Study finds stopping HRT leads to a period of higher risk of bone fracture for most women

A recent study has revealed that the bone fracture protection resulting from menopausal hormone therapy (MHT), also known as HRT, diminishes within a year of discontinuing the treatment.

The study, published in Lancet Healthy Longevity, conducted by experts from the School of Medicine at the University of Nottingham, also indicates that after cessation of treatment, there is a period of increased fracture risk compared to women who have never used MHT. However, this risk eventually decreases to levels similar to or lower than those who have never used MHT.

Menopause triggers a decline in hormone levels in all women, particularly estrogen, leading to various physical and mental symptoms that may necessitate the use of MHT. However, estrogen deficiency also contributes to age-related bone weakening in women. Prior research has shown the protective role of estrogen in MHT in reducing fracture risk during treatment.

Despite the benefits in bone health, MHT is associated with increased risks of breast cancer and blood clots, making long-term use of MHT unfavorable.

Given the potential implications for women relying on MHT to combat bone fragility, understanding the duration and strength of the protective effects post-treatment is crucial. Past studies have provided limited and conflicting information on this aspect, with most focusing on the initial years after treatment cessation.

In this new study, researchers analyzed data from approximately 6,000,000 women across 2,000 GP surgeries in the UK, enabling them to monitor fracture risk for up to 25 years.

The study identified women with a history of fractures (cases) and matched them with women of the same age and practice without fractures (controls). The researchers then compared MHT usage between cases before fractures and their matched controls.

Dr. Yana Vinogradova, the lead author from the Center for Academic Primary Care in the School of Medicine, stated, “Our study findings affirm that women using MHT exhibit a gradual reduction in fracture risk compared to non-users. Importantly, we observed a distinct trend in risk alteration post-discontinuation of therapy.”

“For most women, the bone-protective effects of MHT vanish within approximately a year after stopping treatment, leading to an increased fracture risk compared to non-users. This risk peaks around three years post-discontinuation before declining to levels equivalent to non-users after about ten years. Subsequently, the risk continues to decrease relative to non-users. Therefore, women may benefit from a significantly reduced fracture risk in their later years even after ceasing MHT.”

While the risk pattern was consistent across all menopausal hormonal treatments, the degree of excess risk varied based on the treatment type and duration of MHT usage.

“Our study’s comparison of fracture risk patterns for short and long-term MHT users can aid healthcare providers and patients in discussing treatment options and anticipating changes in fracture risk post-MHT discontinuation. Identifying periods of heightened risk can prompt healthcare providers to assess bone health at treatment cessation, especially for patients with additional fracture risk factors such as smoking or sedentary lifestyle,” Dr. Vinogradova added.

“These novel findings could stimulate further clinical and biological research on menopausal hormonal treatments,” she concluded.