SHBG can be measured in both men and women as it is associated with cardiometabolic, endocrine, and liver health, and has functions beyond hormone transportation.
Sex Hormone Binding Globulin (SHBG) can be measured effectively in men and women. It is produced to some extent in the hypothalamus and pituitary gland but is primarily synthesized in the liver. Therefore, endocrine and liver disorders are associated with alterations in SHBG levels. Low SHBG may be caused by inflammation, elevated androgens, and fatty liver and associated with obesity, metabolic syndrome, glucose dysregulation, insulin resistance, polycystic ovary syndrome, low HDL, increased cardiovascular risk, and increased risk of diabetes, including gestational diabetes.
Higher levels of SHBG may be caused by thyroid hormone, estrogen, and adiponectin and are associated with greater bone resorption, lower bone mineral density, and increased fracture risk. SHBG tends to increase with age in men by approximately 1% per year and may decrease with age in women. SHBG may have a protective role against breast cancer as its binding to breast cancer cells can inhibit proliferation. However, in men, increased SHBG may promote prostate cancer. Genetic factors can also influence SHBG physiology (Goldstajn 2016).
Energy balance, physical activity, and dietary factors can also influence SHBG metabolism. A diet low in protein and fat can increase/restore SHBG, while a diet low in carbohydrates can decrease it. Thyroid hormones stimulate the liver to increase SHBG and can be significantly elevated in hyperthyroidism, while low to normal levels are observed in hypothyroidism. Hyperinsulinemia also reduces liver SHBG production, resulting in decreased serum levels (Thaler 2015).
Ultimately, production and serum levels of SHGB are influenced by many factors and must be assessed while considering endocrine, liver, and cardiometabolic function.
References
Goldstajn, Marina Šprem et al. “Sex Hormone Binding Globulin (SHBG) as a Marker of Clinical Disorders.” Collegium antropologicum vol. 40,3 (2016): 211-8.
Thaler, Markus A et al. “The biomarker sex hormone-binding globulin - from established applications to emerging trends in clinical medicine.” Best practice & research. Clinical endocrinology & metabolism vol. 29,5 (2015): 749-60. doi:10.1016/j.beem.2015.06.005