Risk of early mortality and cardiovascular disease according to the presence of recently diagnosed diabetes and requirement for insulin treatment: A nationwide study

Aims/introduction: We estimated the hazards of cardiovascular diseases (CVDs) and early all-cause mortality in Korean adults according to the presence of recently diagnosed type 2 diabetes (type 2 diabetes for <5 years) and insulin use.

Materials and methods: We used the Korean National Health Insurance Service-National Sample Cohort database (2002-2015) for this longitudinal population-based study. Among adults aged ≥40 years without baseline CVD, individuals without diabetes or with recently diagnosed type 2 diabetes were selected (N = 363,919). The hazard ratios (HRs) for myocardial infarction (MI), stroke, and all-cause mortality during follow-up were analyzed according to three groups categorized by the presence of type 2 diabetes and insulin use.

Results: Within a mean 7.8 years, there were 5,275 MIs, 7,220 strokes, and 15,834 deaths. The hazards for outcomes were higher in the insulin-treated type 2 diabetes group than in the non-diabetes group [HR (95% CI): 2.344 (1.870-2.938) for MI, 2.420 (1.993-2.937) for stroke, and 3.037 (2.706-3.407) for death], higher in the non-insulin-treated type 2 diabetes group than in the non-diabetes group [HR (95% CI): 1.284 (1.159-1.423) for MI, 1.435 (1.320-1.561) for stroke, and 1.135 (1.067-1.206) for death], and higher in the insulin-treated type 2 diabetes group than in the non-insulin-treated type 2 diabetes group [HR (95% CI): 1.914 (1.502-2.441) for MI, 1.676 (1.363-2.060) for stroke, and 2.535 (2.232-2.880) for death].

Conclusions: Recently diagnosed type 2 diabetes patients showed increased risks of incident CVDs and premature mortality, and insulin-treated group demonstrated an additional increase in the risks of these outcomes in adults with recently diagnosed type 2 diabetes, suggesting the need for intensified cardio-protective interventions for adults with insulin-treated type 2 diabetes.