It will dramatically increase the risks of heart disease and thrombosis in women who start the therapy many years after the menopause.
Women who were aged 62 years or so when they started HRT treatment were 22 times more likely to suffer a thromboembolism and seven times more likely to have a heart disease than a woman who was 50 years or so when she started the therapy.
The findings, based on a study of 5,692 women who were taking HRT, are very much in line with the Women's Health Initiative study that first raised the alarm about HRT in 2002. But they add more definition to the health risks.
(Source: British Medical Journal, 2007; 335: 239-44).