Regional differences in cardiovascular risk factor profile cannot fully explain differences in cardiovascular morbidity in the Netherlands: a comparison of two urban areas

BACKGROUND: Our objective was to investigate whether a region in the south of the Netherlands (Heerlen/Kerkrade) had a high burden of cardiovascular disease in comparison with a nearby region (Maastricht) and the average Dutch population, respectively. We also wanted to determine if there are interregional differences in cardiovascular risk factor profile. DESIGN: Cross-sectional study. METHODS: Data from a nationwide registry (CBS) were used to analyse cardiovascular mortality in the two regions and the average in the Netherlands. Data from a primary care morbidity registration network (RNH) were used to compare cardiovascular morbidity and cardiovascular risk factors in both regions. A standardisation procedure was carried out for age and sex. Data were analysed using logistic regression analyses. RESULTS: The overall cardiovascular mortality rate was higher in the Heerlen/Kerkrade region (7.8 per thousand) compared with Maastricht (6.1 per thousand, OR=1.3, 95% CI 1.2-1.5) and the average in the Netherlands (5.7 per thousand). Similarly, most cardiovascular morbidity rates for Heerlen/Kerkrade were more elevated compared with the RNH overall and with Maastricht. Prevalence rates of risk factors such as diabetes mellitus (7.2%, OR=1.5, 95% CI 1.3-1.7) and overweight (10.8%, OR= 2.0, 95% CI 1.8-2.2) were significantly higher in the Heerlen/Kerkrade region compared with Maastricht. There were no differences with regard to hypertension (15.2%, OR=1.0, 95% CI 0.9-1.1). CONCLUSION: Heerlen/Kerkrade is indeed a region with a high burden of cardiovascular disease. Differences in morbidity between Heerlen/Kerkrade and Maastricht cannot be fully explained by differences in cardiovascular risk factor profile.