Hormone replacement therapy (HRT) is less often used today compared to 12 years ago before a large scale study showed that HRT increased a woman’s risk of cancer and heart disease. In 1991 the Women’s Health Initiative (WHI) enrolled 160,000 post menopausal women aged 50-79 to be studied for 15 years. The results of this and other well designed studies showed that HRT is very effective at reducing the symptoms of menopause and reducing risk of breaking a bone.
They also showed that HRT does more harm than good beyond 5 years, although the evidence suggests HRT is likely safe to be used for 3 to 4 years. When we talk about a study revealing increased risk of harm it’s a good idea to talk turkey and be specific about what an increased risk means. In the case of the WHI, the study showed that the overall risk of using HRT for 5 years was 1%. This means that for every 100 women using HRT for 5 years, one woman would get heart disease, have a stroke, get breast cancer or a clot in her leg.
The longer HRT is used, the greater the risk and generally we can say that 10 years of use increases the global risk of disease to 2%. It seems likely that these risks could be dropped dramatically for those using HRT if the dose of the hormones used are lowered. The current evidence shows that using half the typical dose is just as effective as using the full dose. The hormones used in the above studies were pharmaceutical and not bio-identical (as naturally found in the body).
There is very little data on the use of bio-identical hormones and no long term studies looking at safety. While it may be that using bio-identical hormones would be safer than synthetic, we just don’t know. HRT should be considered a last resort for managing the symptoms of menopause and reducing the risk of fracture.
