WAIST CIRCUMFERENCE-HEIGHT RATIO AS A MODIFIABLE RISK FACTOR FOR FECAL INCONTINENCE: NHANES 2005-2010 ANALYSIS

Introduction:
Fecal incontinence is associated with substantial impacts on quality of life. Prevalence estimates range from 2% to as high as 20% based on the methodology used, and is likely underreported by patients. Prior studies have demonstrated inconsistent effects of body-mass index on fecal incontinence. This study sought to further clarify the impact of modifiable measured physical indices of body mass on fecal incontinence in a nationally representative cross-sectional cohort of participants.
Methods:
This study analyzed the National Health and Nutrition Examination Survey (NHANES), an annual cross-sectional, nationally representative health survey. Surveys collected between 2005-2010 included survey components assessing bowel health. Fecal incontinence was defined by accidental bowel leakage of solid stool, liquid, or mucus at least once in the past month. Sample weight adjustment was performed to account for complex survey design. Stepwise multivariate logistic regression models were constructed to assess risk factors for fecal incontinence.
Results:
14,345 participants were identified with responses to the bowel health survey. After stepwise adjustment for covariates (including demographics, comorbidities, dietary factors, socioeconomic factors, depression scores, diarrhea, marijuana use, Figure 1), 7,530 participants were included in the final multivariate model (Figure 2). Waist circumference-height ratio was a significant predictor of fecal incontinence (OR 1.73, 95% CI 1.04-2.88, p=0.036) comparing the 4^th to the 1^st quartile of values. Quartiles of BMI, conversely, did not significantly predict fecal incontinence.
Conclusions:
Waist circumference-height ratio is a significant risk factor for fecal incontinence. While waist-circumference-height ratio predicted fecal incontinence, body-mass index did not. This suggests bowel continence depends on how body mass is distributed. Further study of the role of central deposition of body mass in neuromuscular control of bowel continence is warranted.