Glucocorticoid receptor gene expression in adipose tissue and associated metabolic risk in black and white South African women.

Abstract

BACKGROUND:

Black women have lower visceral adipose tissue (VAT) but are less insulin sensitive than white women; the mechanisms responsible are unknown.

OBJECTIVE:

The study aimed to test the hypothesis that variation in subcutaneous adipose tissue (SAT) sensitivity to glucocorticoids might underlie these differences.

METHODS:

Body fatness (dual energy X-ray absorptiometry) and distribution (computerized tomography), insulin sensitivity (SI, intravenous and oral glucose tolerance tests), and expression of 11β-hydroxysteroid dehydrogenase-1 (11HSD1), hexose-6-phosphate dehydrogenase and glucocorticoid receptor-α (GRα), as well as genes involved in adipogenesis and inflammation were measured in abdominal deep SAT, superficial SAT and gluteal SAT (GLUT) depots of 56 normal-weight or obese black and white premenopausal South African (SA) women. We used a combination of univariate and multivariate statistics to evaluate ethnic-specific patterns in adipose gene expression and related body composition and insulin sensitivity measures.

RESULTS:

Although 11HSD1 activity and mRNA did not differ by ethnicity, GRα mRNA levels were significantly lower in SAT of black compared with white women, particularly in the GLUT depot (0.52±0.21 vs 0.91±0.26 AU, respectively, P<0.01). In black women, lower SAT GRα mRNA levels were associated with increased inflammatory gene transcript levels and abdominal SAT area, and reduced adipogenic gene transcript levels, VAT/SAT ratio and SI. Abdominal SAT 11HSD1 activity associated with increased VAT area and decreased SI in white, but not in black women.

CONCLUSIONS:

In black SA women, downregulation of GRα mRNA levels with obesity and reduced insulin sensitivity, possibly via increased SAT inflammation, is associated with reduced VAT accumulation.

• Authors: J H Goedecke, E Chorell, D E W Livingstone, R H Stimson, P Hayes, K Adams, J A Dave, H Victor, N S Levitt, S E Kahn, J R Seckl, B R Walker, T Olsson
• Journal: International journal of obesity (2005) (Int J Obes (Lond)) Vol. 39 Issue 2 Pg. 303-11 (Feb 2015) ISSN: 1476-5497 [Electronic] England
• PMID: 24854429 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Glucocorticoid
• glucocorticoid receptor alpha
• 11-beta-Hydroxysteroid Dehydrogenases

Topics

• 11-beta-Hydroxysteroid Dehydrogenases (genetics, metabolism)
• Absorptiometry, Photon
• Adult
• Black People
• Body Composition (genetics)
• Cross-Sectional Studies
• Female
• Glucose Tolerance Test
• Humans
• Intra-Abdominal Fat (metabolism)
• Metabolic Syndrome (ethnology, genetics, metabolism)
• Receptors, Glucocorticoid (metabolism)
• South Africa (epidemiology)
• Subcutaneous Fat (metabolism)
• White People