Adiponectin, skeletal muscle adiponectin receptor expression and insulin resistance following dexamethasone

Summary Objective Skeletal muscle is a major site of adiponectin action and of glucocorticoid‐induced insulin resistance. Little human data exist however, regarding the impact of exogenous glucocorticoids on adiponectin receptors in skeletal muscle. Design and patients Twelve subjects with type 2 diabetes and 12 controls underwent blood sampling and muscle biopsy of vastus lateralis before and after 4 days of 4 mg dexamethasone. Measurements (i) Total and high molecular weight (HMW) plasma adiponectin, glucose and insulin; (ii) Skeletal muscle adiponectin receptor AdipoR1 and AdipoR2 mRNA levels by quantitative real time RT‐PCR. Results Baseline total adiponectin (8·0 ± 0·89 vs. 12·5 ± 1·46 µg/ml, P = 0·013), HMW adiponectin (2·8 ± 0·44 vs. 5·9 ± 1·04 µg/ml, P = 0·014) and AdipoR2 mRNA levels (mean ΔCT 14·71 ± 0·35 vs. 13·37 ± 0·28, P = 0·017) were significantly lower in diabetic subjects. After dexamethasone, AdipoR2 mRNA fell in the controls but there was no change in the diabetic group, while there was a significant increase in total (P = 0·002) and HMW adiponectin (P