MedicalResearch.com Interview with:
Tomi Mikkola MD
Helsinki University Hospital
Department of Obstetrics and Gynecology
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In Finland we have perhaps the most comprehensive and reliable medical registers in the world. Thus, with my research group I have conducted various large studies evaluating association of postmenopausal hormone therapy use and various major diseases (see e.g. the references in the B;MJ paper). There has been various smaller studies indicating that hormone therapy might be protective for all kinds of dementias, also Alzheimer’s disease.
However, we have quite recently shown that hormone therapy seems to lower the mortality risk of vascular dementia but not Alzheimer’s disease (Mikkola TS et al. J Clin Endocrinol Metab 2017;102:870-7). Now in this upcoming BMJ-paper we report in a very large case-control study (83 688 women with Alzheimer’s disease and same number of control women without the disease) that systemic hormone therapy was associated with a 9-17% increased risk of Alzheimer’s disease.
Furthermore, this risk increase is particularly in women using hormone therapy long, for more than 10 years. This was somewhat surprising finding, but it underlines the fact that mechanisms behind Alzheimer’s disease are likely quite different than in vascular dementia, where the risk factors are similar as in cardiovascular disease. We have also shown how hormone therapy protects against cardiovascular disease, particularly in women who initiate hormone therapy soon after menopause. Continue reading
MedicalResearch.com Interview with:
Dr. Andrea Gore PhD
Gustavus & Louise Pfeiffer Professor
University of Texas Austin/Div of Pharmacology/Toxicology
MedicalResearch.com Editor’s Note: Dr. Gore, Editor-in-Chief of the Journal Endocrinology, has graciously answered several questions regarding the recent concerns of environmental chemicals linked to both early puberty and early menopause.
Medical Research: How can chemicals found inside the home impact onset of menopause?
Dr. Gore: It is important to clarify that the cause-and-effect relationship between chemicals and menopause is not established. The timing of menopause in women is due to a variety of factors including genetic traits, nutritional status, and general health or chronic disease. Some research on humans, including the recent study by Grindler et al., also suggests that environmental chemicals may contribute to the timing of earlier menopause. Animal models also suggest an advance in the timing of reproductive failure following earlier life exposures to endocrine-disrupting chemicals (EDCs). [See references below]. The question of exactly how chemicals may change the timing of menopause is therefore unresolved, but based on animal studies it is likely that the mechanisms include effects of endocrine-disrupting chemicals on the expression of genes and proteins involved in ovarian function that may lead to premature loss of follicles (eggs). Because the control of reproduction involves the brain and the pituitary gland, as well as the ovary, it is possible that endocrine-disrupting chemicals also impair how these organs regulate reproductive hormones.
- Gore AC, Walker DM, Zama AM, Armenti AE, Uzumcu M. Early
life exposure to endocrine-disrupting chemicals causes lifelong molecular
reprogramming of the hypothalamus and premature reproductive
aging. Mol Endocrinol. 2011;25:2157–2168.
- Shi Z, Valdez KE, Ting AY, Franczak A,GumSL, Petroff BK. Ovarian
endocrine disruption underlies premature reproductive senescence
following environmentally relevant chronic exposure to the
aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin.
Biol Reprod. 2007;76:198–202.
- Akkina J, Reif J, Keefe T, Bachand A. Age at natural menopause and
exposure to organochlorine pesticides in Hispanic women. J Toxicol
Environ Health A. 2004;67:1407–1422.
- Cooper GS, Savitz DA, Millikan R, Chiu Kit T. Organochlorine
exposure and age at natural menopause. Epidemiology. 2002;13:
- Hatch EE, Troisi R, Wise LA, et al. Age at natural menopause in
women exposed to diethylstilbestrol in utero. Am J Epidemiol.
- KnoxSS, Jackson T, Javins B, Frisbee SJ, Shankar A, DucatmanAM.
Implications of early menopause in women exposed to perfluorocarbons.
J Clin Endocrinol Metab. 2011;96:1747–1753.
- Farr SL, Cai J, Savitz DA, Sandler DP, Hoppin JA, Cooper GS.
Pesticide exposure and timing of menopause: the Agricultural
Health Study. Am J Epidemiol. 2006;163:731–742.
Medical Research: What are the primary sources of exposure to these chemicals?
Dr. Gore: Endocrine-disrupting chemicals exposures come from a variety of sources, including plastic containers (e.g. water bottles) and other products, certain foods, personal care products, pesticides, and many others.