The adrenal gland may be a target of LH action in postmenopausal women

Abstract

Objective: LH receptor expression and function have been demonstrated in the human adrenal cortex, but their involvement in normal adrenal function remains elusive. Because cortisol levels have been reported to be higher in postmenopausal women than in age-matched men, the aim of the present study was to investigate a possible association of adrenal function with the elevated LH levels in postmenopausal women. Design and methods: A group of 112 endocrinologically normal postmenopausal women (mean age 67.6, range 50–88 years) was evaluated. A basal fasting morning sample of peripheral blood was taken for the determination of LH, cortisol, dehydroepiandrosterone-sulphate (DHEA-S), oestradiol (E2), testosterone, sex hormone-binding globulin (SHBG), insulin and glucose. Information about reproductive function, anthropometric parameters and arterial blood pressure was recorded. Results: The correlation of LH and cortisol was bimodally distributed, with a significant linear correlation up to the LH level of 41 U/l (n = 78, P<0.01), after which the increase of cortisol levelled off. Significant associations were also found between serum DHEA-S and LH levels (P<0.05), as well as between cortisol and testosterone (P<0.0001), but not between E2 and LH. Multivariate analysis showed that the association of cortisol with LH was independent of age and testosterone; the association of DHEA-S with LH was independent of E2, cortisol and age. Significant associations were also found between E2, testosterone and DHEA-S levels (P<0.001). Conclusions: These results indicate that adrenal cortisol and DHEA-S production may be stimulated by the highly elevated postmenopausal levels of LH; the physiological significance of this association and plausible contribution to the metabolic syndrome observed after the menopause remain to be evaluated.