Being overweight or obese is an established risk factor for urinary incontinence, but a recent study indicates that body composition may also play a role. A multicenter team of researchers examined data from 1,475 women enrolled in the Health, Aging, and Body Composition Study. The participants ranged in age from 70 to 79 at the beginning of the study.

The research team looked at body mass index (BMI), percentage of body fat, and the frequency and type of incontinence episodes among participants over three years. They found that both stress incontinence—episodes of spilled urine during exercise—and urge incontinence—sudden, uncontrollable urination—were twice as common in women with the highest BMIs or greatest proportion of body fat compared with those in the lowest categories. Women who lost grip strength—an indication of reduced muscle mass—also had increased episodes of stress incontinence. However, overweight women who reduced either their BMI or their body fat by 5% were less likely than women who didn't lose weight or shed fat to experience new or persistent stress incontinence. The study was published online Dec. 5, 2016, by the Journal of the American Geriatrics Society.

These findings suggest that while weight loss alone may help alleviate both forms of incontinence, activities that increase muscle mass may be especially helpful for women with stress incontinence.