OBJECTIVE: This study examined the contribution of subcutaneous adipose tissue (SAT) 11βHSD1 to obese African Americans' (AA) elevated metabolic risk, despite a protective obesity phenotype of reduced visceral adipose tissue (VAT) and hepatic fat fraction (HFF) relative to obese Hispanics with similar metabolic risk. DESIGN AND METHODS: Obese AA and Hispanic adults (N = 36(16AA); BMI 35.2 ± 0.6 kg/m(2) , 18-25y) participated, with VAT, SAT, and HFF measured by MRI, SAT gene expression measured by HT-12 microarray and insulin sensitivity (SI), disposition index (DI) by IVGTT. Multiple linear regression examined relationships/interactions of ethnicity and 11βHSD1 expression on outcomes (covariates: age, sex, total fat mass), with standardized β (stβ) reported. RESULTS: SAT 11βHSD1 expression significantly associated with insulin parameters and this varied by ethnicity (Pinteraction <0.1). In AA, 11βHSD1 negatively associated with SI (stβ = -0.58, P = 0.03), DI (stβ = -0.62, P = 0.03) and positively associated with fasting insulin (stβ = 0.54, P = 0.04), with no significant relationship in Hispanics. SAT 11βHSD1 associated with HFF in the combined sample (stβ = 0.42, P = 0.008), with no difference between ethnicites (Pinteraction >0.1). After controlling for HFF, 11βHSD1 associations with metabolic risk in AA became nonsignificant. CONCLUSIONS: These results suggested that in AA and not Hispanics, SAT 11βHSD1 is associated with SI and DI, and may be mediated by HFF.
OBJECTIVE: This study examined the contribution of subcutaneous adipose tissue (SAT) 11βHSD1 to obese African Americans' (AA) elevated metabolic risk, despite a protective obesity phenotype of reduced visceral adipose tissue (VAT) and hepatic fat fraction (HFF) relative to obese Hispanics with similar metabolic risk. DESIGN AND METHODS: Obese AA and Hispanic adults (N = 36(16AA); BMI 35.2 ± 0.6 kg/m(2) , 18-25y) participated, with VAT, SAT, and HFF measured by MRI, SAT gene expression measured by HT-12 microarray and insulin sensitivity (SI), disposition index (DI) by IVGTT. Multiple linear regression examined relationships/interactions of ethnicity and 11βHSD1 expression on outcomes (covariates: age, sex, total fat mass), with standardized β (stβ) reported. RESULTS: SAT 11βHSD1 expression significantly associated with insulin parameters and this varied by ethnicity (Pinteraction <0.1). In AA, 11βHSD1 negatively associated with SI (stβ = -0.58, P = 0.03), DI (stβ = -0.62, P = 0.03) and positively associated with fasting insulin (stβ = 0.54, P = 0.04), with no significant relationship in Hispanics. SAT 11βHSD1 associated with HFF in the combined sample (stβ = 0.42, P = 0.008), with no difference between ethnicites (Pinteraction >0.1). After controlling for HFF, 11βHSD1 associations with metabolic risk in AA became nonsignificant. CONCLUSIONS: These results suggested that in AA and not Hispanics, SAT 11βHSD1 is associated with SI and DI, and may be mediated by HFF.
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: Int J Obes (Lond) Date: 2014-05-20 Impact factor: 5.095