Endocrine Abstracts

Hormonal management of androgen, secondary thyroid hormone and vitamin D insufficiency of patients with Klinefelter syndrome (KS) during transition needs some expertise. While vitamin D supplementation should be smoothly applied, thyroxin should be reserved for primary (auto-immune) thyroid disease. Although the androgen deficiency is generally mild and slowly progressive, timely initiation of testosterone replacement therapy (TRT) has been advocated to ensure a normal adult sexual development and to prevent the consequences of long-term androgen deficiency. However, it is unclear if typical complaints and signs of KS, such as decreased facial and body hair, emotional and social developmental delay, eunuchoid body proportions and poor muscle development are fully corrected by TRT. In addition, the efficacy of TRT in the prevention of the metabolic syndrome, varicose veins, leg ulcers, breast cancer and auto-immune diseases is not clearly defined. On the other hand, careful dose adjustment of testosterone is needed to avoid chronic overexposure, given the higher risk of prostate cancer and aggressive behaviour.

Cryopreservation of semen samples or testicular tissue should be considered before initiating TRT. It is unknown whether the suppressive effect of TRT on spermatogenic function is fully reversible and is dose and route of application dependent. On the other hand, testosterone has beneficial effects on semen volume and prostate volume.

Additional therapy with aromatase inhibitors can be considered in patients with gynecomastia, obesity or elevated E2 concentrations or prior to sperm retrieval.

Changing dose or route of application of TRT is frequently considered in vain to relieve inherent KS specific physical and psychological problems as chronic fatigue, low vitality, decreased concentration and mood changes. Compliance with daily gel administration is challenging for transition patients. Frequent patient visits may be necessary to maintain and assess compliance, to discuss safety and preventive measures and to avoid discouragement.