Measurement of free testosterone and DHEAS levels
Free testosterone (CSB-E05096h, Cusabio Biotech, Wuhan, China) and DHEAS (CSB-E05105h, Cusabio Biotech, Wuhan, China) serum concentrations were measured using commercial enzyme-linked immunosorbent assay kits according to the manufacturers’ protocols. The manufacturer-specified assay sensitivity limits for the detection of free testosterone and DHEAS were 3.75 pg/ml and 10 ng/ml, respectively. The concentrations were determined by comparing the optical densities (450 nm) of the samples with the standard curve. The free testosterone and DHEAS intra-assay CVs were 6.8% and 5.5%, respectively; and the inter-assay CVs values were 10.2% and 8.3%, respectively.