11 October 2021
Summary
Recently, a group of Korean internists published a paper in the journal Scientific Reports describing the results of their analysis of the national health insurance database focusing on the effects of menopausal hormone therapy (MHT) on the incidence of end-stage renal disease (ESRD)[1]. As a total, 4,905 Korean postmenopausal women developed ESRD, among the 1.46 million followed-up for 9 years since 2009. Adjusted hazard ratios (HRs) [95% confidence interval] for ESRD development according to their MHT duration were: no MHT, reference; MHT < 2 years; 0.634 [0.556-0.723]; 2-5 years, 0.721 [0.597-0.871]; > 5 years, 0.654 [0.531-0.806], implying that MHT protects kidneys irrespective of its duration, with ~30% reduced risk of ESRD. Subgroup analyses showed that the beneficial effect of MHT was more pronounced in women aged <65 years and those with diabetes or hypertension, whereas MHT was associated with reduced risk of ESRD similarly in women with body mass index (BMI) < 25 or > 25, or in those with or without pre-existing chronic kidney diseases. The study showed a protective effect of MHT on kidneys on the largest scale ever reported.
Commentary
For many decades, the discussion about the benefits of MHT to prevent chronic diseases in postmenopausal women has centered around cardiovascular diseases and osteoporosis. The effects of MHT on metabolic disorders related to the former, such as dyslipidemia and diabetes, has also been intensively studied, whereas kidneys have hardly been paid enough attention. For example, words “kidney” or “kidneys” cannot be found in the encyclopedic “2016 IMS Recommendations on women’s midlife health and menopause hormone therapy”, which seems to cover almost all the aspects of life that MHT could have any effects on [2]. The negligence may partly be due to the discrepancy found in the past few papers with smaller scales than the present one on the effects of MHT on kidney functions: one study reported a higher prevalence of microalbuminuria in MHT users than non-users [3], while another found that MHT was associated with better estimated glomerular filtration rate (eGFR) and blood pressure (BP) levels than non-users [4].
