By Genevra Pittman
Heavy women are less likely to be diagnosed with endometriosis than their slimmer peers, according to a new study. Researchers following more than 116,000 women found that morbidly obese study participants were 39 percent less likely than normal-weight women to develop the chronic condition - in which uterine tissue grows outside the uterus and causes painful periods and bleeding.
That link was especially strong among women with infertility, according to Dr Divya Shah from the University of Iowa Hospitals and Clinics in Iowa City and her colleagues.
Still, Shah said that the findings don’t prove that carrying around extra pounds protects against endometriosis, which affects more than 5 million women and teen girls in the US. “By no means would I suggest ever that someone gain weight to try to reduce the risk of endometriosis,” she said.
Shah and her colleagues used data from a long-term study of female nurses who were tracked beginning in 1989, when they were 25 to 42 years old. Women reported their height and weight as 18-year-olds and updated researchers on their weight and any new medical diagnoses every two years.
Between 1989 and 2011, about 5,500 of them were diagnosed with endometriosis.
The researchers found both current weight and weight at age 18 were tied to a woman’s risk of endometriosis - so that the heavier she was, the lower her chance of being diagnosed with the condition. Among those with fertility problems, in particular, women with a body mass index (BMI) of 40 or above were 62 percent less likely to develop endometriosis than women on the low end of the normal BMI range, the study team wrote in Human Reproduction.
A five-foot, six-inch woman weighing 248 pounds has a BMI of 40, which qualifies as morbidly obese. At the same height, a woman between 118lbs and 150lbs would be considered normal weight.
Women with infertility tend to have higher rates of other hormonal conditions, Shah said - which may explain the especially strong weight association in that group. For example, polycystic ovary syndrome (PCOS) is one cause of infertility, and women with PCOS are often overweight and don’t typically get endometriosis. So (statistically) that may skew the likelihood of endometriosis in infertile women toward the lower end of the weight spectrum, she said.
Dr Steven Young, who has studied and treated endometriosis at the University of North Carolina at Chapel Hill, said that many studies - and his own clinical experience - suggest the risk is indeed higher in lean women.
Reuters
