Self-reported Intentional Weight Loss and Risk of Death in Moderate Chronic Kidney Disease in the United States

Objective: We hypothesized that intentional weight loss is associated with lower mortality risk, whereas unintentional weight loss is associated with higher mortality risk in chronic kidney disease (CKD). Design and Methods: We examined this hypothesis in 872 participants with age >20 years, body mass index ≥ 25 kg/m² and CKD from 1999-2004 National Health and Nutrition Examination Survey who reported their 1 year prior and current weights and the intent to lose weight. We examined the association of self-reported intentional versus unintentional weight loss with all-cause mortality. Participants with no intent to lose weight and no change in weight were the reference group. A multivariable Cox regression model was used to relate mortality with intentional and unintentional weight losses after adjustment for demographics and comorbidity. Results: There were 446 deaths over 6271 years of follow-up. Compared to the reference group, intentional weight loss of 5% to <10% (hazard ratio (HR) 1.22, 95% confidence interval (CI): 0.74-1.99), intentional weight loss of ≥10% (HR 1.53, 95% CI: 0.75-3.12), and unintentional weight loss of 5% to <10% (HR 1.11, 95% CI: 0.71-1.75) were not associated with mortality; however, unintentional weight loss of ≥10% (HR 1.66, 95% CI: 1.06-2.58) was significantly associated with higher risk of mortality. Retrospective design and self-reported weight loss were the limitations. Conclusions: Intentional weight loss in CKD participants was not associated with lower mortality risk. This might reflect residual confounding. Mechanistic and interventional studies are warranted to determine the effects of intentional weight loss in CKD.