Incident diverticular disease is inversely related to vigorous physical activity

Abstract

Purpose: In 1995, the Health Professionals Follow-up Study published an isolated report of lower diverticular disease risk in physically active men, particularly among those who ran. The purpose of this article was to assess whether this finding can be verified among older men and women of the National Runners' Health Study.

Methods: Survival analyses were applied to incident disease occurring during 7.7 yr of follow-up in 9072 men and 1664 women, representing 84% follow-up of the original >or=50-yr-old cohort. In addition to the usual running distance (km x d(-1)), 80% of the baseline respondents included 10-km footrace performance times (a measure of cardiorespiratory fitness). Results were adjusted for age, sex, and reported intakes of meat, fish, fruit, and alcohol.

Results: A total of 127 men and 21 women reported clinically diagnosed diverticular disease since baseline. The risk for incident diverticular disease decreased 6.2% per km x d(-1) run (P = 0.04). Relative to men and women who ran <or=2 km x d(-1), those who ran an average of >8 km x d(-1) had 48% lower risk (P = 0.05). Each meter-per-second increment in the 10-km performance was associated with a 68% risk reduction (P = 0.04). Men and women who ran >4 m x s(-1) had 70% lower risk for diverticular disease than those who ran <or=2.8 m x s(-1) (P = 0.01), which persisted when adjusted for baseline body mass index (69% risk reduction, P = 0.02) or usual running distance (36% risk reduction, P = 0.03).

Conclusion: These results demonstrate an inverse association between vigorous physical activity and incident diverticular disease among older men and women but are limited by their reliance on self-reported physician diagnosis.

FIGURE 1

Relative risk of self-reported physician-diagnosed diverticular disease by usual running distance relative to the least active runners, adjusted for age, sex, pack-years of cigarette consumption, and intake of meat, fish, fruit, and alcohol. Additional adjustment for BMI where indicated. *P ≤ 0.05 for the reduction in risk relative to the least active runners. Relative risks (rr) per kilometer-per-day increment in daily running distance (as a continuous variable) presented at the top.

FIGURE 2

Relative risk of self-reported physician-diagnosed diverticular disease by cardiorespiratory fitness (10-km race performance time) relative to the least-fit (slowest) runners, adjusted for age, sex, pack-years of cigarette consumption, and intake of meat, fish, fruit, and alcohol. Additional adjustment for usual running distance (km/d) and BMI where indicated. Significance levels relative to the least fit runners are coded: *P < 0.05, †P < 0.01. Significance levels relative to all faster men are presented above the bars and to the left of the arrows (e.g., men who ran faster than 3.6 m/s were significantly less likely to report physician-diagnosed diverticular disease than those who ran 3.2–3.6 m/s, P = 0.04). Relative risks (rr) per meter-per-second increment in the 10-km performance (as a continuous variable) are presented at the top.