Low-Carbohydrate-Diet Score and Mortality in Adults With and Without Chronic Kidney Disease: Results From the Third National Health and Nutrition Examination Survey

OBJECTIVE: The long-term safety of consuming low-carbohydrate diets (LCDs) remains controversial. As high protein and high fat might accelerate chronic kidney disease (CKD) progression, the impact of LCD on mortality might be different in subjects with CKD and subjects without CKD. Therefore, the objective of this study was to assess the association of LCD with mortality among individuals with and without CKD. METHODS: Data from 1158 subjects with CKD and 9523 subjects without CKD in the Third National Health and Nutrition Examination Survey were analyzed. The LCD score was calculated based on a 24-hour dietary recall interview. Mortality was from baseline until 31 December 2015. Cox proportional hazards regression models were fitted to estimate multivariable-adjusted hazard ratios and 95% confidence intervals. RESULTS: During the median follow-up of 24 years, 751 (65%) deaths and 2624 (28%) deaths were recorded in the CKD group and the non-CKD group, respectively. The multivariable-adjusted hazard ratio for all-cause mortality comparing the highest versus lowest quarters of LCD score was 1.51 (95% confidence interval, 1.01-2.25, P for trend = 0.045) in the CKD group. However, there were no association between the LCD score and all-cause mortality in the non-CKD group. CONCLUSIONS: The LCD scores were found significantly positively associated with all-cause mortality in adults with CKD, but not in adults without CKD.