Adipose tissue expression of adipose (WDTC1) gene is associated with lower fat mass and enhanced insulin sensitivity in humans

The overexpression of the adipose gene (adp/WDTC1) in mice inhibits lipid accumulation and improves the metabolic profile. OBJECTIVE: We evaluated subcutaneous fat adp expression in humans and its relation to metabolic parameters. DESIGN, SETTING AND METHODS: Abdominal subcutaneous fat adp expression, insulin sensitivity (clamp) and respiratory quotient (RQ; indirect calorimetry) were assessed in: 36 obese and 56 BMI-, race- and sex-matched type 2 diabetic volunteers (Look AHEAD Adipose Ancillary Study); 37 non-diabetic Pima Indians including obese (n=18) and non-obese (n=19) subjects and; 62 non-obese non-diabetic subjects at the Pennington Center in the ADAPT study. RESULTS: In the Look AHEAD Study, adp expression normalized for cyclophilin B was higher in males vs. females (1.27±0.06 vs. 1.11±0.04; p<0.01) but not after controlling for body fat. Adp expression was not influenced by the presence of diabetes but was related to body fat (r=−0.23; p=0.03), insulin sensitivity (r=0.23; p=0.03) and fasting/insulin-stimulated RQ (r=0.31 & 0.33; p<0.01). In Pima Indians, adp expression was also higher in males vs. females (1.00±0.05 vs. 0.77±0.05; p=0.02) and higher in non-obese vs. obese (1.02±0.05 vs. 0.80±0.06; p=0.03). In the ADAPT study, there was no difference in adp expression between males and females. CONCLUSION: Consistent with animal studies, our results suggest that, high adp expression in human adipose tissue is associated with lower adiposity and enhanced glucose utilization.