Perceived stress and incidence of Type 2 diabetes: a 35-year follow-up study of middle-aged Swedish men.

ABSTRACT

AIM: To explore incident cases of diagnosed diabetes over 35 years of follow-up in relation to self-perceived stress at baseline. METHODS: This was a population-based random sample of 7251 men derived from the Primary Prevention Trial Study, aged 47-56 years at baseline and without prior history of diabetes, coronary heart disease and stroke. Incident diabetes was identified from hospital discharge and death registries as principal or secondary diagnosis. Cox proportional hazards regression was used to evaluate the potential association between stress and diabetes. RESULTS: During a 35-year follow-up, a total of 899 men were identified with diabetes. The crude incidence was 5.2 per 1000 persons-years. At baseline, 15.5% men reported permanent stress related to conditions at work or home. After adjusting for age and competing risk of death, the estimated 35-year conditional probability of diabetes in men with permanent stress was 42.6%, compared with 31.0% for those with periodic stress and 31.2% with no stress. In age-adjusted Cox regression analysis, men with permanent stress had a higher risk of diabetes [hazard ratio 1.52 (95% CI 1.26-1.82)] compared with men with no (referent) or periodic stress [hazard ratio 1.09 (95% CI 0.94-1.27)]. The association between stress and diabetes was slightly attenuated but remained significant after adjustment for age, socio-economic status, physical inactivity, BMI, systolic blood pressure and use of anti-hypertensive medication [hazard ratio 1.45 (95% CI 1.20-1.75)]. When examining principal diagnosis of diabetes cases separately from secondary diagnoses cases, the excess risk of diabetes associated with permanent stress remained significant both in age (only) and multivariable adjusted models. CONCLUSION: Self-perceived permanent stress is an important long-term predictor of diagnosed diabetes, independently of socio-economic status, BMI and other conventional Type 2 diabetes risk factors.