CARDIOVASCULAR DISEASE RISK AMONG PERSONS WITH NORMOGLYCEMIA AND PREDIABETES

Background: Several studies have shown that elevated blood glucose concentrations below the diabetes threshold, is associated with macrovascular complications. We therefore aimed to develop a tool for predicting incident fatal- or non-fatal cardiovascular disease (CVD) in a Danish study population with normoglycemia and prediabetes, defined by HbA1c. Methods: We included all participants with an HbA1c measurement <48 mmol/mol (6.5%) at the 5-year follow-up visit in the Inter99 study. We defined prediabetes according to the ADA criteria of HbA1c levels ≥39 mmol/mol (5.7%). Outcome was incident fatal- or non-fatal CVD during follow-up. We evaluated self-reported dietary and physical activity habits, smoking, alcohol consumption, antihypertensive- and lipid-lowering medication, clinical measurements (including fasting and 2-hour plasma glucose and HbA1c), anthropometrics, family history of diabetes and/or CVD, and socio-demographic factors. We used random forest and survival tree analysis (data driven approach) to identify potential risk factors and interactions to include in the final prediction model. We then fitted a Poisson model with all significant risk factors and interactions for CVD using backwards selection. We used multiple imputations for missing data and split the follow-up time into 1-year age bands. Results: We included 4046 participants of which 225 developed CVD during follow-up. Median follow-up time was 7.5 years (IQR: 7.0-8.1). We found an interaction between age and prediabetes status, with prediabetes lowering the effect of age. The predictive factors of the final model are listed in Table 1. The area under the curve for the prediction model was 0.71 (95%CI: 0.67-0.75). Conclusions: Traditional risk factors for CVD were identified. Having prediabetes increased the risk of CVD markedly and modified the effect of age.