From Screening for Chronic Kidney Disease: Time to Say No
Chronic kidney disease (CKD) is common and often asymptomatic at the time of diagnosis. Yet CKD is associated with substantial increases in the risk for cardiovascular (CV) events and overall mortality. These facts suggest the potential value of population-based screening for CKD.
However, the US Preventive Services Task Force (USPSTF)[1] and American College of Physicians (ACP)[2] have not recommended broad screening for CKD, citing a lack of evidence that screening improves important outcomes. The American Society of Nephrologists (ASN)[3] retorts that all adults should undergo periodic screening for CKD.
Who is right?
Below the fold are recent links to medical journal explorations of the question and related material, with introductory paragraphs for each article cited. Find an introduction to the
free use of Medscape articles at this link and an overview of CKD at
here, with valuable 'external links' at the very bottom.
Don't Stop Looking for CKD!: "I Must Be Missing Something' in ACP Guidelines, Says Kidney Expert"
The American College of Physicians (ACP) recently released a clinical practice guideline on the screening, monitoring, and treatment of stage 1-3 chronic kidney disease (CKD)...generating a fair amount of disagreement with the American Society of Nephrology (ASN), the National Kidney Foundation (NKF), and the Renal Physicians Association (RPA). First, the ACP document affirms the asymptomatic nature of stage 1-3 CKD, and that having CKD has health implications, including mortality, cardiovascular disease, fractures, bone loss, cognitive dysfunction, infection, and frailty. They also comment on the common co-occurrence of hypertension, cardiovascular disease, and diabetes. Furthermore, they state that the diagnosis of CKD, regardless of stage, requires laboratory testing.
First...I find it extremely difficult to understand the rationale for lumping together stages 1, 2, 3A, and 3B CKD without specific reference to the prevailing level of albuminuria. This is a rather disparate group of patients to consider under a single guideline ...[should we] lump all of these diverse patient groups together[?].
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Don't Screen for CKD? Beware!
The Studies: "Chronic kidney disease controversy: how expanding definitions are unnecessarily labeling many people as diseased (BMJ)" and "Lifetime incidence of CKD stages 3-5 in the United States (Am J Kidney Dis).
The Dilemma: The balance between sensitivity and specificity (or true positives and false positives) for a screening test is an important one. The decision about where to draw the line in a screening test to declare that the patient has the disease needs to be thought through carefully, examining the totality of evidence on the disease process. A highly sensitive test won't miss disease, but it may increase the number of false positive tests. A highly specific test may minimize false positives but may also miss cases of disease. The optimal balance between the number of times a [patient and family are put through the anxiety of repeat testing for any disease] hinges on the balance between the effect of false positives on the individual and the desire to diagnose...in its earliest possible stage.
The dilemma of needing to find this balance...is the question we have to answer for ourselves or for society with every screening test. The answer is based partly on personal preference and partly on the natural history and/or treatability of the disease.
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CKD: ASN Recommends Screening, Rejects ACP Statement
The American Society of Nephrology (ASN) strongly recommends regular screening for chronic kidney disease (CKD), regardless of risk factors, according to an ASN statement released October 22. This recommendation contradicts recent guidelines from the American College of Physicians (ACP), which recommended against screening for CKD in asymptomatic adults without risk factors.
According to the ASN ...CKD screening is simple and inexpensive but has the potential to improve and save countless lives by detecting early disease [which is] mostly asymptomatic, and early diagnosis and treatment may slow progression and preserve renal function and quality of life. In the United States, CKD prevalence currently exceeds 20 million, and it is the eighth leading cause of death.
"Stage 1–3 CKD increases the risk for developing acute kidney injury (AKI) from nephrotoxic medications, sepsis, surgery, or contrast dyes for medical imaging. AKI, which occurs in 23% of hospitalized patients, accelerates CKD to end-stage renal disease," Dr. Molitoris said in the release. "This vicious cycle must be stopped."
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The Looming Specter of Chronic Kidney Disease
...a recent paper in the American Journal of Kidney Disease by Grams and colleagues[1] that used Markov chain modeling to estimate the lifetime incidence of chronic kidney disease (CKD), stages 3 through end-stage renal disease (ESRD), in the United States.
This mathematical modeling technique that they used was based on National Health and Nutrition Examination Surveys and other population data. This allowed them to estimate the lifetime risk of developing CKD in patients who didn't already have CKD, and to estimate the progression through the various stages of CKD. The numbers are quite astounding. The residual lifetime risk of developing CKD was:
• Stage 3a or higher CKD: 60%-70% (depending upon gender and ethnicity);
• Stage 3b or higher CKD: 30%-40%;
• Stage 4 CKD: 10%-20%; and
• ESRD: 2%-9%.
[As we know, there are] significant racial [and gender] differences, with black persons having much higher risk of developing stage 4 CKD or ESRD, and they develop CKD at a much younger age than white persons do. ...Women had a higher risk of developing CKD than men, but men had a higher risk of developing ESRD.
When the investigators translate these risks into population prevalences, it is just mind-boggling. They estimated that 13.5 million white people in this country have CKD stage 3 or higher, and 1.8 million black persons -- and then 136 million, or almost 64% of the entire population of the United States, combining white and black persons -- either have or will develop CKD stage 3 or higher. Furthermore, 26 million people either have or will develop CKD stage 4 or higher.
Much debate has taken place about the CKD stage 3a group in particular, and whether they really have CKD or just a reduced glomerular filtration rate (GFR). We should certainly be aware of that reduced GFR, particularly in the dosing of medications, avoidance of nephrotoxins, and so on -- but whether these patients have a "disease" or just reduced GFR, and whether that is an important distinction, remain areas of debate.
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ACP Guidelines: Do Not Screen Asymptomatic Adults for CKD
Adults without symptoms or risk factors should not be screened for chronic kidney disease (CKD), according to new guidelines from the American College of Physicians (ACP). The new evidence-based recommendations, published online October 21 [2013] in the Annals of Internal Medicine, address screening, monitoring, and treatment of adults with stage 1 to 3 CKD.
"There is no evidence that evaluated the benefits of screening for stage 1-3 chronic kidney disease," ACP President Molly Cooke, MD, FACP, said in a news release. "The potential harms of all the screening tests — false positives, disease labeling, and unnecessary treatment and associated adverse effects — outweigh the benefits ... Ordering lab tests is not going to have any impact on clinical outcomes of asymptomatic patients with CKD without risk factors but will add unnecessary costs to the health care system due to increased medical visits and unnecessary tests,"
Background and Related Articles
▼ Chronic Kidney Disease and the Aging Population
The proportion of older people in the general population is steadily increasing worldwide, with the most rapid growth in low- and middle-income countries.[1] This demographic change is to be celebrated, because it is the consequence of socioeconomic development and better life expectancy. However, population aging also has important implications for society—in diverse areas including health systems, labor markets, public policy, social programs and family dynamics.[2] A successful response to the aging population will require capitalizing on the opportunities that this transition offers, as well as effectively addressing its challenges.
Chronic kidney disease (CKD) is an important public health problem that is characterized by poor health outcomes and very high health-care costs. CKD is a major risk multiplier in patients with diabetes, hypertension, heart disease and stroke—all of which are key causes of death and disability in older people.[3] Since the prevalence of CKD is higher in older people, the health impact of population aging will depend in part on how the kidney community responds.
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CKD: Lifestyle Intervention Works
A 12-month exercise training and lifestyle intervention in patients with chronic kidney disease (CKD) was linked to better cardiorespiratory fitness (CRF), body composition, and diastolic function, according to findings of a randomized trial published online August 22 [2013] in the Clinical Journal of the American Society of Nephrology.
"We were hoping to see that patients became fitter and lost weight and learned techniques that would help them maintain this change," coauthor Nicole Isbel, MD, from Princess Alexandra Hospital and the University of Queensland in Brisbane, Australia, said in a news release. "We demonstrated that this could be done safely in spite of patients having a number of other health problems. This was in part because of the expertise of the multidisciplinary team, who frequently adjusted diabetic and blood pressure medications."
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Fluid Intake and Good Health: Not as Simple as You May Think
...is a healthy person who drinks more fluids really flushing anything away that will result in a longer life or fewer trips to the hospital? To address this question, Palmer and colleagues examined the association between fluid intake and outcomes in the Blue Mountains Eye Study.
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Kidney Disease: Healthy Heart Lifestyle May Slow Progression
To protect against chronic kidney disease (CKD) progression and premature death from kidney failure, it might be wise to look at the heart. An article published online May 23 in the Journal of the American Society of Nephrology suggests that improving heart health can also be protective against CKD progression.
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Tight BP Control May Be Deadly for Older Patients With CKD
In elderly patients with chronic kidney disease (CKD), who typically have an above-normal systolic blood pressure (SBP) and a below-normal diastolic blood pressure (DBP), aiming [to tightly control the hi SBP at the expense of the low DBP, as] may actually increase mortality, according to a new study [at Memphis Veterans Affairs Medical Center, TN]. ...a slightly elevated BP (130–159 mm Hg SBP; 70–98 mm Hg DBP) was linked with the lowest all-cause mortality. Combinations of lower SBP and DBP were associated with relatively lower mortality only if the lower DBP was above 70 mm Hg.
"The current guidelines advocate that you treat whichever [blood pressure--systolic or diastolic] is the highest and you don't worry about the lowest," Kovesdy told heartwire . But this study "suggests that [physicians] ought to be careful when treating high systolic blood pressure [in patients with CKD] at the expense of [their] low diastolic blood pressure," he cautioned.
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Popular Drugs Do Little to Prevent ESRD in Older Patients
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) show promise in preventing end-stage renal disease (ESRD) in younger patients, but have marginal benefit for older patients with chronic kidney disease (CKD), according to a simulation study. The new data highlight a possible disconnect between clinical trials and real-world use of the drugs, especially for older. sicker patient populations.
Ann M. O'Hare, MA, MD, from the Department of Medicine, Department of Veterans Affairs Puget Sound Healthcare System; the Department of Medicine, University of Washington; and the Group Health Research Institute, Seattle, Washington, and colleagues report their findings in an article published online January 13 in JAMA Internal Medicine.
According to the Centers for Disease Control and Prevention, 1 in 10 American adults (or more than 20 million people) have some level of CKD, a disease characterized by kidney damage that impairs their ability to properly filter blood. The incidence of CKD is rising most dramatically among people aged 65 years and older and more than doubled from 2000 to 2008, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
Because preventive interventions are typically tested in younger, healthier patients, Dr. O'Hare and colleagues sought to quantify the benefit of such drugs for older, sicker patients. These patients are more representative of the real world, but are less frequently included in clinical trials, and are also less likely to survive long enough to experience the same magnitude of benefit as the younger patients who do enroll in trials.
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Medscape Reference: Chronic Kidney Disease
Chronic kidney disease (CKD) is a common condition in which there is a loss of kidney function over time. CKD is associated with an increased risk of cardiovascular disease and chronic renal failure. Kidney disease is the ninth leading cause of death in the United States.