ABSTRACT
Rationale & Objective: Limited data exist on longitudinal kidney outcomes after nonsurgical obesity treatments. We investigated the effects of intensive lifestyle intervention on kidney function over 10 years. Study Design: Post hoc analysis of Action for Health in Diabetes (Look AHEAD) randomized controlled trial. Setting & Participants: We studied 4,901 individuals with type 2 diabetes and body mass index of ≥25 kg/m2 enrolled in Look AHEAD (2001-2015). The original Look AHEAD trial excluded individuals with 4+ urine dipstick protein, serum creatinine level of >1.4 mg/dL (women), 1.5 mg/dL (men), or dialysis dependence. Exposures: Intensive lifestyle intervention versus diabetes support and education (ie, usual care). Outcome: Primary outcome was estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) slope. Secondary outcomes were mean eGFR, slope, and mean urine albumin to creatinine ratio (UACR, mg/mg). Analytical Approach: Linear mixed-effects models with random slopes and intercepts to evaluate the association between randomization arms and within-individual repeated measures of eGFR and UACR. We tested for effect modification by baseline eGFR. Results: At baseline, mean eGFR was 89, and 83% had a normal UACR. Over 10 years, there was no difference in eGFR slope (+0.064 per year; 95% CI: -0.036 to 0.16; P = 0.21) between arms. Slope or mean UACR did not differ between arms. Baseline eGFR, categorized as eGFR of <80, 80-100, or >100, did not modify the intervention's effect on eGFR slope or mean. Limitations: Loss of muscle may confound creatinine-based eGFR. Conclusions: In patients with type 2 diabetes and preserved kidney function, intensive lifestyle intervention did not change eGFR slope over 10 years. Among participants with baseline eGFR <80, lifestyle intervention had a slightly higher longitudinal mean eGFR than usual care. Further studies evaluating the effects of intensive lifestyle intervention in people with kidney disease are needed.
Lifestyle interventions can improve chronic kidney disease risk factors, specifically diabetes, hypertension, and obesity. But, the effects of lifestyle intervention on change in kidney function (estimated glomerular filtration rate [eGFR]) over time are not well established. We studied Action for Health in Diabetes (Look AHEAD) trial data because all participants were affected by diabetes and overweight or obesity. Look AHEAD randomized participants to intensive lifestyle intervention or diabetes support and education (ie, usual care). We compared eGFR change over 10 years between groups, but found no difference. However, the intervention group maintained slightly higher eGFR than usual care, especially if eGFR was relatively low at baseline. Our study suggests lifestyle intervention may preserve eGFR, but dedicated studies in individuals with chronic kidney disease are needed.
ABSTRACT
BACKGROUND: Kidney transplant programs have variable thresholds to accept obese candidates. This study aimed to examine trends and the social context of obesity among United States dialysis patients and implications for kidney transplant access. METHODS: We performed a retrospective cohort study of 1 084 816 adults who initiated dialysis between January 2007 and December 2016 using the United States Renal Data System data. We estimated national body mass index (BMI) trends and 1-y cumulative incidence of waitlisting and death without waitlisting by BMI category (<18.5 kg/m 2 , ≥18.5 and <25 kg/m 2 [normal weight], ≥25 and <30 kg/m 2 [overweight], ≥30 and <35 kg/m 2 [class 1 obesity], ≥35 and <40 kg/m 2 [class 2 obesity], and ≥40 kg/m 2 [class 3 obesity]). We then used Fine-Gray subdistribution hazard regression models to examine associations between BMI category and 1-y waitlisting with death as a competing risk and tested for effect modification by End Stage Renal Disease (ESRD) network, patient characteristics, and neighborhood social deprivation index. RESULTS: The median age was 65 (interquartile range 54-75) y, 43% were female, and 27% were non-Hispanic Black. From 2007 to 2016, the adjusted prevalence of class 1 obesity or higher increased from 31.9% to 38.2%. Class 2 and 3 obesity but not class 1 obesity were associated with lower waitlisting rates relative to normal BMI, especially for younger individuals, women, those of Asian race, or those living in less disadvantaged neighborhoods ( pinteraction < 0.001 for all). CONCLUSIONS: Obesity prevalence is rising among US incident dialysis patients. Relative to normal BMI, waitlisting rates with class 2 and 3 obesity were lower and varied substantially by region, patient characteristics, and socioeconomic context.