Personality and Risk of Diabetes in Adults: Pooled Analysis of 5 Cohort Studies

Objective: Diabetes is an increasingly important public health concern, but little is known about the contribution of psychological factors on diabetes risk. We examined whether personality is associated with risk of incident diabetes and diabetes-related mortality. Method: An individual-participant meta-analysis of 34,913 adults free of diabetes at baseline (average age 53.7 years, 57% women) from 5 prospective cohort studies from the United States and United Kingdom. Personality dimensions included extraversion, neuroticism, agreeableness, conscientiousness, and openness to experience based on the Five Factor Model. Results: During an average follow-up of 5.7 years, 1845 participants became diabetic. Of the 5 personality dimensions, only low conscientiousness was associated with an elevated diabetes risk (OR = 0.87, 95% CI = 0.82-0.91 per 1 standard deviation increment in conscientiousness). This association attenuated by 60% after adjustment for obesity and by 25% after adjustment for physical inactivity. Low conscientiousness was also associated with elevated risk of diabetes mortality (HR = 0.72, CI = 0.53-0.98 per 1 standard deviation increment in conscientiousness). Other personality traits were not consistently associated with diabetes incidence or mortality. Conclusions: Low conscientiousness-a cognitive-behavioral disposition reflecting careless behavior and a lack of self-control and planning-is associated with elevated risk of diabetes and diabetes-related mortality. The underlying mechanisms are likely to involve health behaviors, such as poor weight management, physical inactivity, and adherence to medical management recommendations.