FAECAL incontinence (FI) is a common issue that greatly affects quality of life and healthcare usage. The role of obesity in FI is uncertain, as studies have conflicting findings when using BMI as a measure. Brent Hiramoto, Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women’s Hospital, Boston, Massachusetts, USA, and colleagues, set out to explore the link between obesity and FI, investigating whether this connection depends on how fat is distributed in the body (measured by waist circumference-to-height ratio [WHtR]).
This study conducted a population-based examination using data from the National Health and Nutrition Examination Survey (NHANES). It involved individuals who took part in the bowel health survey between 2005–2010. The unintentional leakage of solid stool, liquid, or mucus occurring at least once within the previous month was defined as FI. Stepwise multivariable logistic regression models were developed to analyse the factors associated with FI.
A total of 7,606 participants took part, revealing an overall FI prevalence of 9.2%. When categorised by quartiles of body measurements, FI became more prevalent from the first to the fourth quartile for both WHtR (ranging from 5.3–12.5%) and BMI (ranging from 7.1–10.5%). WHtR showed a stronger correlation with FI than BMI across all quartiles of body measurement. In the multivariable analysis, WHtR remained a significant predictor of FI when comparing the fourth to the first quartile of body measurements (odds ratio: 1.77; confidence interval: 1.11–2.80; p=0.017), while BMI did not. A WHtR threshold of >0.592 provided the optimal Youden index for predicting FI in the overall sample.
In this study of American adults representing the nation, WHtR showed a standalone link with higher chances of FI, while BMI did not consistently show such a connection. This indicates that bowel control might rely more on how weight is distributed across the body.
Reference
Hiramoto B et al. Centrally distributed adiposity as a modifiable risk factor for fecal incontinence: U.S. population-based analysis. Clin Gastroenterol Hepatol. 2024;DOI:10.1016/j.cgh.2024.04.002.
