No increased dementia risk after hormone replacement therap

New research has found no link between hormone replacement therapy and dementia risk, however those receiving oestrogen-progesterone therapy for over five years were found to have a small increased risk of Alzheimer’s disease. The BMJ have published the research today (Wednesday 29 September).

Hormone replacement therapy (HRT) is commonly offered to help relieve symptoms of the menopause. The treatment increases the levels of hormones like oestrogen, and the course of treatment can vary considerably from person to person.

Previous research into a possible link with dementia risk has shown mixed results. Some observational studies have linked the treatment to a reduced risk of Alzheimer’s disease – the most common cause of dementia – while others have suggested it could increase the risk of dementia.

Other research has suggested that risk varies depending on the type and dose of hormones used, as well as when people receive the therapy.

Researchers used UK health records to look at women prescribed HRT. They then looked to see who went on to develop dementia, three years after. Scientists were able to look at hormone type, dose, and method of administration.

Over 16,000 women who had menopausal hormone therapy developed dementia during the study.

The researchers found no overall association between use of hormone therapy and risk of dementia, regardless of hormone type, application, dose, or duration of treatment.

However, a smaller analysis looking specifically at those diagnosed with Alzheimer’s disease showed those receiving oestrogen-progestogen therapy were at slightly increased risk.

The dementia risk rose gradually with each year of exposure to HRT.

Dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said:

“Previous research into hormone therapy and dementia risk is mixed and inconclusive. “Studies like this, that look for patterns in medical records can be extremely useful for identifying factors linked with Alzheimer’s risk, but they can’t tell us the root cause of that link. “When looking at the data as a whole, researchers found no link between receiving hormone replacement therapy and an increased risk of dementia. “A smaller sub-group of the data suggests that women who received some forms of hormone therapy over a longer period of five years were slightly more likely to be diagnosed with Alzheimer’s disease – the most common cause of dementia – this increased risk was small, equivalent of up to seven extra dementia cases per 10,000 person years. “Hormone therapy provides important benefits to many women, helping to combat the symptoms that menopause can bring. Women who require hormone therapy should not be put off by these results, and anyone concerned about the effects of this treatment should speak to their doctor.”

You can read the full research in the BMJ here. The title of the paper is ‘Use of menopausal hormone therapy and risk of dementia: Nested case-control studies using QResearch and CPRD databases’.