Smoking and Alcohol Consumption and Risk of Incident Diverticulitis in Women.

BACKGROUND & AIMS: Much of what is known about the effects of alcohol and tobacco use on diverticular disease derives from studies of asymptomatic diverticulosis or complicated diverticulitis. We examined smoking and alcohol consumption and risk of incident diverticulitis in a large cohort of women. METHODS: We conducted a prospective study of 84,232 women in the Nurses' Health Study II (NHS II) who were 39-52 years old and without known diverticulitis at baseline in 2003. Smoking was ascertained every 2 years and alcohol use every 4 years. We used Cox proportional hazards regression to estimate multivariable-adjusted hazards ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During 1,139,660 person-years of follow up, we identified 3018 incident cases of diverticulitis. After adjustment for other risk factors, current (HR, 1.20; 95% CI, 1.04-1.39) and past smoking (HR, 1.20; 95% CI, 1.11-1.30) were associated with increased risk of diverticulitis when compared with never smokers. Women who consumed ≥30 g/d of alcohol had a multivariate HR of 1.26 (95% CI, 1.05-1.50) when compared with women who did not drink. A joint analysis of smoking and alcohol found that individuals who ever smoked and consumed ≥15 g/d of alcohol were at highest risk of diverticulitis (multivariate HR, 1.60; 95% CI, 1.16-2.21), compared with participants who never smoked and reported no alcohol use. CONCLUSIONS: In this large prospective study of women, smoking and alcohol consumption were associated with an increased risk of incident diverticulitis. These data highlight additional modifiable risk factors for diverticulitis that may aid in prevention.

Diverticulosis morphology is associated with risk of diverticulitis.

The size, number and distribution of diverticula vary greatly in patients with diverticulosis. We aimed to study the association between the morphology of diverticulosis assessed on colonoscopy and the risk of diverticulitis. We performed a retrospective, case-control study of cases with a history of diverticulitis and controls with diverticulosis without diverticulitis matched on sex, age (within 5 years) and year of colonoscopy. Diverticulosis characteristics were obtained from endoscopy reports and were categorized according to severity, extent, number and size. We used conditional logistic regression on matched pairs to calculate the odds of diverticulitis among patients with diverticulosis according to differing morphologic characteristics. We identified 85 cases with computed tomography-documented diverticulitis and 85 matched controls with diverticulosis without a diagnosis of diverticulitis. In cases, 60% had left-sided only diverticulosis, 2% had right-sided only and 38% had both right and left-sided diverticulosis; whereas in controls, the distribution was 53%, 18% and 29%, respectively. Cases were more likely to have large diverticula [odds ratio (OR), 3.33; 95% confidence interval (CI), 1.30-8.56 for left colon only and 1.89, 95% CI, 0.78-4.57 for both right and left]. Similarly, when the severity of diverticulosis was compared between the groups, cases were more likely to have moderate or severe diverticulosis (OR, 3.44; 95% CI, 1.51-7.84 for moderate and OR, 8.87; 95% CI, 2.98-26.37 for severe). Diverticulitis cases were more likely to have large diverticula and severe diverticulosis when compared to controls suggesting that size and severity are novel risk factors for diverticulitis.