Diverticular disease and migration – the influence of acculturation to a Western lifestyle on diverticular disease

Abstract
Diverticular disease of the colon is more common in the Western world, compared with non-Western countries. To investigate the risk of diverticular disease in immigrants of diverse ethnicity and in different phases of acculturation. Socio-demographic indicators and the risk of diverticular disease were investigated. The study population was a prospectively followed national cohort of 4 million residents born between 1925 and 1965. Risk ratios (RRs) of hospital admissions and deaths because of diverticular disease and acute diverticulitis from 1991 through 2000 were calculated. The risk of hospital admission because of diverticular disease, after adjustment for age, sex and socio-economic indicators, was lower in non-Western immigrants (RRs = 0.5-0.7) compared with natives and the risk increased with time after the settlement. Women of all origins had a higher risk compared with men (RR = 1.5). This sex-difference increased with age (P < 0.001). Socio-economic status, residency or housing situation were not risk factors. This population-based study found that immigrants from non-Westernized countries had lower relative risks for hospitalization because of diverticular disease than natives, but the risk increased during a relatively short period of time after settlement. Diverticular disease of the colon appears to be an acquired disorder and acculturation to a Western lifestyle has an impact on the risk.