Known risk factors do not explain disparities in gallstone prevalence between Denmark and northeast Germany.
Gallstones are a common disease worldwide, with disparities in the prevalence of the disease in different settings. The aim of the present study was to assess if different distributions of risk factors could explain the disparities in the prevalence of gallstone disease between Denmark and northeast Germany. Data of 5,559 subjects from the Danish MONICA survey and of 3,647 subjects of the German Study of Health in Pomerania were investigated. Gallstone disease was defined as a prior history of cholecystectomy or the presence of sonographically diagnosed gallstones. Logistic regression models were performed to assess the confounding effect of selected risk factors on regional disparities in gallstone disease. After adjustment for age and vocational training, German subjects (women: Odds ratio, OR, 2.46 (95% confidence interval, CI: 2.07-2.91); men: OR, 1.89 (95% CI: 1.52-2.36)) had approximatively twice the odds of gallstones than Danes. Inclusion of lifestyle factors (smoking, alcohol intake, coffee use) did not affect this result, whereas adjustment for body mass index (BMI), lipids, diabetes, and use of oral contraceptives, menopausal hormone therapy (MHT) and parity (women only) changed the estimates considerable, but still Germans (women: OR, 1.65 (95% CI: 1.36-2.00); men: OR, 1.61 (95% CI: 1.27-2.04)) had higher odds than Danes. German individuals had a higher prevalence of gallstones than Danes. This difference was partly explained by a higher BMI, unfavorable lipid levels, higher prevalence of diabetes, and a more frequent use of OR and MHT in German subjects. Further research is needed to evaluate the impact of unmeasured predictors, including genetic components, on the population-related risk of gallstones.