Yoshio N. Hall

Temporal trends in the prevalence of diabetic kidney disease in the United States

CONTEXT Diabetes is the leading cause of kidney disease in the developed world. Over time, the prevalence of diabetic kidney disease (DKD) may increase due to the expanding size of the diabetes population or decrease due to the implementation of diabetes therapies. OBJECTIVE To define temporal changes in DKD prevalence in the United States. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional analyses of the Third National Health and Nutrition Examination Survey (NHANES III) from 1988-1994 (N = 15,073), NHANES 1999-2004 (N = 13,045), and NHANES 2005-2008 (N = 9588). Participants with diabetes were defined by levels of hemoglobin A(1c) of 6.5% or greater, use of glucose-lowering medications, or both (n = 1431 in NHANES III; n = 1443 in NHANES 1999-2004; n = 1280 in NHANES 2005-2008). MAIN OUTCOME MEASURES Diabetic kidney disease was defined as diabetes with albuminuria (ratio of urine albumin to creatinine ≥30 mg/g), impaired glomerular filtration rate (<60 mL/min/1.73 m(2) estimated using the Chronic Kidney Disease Epidemiology Collaboration formula), or both. Prevalence of albuminuria was adjusted to estimate persistent albuminuria. RESULTS The prevalence of DKD in the US population was 2.2% (95% confidence interval [CI], 1.8%-2.6%) in NHANES III, 2.8% (95% CI, 2.4%-3.1%) in NHANES 1999-2004, and 3.3% (95% CI, 2.8%-3.7%) in NHANES 2005-2008 (P <.001 for trend). The prevalence of DKD increased in direct proportion to the prevalence of diabetes, without a change in the prevalence of DKD among those with diabetes. Among persons with diabetes, use of glucose-lowering medications increased from 56.2% (95% CI, 52.1%-60.4%) in NHANES III to 74.2% (95% CI, 70.4%-78.0%) in NHANES 2005-2008 (P <.001); use of renin-angiotensin-aldosterone system inhibitors increased from 11.2% (95% CI, 9.0%-13.4%) to 40.6% (95% CI, 37.2%-43.9%), respectively (P <.001); the prevalence of impaired glomerular filtration rate increased from 14.9% (95% CI, 12.1%-17.8%) to 17.7% (95% CI, 15.2%-20.2%), respectively (P = .03); and the prevalence of albuminuria decreased from 27.3% (95% CI, 22.0%-32.7%) to 23.7% (95% CI, 19.3%-28.0%), respectively, but this was not statistically significant (P = .07). CONCLUSIONS Prevalence of DKD in the United States increased from 1988 to 2008 in proportion to the prevalence of diabetes. Among persons with diabetes, prevalence of DKD was stable despite increased use of glucose-lowering medications and renin-angiotensin-aldosterone system inhibitors.

Frailty and Chronic Kidney Disease: The Third National Health and Nutrition Evaluation Survey

BACKGROUND Frailty is common in the elderly and in persons with chronic diseases. Few studies have examined the association of frailty with chronic kidney disease. METHODS We used data from the Third National Health and Nutrition Examination Survey to estimate the prevalence of frailty among persons with chronic kidney disease. We created a definition of frailty based on established validated criteria, modified to accommodate available data. We used logistic regression to determine whether and to what degree stages of chronic kidney disease were associated with frailty. We also examined factors that might mediate the association between frailty and chronic kidney disease. RESULTS The overall prevalence of frailty was 2.8%. However, among persons with moderate to severe chronic kidney disease (estimated glomerular filtration rate < 45 mL/min/1.73 m2), 20.9% were frail. The odds of frailty were significantly increased among all stages of chronic kidney disease, even after adjustment for the residual effects of age, sex, race, and prevalent chronic diseases. The odds of frailty associated with chronic kidney disease were only marginally attenuated with additional adjustment for sarcopenia, anemia, acidosis, inflammation, vitamin D deficiency, hypertension, and cardiovascular disease. Frailty and chronic kidney disease were independently associated with mortality. CONCLUSION Frailty is significantly associated with all stages of chronic kidney disease and particularly with moderate to severe chronic kidney disease. Potential mechanisms underlying the chronic kidney disease and frailty connection remain elusive.

Vitamin D deficiency and frailty in older Americans

Abstract.  Wilhelm‐Leen ER, Hall YN, deBoer IH, Chertow GM. (Stanford University School of Medicine; University of Washington; Stanford University School of Medicine, Palo Alto, CA, USA). Vitamin D deficiency and frailty in older Americans. J Intern Med 2010; 268: 171–180.

Clinical Manifestations of Kidney Disease Among US Adults With Diabetes, 1988-2014

IMPORTANCE Diabetic kidney disease is the leading cause of chronic and end-stage kidney disease in the United States and worldwide. Changes in demographics and treatments may affect the prevalence and clinical manifestations of diabetic kidney disease. OBJECTIVE To characterize the clinical manifestations of kidney disease among US adults with diabetes over time. DESIGN, SETTING, AND PARTICIPANTS Serial cross-sectional studies of adults aged 20 years or older with diabetes mellitus participating in National Health and Nutrition Examination Surveys from 1988 through 2014. EXPOSURES Diabetes was defined as hemoglobin A1c greater than 6.5% or use of glucose-lowering medications. MAIN OUTCOMES AND MEASURES Albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g), macroalbuminuria (urine albumin-to-creatinine ratio ≥300 mg/g), reduced estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m2), and severely reduced eGFR (<30 mL/min/1.73 m2), incorporating data on biological variability to estimate the prevalence of persistent abnormalities. RESULTS There were 6251 adults with diabetes included (1431 from 1988-1994, 1443 from 1999-2004, 1280 from 2005-2008, and 2097 from 2009-2014). The prevalence of any diabetic kidney disease, defined as persistent albuminuria, persistent reduced eGFR, or both, did not significantly change over time from 28.4% (95% CI, 23.8%-32.9%) in 1988-1994 to 26.2% (95% CI, 22.6%-29.9%) in 2009-2014 (prevalence ratio, 0.95 [95% CI, 0.86-1.06] adjusting for age, sex, and race/ethnicity; P = .39 for trend). However, the prevalence of albuminuria decreased progressively over time from 20.8% (95% CI, 16.3%-25.3%) in 1988-1994 to 15.9% (95% CI, 12.7%-19.0%) in 2009-2014 (adjusted prevalence ratio, 0.76 [95% CI, 0.65-0.89]; P < .001 for trend). In contrast, the prevalence of reduced eGFR increased from 9.2% (95% CI, 6.2%-12.2%) in 1988-1994 to 14.1% (95% CI, 11.3%-17.0%) in 2009-2014 (adjusted prevalence ratio, 1.61 [95% CI, 1.33-1.95] comparing 2009-2014 with 1988-1994; P < .001 for trend), with a similar pattern for severely reduced eGFR (adjusted prevalence ratio, 2.86 [95% CI, 1.38-5.91]; P = .004 for trend). Significant heterogeneity in the temporal trend for albuminuria was noted by age (P = .049 for interaction) and race/ethnicity (P = .007 for interaction), with a decreasing prevalence of albuminuria observed only among adults younger than 65 years and non-Hispanic whites, whereas the prevalence of reduced GFR increased without significant differences by age or race/ethnicity. In 2009-2014, approximately 8.2 million adults with diabetes (95% CI, 6.5-9.9 million adults) had albuminuria, reduced eGFR, or both. CONCLUSIONS AND RELEVANCE Among US adults with diabetes from 1988 to 2014, the overall prevalence of diabetic kidney disease did not change significantly, whereas the prevalence of albuminuria declined and the prevalence of reduced eGFR increased.

Racial Ethnic Differences in Rates and Determinants of Deceased Donor Kidney Transplantation

Contemporary studies have not comprehensively compared waiting times and determinants of deceased donor kidney transplantation across all major racial ethnic groups in the Unites States. Here, we compared relative rates and determinants of waitlisting and deceased donor kidney transplantation among 503,090 nonelderly adults of different racial ethnic groups who initiated hemodialysis between1995 and 2006 with follow-up through 2008. Annual rates of deceased donor transplantation from the time of dialysis initiation were lowest in American Indians/Alaska Natives (2.4%) and blacks (2.8%), intermediate in Pacific Islanders (3.1%) and Hispanics (3.2%), and highest in whites (5.9%) and Asians (6.4%). Lower rates of deceased donor transplantation among most racial ethnic minority groups appeared primarily to reflect differences in time from waitlisting to transplantation, but this was not the result of higher rates of waitlist inactivity or removal from the waitlist. The fraction of the reduced transplant rates attributable to measured factors (e.g., demographic, clinical, socioeconomic, linguistic, and geographic factors) varied from 14% in blacks to 43% in American Indians/Alaska Natives compared with whites. In conclusion, adjusted rates of deceased donor kidney transplantation remain significantly lower among racial ethnic minorities compared with whites; generally, differences in time to waitlisting were not as pronounced as differences in time between waitlisting and transplantation. Determinants of delays in time to transplantation differed substantially by racial ethnic group. Area-based efforts targeted to address racial- and ethnic-specific delays in transplantation may help to reduce overall disparities in deceased donor kidney transplantation in the United States.

Effects of Six versus Three Times per Week Hemodialysis on Physical Performance, Health, and Functioning: Frequent Hemodialysis Network (FHN) Randomized Trials

BACKGROUND AND OBJECTIVES Relatively little is known about the effects of hemodialysis frequency on the disability of patients with ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study examined changes in physical performance and self-reported physical health and functioning among subjects randomized to frequent (six times per week) compared with conventional (three times per week) hemodialysis in both the Frequent Hemodialysis Network daily (n=245) and nocturnal (n=87) trials. The main outcome measures were adjusted change in scores over 12 months on the short physical performance battery (SPPB), RAND 36-item health survey physical health composite (PHC), and physical functioning subscale (PF) based on the intention to treat principle. RESULTS Overall scores for SPPB, PHC, and PF were poor relative to population norms and in line with other studies in ESRD. In the Daily Trial, subjects randomized to frequent compared with conventional in-center hemodialysis experienced no significant change in SPPB (adjusted mean change of -0.20±0.19 versus -0.41±0.21, P=0.45) but experienced significant improvement in PHC (3.4±0.8 versus 0.4±0.8, P=0.009) and a relatively large change in PF that did not reach statistical significance. In the Nocturnal Trial, there were no significant differences among subjects randomized to frequent compared with conventional hemodialysis in SPPB (adjusted mean change of -0.92±0.44 versus -0.41±0.43, P=0.41), PHC (2.7±1.4 versus 2.1±1.5, P=0.75), or PF (-3.1±3.5 versus 1.1±3.6, P=0.40). CONCLUSIONS Frequent in-center hemodialysis compared with conventional in-center hemodialysis improved self-reported physical health and functioning but had no significant effect on objective physical performance. There were no significant effects of frequent nocturnal hemodialysis on the same physical metrics.

Chronic Kidney Disease in the Urban Poor

BACKGROUND AND OBJECTIVES In the United States, relatively little is known about clinical outcomes of chronic kidney disease (CKD) in vulnerable populations utilizing public health systems. The primary study objectives were to describe patient characteristics, incident ESRD, and mortality in adults with nondialysis-dependent CKD receiving care in the health care safety net. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Time to ESRD and time to death were examined among a cohort of 15,353 ambulatory adults with nondialysis-dependent CKD from the Community Health Network of San Francisco. RESULTS The mean age of the CKD cohort was 59.0 +/- 13.8 years; 50% of the cohort was younger than 60 years and 26% was younger than 50 years. Most (72%) were members of nonwhite racial-ethnic groups, 73% were indigent (annual income <

The effect of frequent hemodialysis on nutrition and body composition: frequent Hemodialysis Network Trial.

15,000) and 18% were uninsured. In adjusted analyses, blacks [hazard ratio (95% confidence interval), 4.00 (2.99 to 5.35)], Hispanics [2.20 (1.46 to 3.30)], and Asians/Pacific Islanders [3.84 (2.73 to 5.40)] had higher risks of progression to ESRD than non-Hispanic whites. The higher risk of progression to ESRD among nonwhite compared with white persons with CKD was not explained by lower relative mortality. CONCLUSIONS Adults with CKD stages 3 to 5 cared for within an urban public health system were relatively young and predominantly nonwhite-both factors associated with a higher risk of progression to ESRD. These findings call for targeted efforts to assess the burden and progression of CKD within other public and safety-net health systems in this country.

Burden on caregivers as perceived by hemodialysis patients in the Frequent Hemodialysis Network (FHN) trials

We investigated the effects of frequency of hemodialysis on nutritional status by analyzing the data in the Frequent Hemodialysis Network Trial. We compared changes in albumin, body weight and composition among 245 patients randomized to 6- or 3-times per week in-center hemodialysis (Daily Trial) and 87 patients randomized to 6-times per week nocturnal or 3-times per week conventional hemodialysis, performed largely at home (Nocturnal Trial). In the Daily Trial, there were no significant differences between groups in changes in serum albumin or the equilibrated protein catabolic rate by 12 months. There was a significant relative decrease in pre-dialysis body weight of 1.5 ± 0.2 kg in the 6 times per week group at one month, but this significantly rebounded by 1.3 ± 0.5 kg over the remaining 11 months. Extracellular water decreased in the 6 times per week compared to the 3 per week hemodialysis group. There were no significant between-group differences in phase angle, intracellular water or body cell mass. In the Nocturnal Trial, there were no significant between-group differences in any study parameter. Any gain in “dry” body weight corresponded to increased adiposity rather than muscle mass but was not statistically significant. Thus, frequent in-center hemodialysis reduced extracellular water but did not increase serum albumin or body cell mass while frequent nocturnal hemodialysis yielded no net effect on parameters of nutritional status or body composition.

Neighborhood Poverty and Kidney Transplantation Among US Asians and Pacific Islanders with End-Stage Renal Disease

BACKGROUND Patients with end-stage renal disease often rely on unpaid caregivers to assist them with their daily living and medical needs. We characterized the degree to which patients enrolled in the Frequent Hemodialysis Network (FHN) trials perceived burden on their unpaid caregivers. METHODS Participants completed the Cousineau Perceived Burden Scale, a 10-question scale previously developed in hemodialysis (HD) patients. Associations between baseline burden score and prespecified variables were evaluated using multivariable linear regression. RESULTS Of 412 participants, 236 (57%) reported having unpaid caregivers. Compared to those without unpaid caregivers, these participants had greater comorbidity (Charlson mean 1.8 ± 1.8 versus 1.2 ± 1.7, P < 0.001), lower Short Form-36 (SF-36) Physical Health Composite (PHC) scores (median 33 versus 41, P < 0.001, higher Beck Depression scores (mean 16 ± 11 versus 12 ± 9, P < 0.001), and worse physical function. Median Cousineau score was 35 (interquartile range 20-53) (theoretical range 0-100). Over 50% felt their caregivers were overextended, yet 60% were confident that their caregivers could handle the demands of caring for them. Higher perceived burden was not associated with ability to be randomized. In adjusted analyses, Cousineau score was inversely associated with SF-36 PHC and Mental Health Composite scores and directly associated with Beck Depression score (each P < 0.001). CONCLUSIONS Most HD patients in the FHN trials perceived substantial burden on their unpaid caregivers, and self-perceived burden was associated with worse depression and quality of life. Evaluation of the effects of frequent HD on perceived burden borne by caregivers in the FHN trials will help to establish the net benefits/determents of these intensive dialytic strategies.