Incidence and lifetime risk of hospitalization and surgery for diverticular disease.

BACKGROUND: Studies on incidence rates of first-time colonic diverticular disease are few, and population-based estimates of lifetime risk are lacking. In this observational study, the incidence, admission rates and lifetime risks of hospitalization and surgery for diverticular disease were investigated. METHODS: Considering the entire Swedish population as an open cohort, incidence and admission rates, and lifetime risk estimates (considering death as a competing risk) of hospitalization and surgery for diverticular disease were calculated using data from cross-linked national registers and population statistics from 1987 to 2010. RESULTS: In total, there were 144 107 hospital admissions for diverticular disease in 95 049 individual patients. Of these, 17 599 were admissions with bowel resection or stoma formation in 16 824 patients. The total number of person-years in the population during the study period was 213 949 897. Age-standardized incidence rates were 47·4 (95 per cent c.i. 47·1 to 47·7) for first-time hospitalization with diverticular disease and 8·4 (8·2 to 8·5) per 100 000 person-years for diverticular disease surgery. The corresponding admission rates (including readmissions) were 70·8 (70·4 to 71·2) and 8·7 (8·6 to 8·9) per 100 000 person-years. Following an increase in 1990-1994, rates stabilized. Based on incidence and mortality rates from 2000 to 2010, the estimated remaining lifetime risk of hospitalization from 30 years of age was 3·1 per cent in men and 5·0 per cent in women. The corresponding risk of surgery was 0·5 per cent in men and 0·8 per cent in women. CONCLUSION: Diverticular disease is a common reason for hospital admission, particularly in women, but rates are stable and the lifetime risk of surgery is low.

The genetic influence on diverticular disease--a twin study.

BACKGROUND: The contribution of hereditary factors to the development of diverticular disease (DD) of the colon is unknown. Prevalence and location of diverticula differ in Western world compared to in Asia and several case reports describing families with DD have been published. AIM: To assess the heritability of DD in a large population-based sample of twins. METHODS: The Swedish Twin Registry was cross-linked to the Swedish Inpatient Registry. All twins, born between 1886 and 1980 and not dead before 1969, with a discharge diagnosis of DD were identified. Twins with diagnoses of colon cancer, coeliac disease or non-infectious colitis were excluded to decrease bias. Co-twin odds ratio (OR), concordance rates and tetrachoric correlations were calculated for monozygotic (MZ) and same gender-dizygotic (SS-DZ) twins. Mx-analyses were used to estimate the relative contributions of genetic effects and environmental factors to susceptibility for DD. Calculations were based on both primary and secondary discharge diagnoses to provide estimates reflecting impact of severity of the disease. RESULTS: A total of 104,452 twins met the inclusion criteria. Of these, 2296 had a diagnosis of DD. The OR of developing the disease given one's co-twin was affected was 7.15 (95% CI: 4.82-10.61) for MZ and 3.20 (95% CI: 2.21-4.63) for SS-DZ twins. Similarly, concordance rates and tetrachoric correlations were higher in MZ than those in SS-DZ twins. The heritability was estimated to 40% and the non shared environmental effects to 60%. CONCLUSION: Genetic susceptibility is an important component, along with individual specific environmental factors, for the development of diverticular disease of the colon.

Diverticular disease and the risk of colon cancer - a population-based case-control study.

BACKGROUND: Colon cancer and diverticular disease are most common in the Western world and their incidences tend to increase with advancing age. The association between the diseases remains unclear. AIM: To analyse the risk of colon cancer after hospitalisation for diverticular disease. METHODS: Nationwide case-control study. A total of 41,037 patients with colon cancer during 1992-2006, identified from the Swedish Cancer Register were included. Each case was matched with two control subjects. From the Swedish Inpatient Register, cases and control subjects hospitalised for diverticular disease were identified. Odds ratios (OR) and confidence intervals for receiving a diagnosis of colon cancer after hospital discharge for diverticular disease were calculated. Colon cancer mortality was compared between patients with or without diverticular disease. RESULTS: Within 6months after an admission due to diverticular disease, OR of having a colon cancer diagnosis were up to 31.49 (19.00-52.21). After 12 months, there was no increased risk. The number of discharges for diverticular disease did not affect the risk. Colon cancer mortality did not differ between patients with and without diverticular disease. CONCLUSIONS: Diverticular disease does not increase the risk of colon cancer in the long term, and a history of diverticular disease does not affect colon cancer mortality. The increased risk of colon cancer within the first 12months after diagnosing diverticular disease is most likely due to surveillance and misclassification. Examination of the colon should be recommended after a primary episode of symptomatic diverticular disease.