Abstract P157: Racial Differences In Atrial Natriuretic Peptide And Insulin

Abstract

Low circulating concentrations of the natriuretic peptides (NPs) have been associated with greater risk for Type 2 diabetes (T2D). As a group, African Americans (AA) have lower NP levels and are disproportionately burdened by T2D. Insulin, which is higher in AA, has been shown to regulate NP concentration by increasing the NP clearance receptor. This secondary analysis tests the hypothesis that higher insulin in AA will be associated with lower levels of plasma N-terminal pro-atrial natriuretic peptide (NT-proANP). Participants were 120 AA and European American (EA) men and women ages 19-45 years. Measures of insulin, including fasting insulin and insulin total and incremental area under the curve (AUC and iAUC, respectively, at 30 and 120 m), were derived from an oral glucose tolerance test (OGTT). Insulin sensitivity (SI Clamp ) was assessed using the euglycemic glucose clamp. NT-proANP was measured from fasting samples obtained during the OGTT. Differences in NT-proANP by race was evaluated with analysis of covariance while adjusting for age, sex, and BMI. Linear regression models were used to examine associations between NT-proANP and insulin measures while adjusting for age, sex, race, and BMI. Relative to EA, AA had higher insulin concentrations, lower insulin sensitivity, and lower NT-proANP levels (p<0.05). Fasting insulin and 30 m insulin AUC were inversely associated with NT-proANP (p=0.02, p=0.02, and p=0.04, respectively). These results suggest that the lower NT-proANP observed in AA is related to higher insulin. Future research is needed to investigate the relationship between insulin, ANP, and the NP clearance receptor, particularly in populations at risk for chronic disease.