28/09/2011 13:27 BST | Updated 28/11/2011 05:12 GMT

Study: HRT Could Cause Asthma Attacks

Danish scientists have discovered a significant new link between hormone replacement therapy and asthma attacks.

The research, led by the Danish Paediatric Asthma Centre and Danish Cancer Society, looked at the records of 23,000 women, noting whether they were prescribed HRT and if they had ever needed treatment for asthma.

The results found that women taking the HRT for up to three years, were 29% more likely to develop asthma or have an asthma attack.

Those on the treatment for longer than three years, increase their risk by 39% and ladies on the oestrogen-only hormone replacement for 10 years or more, were 50% more likely to seek treatment for asthma.

This isn’t the first time HRT and asthma have been linked – last year a French study looked at 58,000 women on the hormone treatment and found that 54% developed asthma. However, the recent research has found a risk of dangerous asthma attacks – even among those who’ve never had asthma before.

“Previous research has suggested a link between asthma and female sex hormones, especially HRT. Our findings extend this to severe asthma exacerbations,” says Dr Klaus Bønnelykke, from the study.

Scientists are so concerned about the new findings, they’ve called for all doctors to stop prescribing the treatment to patients who complain of breathing problems.