Associations between cardiorespiratory fitness and diverticulitis in older adults.

Objectives: Examine the independent and joint associations of cardiorespiratory fitness (CRF) and body mass index (BMI) with the prevalence of diverticulitis in older adults.

Methods: 476 older adults (61% Female; 71 ± 5 years) with no history of myocardial infarction, stroke, cancer, inflammatory bowel disease, or diabetes were included in this cross-sectional study. Diverticulitis cases were identified by self-reported physician diagnosis from the medical history questionnaire. Logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of the prevalence of diverticulitis by tertiles of CRF and BMI category. CRF and BMI were further dichotomized into either "unfit" (the lowest one-third of CRF), "fit" (the upper two-thirds of CRF), "overweight/obese" (BMI ≥25.0 kg/m2), or "normal-weight" (BMI <25.0 kg/m2) to investigate the joint association of CRF and BMI with diverticulitis.

Results: Thirty-five (7.4%) participants were identified as having diverticulitis. Compared with the lowest CRF tertile, the ORs (95% CIs) of diverticulitis were 0.52 (0.22-1.22) and 0.33 (0.12-0.94) in the middle and upper CRF tertiles, respectively, after adjusting for potential confounders. After further adjustment for BMI, the association was no longer significant with ORs (95% CIs) of 0.55 (0.23-1.33) and 0.37 (0.12-1.10) in middle and upper CRF tertiles, respectively. Compared with the normal-weight group, the ORs (95% CIs) of diverticulitis were 2.86 (1.05-7.79) and 2.98 (0.95-9.35) in the overweight and obese groups, respectively, after adjusting for possible confounders and CRF. Compared with the "unfit and overweight/obese" group in the joint analysis, the OR (95% CI) of diverticulitis was 0.16 (0.04-0.61) in the "fit and normal-weight" group.

Conclusions: Older adults who maintain higher CRF and lower BMI may have significantly lower odds of diverticulitis, with the lowest odds found in the normal-weight and fit older adults.