Cardiovascular diseases and life expectancy in adults with type 2 diabetes: A Korean national sample cohort study

Abstract

Objective: Although type 2 diabetes is a strong risk factor for cardiovascular disease and mortality, information on its association with mortality and life expectancy according to cardiovascular comorbidities is limited, especially in Asia. Thus, this study assessed mortality and reductions in life expectancy associated with cardiometabolic multimorbidity. Design and Methods: A total of 569,831 participants older than 30 years from Korean National Health Insurance Service-National Sample Cohort were enrolled between 2002 and 2006 and followed for a median of 12.0 years. They were categorized into five mutually exclusive groups according to baseline disease status, as follows: none (reference group); diabetes only; diabetes and stroke; diabetes and myocardial infarction (MI); and diabetes, stroke, and MI. Mortality rates and hazard ratios (HRs), reductions of life expectancy, and age-specific contributions to life expectancy were calculated by constructing life tables. Results: The mortality rates per 1000 person-years were 6.85, 19.86, 67.17, 66.34, and 115.52 in the reference, diabetes only; diabetes and stroke; diabetes and MI; and diabetes, stroke, and MI groups, respectively. The corresponding HRs for all-cause mortality were 1.70 [95% confidence interval (CI), 1.66 to 1.75], 3.66 (95% CI, 3.32 to 4.03), 3.56 (95% CI, 3.06 to 4.14), and 4.79 (95% CI, 3.05 to 7.50) compared with the reference group. The estimated reductions in life expectancy were greater at younger ages and markedly increased with more cardiometabolic comorbidities. Conclusion: Young Asians with type 2 diabetes, especially those with cardiovascular comorbidity, did not live as long than their nondiabetic equivalents. Thus, these individuals require special attention to prevent further reductions in life expectancy.