Development of comorbidities in type 2 diabetes between 2005 and 2017 using German claims data

Against the background of increasing life expectancy over time, several hypotheses have been proposed on the way morbidity has been developing. In type 2 diabetes (T2D), previous research suggests that morbidity compression could be ruled out due to increasing prevalence and life expectancy with T2D over time. Understanding how the health state in individuals with T2D is developing would help identify whether morbidity expansion or a dynamic equilibrium pattern applies for this disease. This study aims to answer the following questions: (1) How do the number and the prevalence of T2D concordant comorbidities develop over time? (2) What does this imply in terms of morbidity development in T2D in Germany? The study used claims data from a statutory health insurance provider in Lower Saxony, Germany. Period prevalence of T2D concordant comorbidities was examined for the periods 2005-2007, 2010-2012 and 2015-2017 in 240,241, 295,868 and 308,134 individuals with T2D respectively. The effect of time period on the number and prevalence of comorbidities was examined by means of (ordered) logistic regression. The age-adjusted predicted probabilities of more severe cardiovascular diseases (CVDs) decreased over the three periods while those of less severe CVDs and other vascular diseases increased significantly in men and women and among all examined age-groups. Predicted probability of having at least one more comorbidity over time also increased significantly among all examined groups. While less and more severe CVDs exhibited different developmental patterns, the results of the study point towards morbidity expansion in T2D. Future studies should focus on mechanisms that contribute to these trends.