24-h Serum Levels of Growth Hormone, Prolactin and Cortisol in Pre- and Postmenopausal Women. The effect of combined estrogen and progestin treatment.

Author(s): Kalleinen N, Polo-Kantola P, Irjala K, Porkka-Heiskanen T, Vahlberg T, Virkki A, Polo O

Affiliation(s): Sleep Research Unit, Department of Physiology, University of Turku; Department of Obstetrics and Gynecology, Turku University Central Hospital, Mehilainen Oy, Turku; Department of Physiology, University of Helsinki, Department of Biostatistics, University of Turku; Department of Mathematics, University of Turku; Department of Pulmonary Diseases, Tampere University Hospital, Finland.

Publication date & source: 2008-03-04, J Clin Endocrinol Metab., [Epub ahead of print]

Publication type:

Objective: To study the 24-h profiles of growth hormone (GH), prolactin (PRL) and cortisol concentrations in older postmenopausal and in middle-aged premenopausal women, before and after estrogen-progestin treatment (EPT). Design: A randomized, placebo-controlled trial. GH, PRL and cortisol were sampled every 20 min for 24 hours in 18 postmenopausal (aged 58-70 years) and 17 premenopausal (aged 45-51 years) women before and after six months of EPT. Results: The mean 24-h GH (1.0 vs 1.8 mU/L, p = 0.033) and PRL (6.8 vs 10.0 ng/mL, p = 0.009) concentrations were lower in postmenopausal than in premenopausal women. After EPT the postmenopausal GH and PRL did not differ from premenopausal baseline levels. Postmenopausal mean 24-h GH (p < 0.001) and PRL (p = 0.002), daytime GH (p < 0.001) and nighttime PRL (p = 0.004) were higher during EPT compared to placebo. Cortisol levels did not differ. Premenopausal mean nighttime PRL (p = 0.026) and cortisol (p = 0.018) were higher during EPT compared to placebo. Postmenopausal PRL and premenopausal GH and PRL concentrations were higher at night than during the day. EPT did not alter this pattern. Conclusions: Menopause was associated with decreased 24-h levels of GH and PRL, which were reversible with EPT. In contrast, cortisol levels were not affected by menopause or EPT. In middle-aged premenopausal women the studied effects of EPT were limited to nighttime increases of PRL and cortisol.