SIGNS OF TESTICULAR INSUFFICIENCY IN ADRENOMYELONEUROPATHY AND NEUROLOGICALLY ASYMPTOMATIC X-LINKED ADRENOLEUKODYSTROPHY - A RETROSPECTIVE STUDY

X-linked adrenoleukodystrophy (X-ALD) is characterized by central nerv ous system demyelination, and impaired steroidogenesis in the adrenal cortex and testis. Most patients develop adrenocortical insufficiency. We studied retrospectively the frequency and severity of testicular d ysfunction in 26 men with X-ALD. Twenty-one had adrenomyeloneuropathy and five patients were neurologically asymptomatic. In addition to obt aining a routine history and physical examination, we studied plasma l evels of testosterone, sex hormone binding globulin, the free androgen index, and the plasma concentrations of dehydroepiandrosterone-sulpha te, LH and FH. In a subset of patients, the testosterone response to h CG and the LH and FSH responses to GnRH were also determined. Clinical signs of gonadal dysfunction were manifested by diminished libido (46 %), largely overlapping with erectile dysfunction (58%), and failure o f the testes to descend (15%). Physical examination revealed diminishe d body sexual hair (50%), gynaecomastia (35%), and small testes (12%). Laboratory studies showed low plasma total testosterone levels in 12% , and an insufficient increase after stimulation with hCG in 88% (15 o f 17 patients tested). Plasma LH concentration was increased in 16%, a nd the plasma FSH level was elevated in 32%. The response of LH concen trations to GnRH stimulation was abnormally high in 47% (nine of 19 pa tients studied), and the response of FSH levels was too low in 16% (th ree of 19 patients tested). In conclusion, in a retrospective study of 26 men' with X-ALD, in 20 some signs of clinical hypogonadism were fo und. Plasma testosterone values were generally in the normal range, bu t upon testing of the hypothalamo-pituitary-testis axis some abnormali ties became apparent.