Early menopause risk for very thin women

VERY slim women are much more likely to experience an early menopause, research has found.

Those who are underweight have a 30 per cent higher chance of hitting the menopause before they are 45.

The study of 80,000 women also found that the risk multiplied 2.4 times if they were underweight and had lost 20lb or more on three separate occasions between the ages of 18 and 30.

One theory is that slim women have lower levels of the sex hormone oestrogen, which is produced by fat tissue.

Oestrogen levels typically fall in women in their late 40s and early 50s and this is what causes the menopause. If they are already very low, however, the menopause will occur at an earlier age.

The study suggests women who are very slim and have gone on yoyo diets are just as likely to experience fertility issues as those who are overweight.

Researchers from the University of Massachusetts, in Boston, looked at 78,759 women aged 25 to 42. Underweight was classified as having a BMI of less than 18.5 – which is equivalent to being 5ft 5in tall and weighing 8st or less.

Women who had been underweight at any age had a 30 per cent higher risk of early menopause compared to those of normal weights.

By contrast, women who were overweight, with a BMI of 25 to 30, had 30 per cent lower odds of hitting the menopause early.

The study, published in the journal Human Reproduction, states there are ‘important implications’ for underweight women and their fertility may start to decline earlier than expected. Dr Kathleen Szegda, the lead researcher, said: ‘Our findings suggest that women who are underweight in early or midadulthood may be at increased risk for early menopause.

‘Up to 10 per cent of women experience early menopause and it is associated with a higher risk of cardiovascular disease, and other health conditions such as cognitive decline, osteoporosis and premature death.

‘So these findings have important implications for women.

‘Underweight women may want to consider discussing the potential implications of these findings with their doctors.

‘Causes of early menopause are not clearly understood.

‘Our findings suggest that being underweight may have an impact on the timing of menopause.

‘More research is needed to understand how it increases the risk of early menopause.’

The menopause normally occurs between the ages of 45 and 55, and in the UK the average age is 51.

But one in ten experience it before the age of 45 and one in 100 before the age of 40 – and often there is no obvious cause.

Kathy Abernethy, of the British Menopause Society, said: ‘The findings of this study highlight the need for women to maintain a healthy weight, for health reasons, not just after menopause, but across all ages.

‘The risks of being overweight are generally better understood, but women often don’t realise the potential hormonal complications of being very underweight, even in younger years.

‘Sustained low weight described in this study of BMI of 18.5 or less would have many health implications for a woman and earlier menopause is one risk.’