Use of menopausal hormone therapy and risks of cardiovascular disease: nested case-control study using the Clinical Practice Research Datalink

PI Title: Dr Yana Vinogradova

Lead member: Nottingham

"Background
Every woman naturally reaches a time in her life when she is no longer able to have children. During this stage of her life – called the menopause – her ovaries stop working normally and the lower levels of the reproductive hormones, oestrogen and progesterone, stop her periods.

The low levels of these hormones, however, can have many other effects on the body. These include troublesome side-effects, such as hot flushes, mood changes, joint pains, sleep disturbance, and vaginal dryness. Some women are very badly affected and can find the problems life-changing.

Many women suffering from menopausal side-effects benefit from menopausal hormone therapy (MHT), which can eliminate or lessen these. There are many such hormonal treatments, all of which use manufactured forms of oestrogen and progesterone. Treatments can be ‘oestrogen only’, but only for women whose womb has been removed. For women having a womb, treatments are more commonly ‘combined’, where the added progestogen protects the womb. Particularly in the UK, MHT treatments have been widely called ‘Hormone Replacement Therapy’ or HRT.

Need for Study
Changes in reproductive hormones can affect the heart and blood vessels, so low levels of these hormones after the menopause may affect the risk of cardiovascular diseases (CVD), such as heart attacks and strokes. Previous studies have suggested that the risks of some cardiovascular diseases (CVD) may be higher among some women who have used MHT/HRT. It is not yet clear, however, either whether this is true only for certain women, or whether or how risk levels may differ between specific treatments. So currently we are uncertain about how MHT/HRT affects the risk of cardiovascular disease in different women, or how the levels of additional risk may vary between specific treatments.

The aim of this research
This study will use a very large database of anonymised GP records to compare CVD cases between women in later life who have used any MHT/HRT with similar women who have not. Individual treatments will be studied and differences between different groups of women will be investigated. This will reveal any evidence in the data for links between specific MHT/HRT treatments and the risk of developing CVD in later life, and also whether different groups of women are more at risk.

Our aim is that the information generated will improve understanding among patients and their doctors about the benefits and risks of using different MHT/HRT treatments, and lead to better prescribing choices."

Amount awarded: £49,700