The menopausal transition has been the center of considerable attention of biomedical and public health research, with hundreds of studies focusing on the physiological, psychological, emotional, and cognitive correlates of reproductive aging. These studies have been based mainly on data obtained in clinical settings or from women in industrialized, urban environments and have been framed within the biomedical research paradigm, which tends to look for universals and for normal vs. pathological dichotomies. There is mounting evidence, however, showing that women differ profoundly in the way they experience menopause, both physiologically and socioculturally. These differences may reflect adaptive responses to the environment and, far from being just “noise”, may prove to be crucial in proposing paradigm shifts in medicine. This study takes an innovative evolutionary demography perspective in trying to understand the physiological underpinnings of the transition from reproductive to post-reproductive life. Life history transitions, such as the menopausal transition, involve a change in energy allocation strategies. During puberty, for example, there is shift in energy allocation from growth to reproductive function. During the menopausal transition, however, energy is allocated away from reproduction and most likely into maintenance and survival. The goal of this study is to provide baseline data on the energy allocation strategies by measuring metabolic correlates of the peri-menopausal period. As the number of ovarian follicles decrease exponentially towards the end of reproductive life, estrogen and progesterone levels drop quite dramatically. In addition to its leading role in female reproductive function, estrogen has also been shown to be a major metabolic regulator.
This project will investigate the association between ovarian reserve, estrogen levels and key metabolic hormones in two populations which differ in ethnicity background and socioeconomic status. A total of 1700 first-void urine samples were collected from 60 peri-menopausal and 30 menopausal indigenous and non-indigenous women of the province of Formosa, northern Argentina. Samples will be analyzed for FSHbeta, cortisol, c-peptide, and adiponectins using a validated Quansys multiplex array. FSHbeta levels will be used to estimate ovarian reserve, while cortisol, c-peptide and adiponectin will be explored as metabolic gate-keepers and regulators. Further analysis will investigate the association between these hormones and demographic, anthropometric, lifestyle, and menopausal symptom reports in both populations.