Body Mass Index and Kidney Disease-Related Mortality in Midlife: A Nationwide Cohort of 2.3 Million Adolescents

ObjectiveThis study aimed to evaluate the association of body mass index (BMI) in adolescence with mortality attributed to kidney disease. MethodsIn this study, 2,294,139 Jewish Israeli adolescents with measured weight and height at 17 years old during the military fitness assessment were analyzed with a follow-up extending up to 45 years. All kidney-related outcomes, coded by the Central Bureau of Statistics from death notifications as the underlying cause of death, were obtained by linkage. Cox hazards models were applied. ResultsDuring 42,297,007 person-years of follow-up (median 18.4 years), 226 deaths related to kidney disease were recorded. There was an increased risk for kidney-related death among adolescents with overweight and obesity with adjusted hazard ratios of 2.7 (95% CI: 1.8-3.9) and 8.4 (5.1-13.8), respectively, with BMI between 18.5 and 22.0 kg/m(2) as the reference. A 15% increased risk for kidney-related mortality (1.11-1.19) per unit increment in BMI was observed. Furthermore, a multivariable spline model indicated a minimum risk for kidney-related mortality starting at BMI of 18.6kg/m(2) with significantly increased risk seen above values of 22.8kg/m(2). The results withstood extensive sensitivity analyses, including stratification of kidney-related death attributed to acute, chronic, and total kidney disease. ConclusionsAdolescent overweight and obesity are risk markers for kidney-related mortality over 4 decades.