Prevalence of undiagnosed diabetes and impaired glucose regulation in 35-59-year-old individuals in Southern Germany: the KORA F4 Study

P>Aims Limited data are available for European populations regarding the prevalence of diabetes and disturbed glucose metabolism in younger individuals. Our aim was to estimate the prevalence of diagnosed and undiagnosed diabetes, isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT) and combined IFG/IGT in a population-based sample (n = 1653) from Southern Germany aged 35-59 years. Methods Oral glucose tolerance tests were carried out in all non-diabetic participants of the KORA F4 Study (2006-2008). Diabetes, IGT and IFG were defined according to the 1999 World Health Organization diagnostic criteria. The original IFG criteria (6.1-6.9 mmol/l) were used as recommended by the European Diabetes Epidemiology Group. Results The age-standardized prevalence was 2.2% for known diabetes, 2.0% for newly detected diabetes, 2.9% for i-IFG, 6.3% for i-IGT and 1.1% for combined IFG/IGT. About half of the cases with overt diabetes were undiagnosed in all age groups. The prevalence of i-IGT was approximately twice as high as that of i-IFG. The proportion of i-IGT varied between 3.2% (age group 35-44 years) and 11.8% (age group 55-59 years); the corresponding numbers for i-IFG were 1.1% and 5.9%. IFG/IGT was present in 1.2% of the total sample, and was most frequently found in the age group 55-59 years (2.4%). Overall, 16% of the study population had either diabetes or abnormalities of glucose metabolism. Conclusions The study reveals for the first time a high prevalence of impaired glucose regulation in the younger and middle-aged German population. The detection of disturbed glucose metabolism or diabetes needs to be improved.