Coping with Kidney Disease E-Book

Mackenzie Walser

• Herausgeber: John Wiley & Sons
• Kategorie: Ratgeber
• Sprache: Englisch

Seitenzahl: 346

Veröffentlichungsjahr: 2010

Beschreibung

A revolutionary program that can indefinitely postpone the need for dialysis

If you've been diagnosed with kidney failure, this book could save your life. If you suffer from diabetes, hypertension, obesity, or any of a host of conditions that put you at risk for kidney disease, you owe it to yourself to read what is in this book. If you are among the 60,000 North Americans who go on dialysis each year, the information in this book could substantially improve your quality of life.

In Coping with Kidney Disease, a leading expert tells you, in plain English, what you need to know to:
* Understand kidney failure
* Recognize early warning signs of kidney failure
* Get a proper diagnosis
* Talk with your doctors about it
* Confidently evaluate treatment options
* Take charge of your treatment
* Delay dialysis or even avoid the need for it altogether


The centerpiece of Coping with Kidney Disease is Dr. Walser's revolutionary 12-step program for avoiding dialysis. Based on treatments he has pioneered with his own patients at the Johns Hopkins University School of Medicine, the program calls for a supplemented low-protein diet supported by treatments to control blood pressure and correct high cholesterol. So effective has this breakthrough strategy proven to be that in many patients it actually worked to slow or arrest the progression of kidney failure to the end stage.

Knowledge is power. Coping with Kidney Disease empowers you with what you need to take charge of kidney disease.

Leseprobe

Table of Contents

Title Page

Copyright Page

Dedication

Acknowledgments

Introduction

The Scope of the Problem

The Lack of Effective Care

The Solution

How to Use This Book

How I Came to Write This Book

Terms, Measures, and Abbreviations

PART I - LOOKING AT THE DISEASE OF KIDNEY FAILURE

Chapter 1 - What Do Kidneys Do and What Happens When They Fail?

What Is Kidney Failure?

How Big a Problem Is Kidney Failure?

The Diagnosis of Kidney Failure

Chapter 2 - Are You at Risk for Kidney Failure?

Genetic or Family Predisposition for Kidney Failure

Diseases That Lead to an Increased Risk of Kidney Failure

Behaviors and Medical History That May Lead to Kidney Failure

Does Eating Too Much Protein Cause Kidney Failure?

Unknown Causes

What Do You Do If You Fall into a Risk Group?

Chapter 3 - Symptoms of Kidney Failure

Self-Testing

Fatigue

Muscle Cramps

Loss of Appetite, Nausea and Vomiting

Easy Bruising

Itching

Shortness of Breath on Exertion

Other Less Common Symptoms

Dependence of Symptoms on Lab Results

PART II - HOW TO TREAT KIDNEY FAILURE

Chapter 4 - Treating Kidney Failure

Dialysis

Free Dialysis Care

The Problem with Dialysis

Kidney Transplants

The Low-Protein Diet (and Predialysis Treatment)

Why You May Not Have Heard about This Treatment

Is Remission of Kidney Failure Possible?

Getting a Predialysis Program Funded

Chapter 5 - Step 1: Assess Your Current Treatment Plan

How to Work with Your Doctor

The Assessment of Care Quiz

Treatment Options

Chapter 6 - Step 2 : Make Lifestyle Changes

Alcohol

Smoking

Drugs

Exercise

Chapter 7 - Step 3: Follow a Low-Protein Diet

Alcohol

Protein

Fat

Carbohydrate

Getting Started on the Very-Low-Protein Diet

Getting Low-Protein Foods at the Store or by Catalog

High Phosphate Foods—Warning

Menu Plans

Diet for Patients with Kidney Stones

Motivation for the Very-Low-Protein Diet

The Low-Protein Diet Versus Other Diets

Taking Supplements with Your Diet

Essential Amino Acid Supplements

Does Protein Restriction Cause Malnutrition?

Chapter 8 - Step 4: Treat Salt and Water Problems

Water Deficit without Salt Deficit

Water Excess without Salt Excess

Salt and Water Excess

Salt and Water Deficit

The Treatment of Hyponatremia

Edema

Diuretics

Judging Your Salt and Water Balance

Chapter 9 - Step 5: Regulate Your Blood Pressure

What Is Blood Pressure?

High Blood Pressure and Kidney Failure

Treating High Blood Pressure

Measuring Your Own Blood Pressure

Medications for High Blood Pressure

Chapter 10 - Step 6: Treat Acidosis

Acidosis

Alkalosis

Treatment

Chapter 11 - Step 7: Treat Anemia and Iron Deficiency

Treatment

Iron Deficiency

Treatment of Iron Deficiency

Chapter 12 - Step 8: Treat Potassium Problems

Excessive Potassium

Treatment of Excessive Potassium

Potassium Deficiency

Chapter 13 - Step 9: Treat Calcium and Phosphate Problems

What Goes Wrong

Treatment of Calcium and Phosphate Problems

Chapter 14 - Step 10: Treat Gout and Uric Acid Problems

Gout and Kidney Failure

Treatment

Chapter 15 - Step 11: Treat Your High Cholesterol

What Is Cholesterol?

Medications for High Cholesterol

Chapter 16 - Step 12: Know the Medications That Slow the Progression of Renal Failure

Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers

Ketoconazole and Low-Dose Prednisone

PART III - TRACKING KIDNEY FAILURE, DIALYSIS OPTIONS, TRANSPLANTS, AND MORE

Chapter 17 - Keeping Close Watch on Your Kidney Failure

Diagnosing and Measuring Kidney Failure

Finding Your Glomerular Filtration Rate

Normal Values for GFR

The Blood Analysis Method for Assessing Kidney Function Using Naturally ...

The 24-Hour Urine Test

Tracking Treatment Success

Measuring the Quality of Life in Predialysis Patients

Chapter 18 - Dietary Treatment of the Nephrotic Syndrome

Chapter 19 - Safe and Unsafe Medications for Patients with Kidney Failure

Nonsteroidal Anti-inflammatory Drugs

Steroids

Chapter 20 - Transplantation as an Alternative to Dialysis

What a Kidney Transplant Involves

Sources of Donor Kidneys

Chapter 21 - When to Opt for Dialysis

Hemodialysis

Peritoneal Dialysis

When Should You Start Dialysis?

The Withholding and Withdrawal of Dialysis

Chapter 22 - Patients Who Have Avoided Dialysis

Patients with Diabetes

Patients with Kidney Disease Secondary to Obstructed Outflow of Urine ...

Patients with Kidney Failure Caused by Drug Abuse

Patients with Polycystic Kidney Disease

Patients with Hypertensive Kidney Disease

Patients with Diseases of the Glomeruli

Appendix 1 - Resources for Patients with Kidney Disease

Appendix 2 - Government Support of Low-Protein Diets

Notes

Glossary

Index

Copyright ® 2004 by Mackenzie Walser, M.D., and Betsy Thorpe. All rights reserved.

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Library of Congress Cataloging-in-Publication Data:

Walser, Mackenzie.

Coping with kidney disease: a 12-step treatment program to help you avoid dialysis/ Mackenzie Walser, with Betsy Thorpe, and contributions by Nga Hong Brereton.

p.cm.

Includes bibliographical references and index.

ISBN 0-471-27423-2 (Paper)

1. Kidneys. 2. Kidneys—Diseases—Prevention. I. Thorpe, Betsy. II.

Brereton, Nga Hong. III. Title.

RC902 .W34 2004

616.6’1—dc22

2003021346

To my wife, Betsy

Acknowledgments

This work arose from my care of 200 adults with chronic kidney disease in the Clinical Research Center of Johns Hopkins Hospital since 1984. I have kept my own records on all of them, and a number of publications already have resulted from this experience. I am particularly indebted to Sylvia Hill for decades of collaboration in every aspect of the work. Without her it simply would not have happened. Capable assistance in the Clinical Research Center was provided by Shirley Barnes, Romila Capers, Gloria J. Jones, Mary Missouri, Flo Perry, Wesla T. Zeller and others and in the Department of Pharmacology by Mimi Guercio. Hong Brereton, my current dietitian, has made major contributions both to the book and to the care of these patients, as have the several dietitians who preceded her: Keena Andrews, Elizabeth Chandler, Gloria Elfert, Tiffany Hays, Millicent Kelly, Celide Koerner, Chris Kutchey, Sylvia McAdoo, Helen Mullan, Elizabeth Tomalis, Mary Ann Van Duyn, Jean Wagner, Lynne Ward, and others. Until radioisotope determinations of kidney function were replaced by creatinine measurements following cimetidine ingestion, Helen H. Drew and Joanna L. Guldan capably performed most of these radioisotopic determinations, under the direction of Dr. Norman D. LaFrance. The many patients that I have followed over the years cannot be acknowledged by name (though many of their case reports appear here under aliases), but their loyalty and support has been critical. Many of them were referred by Dr. Luis F. Gimenez and by the late Dr. Daniel G. Sapir, to both of whom I am very grateful.

As to writing the book, I am indebted to my agent, Ed Knappman, for starting the ball rolling. I am greatly indebted to Dr. Gary Calton for detailed advice on the book and also to Dr. Paul J. Scheel, Jr., Dr. John Deeken, and Braxton Mitchell. My editor-writer, Betsy Thorpe, and I spent nearly a year transforming a book for doctors (the only kind I know how to write) into one for consumers, and I thank her for her help. Elizabeth Zack, Lisa Considine, and Kim Nir at John Wiley & Sons made many helpful comments. Support for the care of these patients and for the writing of the book was provided by grants from the National Institutes of Health, from the estate of Colonel Walter G. Shaffer, and by gifts from other patients.

Introduction

Kidney disease is a huge, underrecognized and undertreated problem in the United States. In Coping with Kidney Disease, I hope to raise awareness about this disease among patients and their families and caregivers, and strongly advocate the benefits of predialysis care. The cornerstone of this treatment is a very-low-protein diet, which, as I have shown through my work with patients at Johns Hopkins University, can effectively delay or indefinitely postpone the need for dialysis in those with kidney failure. This diet, and many other effective treatments, will be explained and illustrated with patient histories throughout the book, such as this one:

Horace Lysenko, a 54-year-old self-employed art consultant, was referred to me four years ago with the following history: One year before, he had developed severe kidney failure caused by obstruction from an enlarged prostate. The prostate gland, which surrounds the urethra, frequently becomes enlarged in older men, obstructing the flow of urine from the bladder. Following surgical relief of the obstruction, his kidney function was only partially restored: Two-thirds of his kidneys had been destroyed by the increased back pressure from his bladder. His kidney function was measured at one-quarter of normal. He was placed on a very-low-protein diet, supplemented by essential amino acids—the treatment outlined in this book. In the ensuing five years, his kidney function has actually improved somewhat. Despite severe damage to his kidneys, he remains free of symptoms and may never go on dialysis.

The Scope of the Problem

Like Horace, millions of Americans have reduced kidney function (that is, kidney failure), and don’t know it. At least 6 million people have an elevated blood level of creatinine, a likely sign of kidney failure. Among older people with diabetes or hypertension (which includes the majority of older people), 1 in 8 has kidney disease. Among noninstitutionalized adults in the U.S., 1 in 10 has either an abnormal amount of protein in their urine or reduced kidney function, or both. Americans of all ages have kidney failure, especially older people, blacks, and Native Americans.

The Lack of Effective Care

Kidney failure is often undertreated by doctors. Patients frequently are told to come back for care only when they are in such discomfort that they are ready for dialysis. Numerous articles have been published in medical journals reporting various means to slow the downhill course of kidney disease; even so, most patients never receive these treatments. Untreated kidney failure usually progresses to end-stage renal disease, at which point dialysis or transplantation becomes essential for survival. Every year some 60,000 people start dialysis in the U.S. But many people on dialysis don’t feel well. In fact, dialysis is so grueling that, according to the official government report of the U.S. Renal Data System for 1999, “1 in 5 patients withdraws from dialysis before death.” In other words, in effect they commit suicide. It should be noted, however, that death by withdrawal from dialysis is usually a “good death,” meaning that suffering is minimized. But clearly it is best to avoid dialysis as long as possible.

The Solution

First, kidney failure has to be identified, and then, measures to treat it must be undertaken. The United States is shockingly deficient in both areas.

Symptoms of kidney failure don’t appear until most of kidney function has already been lost. However, people at risk for kidney disease can check their own urine using simple tests, and get their physicians to check their blood for problems early on. If more at-risk people found out earlier that they had kidney disease, they could markedly improve their future health by taking effective steps immediately.

This book lets people know about the available and effective treatments (many of which can be done in their own home) that can slow the progression of kidney disease. By these means, people can delay dialysis or transplantation for as long as possible or even totally avoid either procedure.

The treatment I describe alleviates symptoms markedly. Appropriate care for kidney failure includes a very-low-protein diet, with supplements, as well as blood pressure control and specific therapies to regulate the metabolism of sodium, potassium calcium, phosphorus, and acid, and to correct anemia, high blood cholesterol, and high blood uric acid (which causes gout). Certain drugs are helpful and others are contraindicated. Transplantation, which has become more successful but is limited by the number of donors, may become more widely available; this book discusses how.

Note: This book does not discuss children with chronic kidney disease. As children are treated at Johns Hopkins exclusively by pediatricians, I have no experience caring for them.

Ella Johnson, a 49-year-old schoolteacher came to Johns Hopkins in 1994 for treatment. She suffered from polycystic kidney disease, an inherited kidney disease that consists of cysts in the kidneys. Her mother had also had polycystic kidney disease and had been treated here for several years. Ella also had high blood pressure and recurrent urinary tract infections. Her left kidney could easily be felt during a physical exam, and was therefore considerably enlarged. She was placed on a low-protein diet supplemented by essential amino acids. She also started fish oil capsules and gets regular exercise. During seven years of follow-up, her kidney failure has progressed very slowly. The rate of loss of her kidney filtration capacity, also known as glomerular filtration rate, is only 1.8 ml per minute per year, compared with an average rate of about 7 ml per minute per year in patients with polycystic kidney disease. At this rate, she will be well into her 70s before she needs dialysis or a transplant.

How to Use This Book

The book is written for a lay audience: patients, their families, and caregivers. Part I presents a primer on kidneys, explaining what happens when kidneys fail and some of the reasons that might have led to their failure. Once that is established, we then move on to what can be done to make life better for a kidney failure patient.

Part II deals with treatment of kidney failure in the predialysis stage, in twelve steps. Chapter 7 sets forth the low-protein diet in detail and contains lists of common foods in order of their protein-to-calorie ratio and their phosphorus-to-calorie ratio (not previously published); this is invaluable information for patients who want to follow the life-saving low-protein, low-phosphorus diet.

Part III deals with measuring the progression of kidney failure, dietary treatment of the nephrotic syndrome (a related condition), medications for people with kidney failure, when to opt for dialysis, transplantation, and several case histories. A list of resources, including books, web sites, and useful products follows, as does a discussion of government support for low-protein diets. Notes are supplied to identify the sources of the information provided, but may be too technical for many readers. A glossary defines unfamiliar terms.

How I Came to Write This Book

I have spent 45 years here at Johns Hopkins University on the full-time faculty in the departments of pharmacology and medicine. Over the past 30 years, my colleagues and I have studied and worked with adult patients suffering from kidney failure, in the hopes of treating them effectively to delay dialysis. Through my studies and those of others, I have become convinced that the best treatment for those suffering from kidney failure is a very-low-protein, supplemented diet, with careful monitoring of lifestyle and of blood pressure to keep kidney failure from progressing. I wrote this book to share with you this knowledge, and hope that you can use it to learn to live with your kidney disease.

Terms, Measures, and Abbreviations

equivalentA quantity of a chemical substance equal to the number of grams that participate in a particular chemical reaction with one mole of reactantESRDEnd-stage renal diseasemcgMicrogram (one millionth of a gram)meanThe average of a number of observationsmedianThe value above which half of the observations fall, and below which the other half fall. The median and the mean of a series of observations may differ considerably if there are a few extremely high or extremely low values. The median is more useful for some purposes.mgMilligram (one thousandth of a gram)microalbuminuriaAn increase in urine protein too small to be detected by the usual clinical tools: specifically, between 30 and 200 mg/day.milliequivalentOne thousandth of an equivalentmillimoleOne thousandth of a molemicromoleOne millionth of a moleMA concentration of one mole per liter of solutionmMA concentration of one millimole per liter of solutionmoleA quantity of a chemical substance equal to its molecular weight in gramsmillimoleOne thousandth of a molemicromoleOne millionth of a moleuMA concentration of one micromole per liter of solutionproteinuriaUrinary protein

PART I

LOOKING AT THE DISEASE OF KIDNEY FAILURE

1

What Do Kidneys Do and What Happens When They Fail?

Before we look at what you can do when your kidneys start to fail, it’s a good idea to review the basics on how the kidneys work in the body. With this knowledge, you will get a better understanding of why the kidneys are so important in the functioning of your body and the extent of the damage that can occur to your health if things do go wrong.

The two kidneys lie in the abdomen on the muscles of the back, near the waist, and are about 5 inches long. The urine formed from each kidney passes down a long tube called the ureter into the bladder, which can expand to contain and store urine. When urine is passed out of the body, it goes through a tube called the urethra (see Figure 1.1 on the following page).

Each kidney is made up of about 1 million units, called nephrons, which begin with a filter, comprising a tuft of capillaries (the tiniest blood vessels), called the glomerulus. At the glomerulus, liquid is derived from the blood plasma, comprising a solution from which most of the protein has been filtered out by the glomerular membrane. This solution, called the glomerular filtrate, passes down a long, winding tubule (meaning little tube) and finally into a pouch called the kidney pelvis, which in turn drains into the ureter. During its passage down the tubule, most of the filtrate is reabsorbed, but some constituents are more completely reabsorbed than others; tubular secretion adds other constituents to the fluid. The final urine is small in volume compared to the glomerular filtrate, and differs from it considerably in composition.

FIGURE 1.1: THE POSITION OF THE KIDNEYS.

From the kidneys, the ureters conduct urine to the bladder, which empties through the urethra. Blood is supplied to the kidneys by two renal arteries from the aorta, the main artery of the body. Reprinted by permission from Kidney Failure, the Facts, by Stewart Cameron, Oxford University Press, 1996.

By these multiple mechanisms the kidneys achieve their remarkable regulatory capacity. It is very important to recognize that the kidneys’ main function is not to excrete wastes; instead, they play a very important role in keeping what is called extracellular fluid constant in its makeup. Extracellular fluid is the medium in which the millions of cells that make up our bodies are bathed. Blood plasma is part of the extracellular fluid, and it circulates throughout the body by the pumping of the heart. The kidneys keep constant the composition of the extracellular fluid, namely its content of salts, acid, nutrients, and many other constituents. The lungs play a similar role in that they remove carbon dioxide and add oxygen to the blood, so as to keep these two constituents constant.

The principal function of the kidneys is to keep constant the composition of the extracellular fluid, with respect to all other constituents. The kidneys also keep the volume of the extracellular fluid constant. By extraordinarily complex and efficient mechanisms, the kidneys regulate the excretion of water, salt, potassium, calcium, acid, and many other elements, whatever the intake of these substances may be.

Hormones regulate many of the kidney’s functions. Hormones are like chemical messengers that are produced in other organs and sent to the kidney via the blood. For example, antidiuretic hormone, a hormone produced in the brain, is secreted in response to the concentration of dissolved solutes in body fluids. A high concentration of dissolved solutes, such as might occur after water loss in a hot environment, stimulates the production of this hormone. The kidney responds to the hormone by making the urine more concentrated and lower in volume, thus conserving water in the body. At the other extreme, a low concentration of dissolved substances, such as might occur after drinking a lot of water, turns off antidiuretic hormone production. As soon as the hormone disappears from the blood (about 30 minutes), the kidneys stop conserving water and do the opposite: The urine becomes very dilute and increases in flow, thus excreting the water load.

Urine flow can range widely depending on a person’s intake of fluids: Minimal urine volume, during severe dehydration, may be as little as 250 ml a day (less than a pint), while maximum urine volume, in the absence of this antidiuretic hormone, is many gallons a day. People who can’t make this hormone or who don’t respond to it, because they have one form or another of a condition called diabetes insipidus (no relation to sugar diabetes), excrete huge volumes of urine and as a result get thirsty. Their fluid intake usually keeps up with their urine output, and they remain only slightly dehydrated most of the time.

The regulation of salt excretion is closely related to the regulation of body water because salt is the dominant dissolved substance in the extracellular fluid. Salt excretion is regulated by hormones that are produced by the adrenal cortex and by the heart. The regulation of salt balance is discussed in Chapter 8.

Another function of the kidneys is the production of important hormones, including:

• Angiotensin, a hormone that raises blood pressure by constricting blood vessels and also stimulates the adrenal cortex to produce yet another hormone, aldosterone, an important regulator of sodium excretion

• Erythropoietin, a hormone that stimulates the bone marrow to produce more red cells whenever their number is reduced; again, this explains why anemia is such a common feature of kidney failure

• Prostaglandins, which help regulate blood pressure, sodium excretion, and other functions.

In addition, the body’s production of vitamin D takes place, in part, in the kidneys, which explains why vitamin D deficiency is a prominent feature of kidney failure.

Clearly, the kidney has many functions besides the excretion of wastes. You cannot live without your kidneys because of the important role they play. Complete loss of kidney function causes death within a few weeks. The good news is that we seem to have much more kidney function than we need, because with adequate care a person can survive with as little as 5 percent of normal kidney function. Thus donation of one kidney does not cause any signs of kidney dysfunction in the donor.

What Is Kidney Failure?

Kidney failure means loss of some (but not all) of the filtration capacity of the kidneys, which can be caused by a fall in blood pressure, a blockage of the blood circulation to the kidneys, blockage of urine outflow, or by disease of the kidneys themselves. Many different kinds of kidney disease are recognized, all of which cause loss of filtration capacity, but some of which are rapidly reversible. These reversible types of kidney failure are known as acute kidney failure.

Acute kidney failure can be caused by drugs toxic to the kidneys, by a severe reduction in kidney blood flow (for example, during surgery), and by many other causes. Urine output usually falls drastically, and waste products accumulate in the blood. But amazingly, complete recovery can occur within a few weeks. Patients often need dialysis temporarily.

Chronic kidney failure is generally not reversible, but often (though not always) gets progressively worse. When about two-thirds of filtration capacity is lost, symptoms of kidney failure begin to appear (see Chapter 3). When seven-eighths or so is lost, survival depends on either starting dialysis or transplanting a new kidney. This is called end-stage renal disease (ESRD).

How Big a Problem Is Kidney Failure?

Over 300,000 patients have end-stage renal disease and are currently on dialysis in the United States, and another 300,000 to 400,000 in other countries. (Hundreds of thousands of others who need dialysis in third world countries don’t get it for economic reasons.) By 2010 there probably will be about 650,000 patients with ESRD in the United States, if the same rate of increase continues. Some of this increase represents wider availability; but kidney failure also seems to be getting more common.

These are the only statistics about the prevalence of kidney disease that have any reliability, and they do not measure prevalence of all cases of kidney failure; they measure the prevalence of end-stage kidney disease only, when dialysis is essential to survival. The prevalence of all cases of kidney disease in the United States can be estimated from large surveys of apparently normal samples of the population, in which a main indicator of kidney function, serum creatinine concentration, is measured in thousands of people. By determining what proportion of people in the sample has elevated creatinine levels and multiplying by an appropriate factor, we can estimate the prevalence nationwide.

The disturbing part of this equation is that most people with elevated serum creatinine levels are unaware of the fact. However, it is by no means certain that all of those who have elevated serum creatinine concentrations will go on to manifest chronic renal failure; in some, their serum creatinine level may spontaneously become normal; in others, it may remain slightly elevated but never rise further. For example, according to a recent study of 3,874 patients with elevated serum creatinine concentrations at an urban Veterans Administration center, followed for four years, many do not lose kidney function over time, including more than half of those with only slightly elevated levels and over a third of those with moderately severe kidney failure. It remains to be determined what differentiates those who progress to ESRD from those who do not.

In one large series of patients with chronic renal failure known as the Modification of Diet in Renal Disease Study, 15 percent exhibited no progression after being followed for at least two years. Sylvie Rottey and her colleagues in Belgium followed 83 patients with initial serum creatinine levels of 2 to 5 mg per dl for an average of five years. They found that half didn’t progress at all during this interval.

The Diagnosis of Kidney Failure

How many people actually know they have chronic renal failure and have been properly diagnosed in order to receive treatment? Unfortunately, the answer to this question is not known even approximately. In a study reported at the American Society of Nephrology meeting in 2000, 889 U.S. relatives of dialysis patients were screened. The majority had signs of kidney disease, but most of these people were “unaware of their renal risk status.” If we compare this statistic to people with diabetes, 70 percent of diabetics were aware that they had diabetes, while only 10 percent of subjects with evidence of chronic renal disease were aware of having it. Perhaps most alarming was the observation that the patients’ physicians, when sent the results of the survey, often failed to change any aspect of their treatment. (We’ll discuss this more in the next chapter.)

A survey of 1,436 adults in Venezuela revealed six individuals with persistently elevated creatinine levels, without apparent cause for acute renal failure. Only one of these six was aware of having chronic kidney disease. This was a surprisingly low frequency.

In a survey of 23,121 healthy Japanese schoolchildren, only 200 had signs of kidney disease, generally undiagnosed previously, emphasizing the relative infrequency of kidney disease in children.

In a large survey of apparently healthy adults in the United States, when the results were multiplied by the U.S. population, 800,000 adults nationwide were estimated to have serum creatinine levels above 2 mg per dl, and 10.9 million to have levels above normal (1.5 mg per dl).

Unfortunately, no surveys have determined how many of those surveyed were aware of having a high creatinine level. Defining prevalence in terms of measures whose results are not known to the subjects may be useful for fund-raising purposes, but it is not useful for these individuals’ medical care.

A striking difference between true prevalence and diagnosed disease was shown in diabetic kidney disease by a report from Atlanta. In 1994 the authors reviewed hospital charts of 260 people with diabetes aged 64 to 75. Only 63 percent of the sample had their urine analyzed during their admission. Of these, 31 percent had urine protein of 1+ or greater, indicating advanced kidney disease. Twenty-five percent of the people with diabetes had elevated serum creatinine, but abnormal kidney function was noted in the discharge summaries of only 8 percent. “None [!] of these patients’ medical records indicated that they had received dietary instructions about protein restriction, education about avoiding unnecessary use of NSAID’s [nonsteroidal anti-inflammatory drugs, see Chapter 19], or education about diabetic renal disease.” (These are some of the treatments we’ll be discussing later in the book). Angiotensin-converting enzyme-inhibitors (ACEIs) or angiotensin-receptor blockers were no more likely to be used in those with abnormal renal function than in those without, despite the fact that these drugs are now widely recommended for patients with kidney disease (see Chapter 9). Thus most of these patients and their physicians apparently were unaware of the presence of renal disease and so did nothing about it.

A similar study of diabetic Medicare beneficiaries was reported from Seattle. Of 785 diabetics, 38 percent had urinary protein of 1+ or greater. But only 26 percent of patients known to have diabetic kidney disease and without contraindications to ACEIs were treated with ACEIs at discharge.

A recent report by Italian nephrologists documents similar findings. They reviewed the charts of 288 diabetics seen at a clinic in 1997. Although blood glucose was recorded in 99 percent, serum creatinine was recorded in only half and urine protein was seldom checked.

According to a recent summary, “30 percent to 40 percent of ESRD patients enter ESRD treatment only after an emergency-room visit triggered by undiagnosed renal failure.” The authors conclude that “the pre-ESRD population is remarkably poorly followed.”

In a recent review, the records of 155,076 patients who started dialysis between 1995 and 1997 were examined. Sixty percent of them had subnormal serum albumin concentrations, indicating malnutrition, and 51 percent had severe anemia. Only a small minority were treated by erythropoietin hormone injections, despite this drug being indicated for renal anemia (see Chapter 11). Heart disease was also prevalent and undertreated. The authors concluded that their data revealed “an alarmingly poor quality of pre-ESRD care among patients beginning dialysis in United States.” Clearly this circumstance accounts in part for the high morbidity and mortality of ESRD patients in the United States. The authors were unable to explain the reasons for their findings.

One factor may be the official government attitude toward predialysis care, which is well illustrated by a recent pamphlet for the general public entitled “Kidney Failure: Choosing a Treatment That’s Right for You” released by the National Institute of Diabetes and Digestive and Kidney Diseases. The pamphlet describes dialysis and transplantation but makes no mention of predialysis care. However, the National Institutes of Health has started a program with the express purpose of education in predialysis care.

It is clear that early renal insufficiency is still widely ignored in the United States.

2

Are You at Risk for Kidney Failure?

Most people who have early kidney failure are unaware of their condition because of the notable lack of symptoms in the early stages. (We discuss symptoms in Chapter 3.) This is true in the case of other diseases too (like diabetes and hypertension) but is particularly common in kidney disease. So those people who are at risk for kidney failure, either because of inherited susceptibilities or risky behaviors, should be aware of the possibility of contracting a kidney problem. In Chapter 3 we discuss how easy it is to discover the presence of kidney disease by utilizing a simple at-home test, but first let’s find out whether you fall into one of the at-risk groups.

Genetic or Family Predisposition for Kidney Failure

Men are slightly more susceptible to kidney failure than women. African Americans comprise 30 percent of those with end-stage kidney disease (ESRD), almost twice their frequency in the population at large. Native-born Americans and Pacific Islanders are also particularly susceptible, but anyone can get kidney disease.

The following groups of people are at high risk for developing kidney disease owing to inherited susceptibility.

Relatives of People on Dialysis

As mentioned, a majority of first-degree relatives of patients (siblings, children, and parents) with ESRD have signs of kidney disease and usually are unaware of it. The explanation is uncertain, but this observation suggests that congenital or familial factors may be of major importance. A check on urine protein and blood pressure of those at risk could identify most of those who may develop kidney failure. Such individuals need to check their own urine protein and their own blood pressure and report to their physician if either is abnormal.

Polycystic Kidney Disease

In this inherited condition, multiple cysts develop in the kidneys. On the average, half of the children of people with this disorder are destined to get the disease. About half of these, in turn, will develop kidney failure. Although all cases of polycystic kidney disease are the result of genetic defects, some of these are spontaneous mutations rather than inherited defects, so that not all patients will have an affected parent. DNA testing is available to determine the presence of the disease right from infancy, but is quite expensive, and the results can be confusing, because several genes may be defective. By age 20 or so, ultrasound examination of the kidneys can detect the disease. If it is present, multiple cysts will be found.

Without sophisticated tests, the disease may not become apparent until age 30 to 50. Sometimes the cysts become enormous, so that they are visible from outside the body. Protein in the urine is not always present during the early stages of the disease, so a blood test for creatinine may be required, followed by an ultrasound examination of the kidneys, to confirm the diagnosis.

Further complications with this disease sometimes include cysts in the liver, but they usually cause few ill effects. More serious are dilatations of the arteries in the brain (aneurysms), which can cause fatal bleeding, and should be surgically obliterated.

Some subjects at risk for polycystic kidney disease elect to forgo these tests and to rely on annual serum creatinine determinations, on the theory that, since no treatment is available, why get the bad news any sooner than you have to? This is obviously a difficult and complex choice, especially for people who plan to marry and have children.

There are also a number of inherited kidney diseases other than polycystic, although they are much less common.

Diseases That Lead to an Increased Risk of Kidney Failure

Sometimes it’s the diseases you already have that can cause trouble for your kidneys. The most common culprits include diabetes and hypertension. A few patients develop kidney failure secondary to potassium deficiency.

Diabetes

People with either kind of diabetes (insulin-dependent and non-insulin-dependent) may get kidney failure after a decade or more of suffering from this disease. People with diabetes now comprise the largest group of patients starting dialysis in the United States and account for a large portion of the deaths from kidney failure. Diabetic kidney disease is relatively easy to detect in the early stages, because traces of protein appear in the urine. However, only one-third of subjects with traces of protein in their urine (microalbuminuria) will go on to develop full-blown kidney disease, with substantial amounts of protein in the urine. People with diabetes can and should test their urine for protein at least once a month. (Details of this test are given in Chapter 3.)

There is now evidence that close control of blood glucose levels in people with insulin-dependent diabetes somewhat reduces the incidence of kidney failure, though only at the cost of more frequent attacks of hypoglycemia. (see Chapter 16.)

For people with diabetes who are overweight (which many are), whether they are insulin-dependent or not, 20 percent weight loss, especially if combined with smoking cessation and increased exercise, can be extraordinarily beneficial. Not only does blood pressure decrease, but also the levels of blood fats (like cholesterol) fall; furthermore, in those who have kidney disease, kidney function improves and urinary protein loss diminishes. Thus all of the complications of diabetes are reduced.

Hypertension

High blood pressure is one of the most common disorders in the United States. The majority of people over 50 suffer from it. Thanks to a persistent campaign by the American Heart Association and others, the importance of controlling blood pressure is more and more widely known, and most patients now get at least some treatment for hypertension. Undertreated or untreated, hypertension can lead to heart failure, strokes, and kidney failure. It was widely assumed in the past that hypertension causes kidney failure.

However, a recent analysis of 10 large trials shows that controlling blood pressure in nonmalignant hypertension (the commonest kind) doesn’t make any difference in the development of kidney failure. Among 26,521 people with high blood pressure followed for an average of five years, only 317 developed kidney failure. Patients who received antihypertensive drugs, who consequently had lower blood pressure than the others, did not have a significant reduction in their chances of getting kidney failure.

It is also widely held that African Americans are more susceptible than whites to kidney disease from hypertension. Dr. Norman Kaplan, an authority on high blood pressure, has recently summarized this issue, and concludes that it is true that most nondiabetic hypertensive African Americans with mild to moderate kidney failure have primarily hypertensive kidney disease. Yet only 10 percent of African Americans with kidney disease can be said to have hypertension as their primary disorder.

Thus the question as to just how often high blood pressure causes kidney failure remains unsettled, in contrast to the widespread view that it is a major cause. Whatever the case may be, it is still highly important for your overall health to treat hypertension effectively with the help of your doctor.

Pregnancy unquestionably makes hypertension worse. Consequently pregnant women should be closely monitored for the development or worsening of hypertension. Late in pregnancy, hypertension may be a sign of preeclampsia or eclampsia, serious complications. If you are pregnant, your blood pressure should be checked frequently.

Treatment of hypertension includes both lifestyle changes and drugs. Protein in the urine is an early sign of kidney damage from high blood pressure. Control of blood pressure is now known to be one of the most important features in the treatment of chronic kidney disease and may in fact stop progression altogether. But first kidney disease and hypertension have to be recognized.

Even in the absence of kidney disease, blood pressure should be maintained below 130/80, according to recent recommendations.

Potassium Deficiency

Potassium deficiency is another cause of kidney failure, though it is uncommon. Kidney function decreases in severe potassium deficiency and may never recover. Chronic diarrhea or overuse of laxatives can induce chronic potassium deficiency and renal failure. The ability of the kidneys to produce highly concentrated urine, and to decrease the output of urine in response to dehydration is characteristically impaired in patients with potassium deficiency, so these patients tend to excrete large volumes of urine (despite their reduced kidney function). Replenishing potassium stores usually restores kidney function, but not always.