The sex hormone-binding globulin (SHBG) test is the way to examine men for low testosterone and women for high testosterone levels. SHBG is a protein that can bind particular hormones, including testosterone, estradiol (estrogen), and dihydrotestosterone (DHT). A healthcare provider may recommend the test with other tests to know the level of sex hormones. The normal SHBG levels may vary from one person to another, depending on several other factors, such as gender and age. Read the article for more detailed information about SHBG and why you need this test.
What is sex hormone-binding globulin?
Sex hormone-binding globulin (SHBG) is a type of protein present in your blood that combines particular hormones. Your liver develops SHBG. A low quantity of it is present in the testes.
SHBG is an old protein usually present in all mammals. Many forms of it are available in fish. SHBG regulates the levels of certain other hormones in your blood and evaluates the control of tissues by these hormones.
What type of hormones does SHBG combine?
Sex hormone-binding globulin generally binds three hormones. They are present in males and females, including:
- Testosterone – A leading sex hormone, especially for males, also available in females.
- Estradiol – is a type of estrogen and a female sex hormone.
- Dihydrotestosterone – A large amount of it is available in males.
SHBG transports these hormones into your bloodstream. Your body’s cells cannot utilize hormones in this bound state as they are available. It is the approach of your body to control hormone levels.
Your body produces sexual and reproductive tissues using testosterone and estrogen because they are essential hormones. SHBG helps move the active form of these hormones throughout your body.
In the cases of low SHBG levels, your body utilizes more unbound sex hormones that are present. The high SHBG levels mean your body has lower free sex hormones.
What is the sex hormone binding globulin test?
The sex hormone-binding globulin test is a blood test. A healthcare provider will recommend this test to determine SHBG protein levels in your blood.
An SHBG test may be ordered during the same interval as other tests to observe testosterone levels. A doctor will generally suggest these tests if they think you have an abnormal test. For men, that may show you have low testosterone levels.
Your SHBG levels may be higher if you are a woman. The SHBG test often helps to examine low or high levels of testosterone. For men, 45% to 65% of testosterone in the blood is usually bound with SHBG. The remaining weakly and reversely bound with albumin (the leading protein in the blood).
2% to 3% of testosterone is instantly present in the tissues as free testosterone. However, testosterone weakly bound to albumin is also bioavailable and can easily be used through the body’s tissues.
Slightly higher testosterone is bound to SHBG in the blood (66% to 77%) in women than in men. For women, SHBG has a function to control bioavailable male sex hormone levels (androgens) along with estrogen that flows throughout the body. The SHBG possesses a higher attraction for the androgens testosterone and DHT. If the SHBG test results show low SHBG, women may have symptoms of high androgen levels.
A total testosterone test does not help differentiate between bound and unbound testosterone. It only measures the overall testosterone level in the blood. The test is mostly enough to examine people for high or low testosterone formation.
However, if the SHBG test results are abnormal, the total testosterone may not correctly show the testosterone available in your body tissues. You may need to take the SHBG test if your signs and symptoms do not correspond with the total testosterone test results.
When do you need the SHBG test?
SHBG tests are generally not included in a regular checkup. A healthcare provider may recommend the test if:
- You experience signs and symptoms of abnormal SHBG levels
- A total testosterone test results do not show clear and complete details
- To know the reason for high or low testosterone or estrogen levels.
In men, the test help to find the cause of the following conditions, including:
- Low sex drive
- Erectile dysfunction
In women, the test help to identify the cause of these conditions, such as:
- Acne (a skin disease)
- Irregular menstrual periods
- Growth of body and facial hair
Factors That May Affect Your SHBG Levels:
Here are the factors that may influence your normal SHBG levels include:
- Family history
Several other conditions can lead to very low or very high SHBG. A healthcare provider will note these factors and ask about any symptoms you have to understand whether or not you have abnormal SHBG levels.
What will be the symptoms if you have low SHBG?
A provider may recommend an SHBG test for both males and females if you experience the symptoms of low SHBG levels. Your body utilizes more free sex hormones if you have low SHBG levels.
Here are the symptoms of excessive free testosterone in men, including
- Fluid deposition
- Weight gain
- Acne (a common skin condition that results when the hair follicle within the skin becomes blocked)
- Expansion in the muscle mass
- High appetite
- Changes in the mood or behavior
The high estrogen levels in men can result in:
- Erectile dysfunction (ED)
- Increase in the breast tissue
High testosterone in women may lead to these symptoms include:
- Menstrual changes
- Growth of body and face hair
- Behavior or mood changes
High estrogen in women can result in:
- Swelling or tenderness in the breast
- Changes in the mood or behavior
- Abnormal periods
Speak to a healthcare provider if you have these signs and symptoms of low SHBG levels.
What is the procedure for the SHBG test?
An SHBG test is a blood test that needs your blood sample. You can schedule this test online before visiting the laboratory.
Following are the simple steps that you need to take a blood sample, including
- You need to wear off the part of your cloth from one of your veins
- A provider will inject the needle into a vein in your arm
- A small amount of blood will collect in a test tube attached to a blood needle.
- After that, the blood needle will be brought out, and a bandage to your vein site.
- Your blood sample will place at the laboratory for examination
- The blood test will usually take at least five minutes
What are the preparations needed for the SHBG test?
You do not require specific preparation for the SHBG test. If your provider orders more tests, you may recommend fasting (avoiding drinking or eating) for several hours. Inform your healthcare provider if you use supplements or drug medications or carrying an eating disorder. Since these may change your test results, it is necessary to discuss using them with your healthcare provider.
Normal sex hormone-binding globulin (SHBG) levels
Normal SHBG levels usually vary from one person to another. These may change in quantity throughout your life. The recommended value for SHBG in adults is 10 to 57 nanomoles per liter (nmol/L) for males and 18 to 144 (nmol/L) for females. The normal ranges may vary slightly among laboratories as these may use different measurement methods.
Women usually have higher SHBG levels compared to men. However, the SHBG levels generally increase with men’s age since fall occurs in their testosterone levels.
Cause of low SHBG
If your SHBG test results are low, they may show any of the following medical conditions, such as:
- Cushing’s syndrome – When your body produces a large amount of cortisol.
- Type 2 diabetes – Type 2 diabetes develops when your body fails to manage your blood sugar levels.
- Hypothyroidism – A condition when your thyroid does not develop needed thyroid hormone.
- Cancer testes – It may only occur in males.
- Polycystic ovary syndrome – PCOS is a hormonal disorder in females that may lead to infertility.
Cause of high SHBG
On the other hand, if you have high sex hormone binding globulin, it might show one of these conditions, including:
- Hyperthyroidism – A condition in which your thyroid develops a large amount of thyroid hormone.
- Addison’s disease – Your adrenal gland does not develop the required specific hormones.
- Pituitary disorders – It is a gland present under your brain that regulates several body functions.
In a few scenarios, a healthcare provider will compare the SHBG levels to the total testosterone levels in your body. It will allow them to examine the amount of body testosterone that utilizes.
If you experience problems with the ratio of SHBG to testosterone, it may show several specific conditions, such as
Hypogonadism – A condition that causes low testosterone levels often present in males.
Androgen deficiency – Androgen is the group of essential sex hormones. Their low levels may develop symptoms that differ between males and females.
Ways To Increase SHBG Levels
The treatment may start when the provider detects the cause of a low SHBG. A healthcare provider will inform you of the SHBG test results with you and possible treatment methods. You should follow the advice and recommendations of your doctor.
Studies proved that applying the following ways in your lifestyle can help increase SHBG levels:
- Daily exercise
In the experiment conducted on sedentary men aged 40 to 75, one-year offers of intermediate aerobics exercise resulted in high SHBG and DHT. However, the exercise program didn’t influence the other androgens within this group.
A big trial in several people claimed that SHBG rises through daily exercise. The research observed women having postmenopausal, often overweight with recent sedentary. The one-year-long exercise program involved about 178 minutes of aerobics per week.
- Take Coffee
A study conducted on women having age above 60 shows taking two or more cups of caffeinated coffee is associated with higher SHBG levels.
- Reduce sugar from the diet:
A recent study of women having postmenopausal observed the connection between diet and SHBG.The studies show that low glycemic load or glycemic index dies with low sugar and high fiber may be associated with increased SHBG levels.
However, still, more research is required to understand this relationship.
- Add fiber
A study involving men aged 40 to 70 observed that getting fiber leads to high SHBG levels, while protein intake reduces their levels.
- Weight lose
A study indicates that losing weight in children if they are obese can increase their SHBG levels. You can try a different weight loss program or talk to a provider online to receive a personalized diet and weight loss plan.
- Use particular oral contraceptives:
A meta-analysis of women having PCOS showed that the SHBG levels increase after the treatment duration of three months to one year by taking particular combined oral contraceptives.
- Take specific supplements
Several herbal and dietary supplements are declared to help reduce SHBG levels to increase testosterone. Others may help, which is difficult to understand with certainty.
Supplements are generally not regulated by the Food and Drug Administration (FDA), so the producers or manufacturers can easily give claims that are not always trustable.
Few supplements include ingredients that can develop severe side effects by reacting with prescription medications or irritate the already-carrying health problems.
Speak to a healthcare provider before using a new supplement. It is the way to know the ingredients used in the product formation and the risk for particular side effects.
The SHBG test is essential to check the SHBG protein levels in the blood. SHBG levels usually change with time in a person’s life. A doctor will ask about your symptoms and consider other factors to recommend the SHBG test. If you experience abnormal test results, a healthcare provider will analyze your symptoms to know the hidden cause.
In a few cases, a few lifestyle changes may recover back your SHBG levels. In others, a group of prescription medications and other therapies may require. If you do not have any conditions, a healthcare provider will guide you about the measures you need to take. You may also consult a provider online if you are experiencing symptoms of low SHBG levels.