Aims To project the number of people with Type 2 diabetes in Germany between 2015 and 2040.Methods Based on data from 65 million insurees of the German statutory health insurance, we projected the agespecific prevalence of diabetes using mathematical relations between prevalence, incidence rate and mortality. We compared several scenarios regarding temporal trends in the incidence and mortality rate. The projected age-specific prevalence was applied to the projected age structure of the German population between 2015 and 2040 to calculate the number of people with Type 2 diabetes.Results Application of current age-specific prevalence estimates to the projected age structure in 2040, although ignoring temporal trends in incidence and mortality, yielded an increase in the number of Type 2 diabetes cases from 6.9 million in 2015 to 8.3 million (+21%) in 2040. More realistic scenarios that account for decreasing mortality rates and different trends in the incidence rates project between 10.7 million (+54%) and 12.3 million (+77%) Type 2 diabetes cases in 2040.Conclusions For the first time, we projected the number of future Type 2 diabetes cases for the whole adult population in Germany. The results indicate a relative increase in the number of Type 2 diabetes cases of between 54% and 77% from 2015 to 2040. Temporal trends in the incidence rate are the main drivers of this increase. Simply applying current age-specific prevalence to the future age structure probably underestimates the future number of Type 2 diabetes cases.

Aim This study aimed to determine cross‐sectional relationships between diabetes distress and health‐related variables, and prospective associations between diabetes distress and future glycaemic control (HbA1c) and health status among young adults with early‐onset Type 1 diabetes. Methods Data were collected from a nationwide cohort study of adults whose Type 1 diabetes onset occurred from 0 to 4 years of age during 1993–2002. Questionnaire surveys were conducted in 2012–2013 and 2015–2016 (N = 584). Diabetes distress was assessed via the Problem Areas in Diabetes (PAID) scale (0–100 points), depressive symptoms via the Patient Health Questionnaire‐9 (PHQ‐9) and health status via the 12‐Item Short Form Health Survey (SF‐12) questionnaire. Multivariable linear regression analyses were applied to cross‐sectional and longitudinal data. Results In the cross‐sectional analyses, higher PAID scale total scores (representing higher distress levels) were observed in women than in men and in participants with more severe depressive symptoms. PAID scores were lower in individuals with better physical and mental health. A 1 mmol/mol increase in HbA1c was associated with a 0.28‐point increase [95% confidence interval (95% CI) 0.20, 0.36] in diabetes distress. In longitudinal analyses adjusting for age, sex, socio‐economic index and HbA1c at baseline, a 10‐point higher PAID score at baseline was associated with a 1.82 mmol/mol higher HbA1c level (95% CI 0.43, 3.20) and a 2.48‐point lower SF‐12 mental health score (95% CI −3.55, −1.42) three years later. Conclusions The cross‐sectional and longitudinal analyses results suggest that diabetes distress impairs health‐related outcomes in young adults with early‐onset diabetes.