SHBG and polycystic ovary syndrome: Recently, biochemical and genotype data obtained from a PCOS genome-wide association study (GWAS) led to the postulation of only two subtypes of PCOS, a “reproductive” type (21–23% of all cases), characterized by low BMI, glucose and insulin levels, higher luteinizing hormone (LH) and sex hormone-binding globulin (SHBG), and a “metabolic” group (37–39%), characterized by higher BMI, glucose and insulin levels, but lower SHBG and LH levels [99].