Optimism and Incident Type 2 Diabetes in U.S. Army Active Duty Soldiers

Introduction: Diabetes is a major health concern in the U.S. Optimism has shown protective associations with a number of cardiovascular-related health behaviors and health outcomes, but evidence to date is limited regarding optimism’s association with diabetes. The present study sought to quantify the association between optimism and the onset of type 2 diabetes in a large sample of initially healthy U.S. Army active duty Soldiers.

Methods: This project integrated data from the Global Assessment Tool (GAT), the Military Health Systems Data Repository (MDR), the Periodic Health Assessment (PHA), and the Defense Manpower Data Center (DMDC) in the Person-Event Data Environment (PDE), a secure Army data repository and analysis environment. For this study, we examined a sample of over 100,000 U.S. Army active duty Soldiers who completed the GAT between 2009 and 2010 and were free of diabetes (type 1 or type 2) at baseline. We used diagnostic codes from electronic medical records to identify incidence of type 2 diabetes. Optimism was assessed with 4 items adapted from the revised Life Orientation Test that were included on the GAT. We performed a series of survival analysis models to examine the association between baseline optimism and type 2 diabetes incidence over an approximately 7.5 year follow-up period. Models adjusted for relevant demographic characteristics (e.g., age, gender, race/ethnicity, education, and marital status) and other potential confounders (e.g., rank, deployment), as well as a number of health factors that may be on the pathway linking optimism with diabetes (e.g., body mass index [BMI], smoking status, family history of diabetes).

Results: Every unit increase in optimism was associated with an approximately 10% decrease in the risk of acquiring type 2 diabetes, even after adjusting for demographic characteristics and health-related factors. Family history of diabetes, current smoking, BMI, and being non-White (compared to White) were all associated with an increased risk of developing diabetes.

Conclusions: Integrating over 7 years of data from multiple Army data sources, we found that greater baseline optimism was associated with a decreased risk of developing type 2 diabetes in a large sample of initially healthy men and women. Future research should examine the mechanisms by which optimism is associated with diabetes risk, and the extent to which boosting optimism through targeted interventions may also help reduce diabetes risk.