BACKGROUND

The aim of the present study was to compare the association between cardiovascular diseases (CVD) and prediabetes defined by either fasting plasma glucose (FPG), HbA1c, or their combination in a Korean population.

METHODS

In all, 76 434 South Koreans who voluntarily underwent a general health examination in the Health Screening & Promotion Center (Asan Medical Center) were analyzed after excluding patients with a previous history of CVD. Cardiovascular events and death due to CVD during a median follow-up period of 3.1 years (interquartile range 1.9-4.3 years) were identified from the Nationwide Health Insurance Claims Database and death certificates using ICD-10 codes.

RESULTS

Age- and sex-adjusted hazard ratios (HRs) for overall CVD events were significantly greater for subjects with prediabetes defined by FPG only (HR 1.19; 95% confidence interval [CI] 1.08-1.31), HbA1c only (HR 1.28; 95% CI 1.16-1.42), and combined criteria (HR 1.20; 95% CI 1.09-1.32) compared with the normoglycemic group. After adjusting for multiple conventional risk factors (e.g. hypertension, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, smoking status, family history of CVD, and BMI), the HRs for overall CVD were significantly increased only for participants with prediabetes defined by HbA1c. Age- and sex-adjusted HRs for major ischemic heart disease events were significantly increased for subjects with prediabetes defined either by HbA1c or combined criteria. Similarly, age- and sex-adjusted HRs for percutaneous coronary intervention were significantly higher for subjects with prediabetes defined by HbA1c only. For diabetes, the multivariate-adjusted HRs for all outcomes were significantly increased by all three criteria.

CONCLUSIONS

Adding an HbA1c criterion when defining prediabetes in Koreans can help identify individuals with an increased risk of CVD.