NT-proBNP and metabolic risk factors in two ethnic groups: the SABPA cohort study

Abstract

Background: Natriuretic peptides are vasoactive peptides with several metabolic actions. Purpose: We aimed to explore associations of N-terminal pro-brain natriuretic peptide (NT-proBNP) with metabolic traits in a mixed ethnic African-Caucasian cohort. Methods: Within the Sympathetic activity and Ambulatory Blood Pressure in African Prospective cohort study (SABPA), baseline examination was performed between 2008 and 2009, and re-examination after a 3-year follow-up in 397 South African teachers (African n = 194; Caucasian n = 203). Results: In cross-sectional linear regression analyses, each 1SD increment of age and sex adjusted NT-proBNP was inversely associated with body weight (ß = -2.23; p = 0.042), body mass index (ß = -1.01; p = 0.007), waist circumference (ß = -1.82; p = 0.033), HbA1c (ß = -0.14 %; p = 0.009), insulin (ß = -1.66; p = 0.002), homeostatic model assessment of insulin resistance (ß = -0.47; p = 0.006) and triglyceride levels (ß = -0.04; p = 0.002). Intra-ethnic differences were observed, where lower NT-proBNP levels affected glucometabolic status stronger among Africans. Each 1SD increment of age, sex, waist circumference and follow-up time adjusted NT-proBNP was associated with reduced odds of incident diabetes, and subjects within the highest quartile of NT-proBNP were at lowest risk compared with the lowest quartile (OR 0.24; CI95% 0.06-0.96; p = 0.041). Conclusions: In a cohort consisting of two ethnic groups, NT-proBNP in the high normal range is associated with lower prevalence of metabolic risk factors such as high BMI, increased waist circumference, impaired glucose tolerance, high insulin levels and hypertriglyceridemia, with strongest associations for Africans. Inspite of similar NT-proBNP concentrations, BNP may affect the propensity for metabolic disturbances differently in Africans and Caucasians