Of the total of 5,145 participants enrolled in Look AHEAD, 3,063 (59.5%) were women. We excluded 29 women who did not answer the urinary incontinence self-reported questions and 40 women who answered that they had weekly incontinence in the last year but none in the last week, leaving a total of 2,994 women for our analysis. The mean ± SD age of participants in the analytic sample was 58.0 ± 6.8 years (range 45–76 years).
Among women in Look AHEAD, 27% reported at least weekly incontinence with 11% reporting daily episodes (). The prevalence of weekly incontinence was highest among non-Hispanic white (32%) followed by American Indian/Alaskan Native (31%), Hispanic (22%), African American (18%), and Asian (12%) women (P < 0.001). Of the women with incontinence symptoms in the past week, 396 (52%) reported stress-predominant incontinence, 298 (39%) reported urgency-predominant incontinence, and 64 (8%) reported an equal number of stress and urgency incontinence episodes. Fifty-four women were unable to be classified because of incomplete responses.
Frequency of urinary incontinence in the past year by race/ethnicity among women with type 2 diabetes at baseline: Look AHEAD trial
Women with weekly incontinence differed significantly from women without incontinence in several ways (). Incontinent women were more obese, had higher BMI and waist circumferences, and had lower average fitness levels. They were more likely to be postmenopausal, to have reported a prior hysterectomy, and to be current users of oral estrogen therapy. They were older and reported worse overall health, more frequent urinary tract infections, higher Beck Depression Inventory scores, and more frequent history of claudication, arthritis, liver disease, asthma, and sleep apnea; they were also more likely to be current or former smokers. There was little difference between women with and without urinary incontinence with respect to parity, blood pressure, or history of myocardial infarction, stroke, CABG, or PTCA.
Baseline characteristics of Look AHEAD women by incontinence status
In this middle-aged and older trial cohort of overweight and obese women with type 2 diabetes, retinopathy (7.5%) was the most prevalent diabetes-associated complication, followed by microalbuminuria (albumin-to-creatinine ratio >30 μg/mg [2.2%]) and peripheral neuropathy (1.5%) (). Fewer women with incontinence had retinopathy (P = 0.03), but there was little difference between women with and without urinary incontinence with respect to neuropathy, microalbuminuria, diabetes duration, diabetes control, or diabetes treatment regimen.
Risk factors for urinary incontinence overall, as well as for stress and urgency urinary incontinence, were examined in separate stepwise multivariable logistic regression models. In all three models, non-Hispanic white ethnicity, prior hysterectomy, and ≥1 urinary tract infection in the past year significantly increased the odds of weekly or more frequent incontinence (). Specifically, compared with non-Hispanic whites, African American women had a 55–70% lower odds of overall weekly incontinence and incontinence by both types. Prior hysterectomy was related to a 40–80% increase in odds of incontinence, and urinary tract infections in the past year were associated with a 55–90% increase in odds of incontinence.
Factors significantly associated with overall and type of incontinence
For weekly or more overall incontinence, women with BMI of 35–39 kg/m2 (OR 1.65 [95% CI 1.20–2.28]) and ≥40 kg/m2 (1.84 [1.32–2.55]) had higher odds of incontinence than less obese women, with similar findings for stress incontinence. Other risk factors associated with weekly or more overall incontinence and stress incontinence but not urgency incontinence included liver disease, higher Beck Depression Inventory scores, and more alcoholic drinks per week.
Risk factors for overall incontinence and urgency incontinence included age >70 years (two- to threefold increased odds), sleep apnea (55–85% increased odds), asthma (45–60% increased odds), and ever smoker (25–65% increased odds). Other risk factors for urgency-predominant incontinence included poor overall health (50% increased odds) and increasing waist circumference (2% increased odds per unit increase).
To identify factors associated with incontinence that differed in African American, non-Hispanic white, American Indian/Alaskan Natives, and Hispanic women, we examined interactions between race and each predictor variable, adjusting for clinic site. No interaction reached the P < 0.05 level of significance.