Studies of menopausal hormone therapy reviewed
Treatment with estrogen in menopause is both good and bad for women's health. The picture is complex and the scientific evidence sometimes scanty or only moderately solid, a study shows. University of Gothenburg researchers took part.
The study, now published in the journal PLOS Medicine, is a systematic review and critical analysis of previous research in the field. The documentation contains numerous published studies, comprising both research overviews and original studies of various kinds.
The focus is on women's health associated with menopausal hormone therapy (MHT) involving estrogen replacement during menopause. Besides the relief from, for example, hot flashes and night sweats that this treatment is intended to provide, it represents many pros and cons for health.
All effects of MHT on health found in previous systematic reviews registered in leading databases up to 2017 were included in the present study. The scientists surveyed the evidence and scrutinized methods.
Advantages and risks
Research included showed that women receiving MHT are at lower risk for bone fracture, diabetes and cancer of the esophagus, stomach, and colon. But their risk of getting stroke, blood clots, gallbladder disease, and breast and ovarian cancer is evidently higher.
The scientists make no assertion that previous research results were wrong, but the general picture they provide is that the quality of the systematic research reviews that have now been examined is low or only moderately good.
This applied, for example, to clinical data suggesting that estrogen treatment in menopause reduces the risk of coronary heart disease. According to the researchers, research on the impact of MHT on overall mortality in women aged up to 60, or in the ten years following the last menstrual period, was similarly inconclusive.
The researchers behind the present study are based at about 10 universities, including Stanford University in California and Chongqing Medical University in China. The first author is Guo-Qiang Zhang, a doctoral student at the Krefting Research Center, Sahlgrenska Academy, University of Gothenburg.
"Hormone treatment in menopause has a complex balance between health benefits and risks, and the overall assessment we made was that the quality of the available systematic reviews ranges from moderate to poor," he states.
Under current guidelines, women can be offered treatment with estrogen for unpleasant menopausal symptoms, and for preventive purposes if their osteoporosis risk is elevated, as long as the risk of cardiovascular disease is low and there is no other reason to withhold MHT.
"The whole spectrum of effects, along with women's own values and preferences, must be taken into account in treatment decisions. Nonhormonal therapies may also be considered. Clinically active researchers should also evaluate the strength of evidence in the systematic reviews," Guo-Qiang Zhang concludes.