Stable Heavy Body Shape Throughout the Life Course Increases the Risk of Chronic Kidney Disease

Evidence on the association between dynamic changes of obesity throughout the life course and chronic kidney disease (CKD) remains lacking. This study aimed to investigate the relationship between body shape trajectories from early to middle age and CKD, supplemented by Mendelian randomization to explore potential causal relationships.

Body shape at different ages in Henan Rural Cohort Study was retrospectively assessed by Stunkard body diagram, and group-based trajectory models were employed to identify trajectories of body shape. Logistic regression model was employed to assess the relationships between body shape trajectories and estimated glomerular filtration rate decrease, albuminuria, and CKD. Life expectancy and CKD-free life expectancy (CFLE) were calculated by the Sullivan method. Two-sample Mendelian randomization analysis was used to explore potential causal relationship.

Five body shape trajectories from the 17,496 subjects were identified: lean-stable, lean-marked increase, medium-stable, medium-moderate increase, and heavy-stable. Compared to the lean-stable group, the adjusted odds ratios with 95% confidence interval for CKD in the heavy-stable group were 1.37 (1.01, 1.86) in men and 1.28 (1.02, 1.61) in women, respectively. In addition, CFLE was shortest in the heavy-stable group for both genders. Corresponding genetic, the causal risk effects of CKD were 1.18 (1.01, 1.37) and 1.36 (1.15, 1.62) for childhood body mass index and adult body mass index, respectively.

Participants with stable heavy body shape throughout the life course had the highest prevalence of CKD and the shortest CFLE, and genetic evidence supported causality for the associations. This study identifies a lifelong heavy body shape as a risk marker for CKD.