Women who've had multiple births, are on hormone replacement therapy or underwent early puberty are at significantly higher risk for knee or hip replacement surgery, reports one of the largest studies to look at the relationship between reproductive issues and joint replacement surgery.
The findings, published on-line today ahead of print in Annals of the Rheumatic Diseases, are based on the experiences of some 1.3 million middle-aged women in the United Kingdom. Researchers at the University of Oxford tracked the women beginning in 1996 for about six years -- from around the age of 50 upwards -- to see if they had a knee or hip replaced due to osteoarthritis, an inflammatory joint disease.
A little more than 12,000 required a hip replacement by the end of the study period and just under 10,000 needed a knee replacement.
After quizzing the women on how when they had their first and last periods, how many children they had and whether they had used oral contraceptives and hormone replacement therapy (HRT), several patterns emerged.
If a woman started menstruation before the age of 11, her probability of having both hip and knee replacement surgery increased between 9 and 15 percent, the researchers found. Every successive birth increased the risk of a hip replacement by 2 percent and a knee replacement by 8 percent.
While previous use of oral contraceptives did not appear to have an effect, current use of hormone replacement therapy boosted the chances of a hip replacement by 38 percent and of a knee replacement by 58 percent, the study found.
"These findings, along with other evidence, strongly suggest that the female sex hormone, estrogen, plays a role in the development of osteoarthritis of the hip and knee and the subsequent need for joint replacement," lead study author Bette Liu, of the University of Oxford, said in an e-mail to The Star-Ledger.
Estrogen is a female sex hormone that controls the reproductive cycle, and prepares the body for pregnancy.
Liu cautioned that the is evidence is not strong enough to recommend women change their use of HRT. In fact, the study suggests that such "non-biological factors" as women having greater access to health services if they are on hormonal therapy could be a factor in them having joint replacement surgery.
Overall, women have a higher incidence of osteoarthritis, in particular of the knee, when compared to men, the study notes.
No comments:
Post a Comment