Seasonal variation of plasma dehydroepiandrosterone sulphate and urinary androgen excretion in post-menopausal women.

Urinary levels of the glucuronides of androsterone, aetiocholanolone, 5 alpha-androstane-3 alpha, 17 beta-diol and 5 beta-androstane-3 alpha, 17 beta-diol, were determined in twenty-two-post menopausal women both in spring and in autumn--winter. In sixteen women dehydroepiandrosterone sulphate plasma levels were also measured. Plasma DHAS levels as well as urinary metabolite excretion values were significantly higher in autumn--winter than in spring. This seasonal variability should be taken into account in long-term studies involving adrenal hormone levels, excretion or metabolism. Moreover this seasonal variability might be of relevance for the cyclical growth rate of hormone dependent tumours such as breast cancer.