Objective: To determine whether diabetes predicts infection-related mortality and to clarify the extent to which this relationship is mediated by comorbid conditions that may themselves increase risk of infection.
Research design and methods: We performed a retrospective cohort study using the Second National Health and Nutrition Examination Survey Mortality Study of 9,208 adults aged 30-74 years in 1976-1980. We defined demographic variables, diabetes, cardiovascular disease (CVD), and smoking by self-report; BMI, blood pressure, and serum cholesterol from baseline examination; and cause-specific mortality from death certificates.
Results: Over 12-16 years of follow-up, 36 infection-related deaths occurred among 533 adults with diabetes vs. 265 deaths in 8,675 adults without diabetes (4.7 vs. 1.5 per 1,000 person-years, P < 0.001). Diabetes (RR 2.0, 95% CI 1.2-3.2) and congestive heart failure (2.8, 1.6-5.1) were independent predictors of infection-related mortality after simultaneous adjustment for age, sex, race, poverty status, smoking, BMI, and hypertension. After subdividing infection-related deaths into those with (n = 145) and without (n = 156) concurrent cardiovascular diagnoses at the time of death, diabetic adults were at risk for infection-related death with CVD (3.0, 1.8-5.0) but not without CVD (1.0, 0.5-2.2).
Conclusions: These nationally representative data suggest that diabetic adults are at greater risk for infection-related mortality, and the excess risk may be mediated by CVD.