Omental adipose tissue type 1 11β-hydroxysteroid dehydrogenase oxoreductase activity, body fat distribution, and metabolic alterations in women

Abstract

Context: Modulation of adipose tissue exposure to active glucocorticoids by type 1 11β-hydroxysteroid dehydrogenase (11β-HSD1) is involved in abdominal obesity of rodent models, but only a few studies have related 11β-HSD1 oxoreductase activity to fat distribution in humans. Objective: The objective of the study was to examine the link between 11β-HSD1 oxoreductase activity, fat distribution patterns, and the metabolic profile in women. Methods:Omental(OM) and sc adipose tissue samples were obtained from 36 lean to obese women (aged 47.2±5.3 yr; body mass index 29.1±5.2 kg/m2) undergoing gynecological surgery. Measures of body composition, fat distribution, blood lipids, and insulin sensitivity were obtained. 11β-HSD1 oxoreductase activity was measured over a 24-h period by the reduction of [14C]cortisone in adipose tissue homogenates. Results: 11β-HSD1 oxoreductase activity was higher in OM compared with sc adipose tissue (9.6±4.9 vs. 7.9±4.2 pmol/mg · h, P < 0.01).OM11β-HSD1 oxoreductase activity was positively associated with OM adipocyte size (r = 0.67, P < 0.0001) and visceral adipose tissue area (r = 0.57, P < 0.0003). A positive correlation was also observed between the OM/sc 11β-HSD1 oxoreductase activity ratio and the OM/sc adipocyte size ratio (r = 0.37, P < 0.05) as well as the visceral/sc adipose tissue area ratio (r = 0.36, P < 0.05). Women in the highest tertile of OM 11β-HSD1 oxoreductase activity had larger OM adipocytes, increased OM lipolysis, increased lipoprotein lipase activity, decreased high-density lipoprotein cholesterol, decreased adiponectin levels, and an increased homeostasis model assessment of insulin resistance index compared with women in the lower tertile (P < 0.05). Conclusions: These results suggest that a relatively higher 11β-HSD1 activity in OM vs. sc adipose tissue is associated with preferential visceral fat accumulation and concomitant metabolic alterations. Copyright © 2009 by The Endocrine Society.