Luteinizing hormone (LH)

Latest Edit: Hector 2014-03-24 (EDT)

See Also	Lab Tests

Luteinizing hormone (LH) is commonly measured to evaluate menopause, pituitary function, including fertility issues, gonadal failure, maturation concerns or pituitary tumors.

Discussion

• Luteinizing hormone is also known as Interstitial Cell Stimulating Hormone (ICSH)
• LH is produced in the anterior pituitary gland in reponse to stimulation by gonadotropin-releasing hormone (GNRH). Control of LH production is a complex system involving hormones produced by the ovaries or testes, the pituitary and the hypothalamus.
• High levels of LH (and FSH) at mid-cycle triggers ovulation for women.
• LH stimulates the ovaries to produce steroids, primarily estradiol.
• In men, LH stimulates a Leydig cells which reside in the testes to produce testosterone.
• Indications for assessing LH levels include:

• difficulty getting pregnant, irregular or heavy menstrual periods
• symptoms of pituitary or hypothalamic disorders
• symptoms of ovarian or testicular disease
• delayed or early childhood sexual maturation

Patient Preparation

• No fasting required.
• LH can be measured in blood, or urine

• Factors which can cause increased levels

• radiation therapy
• Medications such as cimetidine, digitalis, levodopa, anticonvulsants, clomiphene, naloxone, and spironalactone

• Factors which can cause decreased levels

• radiation therapy
• Medications such as estrogens, progesterones, testosterone, steroids, digoxin, oral contraceptives, and phenothiazines.
• stress
• malnutrition
• anorexia nervosa

Clinical Implications

High levels indicate:

• primary ovarian failure

• failure to develop ovaries
• Turner's syndrome, Kalllmann's syndrome
• Defect in steroid production by the ovaries, such as 17 alpha hydroxylase deficiency
• radiation
• chemotherapy
• autoimmune disease
• polycystic ovarian syndrome (PCOS)
• Adrenal disease
• Thyroid disorders
• Ovarian tumor

• primary testicular failure

Low levels indicate:

• Secondary ovarian failure

Associated Tests

• FSH, Testosterone, Progesterone, Estrogens