Long-term depot specific changes in adipose tissue after treatment of acromegaly

Abstract

Context: Patients with active acromegaly present a decreased adipose tissue (AT) mass, and short-term studies show that treatment leads to AT depot-specific gain. However, it remains unclear if the increase is persistent in the long-term perspective and/or is sex-dependent.

Design: To characterize the depot-specific changes of AT after treatment of acromegaly and identify contributing factors.

Methods: Adipose tissue, including visceral (VAT), subcutaneous (SAT), and total (TAT), and android to gynoid ratio (A/G ratio) were measured by dual energy X-ray absorptiometry at diagnosis (n = 62), and after treatment at short-term (median (IQR) 1.9 (1.5-2.3)) and long-term 5.5 (3.9-9.5) years, and correlated to clinical and biochemical measurements. Growth hormone (GH), insulin-like growth factor 1 (IGF-1), glucose and HbA1c levels, gonadal status, and the presence of diabetes mellitus were recorded. Remission status was assessed at the long-term visit (IGF-1/ULN ≤ 1.3). Differences in the temporal course of AT from baseline to short- and long-term follow-up according to sex, diabetes, gonadal, and remission status were evaluated by mixed model analysis, adjusted for age.

Results: Despite a stable body mass index, VAT and A/G ratio increased at both time points, whereas SAT mainly increased at short-term, plateauing afterwards (P < .05 for all). Visceral adipose tissue and A/G ratio were higher in men (P = .035 and P < .001), and the A/G ratio increased more than in women (P = .003). Glucose and HbA1c decreased short-term (P < .05) and remained stable at long-term. The increase in AT depots correlated with the decrease of disease activity at long-term. Remission status had no effect on changes in AT mass during follow-up.

Conclusion: Treatment of acromegaly leads to an increase in AT mass in a depot- and sex-specific manner both at short-term and long-term follow-up. Glucose metabolism improves rapidly after disease control and persists.

Keywords: diabetes mellitus; dual energy X-ray absorptiometry; remission; subcutaneous adipose tissues; transphenoidal pituitary surgery; visceral adipose tissue.