Postmenopausal women undergoing estradiol-based hormone therapy have a significantly decreased risk for mortality due to vascular dementia and a modestly decreased risk for mortality due to Alzheimer’s disease, according to research published in the Journal of Clinical Endocrinology & Metabolism.
Tomi S Mikkola, MD, PhD, from the department of obstetrics and gynecology at Helsinki University Hospital in Finland, and colleagues identified 489,105 Finnish women in a national drug reimbursement register who were using hormone therapy between 1994 and 2009. There were 581 women who died of vascular dementia and 1057 patients who died from Alzheimer’s disease between 1998 and 2009 in this patient population.
The researchers compared the mortality rate of women who used hormone therapy for less than 5 years and those who used hormone therapy for 5 years or more with women in the general population. Dr Mikkola and colleagues also compared the rates of mortality associated with vascular dementia and Alzheimer’s disease in women initiating hormone therapy before age 60 and at age 60 or older.
“[E]stradiol-based systemic [hormone therapy] use was associated with a reduced risk of death both from [vascular dementia] and Alzheimer’s disease, but the risk reduction was larger and appears sooner in vascular dementia than Alzheimer’s disease,” Dr Mikkola and colleagues wrote. “Our data imply that, in absolute numbers, of 10,000 women using any type of [hormone therapy] for over 5 years and with follow-up for 10 years, 10 fewer would die due to [vascular dementia] and 5 fewer due to Alzheimer’s disease.”
Overall, risk for vascular dementia-related mortality was reduced by 37% to 39% for both women who used hormone therapy for less than 5 years and those who used hormone therapy for 5 years or more across all hormone therapy types, including estradiol-only and estradiol-progestin combination therapies. While risk for Alzheimer’s disease mortality did not decrease for women with less than 5 years of hormone therapy use, risk was decreased by 15% in women who used hormone therapy for 5 years or more. The researchers found no significant association between mortality risk reduction and hormone therapy initiation before age 60 or at age 60 or older.
Dr Mikkola and colleagues noted 1 limitation of the study was that the register did not indicate whether women undergoing hormone therapy at 1994 were beginning or continuing treatment.
“Because the register was initiated in 1994, we could not differentiate whether a woman who bought [hormone therapy] in 1994 was a new starter or was continuing her treatment initiated before 1994,” the researchers wrote. “Therefore, all women older than 52 years who bought systemic [hormone therapy] in 1994 were assumed to have initiated this type of treatment at the age of 52 years, the mean age at [hormone therapy] initiation in our study population, and the pre-register [hormone therapy] exposures were estimated accordingly.”
Disclosure: Dr Mikkola is a speaker and has received consulting fees from Mylan and Novo Nordisk. Dr Savolainen-Peltonen is a speaker for Mylan and received funding for congress trips from Mylan and Finox Biotech. Dr Tuomikoski is a speaker and/or received consulting fees from Mylan, Novo Nordisk and Orion, and received funding for congress trips from Mylan.
- Mikkola TS, Savolainen-Peltonen H, Tuomikoski P, et al. Lower death risk for vascular dementia than for Alzheimer’s disease with postmenopausal hormone therapy users. J Clin Endocrinol Metab. 2016 Dec 1. doi:10.1210/jc.2016-3590.