Laboratory Findings
Posted by admin on August 23rd, 2010Leydig cell function may be estimated by a morning measurement of bioavailable (free) testosterone; a value < 67 ng/dL signifies hypogonadism. A total testosterone value of < 300 ng/dL is also diagnostic of hypogonadism, but the free fraction is more sensitive because of the increased binding of testosterone to sex hormone-binding globulin in the elderly. The level of luteinizing hormone is normal or low in almost all hypogonadal men. Dynamic testing with gonadotropin-releasing hormone adds little information, because the response is usually proportional to the basal luteinizing hormone level. A normal prolactin level helps exclude a pituitary tumor as the cause of hypogonadism.
Treatment
Hypogonadism is treated with androgen therapy. Long-acting esters of testosterone and 19-nortestosterone (the enanthate and the cyclopen-tylpropionate) are administered IM in a dose of 100 to 200 mg every 1 to 3 wk (usually as 100 mg each week, 200 mg every 2 wk, or 300 mg every 3 wk). Alternatively, oral forms of testosterone derivatives, which have an alkyl group in the 17 position, are usually prescribed as 5 to 50 mg/day of methyltestosterone (10 to 50 mg orally or 5 to 25 mg bucally). The IM formulations are generally preferred because the oral agents
Tags: Laboratory Findings
