Changes in white adipose tissue gene expression in a randomized control trial of dieting obese men with lowered serum testosterone alone or in combination with testosterone treatment

Purpose The aim of this study was to determine early weight loss-associated changes in subcutaneous abdominal white adipose tissue (WAT) gene expression in obese men with lowered serum testosterone by RNA next-generation sequencing. Methods Fourteen men, mean age (IQR) 51.6 years (43.4–54.5), BMI 38.3 kg/m 2 (34.6–40.8) and total testosterone 8.4 nmol/L (7.5–9.5) provided subcutaneous WAT samples at baseline and after 2 weeks of a very low energy diet. Results Body weight loss was similar in participants receiving testosterone ( n = 6), −5.27 kg [95% CI −6.17; −4.26], and placebo ( n = 8), −4.57 kg [95% CI −6.10; −3.55], p = 0.86. In placebo-treated men, of the 14,410 genes expressed in subcutaneous WAT, four genes, Angiopoietin-like 4, Semaphorin 3 G, Neuropilin 2 and Angiopoietin 4, were upregulated (adjusted false discovery rate P < 0.05). In an exploratory analysis comparing men receiving testosterone and placebo, the most-upregulated gene in the testosterone group (exploratory p < 0.0005) was the neuropeptide y receptor 2. Conclusions In obese men, dieting is associated with upregulation of WAT-expressed Angiopoietin-like 4, a secreted protein that regulates lipid metabolism, Semaphorin 3 G, a proposed adipocyte differentiation factor and secreted adipokine, and its receptor Neuropilin 2, as well as Angiopoietin 4, a vascular integrity factor. In an exploratory analysis, testosterone was associated with the upregulation of neuropeptide y receptor 2, a receptor involved in appetite regulation. Further studies are needed to confirm these observations and their potential biological implications. Trial registration clinicaltrials.gov, Identifier NCT01616732, Registration date: June 8, 2012.