Diabetes type 2 in the Berlin Aging Study II: Cross-sectional and longitudinal data on prevalence, incidence and severity over on average seven years of follow-up

Aims: Aim of the current study was to describe the prevalence, incidence, and severity of diabetes mellitus type 2 (T2D) in a cohort of older men and women aged 60 years and above over the course of on average 7 years, since longitudinal data on this topic are scarce for this age group in Germany. Methods: Baseline data of 1671 participants of the Berlin Aging Study II (BASE-II; 68.8 +/- 3.7 years) and follow-up data assessed 7.4 +/- 1.5 years later were analysed. The BASE-II is an exploratory, observational study on cross-sectional and longitudinal data of an older population. T2D was diagnosed based on self-report, antidiabetic medication use and laboratory parameters. T2D severity was determined by the diabetes complications severity index (DCSI). Prognostic capacity of laboratory parameters was evaluated. Results: The proportion of participants with T2D increased from 12.9% (37.3% women) at baseline to 17.1% (41.1% women) with 74 incident cases and 22.2% not being aware of the disease at follow-up. The incidence rate is 10.7 new T2D diagnoses per 1000 person-years. More than half of the 41 newly identified incident T2D cases were diagnosed solely by the 2 h-plasma glucose test (OGTT) and diagnosis based on OGTT as the only criterion among incident cases was found more frequently in women (p = 0.028). T2D severity expressed by the DCSI significantly increased from baseline to follow-up (mean DCSI 1.1 +/- 1.2 vs. 2.0 +/- 1.8; range 0-5 vs. 0-6). Cardiovascular complications had the highest impact (43.2% at baseline and 67.6% at follow-up). Conclusions: A comprehensive picture of T2D with respect to prevalence, incidence, and severity in older people of the Berlin Aging Study II is provided.