Associations between poor mental health and mortality in adults with and without diabetes in Germany

Objectives

To examine the association of poor mental health with all-cause mortality among adults with and without diabetes in Germany.

Methods

Participants (N = 7,124) aged 18-79 years from the German National Health Interview and Examination Survey 1997-1999 were followed up for mortality until 2024. Mental health was assessed at baseline using the 5-item Mental Health Inventory (MHI-5), which measures anxiety and depression symptoms as well as overall well-being. MHI-5 scores range from 0 to 100, with a score ≤50 indicating poor mental health. Participants were classified into four groups based on diabetes (ever physician-diagnosed diabetes or use of antidiabetics) and poor mental health: both conditions (n = 70), diabetes only (n = 286), poor mental health only (n = 695) and neither condition (n = 5,869). Cox regression models were fitted adjusting for age, sex, educational level, health behaviors (smoking, sport, body mass index, alcohol consumption) and comorbidities (hypertension, hyperlipidemia, cardiovascular diseases, cancer) at baseline. Survey weights were applied.

Results

After a mean follow-up of 22.6 years, 50, 212, 209 and 1,498 deaths were recorded in the four groups of individuals with both conditions, diabetes only, poor mental health only and neither condition, corresponding to mortality rates of 41.9, 46.6, 13.4, and 11.6 per 1,000 person-years, respectively. Compared with individuals with neither condition, hazard ratios (HR) were 2.12 (95% confidence interval 1.61–2.79) for those with both conditions, 1.41 (1.18–1.68) for those with diabetes only and 1.09 (0.89–1.34) for those with poor mental health only. Compared with individuals with diabetes only, HR was 1.51 (1.10–2.06) for individuals with both conditions.

Conclusions

Poor mental health was associated with excess mortality among adults with diabetes, whereas no clear association was observed among adults without diabetes, highlighting the importance of mental healthcare in diabetes management.

Key messages

• Poor mental health was associated with excess mortality among adults with diabetes, whereas no clear association was observed among adults without diabetes.

• Mental healthcare of people with diabetes should be integrated into their diabetes management.