To prevent fractures, hormone replacement therapy (HRT) should be started within a few years of the menopause, a new analysis reported recently suggests.
The analysis was presented by Dr David Torgerson (centre for health economics and department of health studies, University of York) at a conference organised by the Royal Society of Medicine on November 15. He said that numerous trials had shown HRT to be an effective treatment for preventing postmenopausal bone loss but the main evidence for its effectiveness came from observational data, which were subject to a range of biases.
There were no published randomised trials that had fracture as a primary endpoint. However, two recent randomised trials had included fracture as a secondary endpoint. These had produced conflicting results. The Heart and Oestrogen/Progestogen Replacement Study (HERS) study (the largest HRT trial published to date) had shown no statistically significant effect on fractures whereas a five-year Finnish study had reported significant fracture efficacy. To try to clarify matters, Dr Torgerson had carried out a meta-analysis. He analysed data from 23 randomised trials in which fracture data were collected. These involved 8,807 women, with an average 3.7-year follow-up.
Overall, the trials showed a statistically significant 30 per cent reduction in non-vertebral fractures. "But there was a gentle decline in effect with women's age at randomisation, "Dr Torgerson said. There had been a 40 per cent reduction in non-vertebral fractures in women aged less than 60 at randomisation but only a 9 per cent reduction in women over 60 at randomisation. Also, a new, large study, involving older women (mean age 73), for which he had so far only seen an abstract, had shown no effect of HRT on fractures. This age effect could explain the HERS results, Dr Torgerson said, since women in HERS were older than those in the Finnish study.
His conclusion was that HRT significantly reduced fracture risk if started within a few years of the menopause and continued, but that there was no good evidence to suggest it prevented fractures if started 10 years or more post-menopause — a regimen favoured by some specialists. "That is not to say it doesn't work, but the evidence is not there, "he said.