SHBG and diabetes mellitus: We previously have demonstrated that HbAA was negatively associated with BMI, fat mass,[27] reduced serum insulin and insulin resistance in the NHANES cohort.[2] It was reported that low serum SHBG concentrations were associated with insulin resistance and type 2 diabetes mellitus.[28, 29] Previous analyses have also identified that sex hormones were inversely correlated with adiposity (abdominal and visceral fat) in men.[30, 31] It is not known yet about the causal relationship between low concentrations of sex hormones and insulin resistance/fat mass.