Düsseldorf, 20.03.2023

Falling Incidence of Type 2 Diabetes Despite High Prevalence – A Reason for Hope?

Using the sixty-three million people with statutory health insurance as a basis, the German Diabetes Center (DDZ) has compiled the first study of trends associated with the incidence of type 2 diabetes (T2D) in Germany over a period of six years. The findings show a decline in the number of new cases in almost all 401 administrative districts and urban municipalities, as well as nationwide. In contrast, an increase in the number of cases in younger age groups was observed.

To date, few studies have examined temporal changes in T2D incidence rates in Germany: they either only looked at shorter periods or the progression over time in comparatively large regions. “For this reason, it was important for us to study the longest possible period to help identify trends and not only have a snapshot,” explains lead author Dr. Thaddäus Tönnies from the Institute for Biometrics and Epidemiology, a partner of the German Center for Diabetes Research (DZD). Therefore, the researchers modeled age- and sex-specific trends, as well as regional trends, for the T2D incidence rate for the years 2014 to 2019. They were assisted by the Central Research Institute of Ambulatory Health Care in Germany, which provided anonymized data on all people with statutory health insurance in Germany (approx. 85% of the population, equivalent to 63 million insured persons). The corresponding ICD codes were used to help identify new type 2 diabetes cases, with at least two codes in two different quarters required for definition as an incident case.

Nationwide: Fewer New Cases but Younger Patients
An annual total of approx. 450,000 cases was recorded. At the same time, the working group found that the incidence rate decreased by 2.4% for women and 1.7% for men across all age groups, especially in older age groups. “The fact that the nationwide incidence appears to be declining by around 2% annually is a positive development – although the number of new cases remains immense,” says Dr. Tönnies. A cause for concern is the fact that the number of new cases in the 20-to-39-year-old age group is on the increase: annually 2.9% for men and 2.4% for women. “Type 2 diabetes is no longer only a disease affecting the old,” says the expert; “younger people are now more commonly being diagnosed with type 2 diabetes”.

Therefore, it is no surprise that the overall proportion of those affected continues to rise. “The fact that the prevalence shows an increase within the same period appears to be a contradiction,” explains Professor Oliver Kuß, Director of the Institute for Biometrics and Epidemiology at the DDZ. “Improvements in the care of people with type 2 diabetes lead to greater life expectancy and results in those affected making up a higher proportion of the total population”.

Lagging Behind at the District Level: The Eastern German States and Saarland
As with the nationwide incidence rate, there was also a decline in the SIR value at the district level during the observation period. The SIR is the factor by which the incidence rate of a district differs from that of the nationwide incidence rate in 2014. If a district shows SIR < 1, SIR = 1 or SIR > 1, this corresponds to a lower, unchanged, or higher incidence rate compared to the nationwide incidence rate in 2014.


Fig.: Spatial-temporal trends for the age- and gender-adjusted type 2 diabetes incidence rate ratio
(“standardized incidence ratio”, SIR) in Germany between 2014 and 2019. Source: Deutsches Ärzteblatt

In 2019, significantly more districts were below the nationwide incidence rate than in 2014. Correspondingly, almost all districts also displayed a declining SIR with the annual mean reduction being -2.2 %. However, it was also observed that the Eastern German States and Saarland tended to be above the nationwide rate and, in contrast, Northwestern and Southern German tended to be below the 2014 rate (see Fig.). In 14 districts, an increasing trend was observed: In the districts Main-Linzig, Dessau-Roßlaum, and Gotha, the annual factor increase was more than 1%.

For this reason, researchers were unable to definitively report a positive shift. “Although this study indicates a slight reduction in new cases for the first time, further intensive monitoring is needed to determine whether this trend will continue,” stresses Professor Michael Roden, Professor and Chairman of Internal Medicine, Endocrinology and Metabolic Disorders at Heinrich Heine University Düsseldorf and scientific director and executive board member of the DDZ. As shown in data from Denmark, the dynamic of the situation could rapidly shift in the opposite direction. A potential unknown number of undiagnosed or incorrectly coded cases must be taken into consideration when determining the limitations of the study. Preventative measures, targeted exercise courses, healthy dietary habits, and health education must be increasingly promoted to help turn this initial trend into a long-term change in direction for Germany.


Original publication:
Tönnies T, Hoyer A, Brinks R, Kuss O, Hering R, Schulz M: Spatio-temporal trends in the incidence of type 2 diabetes in Germany – analysis of the claims data of 63 million persons with statutory health insurance from 2014 to 2019. Dtsch Arztebl Int 2023; 120: 173-9. DOI: 10.3238/arztebl.m2022.0405

Contact: 
Isabelle Keller 
Press officer DDZ 
isabelle.keller(at)ddz.de  
+49 (0)211 3382-450 

The German Diabetes Center (DDZ) serves as the German reference center for diabetes. Its objective is to contribute to the improvement of prevention, early detection, diagnosis and treatment of diabetes mellitus. At the same time, the research center aims at improving the epidemiological data situation in Germany. The DDZ coordinates the multicenter German Diabetes Study and is a point of contact for all players in the health sector. In addition, it prepares scientific information on diabetes mellitus and makes it available to the public. The DDZ is part of the Leibniz Association (Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz, WGL) and is a partner of the German Center for Diabetes Research (DZD e.V.). www.ddz.de/en 

The German Center for Diabetes Research (DZD) is a national association that brings together experts in the field of diabetes research and combines basic research, translational research, epidemiology and clinical applications. The aim is to develop novel strategies for personalized prevention and treatment of diabetes. Members are Helmholtz Munich – German Research Center for Environmental Health, the German Diabetes Center in Düsseldorf, the German Institute of Human Nutrition in Potsdam-Rehbrücke, the Paul Langerhans Institute Dresden of Helmholtz Munich at the University Medical Center Carl Gustav Carus of the TU Dresden and the Institute for Diabetes Research and Metabolic Diseases of Helmholtz Munich at the Eberhard-Karls-University of Tuebingen together with associated partners at the Universities in Heidelberg, Cologne, Leipzig, Lübeck and Munich. www.dzd-ev.de/en  

Press contact

Birgit Niesing

niesing(at)dzd-ev.de
+49 (0)89 3187-3971


Dr. Astrid Glaser

glaser(at)dzd-ev.de
+49 (0)89 3187-1619

Spatial-temporal trends for the age- and gender-adjusted type 2 diabetes incidence rate ratio. (“standardized incidence ratio”, SIR) in Germany between 2014 and 2019. Source: Deutsches Ärzteblatt