From the Guidelines
Elevated sex hormone-binding globulin (SHBG) levels indicate a condition where there is increased binding of sex hormones in the bloodstream, which can lead to reduced levels of free or bioavailable hormones. This elevation can occur due to several factors including liver disease (particularly cirrhosis) 1, hyperthyroidism, eating disorders, HIV infection, or estrogen excess states such as pregnancy. Certain medications like oral contraceptives, estrogen therapy, anti-epileptics 1, and some anti-psychotics can also increase SHBG levels. The clinical significance of elevated SHBG is that it reduces the amount of free testosterone and estrogen available to act on target tissues, potentially causing symptoms of hormone deficiency despite normal or even elevated total hormone levels. In men, this may manifest as decreased libido, erectile dysfunction, or reduced muscle mass, while women might experience menstrual irregularities or menopausal symptoms. When evaluating hormone status, it's essential to consider both total hormone levels and SHBG levels to accurately assess the bioavailable hormone fraction that is physiologically active, as highlighted in the context of polycystic ovary syndrome (PCOS) diagnosis 1. Key factors influencing SHBG levels include age, weight, and medication use, which can impact the accuracy of androgen measurement methods 1. In the context of liver disease, the reasons for SHBG rise remain unclear, although SHBG synthesis is stimulated by estrogens 1. Overall, understanding the causes and effects of elevated SHBG is crucial for accurate diagnosis and management of hormone-related conditions.
From the Research
Elevated Sex Hormone-Binding Globulin (SHBG) Levels
Elevated SHBG levels can indicate several conditions, including:
- Hyperthyroidism, as high thyroid hormone levels can increase SHBG production 2
- Hypogonadism, a condition characterized by low sex hormone production, which can lead to increased SHBG levels 2
- Androgen insensitivity, a condition where the body is unable to respond to androgens, resulting in high SHBG levels 2
- Hepatic cirrhosis, a liver condition that can affect SHBG production 2
- Certain metabolic disorders, such as metabolic syndrome, which can be associated with high SHBG levels 3, 4, 5
Association with Diseases
Elevated SHBG levels have been linked to various diseases, including:
- Polycystic ovary syndrome (PCOS), although low SHBG levels are more commonly associated with PCOS 4
- Obesity, as SHBG levels can be influenced by body mass index and metabolic factors 3, 4, 5
- Cardiovascular disease, as low SHBG levels have been linked to an increased risk of ischemic stroke 6
- Thyroid function disorders, as SHBG levels can be affected by thyroid hormone levels 2, 5
Clinical Significance
Measuring SHBG levels can be useful in the evaluation of certain disorders, such as:
- Androgen metabolism disorders, as SHBG levels can help identify individuals with excessive androgen activity 2
- Hirsutism, a condition characterized by excessive hair growth in women, as SHBG levels can help predict response to estrogen therapy 2
- Infertility, as SHBG levels can be associated with reproductive disorders 5