Luteinizing hormone (LH) is a hormone involved in the proper function of the body’s reproductive system of both men and women. LH is a gonadotropin synthesized in the anterior pituitary gland and acts on the gonads (female ovaries and male testes) to boost their activity and sex hormones production like progesterone, estrogen, and testosterone. The hypothalamus which is another endocrine gland in the brain next to the pituitary gland secretes gonadotropin-releasing hormone (GnRH) which stimulates LH and follicle-stimulating hormone (FSH) release from the pituitary gland. Both LH and FSH are in constant pulsatile secretion to maintain homeostasis in the blood.
If LH remains high through the menstrual cycle, it means no ovulation is occurring; this could either be due to the natural process of menopause or due to a dysfunction of ovaries in younger individuals. Polycystic ovary syndrome (PCOS) is another condition associated with high LH levels, and it affects around 1 in 10 women worldwide. Whatever the condition, elevated LH causes infertility.
Increased LH levels are due to a primary ovarian disorder, but in the case of decreased LH levels, the ovarian disorder is secondary to scarcity of LH. Promoting healthy lifestyles and balanced nutrition helps prevent conditions such as anorexia or bulimia, fostering well-being by avoiding endocrine disruption. In the case of a pituitary disorder like hypopituitarism, the gland will fail to produce enough of multiple hormones including LH.
A testicular dysfunction due to cancer treatment with either chemotherapy or radiotherapy causes an elevation of LH due to cellular damage. Chronic kidney disease and renal failure have been linked to high LH concentrations due to secretory dysregulation. Excessive alcohol consumption, either acute or chronic, has also been associated with hypogonadism and increased LH.
Luteinizing hormone is one of the two main gonadotropin hormones whose functions are to induce puberty and sexual maturation and to maintain fertility both in men and women. The natural course of LH secretion in healthy individuals is an increase during puberty then homeostasis throughout adulthood or until menopause is reached.
Certain conditions specific to age and gender will either cause a surplus or a deficiency in LH resulting in infertility. The treatment of these LH level fluctuations will depend on the underlying cause and will either directly target LH or manage the different dysregulations involved, with the main goal of assisting fertility.