Endocrine Abstracts

Objective: The cardiac hormone brain natriuretic peptide (BNP), including the N-terminal fragment of the prohormone (NT-proBNP) have in cross-sectional studies been demonstrated to be inversely associated with BMI. Clearance of these peptides by adipocyt specific receptors have been suggested. We therefore investigated the impact of weight loss on plasma levels of NT-proBNP and adiponectin in obese individuals.

Methods: A total of 20 obese women and 2 men (BMI >28 kg/m²), age 61.7 (±6.6) year (mean±S.D.) were included. All subjects were without cardiovascular disease. NT-proBNP was <125 pg/ml, which is the recommended cut-off value for rule out a diagnosis of heart failure. The participants were on a low energy diet of 3.4–5 MJ/day for 1 year. Body weight, body composition measured by DEXA scan, as well as plasma levels of NT-proBNP and adiponectin were measured at baseline and after 52 weeks.

Results: Mean total weight loss was 15.4% (±1.7%) and DEXA scan revealed, that this primarily was due to loss in body fat of 27.2% (±3.2%), the decrease in lean tissue mass was 3.0% (±1.2%) (mean±SE). Plasma levels of NT-proBNP increased from 50.2 (39.7–83.3) pg/mL at baseline to 90.3 (49.0–118.9) pg/ml after 52 weeks, median (interquartile range) (P=0.003). Plasma adiponectin levels increased from 14.2 (9.0–17.25) to 16.5 (10.4–19.9) mg/l (P=0.004). Furthermore, a significant association between percent weight loss and increase in plasma adiponectin levels (R=0.59, P=0.004), and a trend towards an association with increase in NT-proBNP levels (R=0.31, P=0.15) were found.

Conclusions: Plasma levels of NT-proBNP increases significantly during weight loss, suggesting a possible role of adipose tissue in the clearance of this peptide from circulating plasma. The observed increase in adiponectin supports, that plasma levels are regulated by a negative feedback mechanism.