Overview

KIDNEY STONE PREVENTION

Bariatric Surgery and Kidney Stones

Some weight loss surgeries raise kidney stone risk, others do not. Here is my first article on the problem of bowel disease and stones. These common surgeries, whether they cause stones or not, greatly alter physiology of calcium, oxalate, citrate, even urine volume, so anyone concerned about stone disease should want to know their effects. This article tells about the procedures themselves, how they work, and what one needs to do for kidney stone prevention. It is therefore a fundamental article on which many others will come to depend.

Diet Protein and Stones

Animal protein does not increase kidney stone risk. I know many may think so. Meats just seem like culprits. But this fine science by two remarkable contributors, Drs. Gary Curhan and Eric Taylor simply disproves ‘what everyone knows is true’. Over the ranges of what large groups of women and men ate, over many years, they detected no effect of animal protein to increase the rate of new stone onset. At the highest ranges within their groups stone rates did edge up, so massive excess is not a good idea. But let us say that within the range of 0.8 to 1 gm of protein per day per kilogram of body weight, which is the present US ideal diet intake, we need not fear animal protein, and have no reason to limit intake.

On the other side, Curhan and Taylor have bolstered their older observations and now show definitively that higher food potassium intakes from plants – fruits and veggies – reduce risk of new stones remarkably. So the US recommendations of 4,000 mg of potassium from these sources should greatly benefit kidney stone patients. Rather than the old and improper advice to limit animal protein, we need to tell everyone that grandma was right: Eat your vegetables, and all will be well.

Treating Hypertension in Kidney Stone Patients

Lower is better – that is the main burden of the new US hypertension guidelines. This applies to all of us. But kidney stone formers have a special place because their diet and treatment needs for stones closely overlay with those for blood pressure. The good part is synergy: If careful, treatment for the one will do for the other. The alternative is a piling up of treatments that eventually tire patients and lead to dropout. In this article I detail how to do the better way. The article is long because it includes home blood pressure techniques, and the evidence for lower treatment goals. But it is worth the read. Lower blood pressure saves lives, prevents strokes. It is so important. Give it your time.

Distal Renal Tubular Acidosis(dRTA)

This uncommon condition arises from selective impairment of urine acidification. As one result, kidneys cannot remove daily acid load efficiently and acid accumulates in the body. Because the urine they produce is excessively alkaline, kidney tubules plug with calcium phosphate crystals, and patients produce often very large numbers of kidney stones. Potassium alkali is needed to counteract the acid retention and restore blood to its proper pH. But the alkali can raise urine pH even more, so stone prevention usually requires the same combination of high fluids, and low diet sodium – to lower urine calcium as much as possible – as we use for calcium stone formers in general. One cause of dRTA is inherited defects of acid transporters, so the condition can run in families. Another is a group of autoimmune and acquired immune diseases. A third is a mixture of drugs that cause a picture like dRTA. Since perhaps 1959, scientists have encountered patients with normal blood acidity who form calcium phosphate stones and, when challenged with an extra acid load fail to lower their urine pH to levels attained by similarly challenged normal people. The unfortunate name ‘incomplete’ dRTA, coined for this rather common situation has plagued the field for decades since. It implies something special by way of treatment or prognosis, and perhaps cause. But with time it appears less and less useful as a diagnostic category and probably is best forgotten. Patients with this diagnosis so much resemble idiopathic calcium phosphate stone formers, and are treated identically to them, the special name has no value.

Online Education Course Lessens Stone Risk

If the kidney stone diet – nee the ideal US diet – offers real potential to protect against not only kidney stones but also a host of other major diseases, one must admit to a certain bafflement about how to get the diet into use. I presume that time will bring good diet into every home, but for now we need more than patience. In what is certainly the most modest experiment of my career, I and Jill Harris have deployed an online course for stone patients in hopes of promoting their use of the diet and here are the initial results. The work Jill did with her first set of patients produced about the same lowering of 24 hour urine stone risk as Professor Borghi achieved with a comparable diet in his notable prospective kidney stone prevention trial. We have no controls, so you might say everyone would have done as well without us. But patients say otherwise – not published here. The usual obeisance to convention includes a hope for new funded research to further explore this model. But we demur. Obviously, funded trials like those of Borghi will return results like his. This is, possibly, of value in confirmation. But innovation in this one tiny area of health care delivery now concerns cost and convenience, acceptance in the real world, and most of all scalability. Can one person scale up to lower risk for reasonable numbers of patients? If so, can that experience be replicated within the cost structures not of NIH funding but of individual enterprise? Do social media and the general web now permit inexpensive and effective dissemination of diet information. Can they drive effective, inexpensive, and large scale diet change? 

Treat the Patient Not Just the Stones

We cannot ignore the excellent body of work that has disclosed undeniable associations between stone forming and significant bone, hypertensive, and kidney disease. Multiple investigators have found that having stones predicts higher risks we need to mitigate through treatment that can both reduce stone forming and protect against fractures, high blood pressure, and kidney disease. The main stay of such treatment is the kidney stone diet. It so much resembles the diet recommended for all Americans I cannot but say every stone formers should adopt it. While incomplete treatments like very high fluid intake, or perhaps rigorous low oxalate diet may stave off stones, they fail to address the range of diseases to which stone formers are more prone than otherwise normal people. There is no sense to such incomplete measures when proper diet can do so much more.

Why Delay Prevention

As I thought about modern prevention of the common stone using diet and fluids, I asked myself when treatment should start. Many say why bother unless a person formes multiple stones – as if to qualify as an established stone producer. I think that is not right. My review of published trials shows that the outcome for treated patients dims as they have had more stones before treatment began. Moreover, the ideal diet for stone prevention matches exactly with the ideal diet for the US population. So why wait at all about diet? As for fluids, the same. Why wait. Even more, why wait for the first stone. Stones are very familial. If you have them, your family members are at increased risk. I will not quibble about how much more risk, because I do not care. If the diet is the one we are all supposed to eat, why not eat it now if you have a relative with stones? As for attention to hydration, the same. That impatience led to this article.

QUICK LINKS TO KIDNEY STONE ARTICLES

KIDNEY STONES IN GENERAL

Kidney Stones

What is In It?

What kidney stones are Structure of stones
Matrix of Stones The organic part of stones
Types of kidney stones A primer showing stone types
Kidney Stone analyses How it is done; how often is it needed
Quality of kidney stone analysis Flaws in commercial labs
Nephrocalcinosis A radiological term easily misunderstood
Kidney Stones Themselves  A review of several articles on stones
Pain from kidney Stones  How stones cause pain
The Kidney Stone Guide Book Overview of Kidney Stones
How Kidneys Function How Kidneys Produce Stones and Stones Reduce Kidney Function

CALCIUM KIDNEY STONES

 Diet/Fluids

What is In It?

The Science of the Kidney Stone Diet Evidence for the kidney stone diet
The Kidney Stone Diet Best diet for stone prevention
The Science and Politics of the US Diet Guidelines From 1977 to 2020 – scandal, politics, how to eat
How to Eat the Kidney Stone Diet Special aspects of the kidney stone diet
How to Eat a Low Salt Diet How to shop and select for low sodium diet
The Low Oxalate Diet Our best oxalate lists and how to use them
High Calcium Low Sodium Diet Our best list of the best bargains
How Much Protein Should you Eat Does protein cause stones or bone disease?
How Much Fluid is Enough How supersaturation varies with urine flow
Variety of Fluids Fluid options and how to plan a day
How to Drink enough Tips on ways to make high fluids a pleasure
The Low Flows What makes some people avoid fluids
ACP Fluid Guidelines  Faulty but useful
Does Water Prevent Kidney Stones – What’s your Bet? Review of water trial data

 

Treatments

What is In It?

Cost of potassium citrate How to lower the cost of alkali treatment
Kidney Stone prevention by citrate How citrate prevents stones
Thiazide to Prevent Kidney Stones  The drugs and how they work
Ureteroscopy New techniques vs. old ones
Prevention of Calcium kidney stones The treatment trials and what they say
ACP  Med Guidelines Faulty but useful
Rebuke of ACP Guidelines Critique by an expert
Coke Treatment Probably nonsense but popular on the web

 

Evaluation

What is In It?

Putting it all together The whole process of prevention
5 Steps to Kidney Stone Prevention Details of the stages in evaluation and treatment
How to Be a Successful Patient Organize properly for medical visits
Take Charge of kidney Stone Prevention A summary with emphasis on diet management
How To Do 24 Hr Urines The central test: Common mistakes you can avoid
Web apps & smart bottles Are fancy new devices worthwhile?
24 hr urines – Ca Stones How to read your own tests
24 hr urines – UA Stones How to read your own tests
My Lab Report: 5 Questions How treatment follows test results
Style of Practice My personal clinical approach to stone prevention
Assessment of Plaque CT estimate of kidney calcium deposits

 

How Kidney Stones Form

What is In It?

Video: How Kidney Stones Form Crystal formation in kidneys
Growth on Plaque Tissue calcium deposits anchor growing stones
Tubule Plugging Crystals plug nephrons; stones overgrow
Medullary Sponge Kidney A disease with tiny crystals in cysts
Role of Immunity Innate immune system and plaque

 

Supersaturation

What is In It?

An Introduction A simple explanation and home experiment
Video: Supersaturation Serious but narration makes things easier
Use of Supersaturation Role in clinical practice
Why Use 24 Hour Urines?  Benefit of 24 hour urine averages
Science of Supersaturation Review of selected scientific papers
Supersaturation  A review of multiple articles

 

Urine Risk Factors

What is In It?

Oxalate Physiology  Control of Urine Oxalate
Hypercalciuria in General Idiopathic and from systemic diseases
Idiopathic Hypercalciuria Pathophysiology of IH
How Salt Works Sodium physiology BP and IH
Salt Stones and Bones  Bone disease in IH and role of sodium
How Citrate Works Physiology of urine citrate regulation
Calcium binding Importance of citrate calcium binding
Crystal Inhibition Citrate effects on stone crystals
Citrate and Metastable limits  Citrate inhibition of crystal formation
Dr. Charles Pak An homage to a founder of citrate usage

 

Phenotypes

What is In It?

CaOx Stone Formers General appearance – plaque emphasized
Phosphate Stone Formers Plugging, young women predominate
Medullary Sponge Kidney Case 4: A patient with MSK, shows OR and tissues

 

CYSTINE STONES

How Stones Form

What is In It?

Cystinuria A general overview

 

QUICK LINKS TO ARTICLES ABOUT SCIENCE

Science and medicine

What is In It?

Three Medical Sciences  Discovery, trials, and diagnosis
Science in medicine Basic science in clinical practice
Applied Medical Science  The scientific basis of trials
 Science Marries Medicine Stone disease as an instance