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.