Synonym

• LH
• Luteotropin
• ICSH
• Interstitial cell-stimulating hormone

Tubes

• Red or tiger top tube
• 5 mL of venous blood
• 3 specimens drawn at 60 minute intervals is preferable

Additional information

• If patient is female, indicate phase of menstrual cycle on lab request
• Handle sample gently to prevent hemolysis
• Same assay/method to be followed for repeated tests

Info

• The Luteinizing hormone (LH) test measures the concentration of LH in the blood
• LH is a glycoprotein gonadotropin hormone synthesized by basophilic cells in the anterior lobe of the pituitary gland
• LH production is under complex regulation by the hypothalamus, through gonadotropin-releasing hormone (GnRH), the pituitary, and by gonadal sex hormones such as estrogen and progesterone in females and testosterone in males
• In females, LH is responsible for a sequence of cellular events resulting in the rupture of the dominant follicle and ovulation, as well as stimulating theca cells to secrete progesterone, luteinization of the ovarian follicle, and postovulatory follicular function
• In males, LH stimulates the interstitial cells of Leydig to produce testosterone, necessary for spermatozoa development and maturation in conjugation with follicular stimulating hormone (FSH)

Clinical

• The clinical utility of testing LH levels, includes:
• Evaluation of menstrual disorders such as amenorrhea
• Evaluation of precocious puberty in girls below the age of 9 yrs and below 10 yrs in boys
• Aids in the diagnosis and treatment of infertility
• To evaluate ovarian reserve of egg supply in females
• To evaluate low sperm count in males
• Assists in the detection of ovulation and monitors therapy to induce ovulation
• Evaluation of failure of sexual maturation in adolescence
• Assists in distinguishing between primary (ovarian or testicular) and secondary (pituitary or hypothalamic) gonadal failure or hypogonadism
• Evaluation of ambiguous sexual differentiation in infants
• Evaluation of impotence and gynecomastia in males
• Hypogonadism may clinically manifest as (manifestation depends on the age of onset such as pubertal or postpubertal, sex, and primary or secondary causes of hypogonadism):
• Males
• Weakness
• Eunuchoidal body habitus
• Decreased libido
• Depressed mood
• Small testes
• Impotence
• Gynecomastia
• Lack of secondary sexual characteristics
• Osteoporosis
• Females
• Delayed or precocious puberty
• Irregular periods
• Amenorrhea
• Decreased libido
• Infertility
• Decreased vaginal secretions
• Breast atrophy
• Osteoporosis
• In women, absence of midcycle peak in plasma LH levels may indicate anovulation
• Insufficient LH levels may lead to low levels of progesterone in the latter part of the menstrual cycle, thereby insufficient luteal support exists for implantation and early pregnancy (luteal phase deficiency)
• Elevated basal LH with an LH/FSH ratio >2 and increase of ovarian androgen in an essentially nonovulatory adult woman is presumptive evidence of Polycystic Ovary Syndrome (Stein-Leventhal syndrome)
• Postmenopausal women (not on estrogen) have LH levels 3-5 times higher than levels found during the follicular phase in women of reproductive age

Additional information

• LH is released in episodic spikes with day to day variation of 30%
• LH secretion follows a circadian rhythm with peak values seen in early sleep and lowest in late afternoon; highest in summer and lowest in winter
• LH results should be interpreted in conjugation with the patient’s clinical situation and data from other tests as levels can differ based on the assay method, age, sex, degree of sexual development, drug treatment, menstrual status, and pregnancy
• Factors interfering with test results include:
• Human chorionic gonadotropin (hCG) cross-reacts with LH in most immunoassays (false elevation) as occurs during pregnancy or hCG-secreting tumors
• Radioisotopes administered within 1 wk before test
• Hemolysis of blood sample
• Pregnancy
• Renal failure (false increase due to increased alpha subunit)
• Inactive fragments are also detected by assay
• Failure to observe pretest restrictions of medication/drugs
• Related laboratory tests include:
• Antisperm antibody
• Beta-HCG
• Follicle stimulating hormone (FSH)
• Gonadotropin releasing hormone (GnRH)
• Prolactin
• Testosterone
• Thyroid function tests (T3, T4, TSH)

Nl Result

Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.

^*Not on estrogen replacement therapy

High Result

Conditions associated with elevated LH levels include:

• Primary hypogonadism (ovarian or testicular dysfunction/failure)
• Females
• Ovarian agenesis
• Turner syndrome (ovarian dysgenesis)
• Ovarian steroidogenesis defect (17 alpha hydroxylase deficiency)
• Polycystic ovary syndrome (PCOS; Stein-Leventhal syndrome)
• Adrenal disease
• Thyroid disease
• Ovarian tumor
• Males
• Congenital absence of testicle or testicles (anorchia)
• Cryptorchidism
• Gonadal agenesis
• Klinefelter syndrome
• Noonan syndrome
• Viral infection (mumps)
• Trauma
• Germ cell tumor
• Autoimmune disease
• Chemotherapy
• Radiation
• Surgery
• Menopause
• Renal failure
• Primary or secondary gonadotroph tumors
• Endometriosis
• Drugs
• Bicalutamide
• Bromocriptine
• Clomiphene
• Finasteride
• Gonadotropin-releasing hormone
• Goserelin
• Growth-releasing hormone
• Hydrocortisone
• Ketoconazole
• Leuprolide
• Nafarelin
• Naloxone
• Nilutamide
• Propranolol (in males)
• Spironolactone

Low Result

Conditions associated with decreased LH levels include:

• Secondary gonadal dysfunction/failure (hypothalamic or pituitary origin)
• Hyperprolactinemia
• Panhypopituitarism
• Pituitary lesions
• Cushing syndrome
• Severe chronic illness
• Kallman syndrome(associated with anosmia)
• Prader Willi syndrome
• Laurence-Moon syndrome
• Bardet-Biedl syndromes
• Fertile eunuch syndrome
• Iron overload
• Alcohol abuse
• Drugs (given below)
• Starvation / low body weight
• Malnutrition
• High altitude
• Heavy exercise
• Acute illness
• Chronic systemic disease
• Anorexia nervosa / bulimia
• Severe stress
• Advanced prostate cancer
• Drugs
• Anabolic steroids
• Anticonvulsants
• Carbamazepine
• Conjugated estrogens
• Corticotropin-releasing hormone
• corticosteroids
• Danazol
• Diethylstilbestrol
• Digoxin
• D-Trp-6-LHRH
• Estrogens
• Ethinyl estradiol
• Medroxyprogesterone
• Megestrol
• Mestranol
• Metformin
• Norethindrone
• Octreotide
• Oral contraceptives
• Opiates
• Phenothiazines
• Phenytoin
• Pimozide
• Pravastatin
• Prednisone
• Progesterones
• Propranolol (in females)
• Stanozolol
• Tamoxifen
• Testosterone
• Tetrahydrocannabinol (THC)
• Thioridazine
• Toremifene
• Valproic acid

References

• ARUP Consult®. Hypogonadism. [Homepage on the internet]©2007. Last reviewed in May 2007. Last accessed on June 19, 2007. Available at URL: http://www.arupconsult.com/Topics/Endocrine_Disease/Hypogonadism.html
• ARUP Laboratories®. Luteinizing Hormone, Serum. [Homepage on the internet]©2007. Last accessed on June 19, 2007. Available at URL: http://www.aruplab.com/guides/ug/tests/0070093.jsp
• eMedicine®. Luteinizing Hormone Deficiency. [Homepage on the Internet]© 1996-2006 by WebMD. Last updated on August 2, 2005. Last accessed on June 19, 2007. Available at URL: http://www.emedicine.com/med/topic1341.htm
• Eskelinen et al. Biochemical reference intervals for sex hormones with a new AutoDelfia method in aged men. Clin Chem Lab Med. 2007;45(2):249-53.
• Jones ME et al. Effect of delays in processing blood samples on measured endogenous plasma sex hormone levels in women. Cancer Epidemiol Biomarkers Prev. 2007 Jun;16(6):1136-9.
• Laboratory Corporation of America®. Luteinizing Hormone (LH), Serum. [Homepage on the internet]©2007. Last accessed on June 19, 2007. Available at URL: http://www.labcorp.com/datasets/labcorp/html/chapter/mono/ri007600.htm
• LabTestsOnline®. LH. [Homepage on the Internet]© 2001-2007. Last reviewed onJune 6, 2006. Last accessed on June 19, 2007. Available at URL: http://www.labtestsonline.org/understanding/analytes/lh/test.html
• Nasu K et al. Granulosa cell tumor associated with secondary amenorrhea and serum luteinizing hormone elevation. Int J Clin Oncol. 2007 Jun;12(3):228-30. Epub 2007 Jun 27.
• Skipor J et al. Luteinising hormone attenuates the vascular response to norepinephrine. Acta Vet Hung. 2007 Jun;55(2):251-7.
• Wunder DM et al. Hypogonadism in HIV-1-infected men is common and does not resolve during antiretroviral therapy. Antivir Ther. 2007;12(2):261-5.