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My book chapter makes the prime point that low urine pH causes uric acid to crystallize in urine and produce kidney stones. But it does not detail what lowers urine pH to such an extreme. In part, bowel diseases lower urine pH. That is another subject altogether, because they also cause calcium stones. So they need their own articles. But in the main, low pH arises in people who are obese, have metabolic syndrome, diabetes, vascular disease all in some combinations. As an alternative,sometimes low pH associates with gout and none of these are present. In either case, this article concerns what kidneys do to lower pH in the absence of an obvious systemic cause. This article parses out and pulls … Continued

Primary hyperparathyroidism (PHPT) is a systemic disease caused by an excess of parathyroid hormone secretion. It causes calcium kidney stones but also multiple other abnormalities, especially of bone. Here, I am concerned with that subset of PHPT patients with kidney stones. A Curable Cause of Kidney Stones Unlike most stone formers those with PHPT have a good chance at permanent cure. This makes detection of PHPT a paramount aim for patients and their physicians. As I shall tell you, PHPT raises serum calcium above normal and is detected from blood test results. The elevation of serum calcium can be slight and variable so patience and persistence matter a lot. Once diagnosed, PHPT can be cured by a surgery that modern … Continued

Our newest venture – the Kidney Stone Prevention Course. It arose from this idea: Kidney stone prevention depends a lot on proper diet and fluids, which patients control. This site tells people what that diet and what those fluids should be, but not how to eat that diet or drink those fluids in real life. They have to learn how. So we built the kidney stone prevention course to help them learn. Just as Raphael imagined generations of brilliant minds come alive together in The School of Athens (Raphael, 1509 -1511; Apostolic Palace in the Vatican.), we – on a vastly lower plane of existence – imagined and have, in the kidney stone prevention course actuated the knowledge on this site into real life.  … Continued

Do you need a low oxalate diet? Who does? Who does not? How can you tell? I chose the gorgeous painting by Raphael that hangs in the Musée Condé Chantilly because three surpasses one. Who Needs Low Oxalate Diet? Most of all, those whose stones contain calcium oxalate crystals and urine oxalate enough to promote such stones. Less so those with systemic diseases – bowel disease, malabsorption syndrome, bariatric surgery, and primary hyperoxaluria – that raise urine oxalate. Their diseases require many treatments, only one of them low oxalate diet. Therefore, I write here for only patients without a systemic cause of stones. Do Your Stones Contain Calcium Oxalate? If your stones contain little or no calcium oxalate crystals, and urine oxalate itself poses no danger to your kidneys, low oxalate … Continued

Would anyone bet against water to prevent stones? Here is the first of new articles that highlight stone treatments in a simple format. These new articles were provoked by what patients asked for, and by Freakonomics. Because patients asked for clear answers about treatments, I lifted ‘water’ out of my long article on treatment of calcium stone formers, and simplified the style so the main points stand out. I also suggest betting, something we all understand. Freakonomics offers a three part podcast about the woeful state of medicine. Doctors, they say, rely on received wisdom, poor clinical trial design, and bad data. At the end I ask you to vote if we kidney stone physicians suffer from these three defects, and by how much. Voting sharpens the mind, or should. … Continued

My Question Tell me what you want next on this site; that is my question. I have been writing this site – with the able help of my co-authors – since July 2014, and have reached what I might call a kind of plateau. Much of what I came to say about the most common kinds of kidney stone patients is said. Because the main work is done for the moment I have come with my question to you. The readership of the site has grown from 50 people in the first month to a present running average of 55,000 – 58,000 people monthly, depending on the season, and many of the visitors read quite a bit each. People find the site valuable, … Continued

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

A Remarkable Concordance 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. I shall call this the Ideal US Diet. Surprisingly, though aimed at stone prevention and management of bone disease from idiopathic hypercalciuria, decades of kidney stone research have identified precisely the same diet. Even more surprising, the Diet Against Systolic Hypertension (DASH) diet resembles the current Recommended US Diet, and stone researchers have found a reduced risk of stone disease in people who eat ‘DASH – … Continued

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

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

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.

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.

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.

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.

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.

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.

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?

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.

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.

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.

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. 

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.

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

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

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.