Of these, a low SHBG level is associated with metabolic syndrome, obesity, insulin resistance and type 2 diabetes, hypothyroidism, hormone excess (androgen, progestin, growth hormone, and glucocorticoid), and a higher risk of cardiovascular disease and breast cancer [17,18,19,20], while conditions associated with an increased SHBG level include aging, hyperthyroidism, liver disease, human immunodeficiency virus disease, bone loss, and a higher risk of fracture [21,22]. This evidence concerns the gene SHBG and breast cancer.