Abstract
BACKGROUND: Dysglycaemia is associated with overall cardiovascular disease even at prediabetes levels. The aim of this study was to explore the association between glucose levels and future risk of developing atrial fibrillation and heart failure, respectively. METHODS: In this prospective cohort study subjects from the Swedish AMORIS-cohort with fasting glucose from health examinations 1985-1996 without previous cardiovascular disease (N = 294,057) were followed to 31 December 2011 for incident atrial fibrillation or heart failure. Cox proportional hazard models with attained age as timescale and adjustments for sex, cholesterol, triglycerides, and socioeconomic status were used to estimate hazard ratios by glucose categorized groups (normal glucose 3.9-6.0 mmol/L, impaired fasting glucose; 6.1-6.9 mmol/L, undiagnosed diabetes ≥ 7.0 mmol/L, and diagnosed diabetes). RESULTS: During a mean follow-up time of 19.1 years 28,233 individuals developed atrial fibrillation and 25,604 developed heart failure. The HR for atrial fibrillation was 1.19 (95% confidence interval 1.13-1.26) for impaired fasting glucose, 1.23 (1.15-1.32) for undiagnosed diabetes and 1.30 (1.21-1.41) for diagnosed diabetes. Corresponding figures for heart failure were; 1.40 (1.33-1.48), 2.11 (1.99-2.23), 2.22 (2.08-2.36) respectively. In a subset with BMI data (19%), these associations were attenuated and for atrial fibrillation only remained statistically significant among subjects with diagnosed diabetes (HR 1.25; 1.02-1.53). CONCLUSIONS: Fasting glucose at prediabetes levels is associated with development of atrial fibrillation and heart failure. To some extent increased BMI may drive this association.