Global diabetes prevalence estimates for adults in 2000, which were derived from population-based data using oral glucose tolerance tests, were recently reported by Wild et al. (1). Because there are few OGTT-based data in the European region, estimates from a regional study carried out in the Netherlands were applied to 13 other countries, including Germany (2). For Germany, a prevalence of 4.1% was estimated, which corresponds to 2.6 million people with diabetes in 2000 (1).

In the German National Health Interview and Examination Survey in 1998, prevalence of known diabetes (self-reported) was assessed in a representative sample (aged 18–79 years) (3). Furthermore, from 1999 to 2001, glucose tolerance tests were carried out in the population-based KORA Survey 2000 (Augsburg, Germany) among 1,353 subjects aged 55–74 years (4). Both provided higher age- and sex-specific prevalence estimates than the Dutch study (2). Thus, ∼5% of the adult German population had known diabetes in 1998. In addition, at least in the age-group >55 years, one-half of the total cases were undiagnosed (4). The total diabetes prevalence (diagnosed and undetected cases) in the 55- to 74-year age-group was 16.6% in the KORA Survey (4). As the one-for-one ratio for known/undiagnosed case subjects is valid for all age-groups, the total diabetes prevalence in the adult German population in 2000 was ∼10%, corresponding to 6.3 million people. Germany should be listed among the 10 countries with the highest estimated number of people with diabetes in the world (1).

Thus, there is a greater diversity of diabetes prevalence in European countries than suggested by Wild et al. There are also differences in known risk factors for type 2 diabetes at the population level in European countries, e.g., the prevalence of obesity in Germany (20%) was almost twofold higher than in the Netherlands (5). Furthermore, the percentage of persons who did not partake in physical activity during their leisure time was higher in Germany (22.6%) than in the Netherlands (14.4%) and other European countries, which may partly explain the wide variation of diabetes prevalence (6).

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