How Thyroid Affects Male Fertility
Men who experience male infertility may overlook the possibility of a dysfunction in the thyroid gland as its underlying cause. Recent research evidence suggests that hyperthyroidism adversely affects fertility, spermatogenesis, and metabolism of the sex hormones. Thyroid malfunction may lower sperm motility in men, and if left untreated, may lead to an overall deterioration in their reproductive health.
The Thyroid Gland, Hypothyroidism, and Hyperthyroidism
The thyroid is an endocrine gland present at the base of your neck and resembles a butterfly. Its hormones keep your blood pressure, heart rate, and metabolism within normal ranges. Your weight gain and loss, cholesterol levels, and certain functions of your central and peripheral nervous systems also depend on it. It also controls the way your body adjusts temperature and utilizes energy.
The thyroid gland uses iodine to secrete its hormones: triiodothyronine (T3), and thyroxine (T4). The hypothalamus and pituitary gland in the brain maintain optimal hormonal levels by regulating the thyroid-stimulating hormone (TSH).
Hypothyroidism refers to low thyroid levels that may lead to low metabolism and libido, infertility, goiter, muscle weakness, fatigue, weight gain, hair loss, and depression. Men may also experience depression and increased susceptibility to infections.
Elevated thyroid levels manifest as rapid heartbeat, insomnia, sweating, anxiety, weight loss, bulging eyes, altered appetite, goiter, and infertility. Some men may experience an overgrowth of thyroid tissue as a small growing lump that causes difficulty in swallowing. It may also suppress the activity of the thyroid gland and cause hyperthyroidism.
Understanding the Thyroid Dysfunction – Male Fertility Link
Adverse effects on male reproductive health
Thyroid dysfunction directly affects male sexual function. Research evidence indicates that Erectile Dysfunction (ED), a serious concern for men is directly related to thyroid dysfunction. Krassas and his colleagues discovered that men diagnosed with ED also suffered from thyroid dysfunction. Treating thyroid also resolved ED.
Further, Gabrielson and colleagues also found that thyroid dysfunction could trigger sexual dysfunction. Thyroid gland abnormalities affected levels of circulating sex hormones by affecting central and peripheral nerve pathways, psychiatric malfunction, and dysregulation of the autonomic nervous system. All these factors collectively resulted in impaired sexual function. They identified ejaculatory dysfunction, impaired libido, and ED in all forms of thyroid disorders. Men with hypothyroidism experienced delayed ejaculation, and those with hyperthyroidism experienced premature ejaculation.
Altered hormone secretion, sperm quality, and sperm characteristics
Thyroid dysfunction affects testicle function and damages sperm. Experiments indicate that hypothyroidism leads to a decrease in sperm size and gene expression linked to cation sperm channel (CatSper genes).
The cation sperm channel helps with fertilization during chemotaxis (movement of the sperm towards the egg), hyperactivation (rapid movement of sperm tail while penetrating the egg), and acrosome reaction (separation of the outer sperm membrane and enzyme release to dissolve the egg membrane for fusion with the oocyte).
Hypothyroidism could also cause teratozoospermia (abnormal sperm morphology), reduce sperm vitality, and delay its transit through the epididymis. It also reduces the integrity of the acrosome.
Hyperthyroidism causes a decrease in semen volume and density. It affects the morphology and motility of sperm. Men may require treatment for hypospermia (low semen volume), oligozoospermia (low sperm count), teratozoospermia, and asthenozoospermia (reduced sperm motility).
Men with thyroid disorders also experience considerable alterations in their hormone levels. They may experience altered levels of luteinizing hormone or LH (regulates testes function), and gonadotropin-releasing hormone or GnRH (releases LH). Hypothyroidism decreases testosterone levels while hyperthyroidism increases testosterone and sex hormone-binding hormonal globulin or SHBG levels (SHBG protein is found in the blood and attaches to testosterone to transport it throughout the body).
Testing and Treating Thyroid Dysfunction
The primary objective of treating thyroid dysfunction is to balance hormone levels in the body. Testing levels of T3, T4, and TSH in the blood confirm a suspected diagnosis of hypothyroidism or hyperthyroidism. Your doctor may also test for iodine uptake or thyroid cancer.
Physicians assume a suitable approach to either reduce overproduction in hyperthyroidism with medication or initiate hormonal replacement for hypothyroidism. Hormone levels are also rectified to function within normal levels through diet supplements, exercises, and surgery.
As a final thought, a diet rich in magnesium, calcium, iodine, and protein, and vitamins A, B, and C provides an optimal environment in your body to achieve the required hormonal balance.
