Clinical Information

This assay has not been validated for newborn testing. In patients receiving therapy with high doses of biotin (> 5 mg/day), no sample should be taken until at least 8 hours after the last biotin administration. Thyrotoxicosis increases SHBG concentrations. Patients with anorexia nervosa have high SHBG concentrations. SHBG is also produced by placental tissue and, therefore, values will be elevated during pregnancy. Reference ranges for pregnant women have not been established at our institution. Therapies/behavior alterations that may potentially increase SHBG concentrations include reducers of bioactivity of androgens (e.g., androgen receptor antagonists, alpha-reductase inhibitors) or reduction of insulin resistance (e.g., weight loss, metformin, peroxisome proliferator-activated receptor gamma agonists). Clinical assays may not be available for many therapeutic synthetic androgens and estrogens (e.g., ethinyl-estradiol). In those instances, increasing SHBG concentrations may be associated with anti-androgen or estrogen therapy, while SHBG reduction can be associated with androgen treatment. For patients presenting with cirrhosis or subclinical thyroid conditions, carefully evaluate results as these conditions can potentially cause erroneous sex hormone-binding globulin (SHBG) results. In laboratories at OSUWMC, sex hormone-binding globulin measurement is used for the assessment of the free testosterone fraction (calculated free testosterone).  For assays employing antibodies, the possibility exists for interference by human anti-animal antibodies (i.e., heterophile antibodies) in the patient sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures utilizing immunoglobulins or immunoglobulin fragments may produce antibodies, (e.g., HAMA), that interfere with immunoassays. This may falsely elevate or falsely decrease the results.