Regional differences in the prevalence of known Type 2 diabetes mellitus in 45-74 years old individuals: results from six population-based studies in Germany (DIAB-CORE Consortium).

AIM: In Germany, regional data on the prevalence of Type 2 diabetes mellitus are lacking for health-care planning and detection of risk factors associated with this disease. We analysed regional variations in the prevalence of Type 2 diabetes and treatment with antidiabetic agents. METHODS: Data of subjects aged 45-74 years from five regional population-based studies and one nationwide study conducted between 1997 and 2006 were analysed. Information on self-reported diabetes, treatment, and diagnosis of diabetes were compared. Type 2 diabetes prevalence estimates (95% confidence interval) from regional studies were directly standardized to the German population (31 December 2007). RESULTS: Of the 11,688 participants of the regional studies, 1008 had known Type 2 diabetes, corresponding to a prevalence of 8.6% (8.1-9.1%). For the nationwide study, a prevalence of 8.2% (7.3-9.2%) was estimated. Prevalence was higher in men (9.7%; 8.9-10.4%) than in women (7.6%; 6.9-8.3%). The regional standardized prevalence was highest in the east with 12.0% (10.3-13.7%) and lowest in the south with 5.8% (4.9-6.7%). Among persons with Type 2 diabetes, treatment with oral antidiabetic agents was more frequently reported in the south (56.9%) and less in the northeast (46.0%), whereas treatment with insulin alone was more frequently reported in the northeast (21.6%) than in the south (16.4%). CONCLUSION: The prevalence of known Type 2 diabetes showed a southwest-to-northeast gradient within Germany, which is in accord with regional differences in the distribution of risk factors for Type 2 diabetes. Furthermore, the treatment with antidiabetic agents showed regional differences.