Age, race, BMI influence type of incontinence in women

May 23, 2007

Whether a woman develops stress urinary incontinence, urge urinary incontinence, or mixed urinary incontinence is largely a product of a confluence of age, race, and body mass index, according to a cross-sectional analysis of the Reproductive Risks of Incontinence Study at Kaiser, a population-based study of 2,109 women over age 40 funded by the National Institute of Diabetes and Digestive and Kidney Diseases.

Whether a woman develops stress urinary incontinence, urge urinary incontinence, or mixed urinary incontinence is largely a product of a confluence of age, race, and body mass index, according to a cross-sectional analysis of the Reproductive Risks of Incontinence Study at Kaiser, a population-based study of 2,109 women over age 40 funded by the National Institute of Diabetes and Digestive and Kidney Diseases.

Investigators at the University of California, San Francisco, and Kaiser Permanente compared data from patient self-reports, interviews, and medical records from a racially diverse population of women (mean age, ±56.9 years). Type of incontinence was assigned by the predominance of stress- or urge-related episodes in a 7-day period.

Multivariate analysis identified strong correlation between BMI and stress, urge, and mixed incontinence: When compared to women with a BMI of 20, women with a BMI of 30 had a three-fold risk of one or both types of incontinence. In addition, as women aged, they were significantly more likely to experience urge or mixed, rather than stress incontinence (p=.0006). African-American women also had overall lower odds of having incontinence of any type compared to Caucasian women, and were more likely to develop urge incontinence rather than other types of incontinence.

"The uniqueness of our study lies in this cohort's ethnic diversity and wide range of ages. The result is the ability to identify heterogeneity among the risk factor profiles for each type of urinary incontinence," first author Jennifer F. Mehdizadeh, MD, of UCSF, told Urology Times at the AUA annual meeting Tuesday.

Surprisingly, diabetes and smoking appeared to have little or no influence on risk of incontinence of any type, even as women aged.

The message, Dr. Mehdizadeh said, is that "when these women come into your office and they have modifiable risk factors, such as obesity and diabetes, you can help the patient make lifestyle changes that will not only improve their overall health, but also potentially decrease their incontinence."