO PREVENT CALCIUM AND URIC ACID STONES

Potassium citrate, thiazide diuretic agents, and allopurinol are the three medications that have a proven ability to reduce kidney stone formation.

Because fluids are so valuable and safe, we have emphasized their use as a basic treatment for all forms of stone disease. Here, I present the evidence that potassium citrate adds protection. The evidence is in the form of 5 trials that appear well done.

Some of the background for this article was already prevented in our discussion of the costs of this drug. Likewise, that discussion presented alternative sources of alkali that should more or less mimic the protective effects of the drug despite lack of direct trial data. I say this because the drug is a simple alkaline salt. 

The article is written for anyone. Physicians will fill in more blanks than patients, but patients can easily analyse the numbers.

OBJECTIVES OF APPLIED MEDICAL SCIENCE

I have alluded to objectives in my discussion of applied, basic, and empirical science, which was a good place for their first mention but too narrow for a proper exposition. They are in the first case an expression of need, in the second case of desire, and in the third arise from perhaps an altogether different source. Here I am concerned with objectives of applied medical science. CLASSES OF NEEDS What can be the perceived needs of medicine but treatments, prevention, tests – to aid diagnosis or prognosis, methods, techniques and devices? EXAMPLES OF EACH CLASS Consider a patient with calcium oxalate stones not due to systemic disease, ‘idiopathic’ stones. Treatments This refers to stones present; they are there and surgeons need … Continued

ACP GUIDELINES: MEDICATION

This post concerns guidelines just released by the American College of Physicians (ACP) concerning prevention of calcium kidney stones. In the article two specific guidelines are proposed. The first, on fluid management, is covered in another post. Here I discuss their views concerning uses of medication. The discussion here is in advance of what is already on the site. Whereas I and others have put up more than a few articles about fluids, the issue of medications has not arisen. This is because medications have always been used to alter excretion rates of three atoms or molecules in urine thought to alter risk of calcium kidney stones: calcium, citrate, and uric acid. I have not as yet set the foundation for discussion of … Continued

ACP GUIDELINES: FLUIDS

The American College of Physicians has published its Clinical Guidelines on dietary and pharmacological management of kidney stones in adults. My purposes are to place the results of their deliberations in clinical context and also draw some conclusions about research we might want to perform. Though only two in number, their recommendations cover virtually our entire field of practice. For this reason I thought it best to consider each of the two separately, in different posts. As a simplification, I accept the statistical analysis as correct. Partly I suspect it is correct. Partly, I am not engaged with the methods of the analysis so much as I am with how we view their results and their conclusions. The ACP Guidelines can be influential among primary care physicians. As people involved with … Continued

BASIC SCIENCE IN MEDICAL PRACTICE

WHAT IS THE QUESTION? I understand that some physicians are skilled basic scientists, and that many physicians enjoy reading about basic science. But how does a knowledge of basic science benefit the patients of physicians who have such knowledge? There are two parts to this question. How can being a basic scientist benefit a physician in the practice of medicine, and how can a knowledge of the results of basic science benefit a physician in the practice of medicine. Of these two, I mean to consider only the second: How does a knowledge of basic science results benefit the practice of medicine. Of course, here, I mean practice of medicine concerned with kidney stones – the disease within the province of this site … Continued

SCIENCE AND MEDICINE

Three Sciences of Medicine Certainly we all agree that modern medicine takes its power from science. One kind of science concerns how we can do things. Let me call it ‘applied science’ for want of a name. The other kind concerns how nature does things. This is often called ‘basic science’ or ‘natural science’. Drug development and drug trials are obvious examples of the first. Mechanisms of disease are examples of the second. These statements are so obvious I hesitate to make them, yet in such phrases as ‘evidence based medicine’, ‘basic vs. applied science’, ‘personalized medicine’, and ‘translational research’ the distinction, itself perfectly clear, can blur. If basic science seeks to learn how nature does things, empirical science seeks to … Continued

THE SCIENCE OF FLUID PRESCRIPTION FOR KIDNEY STONES

How does anyone really know the amount of fluids you need for stone prevention? Dr. Elaine Worcester and I have put together much of what is known about the topic and offer some reasonable guidelines. Our caveat: These are guidelines, but have your physician do the final decision. Not everyone can drink large amounts of fluids, and not every patient needs the maximum amount, either.

PRICE OF POTASSIUM CITRATE

I never have been a remarkable shopper, so those who know me well might wonder at a post about prices. Even so, patients have complained and wanted alternatives to potassium citrate pills which have become too costly for them. I did a bit of web shopping for retail prices, and although they vary, even the lowest seem too high for most budgets. A very brief look at insurance plans under Medicare: Some plans just pay the whole bill; some charge $10.00 for 100 pills; some charge a percentage of retail; some do not pay. So I have put together alternatives which taken in aggregate permit everyone to piece together a replacement for all or at least some fraction of these pills whose price has become just too high.

ROLE OF INNATE IMMUNITY IN PLAQUE FORMATION

The complex but interesting featured graphic introduces aspects of the innate immune system which is present and active in the kidney and may have a role in stone genesis. Although innate immunity in kidney is a well established area of research, the specific links to plaque and stone formation have not been explored thus far. So, my post is meant to interest people in the possibility and perhaps give rise to some new scientific research. Toll Like Receptors (TLRs) The innate immune system is an ancient system of defense against environmental threats that is found in all classes of plant and animal life. Innate immunity provides immediate, non-specific defense against infection and products of cell damage or stress. Toll-like receptors (TLRs), … Continued

CAN PAPILLARY DENSITY PREDICT NEW STONES?

Ciudin et al JOURNAL OF ENDOUROLOGY Volume 28, Number 8, August 2014 Mary Ann Liebert, Inc. Pp. 1016–1021 Dr Jim Lingeman sent along a PDF of this article, which seems so useful and so germane to our current posts I decided to write about it. WHAT THE AUTHORS DID They Identified People with Prior CT Scans They did a cohort followup study of an initial 1000 people who had an CT performed between January and March 2005. From the 1000, 576 fulfilled their initial inclusion criteria which included that the CT was not performed for stone disease. Of these 177 were lost to followup leaving 362 study patients. They Measured Radiological Papillary Density In each of these 362 cases, papillary radiographic density was estimated by … Continued

SOMETHING YOU CAN DO AT HOME

Supersaturation Because crystals are at the heart of all kidney stones, when we talk about preventing stones we mean preventing crystals from forming and from growing. Fortunately, universal and quantitative laws govern how atoms and molecules form crystals so we can predict the risk of crystals using equations that apply everywhere, even in the kidneys and urine. Supersaturate your own sugar solution One way to understand these laws is to make crystals on your own. Find a heat resistant glass container, fill it with water, and stir in table sugar until no more will dissolve and there is extra sugar at the bottom. The water is ‘saturated’ with sugar, meaning it holds all it can. It is ‘full’ of sugar. … Continued

SUPERSATURATION IN CLINICAL PRACTICE

What Supersaturation Is Supersaturation is not some arcane computation lifted out of physical chemistry and placed on 24 hour urine kidney stone reports as a kind of flourish, or occasion for learned teaching. It is the sole driving force for crystallization, and, at least to me, the main variable I follow in my practice of stone prevention. Solubility The superb and recent review of supersaturation I placed in the Science section makes clear its true physical meaning. You can saturate a solution easily. Simply stir it with an excess of any substance at a constant temperature, and eventually the concentration of the substance will come to some final and unchanging concentration. By excess, I mean there will be some of the solid … Continued

SUPERSATURATION AND THE STONE CRYSTALS

A NEW AND USEFUL REVIEW THE FUNDAMENTAL MEASUREMENT OF STONE PROPENSITY The three Moirai, or the triumph of death, Flemish tapestry ca 1520, Victoria and Albert Museum, London, depicts Clotho, who spins the thread of life, Lachesis, who measures out the length of the thread, and Atropos, the inexorable, who cuts the thread. In book 11 of the Odyssey, Odysseus travels to the underworld where, among other matters, he learns from Tiresias his own ‘fate’; that he will return to his home and his own wife; that he will travel again to a place so far from the sea his oar will go unrecognized; and that he will die in peace, by the sea and among his own people. But he must make an offering in … Continued

WHAT KIDNEY STONES ARE

A few general words about kidney stones I suppose anyone who produces kidney stones knows they are hard and unwanted objects made in the kidney that cause pain, bleeding, and obstruction of the urinary tract, and lead to urinary infections and surgery. Most patients come to realize that stones recur, because over half of those who have formed only one stone will form another within 5 – 10 years. Many patients have seen the stones they form, black, or orange, or yellow, or gray, smooth or spiky, surprisingly small for all the trouble they cause, or surprisingly large to think it really passed through the urinary tract. All patients who have formed stones, at least all the ones I have ever met, want … Continued

ART OF STONE PREVENTION

A particular manner Here and there physician friends have asked me about how I practice. But however much I have written about kidney stones, nowhere before have I told about how I practice because I feared my style might seem too odd. But it is not if you consider how narrowly I have chosen to focus. My clinical life is based on several facts. One is that doctors send me their patients and expect that I will prevent recurrent stones. That is all they want from me. This means that I can depend on other physicians to do everything else, focus on the pathogenesis of kidney stones in a particular patient and fashion for that patient a program of prevention which will … Continued

TYPES OF KIDNEY STONES: A PRIMER

The crystals of the common kidney stones I suppose I could have made my pie chart smaller but I wanted it to shine out like some odd colored moon because the names of the stones are so important and so much of what we do depends upon knowing them. They names of kidney stones are the names of the crystals which make up the hard part of the stones: CAOX, Calcium Oxalate; CAP, Calcium phosphate; UA, Uric Acid; Cystine; Struvite. The pie wedges show their relative abundances to each other in our large population of stone forming patients. Calcium oxalate stones are the most common by a wide margin, and that has been true in every accounting of stone types I … Continued

HOW BAD IS KIDNEY STONE ANALYSIS?

Two related posts, for patients and for physicians, emphasize the fundamental importance of the kidney stone crystal composition in management of kidney stones and by direct extension the importance to patients and their physicians of sending stones for analysis. Here, in a scientific forum, one needs to raise the obvious and complementary issue of quality: can patients and their physicians rely on the results of stone analyses? There is a gold standard Basiri et al recently reviewed all available papers concerning analysis of kidney stone crystals. Like many others, some of whom they reference, X-ray diffraction does indeed reveal the crystal structures and if applied to several regions of a stone is perhaps the ideal method on which to base research … Continued

THE MAJESTIC VOID: ROLE OF STONE MATRIX

When I wrote the original article in 2014 limitations of proteomics seemed the main obstacle. This new work by Dr Frank Witzmann shows us the other side of the problem. A master of the modern proteomic techniques, with them Frank shows that the number of unique proteins in just two human calcium oxalate kidney stones is over 1,000. If inadequacy of technique stymied us two years ago, inadequacy of intellect – at least of mine – stymies at least me, now. What to make of so many proteins! What are they doing there? Which ones matter in stone genesis? We have the methods, we have stones to work on, but what shall we ask? As always, the magic is in the vision.