Risk factors of admission for acute colonic diverticulitis in a population-based cohort study: The North Trondelag Health Study, Norway.

AIM To assess risk factors of hospital admission for acute colonic diverticulitis. METHODS The study was conducted as part of the second wave of the population-based North Trondelag Health Study (HUNT2), performed in North Trondelag County, Norway, 1995 to 1997. The study consisted of 42570 participants (65.1% from HUNT2) who were followed up from 1998 to 2012. Of these, 22436 (52.7%) were females. The cases were defined as those 358 participants admitted with acute colonic diverticulitis during follow-up. The remaining participants were used as controls. Univariable and multivariable Cox regression analyses was used for each sex separately after multiple imputation to calculate HR. RESULTS Multivariable Cox regression analyses showed that increasing age increased the risk of admission for acute colonic diverticulitis: Comparing with ages < 50 years, females with age 50-70 years had HR = 3.42, P < 0.001 and age > 70 years, HR = 6.19, P < 0.001. In males the corresponding values were HR = 1.85, P = 0.004 and 2.56, P < 0.001. In patients with obesity (body mass index >= 30) the HR = 2.06, P < 0.001 in females and HR = 2.58, P < 0.001 in males. In females, present (HR = 2.11, P < 0.001) or previous (HR = 1.65, P = 0.007) cigarette smoking increased the risk of admission. In males, breathlessness (HR = 2.57, P < 0.001) and living in rural areas (HR = 1.74, P = 0.007) increased the risk. Level of education, physical activity, constipation and type of bread eaten showed no association with admission for acute colonic diverticulitis. CONCLUSION The risk of hospital admission for acute colonic diverticulitis increased with increasing age, in obese individuals, in ever cigarette smoking females and in males living in rural areas.