Are adolescent boys with Klinefelter syndrome androgen deficient? A longitudinal study of Finnish 47,XXY boys

• Testosterone (T)-substitution therapy is widely used in adult patients with Klinefelter syndrome (KS) to prevent symptoms and sequels of androgen deficiency, but it is currently unknown if adolescent boys with KS benefit from early T therapy. To evaluate the optimal age to start T substitution, we searched for signs of androgen deficiency in pubertal boys with KS. 14 nonmosaic 47,XXY boys, aged 10-13.9 y, were followed up for 4-37 mo with staging of puberty and frequent reproductive hormone measurements. Furthermore, indices reflecting androgen action (serum SHBG, leptin, and prostate-specific antigen (PSA) levels) were studied. Both onset and progression of puberty according to Tanner stages were normal in boys with KS. Consistently, serum T concentrations increased as expected and remained normal throughout follow-up. Changes in the indices of androgen action (decreases in serum SHBG and leptin, and increase in serum PSA concentrations) occurred normally, except that average leptin levels were higher in the boys with KS (KS boys 11.8 +/- 7.0 microg/L; controls 7.6 +/- 4.7 microg/L; p = 0.033). Despite normal T concentrations, the KS boys displayed from the age of 13 y elevated serum FSH and LH levels, and exaggerated gonadotropin responses to gonadotropin-releasing hormone. These data do not demonstrate an unequivocal androgen deficiency in adolescent boys with KS that would necessitate androgen supplementation therapy during early puberty.

Nyckelord

Adolescent

Androgens/*deficiency

Follicle Stimulating Hormone/blood

Gonadotropin-Releasing Hormone/pharmacology

Humans

Karyotyping

Klinefelter Syndrome/*genetics

Leptin/blood

Luteinizing Hormone/blood

Prospective Studies

Prostate-Specific Antigen/blood

Puberty

Sex Hormone-Binding Globulin/metabolism

Testosterone/blood

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)