Abstract MP46: Fasting Glucose Variability in Young Adulthood and Incident Diabetes, Cardiovascular Disease, and Mortality: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

Abstract

Introduction: Whether long-term variability in fasting glucose (FG) independent of incident diabetes mellitus (DM) is associated with incident cardiovascular disease (CVD) and mortality is unclear. Hypothesis: Higher variability of FG would be associated with higher risk for incident CVD and mortality as compared with lower FG variability, independent of increases in FG over time and the development of DM. Methods: We studied 4210 black and white CARDIA participants, ages 18 to 30 years (1985-1986) at baseline and calculated 2 measures of long-term glucose variability, the coefficient of variation about the mean (CV-FG) and the absolute difference between successive FG measurements (average real variability; ARV-FG) before the onset of DM. We estimated hazard ratios (HR) for incident CVD and mortality over 30 years of follow-up with adjustment for time-varying CVD risk factors. Results: There were 417 incident cases of DM, 195 incident CVD events (122,279 person-years) and 237 deaths (123,505 person-years). The HR for incident CVD per 1-standard deviation (1-SD) higher CV-FG was 1.24 (95% confidence interval [CI]: 1.08, 1.42) and for ARV-FG was 1.14 (95% CI: 1.01, 1.28) after adjustment for demographics, baseline FG, change in FG, and time-varying education, smoking, alcohol consumption, body mass index, physical activity, systolic blood pressure (BP), BP medications, low-density lipoprotein cholesterol, cholesterol medications, incident DM, and DM medications (Figure 1A and 1B). HRs for mortality were similar in magnitude for 1-SD ARV-FG (HR: 1.22, 95% CI: 1.10, 1.35) and slightly weaker for CV-FG (HR: 1.12, 95% CI:0.98, 1.27) after adjustment for time-varying CVD risk factors. The majority of mortality and the variability-mortality association was due to non-CVD mortality. Associations were similar in magnitude when restricted to individuals without incident DM. Conclusion: Higher intra-individual FG variability during young adulthood before the onset of DM was associated with incident CVD and mortality.