The Relationship between Sodium Intake and Albuminuria in U.S. Adults with Chronic Kidney Disease With and Without Diabetes

Abstract

Introduction: Low sodium diet has been shown to have blood pressure lowering effects and as such promising effect on slowing CKD progression. The aim of this study is to examine if the relationship between sodium intake and albuminuria differs by diabetes status in patients with CKD. Methods: We used National Health and Nutrition Examination Survey for adults ≥ age 20 between 2007-2014. Primary outcome variable was Albumin-to-creatinine ratio (ACR). CKD stage was based on estimated glomerular filtration rate and Albumin-to-creatinine ratio. Sodium (Na) intake was calculated as the sum of total dietary and supplement intake. Diabetes and prediabetes were self-reported. Statistical analysis was performed using survey commands to provide nationally representative estimates. A generalized linear regression model was run adjusting for relevant covariates using log transformed ACR, with estimates exponentiated to provide mean ratios (MR). Results: About 3535 adults, representing 28,787,552 U.S. adults were included in the study. The mean Na intake for the cohort was 3,082mg (median 2,783mg) and 26% of the cohort had sodium intake <2,000mg. In the unadjusted analysis, an increase of 1,000mg Na was significantly associated with higher ACR (MR=1.04, 95% CI 1.00-1.08). In addition, non-Hispanic blacks (NHB) (MR=1.82, 95% CI 1.52-2.19) and Hispanics (MR=2.31, 95% CI 1.96-2.72) had higher ACR compared to non-Hispanic whites (NHW). After adjusting for relevant covariates including CKD stage, participants with diabetes were more likely to have ACR (MR=1.52, 95% CI 1.28-1.80) while the relationship between Na intake and ACR lost significance (p=0.05). Conclusions: For every 1000mg increase in sodium intake participants were 4% more likely to have albuminuria. NHB were 82% and Hispanics were 131% more likely to have albuminuria compared to NHW. Future prospective studies should focus on examining the relationship between sodium intake and albuminuria among minorities. Disclosure M.N. Ozieh: None. E. Garacci: None. R.J. Walker: None. L.E. Egede: Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases. Advisory Panel; Self; Novo Nordisk Inc..