310 - Urinary nitrates in relation to glomerular filtrate rate (GFR) and albumin-creatinine rate (ACR)

Abstract

Background Intervention studies have shown that dietary nitrate supplementation significantly increased circulating nitrates and inhibited platelet aggregation, improved vascular function and lowered blood pressure. Thus, studying physiological functions that are associated with circulating nitrates may help us to identify a population who are likely to have lower circulating nitrates and may need supplementation. Circulating nitrates reflect cumulative influences of production of nitric oxide and nitrate metabolism. Animal studies have shown that the production of nitric oxide (NO) is reduced in chronic kidney disease (CKD) and is associated with the progression of CKD. Further, nitrate metabolism can be significantly influenced by gut microbiome composition. Compared to people with normal renal function, individuals with reduced renal function have different gut microbiome composition. Until now, no studies have examined the association between circulating nitrates and renal function among healthy individuals who have not been diagnosed with CKD. Glomerular filtrate rate (GFR) and albumin-creatinine rate (ACR) have been used to assess renal function. Our study aimed to determine if there was an association between urinary nitrates and GFR or ACR. Methods Using a cross-sectional design, we analyzed data obtained from 5,071 adults, ages 18-85, enrolled in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). Demographic data were obtained and urinary nitrates, creatinine, GFR and ACR ratio were assessed among these individuals. We classified GFR into three categories: ≥90 mL/min/1.73 m2 (normal renal function), 60-90 mL/min/1.73 m2 (renal insufficiency) and Results We have found that urinary nitrates were inversely associated with renal function.