Postmenopausal women who are overweight or obese appear to have
a greater risk of developing, renal cell carcinoma, a common form
of kidney cancer, and study findings suggest that a larger waist
girth and a history of weight loss and regain further increase this
risk.
"Our study suggests that the risk of renal cell carcinoma can be
lowered if overweight individuals lose excess central body fat and
then maintain stable weight at a more desirable level," Dr. Juhua
Luo, of Karolinska Institutet, Stockholm, Sweden told Reuters
Health.
Luo and colleagues analyzed data from more than 140,000 U.S.
women, aged 50 to 79 years, enrolled in the Women's Health
Initiative study.
They compared associations between the development of renal cell
carcinoma, a cancer of the lining of the kidney, and the women's
body weight and frequency of weight loss and regain (weight
cycling) over an average of 7.7 years.
The findings are published in the American Journal of
Epidemiology.
Overall, obese women with a body mass index (BMI) at or above
35, had a 60 percent excess risk of renal cell carcinoma compared
with women of normal weight (BMI less than 25), the researchers
note. This risk increased 3 percent for every unit increase in
BMI.
When the investigators analyzed abdominal obesity as an
independent risk factor they found that each 0.1-unit increase in
waist-to-hip ratio increased the risk of developing renal cell
carcinoma by 24 percent.
Moreover, women with a history of 10 or more weight cycles had
more than double the risk of developing renal cell carcinoma,
compared with women who held a steady weight over the study period,
the investigators note.
The researchers say their findings provide further evidence that
obesity, particularly central adiposity, is associated with
increased risk of developing renal cell carcinoma, and that a
history of weight cycling may further increase this risk among
postmenopausal women.
(Agencies via China Daily October 12, 2007)