To investigate the association between dietary inflammatory index with pelvic floor disorders in a nationally representative U.S. sample.

A cross-sectional survey was conducted using data from the 2005-2010 National Health and Nutrition Examination Survey. Non-pregnant women ≥ 20 years who completed the questionnaires on 24-hour dietary recall and pelvic floor functions were included for analysis. Weighted multivariable logistic analysis adjusting for possible confounders was used to evaluate the association between the dietary inflammatory index and pelvic floor disorders. The exposure-response relationship was further explored by restricted cubic spline functions.

Among 6406 women, the dietary inflammatory index ranged from -5.20 to 4.83. The weighted prevalence of pelvic floor disorders was 23.87 (22.49-25.31) %, with 16.69 (15.34-18.13) % of urinary incontinence, 9.17 (8.26-10.16) % of fecal incontinence, 2.80 (2.32-3.37) % of pelvic organ prolapse. With a one-unit increment of the dietary inflammatory index, the risk of pelvic floor disorders would increase 8% (OR 1.08, 95% CI: 1.02-1.13). Compared with women in the lowest dietary inflammatory index group, such risk raised 56% in pelvic floor disorders (95% CI: 1.22-1.99), 34% in urinary incontinence (95% CI: 1.02-1.78), and 95% in fecal incontinence (95% CI: 1.22-3.13) among those in the highest group. The exposure-response associations were linear. (P for non-linearity =0.606, 0.884, and 0.188). In the analysis stratified by BMI, only among the obese group (BMI ≥ 30 kg/m2), women in the highest DII group had a 69% higher risk of pelvic floor disorders (OR 1.69, 95% CI: 1.13-2.53), 57% increased risk of urinary incontinence (OR 1.56, 95% CI: 1.19-2.12), and about three times risk of fecal incontinence (OR 2.90, 95% CI: 1.28-6.53) compared with those in the lowest DII group.

Results from our study indicated that nearly one-fourth (23.87%, 95% CI: 22.49-25.31%) of U.S. nonpregnant women aged 20 or more complained of one or more pelvic floor disorders. Urinary incontinence was the most common among three subsets. Meanwhile, we found that women with a pro-inflammatory diet pattern (higher DII score) have a significantly increased risk of pelvic floor disorders even after controlling potential confounders. Such risk would significantly increase 56% among women with a pro-inflammatory diet pattern compared to women with an anti-inflammatory one. The same was true for urinary and fecal incontinence, except for POP. Furtherly, the exposure-response curves revealed linear relationships between DII and pelvic floor disorders and their subsets, meaning that the odds of pelvic floor disorder and their subsets would linearly increase with an increased DII. The BMI-stratified subgroup analysis revealed that obese women with consumption of a pro-inflammatory diet could increase the risk of pelvic floor disorders.

Women with a pro-inflammatory diet have an increased risk of pelvic floor disorders, including urinary and fecal incontinence, which is more obvious in those with obesity.

Continence 2S2 (2022) 100403
DOI: 10.1016/j.cont.2022.100403