Study finds HRT may increase need for hip, knee replacements
November 3rd, 2008 by Jennifer Walker-Journey
Women who have never given birth and women who take postmenopausal hormone replace therapy (HRT) may have a higher risk of severe hip or knee and osteoarthritis, according to a story by Med Page Today. The medical publication credits the Million Women Study, a confidential national study of women’s health involving more than one million UK women aged 50 and older. The project is a collaborative project between Cancer Research UK and the National Health Service and focuses on the effects of HRT. Because the study group is so large, a broad range of topics can be addressed.
According to the study, women who have never given birth had, per child, a two percent adjusted increase in the risk of having a hip replacement and an eight percent increase of knee replacement. Current use of HRT was associated with a 38 percent increase in hip replacement and a 58 percent increase in knee replacements. There was no explanation why there was a greater risk of hip replacement over knee replacement.
The study also found that women who had their first period at or before age 11 were nine percent more likely to have a hip replacement and 15 percent more likely to have knee replacement compared to women who started their periods after age 11. Researchers also found that past use of oral contraceptives had no relationship to hip or knee replacements.
The researchers noted that estrogen is well known to prevent bone loss, however past research is divided as to whether estrogen is damaging to cartilage.