The largest study of its kind has found menopause is not associated with an increased risk of disability in women with multiple sclerosis (MS).
Until now, the impact of reduced sex hormones on women with MS had only been the subject of small studies, some with conflicting results.
Published in JAMA Neurology, the Monash University-led project assessed whether menopause modified the risk of disability progression for women with relapse-onset MS. It did not.
MS is a chronic autoimmune and neurodegenerative condition, which impacts the immune and nervous systems. It affects three times more women than men and impacts 1 in 800 Australians.
Senior author Associate Professor Vilija Jokubaitis, who is Deputy Head of Monash University's School of Translational Medicine Department of Neuroscience, said until now, the impact of menopause on MS disease trajectory remained unclear.
"MS disability typically gets worse in both men and women as people age, with a noticeable shift at about the age of 50, which is also around the age of menopause for most women," Associate Professor Jokubaitis said.
"During perimenopause, the amount of estrogen and progesterone in women fluctuates a lot, before levels of these hormones fall significantly at menopause. In this study we asked whether the loss of sex hormones at menopause could be the reason for MS worsening in women at midlife.
"Previous studies have also looked at this question but have reported conflicting results. These studies have been quite small, reporting on between 74-148 post-menopausal women studied over long periods of time.
"Ours is therefore the largest study of its kind. Our research found that menopause is not associated with an increased risk of disability accumulation in women with MS. Therefore, the increases in disability we see around the age of 50 are not directly due to menopause, but are likely due to other aging processes that affect all people irrespective of sex or gender."
The study used data from the MSBase Registry, the world's largest MS clinical outcomes register that follows over 120,000 people with MS around the world and is headquartered in Monash University's Department of Neuroscience.
It also observed 987 Australian women with MS recruited from eight Australian neuroimmunology-specialist centres, of which 404 (40 per cent) had undergone menopause. They were followed on average for just over 14 years.
"Whilst reproductive ageing may be additive to the effects of somatic (physical) ageing, our study does not support menopause as the leading factor for disability progression in older women with MS," the study found.
First author Dr Francesca Bridge, a neurologist who treats MS patients at Alfred Health, said the results should reassure women with MS undergoing menopause, and their doctors, that it wouldn't make their MS worse.
"The menopausal transition can be challenging for many women," Dr Bridge said. "This study gives women with MS one less thing to be concerned about. It will guide the health/clinical management of women with MS through the menopausal transition.
"The study findings are particularly important for doctors including neurologists, who will now be able to give reassuring advice to their patients that menopause won't make their MS disability worsen faster."
Dr Bridge said the menopausal transition was challenging regardless, with symptoms including hot flushes, memory issues, mood disturbance and urinary dysfunction, which could overlap with pre-existing MS-related symptoms.
She said the results would guide clinical conversations around the management of menopause and its symptoms, including lifestyle modifications, and the use of menopausal hormonal therapies (MHT) and non-hormonal therapies to improve quality of life.
"Women with MS will benefit from the holistic management of menopausal symptoms with lifestyle measures such as exercise and maintaining a healthy diet, as well as pharmacological measures such as menopausal hormone therapy (MHT) and non-hormone-based medications to improve their symptoms and quality of life," she said.
Read the research paper here
The data collection in the additional survey was part of a women's health grant from the NHMRC.
