Hormone Therapy Decreases Fracture Risk in Postmenopausal Women

Mattias Lorentzon, MD, PhD

Research from a study performed by investigators at the University of Gothenburg suggests hormone therapy reduces the risk of fracture in women regardless of their baseline fracture risk.

Presented at the World Congress on Osteoporosis, Osteoarthritis, and Musculoskeletal Disease (WCO-IOF-ESCEO) 2020 virtual congress, study results indicate hormone therapy with estrogen or estrogen plus progestin was associated with a 28% reduction in all fractures and a 34% reduction in osteoporotic fractures over an 8-year follow-up period.

“Over 8.2 years of follow-up, hormone therapy was with a reduced risk of fracture. This lower risk ranged from 28% for any fracture to 40% for major osteoporotic fracture with hormone therapy,” said study presenter Mattias Lorentzon, MD, PhD, chief physician at the Osteoporosis Clinic at the Sahlgrenska University Hospital, during his presentation.

Based on previous analyses of the Women’s Health Initiative (WHI)’s Hormone Therapy Trials, which were conducted in the early 1990s, some clinicians have hypothesized hormone therapy could reduce risk of fracture, but other observational data has suggested other antiresorptive therapies could impact baseline fracture risk. To understand whether the reduction in fracture risk seen with hormone therapy in the WHI Hormone Therapy trials was dependent on baseline FRAX scores.

With this in mind, Lorentzon and a team of colleagues designed their study as a matched analysis of the 27,346 postmenopausal women included in the WHI Hormone Therapy trials. From the study, investigators obtained data related to 13,816 women receiving hormone therapy with either estrogen alone or estrogen plus progestin and 13,530 women receiving placebo therapy. From these, investigators identified a cohort 12,739 patients receiving hormone therapy and 12,650 matched patients receiving placebo therapy for inclusion in their study. Investigators noted baseline characteristics were similar between the matched cohorts.

As part of the trials, women had their clinical risk factors recorded through use of questionnaires and FRAX scores for major osteoporotic fracture were calculated without using bone mineral density. For their analysis, investigators identified all incident clinical fractures, with the exception of other than fractures of the fingers, toes, ribs, sternum, skull, face and cervical vertebrae fractures, through medical records.

Over a follow-up period lasting a mean of 8.2±1.5 years, hormone therapy was associated with a significant reduction in the risk of any clinical fracture (HR, 0.72; 95% CI, 0.65-0.78), major osteoporotic fracture (HR, 0.60; 95% CIC, 0.53-0.69), osteoporotic fracture (HR, 0.66; 95% CI, 0.58-0.74), and hip fracture (HR, 0.66; 95% CI, 0.45-0.96). Results indicated treatment was similarly effective in reducing risk of any fracture, major osteoporotic fracture, and hip fracture in women regardless of baseline FRAX major osteoporotic fracture probability. Additionally, investigators pointed out there was no significant interaction between hormone therapy and FRAX probably for any fracture, major osteoporotic fracture, or hip fracture (P >.30).

“In conclusion, hormone therapy was effective in women regardless of baseline fracture risk and this was true for all study fracture outcomes,” added Lorentzon.

This study, “Hormone therapy reduces the risk of fracture regardless of baseline fracture risk – results from the Women’s Health Initiative hormone therapy trials,” was presented as WCO-IOF-ESCEO 2020.