Hormone replacement therapy 'can raise the risk of hearing loss by 25 per cent', study of 200,000 women finds

It has been hailed as a lifesaver for women going through the menopause. But hormone replacement therapy (HRT) is being linked to an increased risk of hearing loss.

Menopausal women using HRT had a 25 per cent higher risk of losing their hearing than non-users, according to a study based on more than 200,000 women in the UK.

The researchers also warned that the chances of hearing damage increase with how long HRT is taken.

There has been a huge rise in the uptake of hormone therapy over the past five years, in part because of high-profile campaigns fronted by celebrities such as Davina McCall and Mariella Frostrup.

HRT, which replenishes the female sex hormones oestrogen and progesterone that are lost during menopause, helps counter hot flushes, night sweats, anxiety, mood swings and osteoporosis.

But academics at Shandong University in China say in the medical journal Maturitas: 'In menopausal women, hormone therapy users had 25 per cent higher risk of hearing loss compared with non-users.

'Our findings suggest that menopausal hormone therapy use in women who underwent natural menopause at the typical age – 46 to 55 – was associated with an increased risk of hearing loss, whereas no significant association was observed in women with premature or late menopause.'

Although several studies have found that women's hearing declines faster around the menopause, it is unclear why.

Scientists are also unsure why hormone therapy should affect hearing.

Although there are oestrogen receptors in the ear's auditory system, little is known about how they work.

However, other researchers have pointed out that hormone levels affect bone density, and lower bone density has been found to impair middle ear transmission.

A previous study with perimenopausal mice suggested that oestrogen plus progestin – a man-made form of progesterone – could accelerate age-related hearing loss.