Sex Hormone Binding Globulin (SHBG) is a protein produced primarily by the liver. Its main function is to bind to and transport sex hormones throughout the body. This article explores the various reasons why SHBG levels might be elevated in males.
SHBG’s Role in Male Hormones
SHBG plays a significant role in regulating the availability of sex hormones in males. It primarily binds to androgens, male sex hormones like testosterone and dihydrotestosterone (DHT). When bound, these hormones become biologically inactive and unavailable for cells to use.
Hormones exist in two states: “bound” or “free.” Bound hormones are attached to proteins like SHBG, while free hormones are not bound and can exert their effects. Elevated SHBG means more testosterone and DHT are bound, reducing free, active hormones. Only free hormones can interact with target cells and produce biological responses.
Underlying Medical Conditions
Several medical conditions can lead to an increase in SHBG levels in males. Hyperthyroidism, an overactive thyroid gland, significantly contributes to elevated SHBG. Excess thyroid hormones stimulate the liver to produce more SHBG.
Compromised liver function, such as chronic liver disease or cirrhosis, can also affect SHBG levels. While the liver produces SHBG, certain conditions can alter its synthesis or clearance, leading to higher levels.
Estrogen excess in males is another common cause. Conditions like obesity (which converts androgens to estrogen) or specific tumors can increase estrogen, stimulating the liver to produce more SHBG. Certain medications or environmental exposures mimicking estrogen also contribute. Androgen Insensitivity Syndrome (AIS), a genetic condition where cells don’t respond properly to androgens, is a less common but significant cause. In AIS, the body compensates by producing more testosterone, which increases SHBG.
Lifestyle and Other Contributing Factors
Beyond specific medical conditions, various lifestyle choices and other factors can influence SHBG levels in males. Chronic heavy alcohol consumption can impact liver function, affecting SHBG production and regulation, leading to elevated levels.
Diet and nutrition also play a part. Very low-fat or high-fiber diets have been associated with increased SHBG. Nutritional deficiencies, such as zinc deficiency, might also influence SHBG levels.
Specific medications can also elevate SHBG, including certain anticonvulsants, some antifungal drugs, and opioid medications. Exogenous estrogens also increase SHBG, similar to internally produced estrogen excess. SHBG levels can also naturally increase with age.
When to Consult a Healthcare Professional
A high SHBG result is a laboratory finding, not a diagnosis. It indicates an imbalance but doesn’t pinpoint the underlying cause. If a male receives a blood test showing elevated SHBG, or experiences symptoms suggesting a hormonal imbalance, consulting a medical professional is advisable.
Only a qualified healthcare provider can evaluate a high SHBG result within an individual’s overall health, symptoms, and other lab findings. They can conduct further tests to diagnose the underlying cause and recommend appropriate management or treatment. Self-diagnosis or attempting to treat high SHBG without professional guidance is not recommended.