HbA1c and atrial fibrillation: a cross-sectional study in Japan

Background: The aim of the present study was to investigate whether the prevalence of atrial fibrillation (AF) is associated with the level of glycated hemoglobin (HbA1c) in Japanese adults in Kurashiki-city.

Methods: Adult residents (≧ 40 years old) were examined twice, in 2006 and 2007. Electrocardiography was conducted to determine the presence of AF. After categorizing all participants into two groups (HbA1c <6.5% as low group and ≧ 6.5% as high group), factors independently associated with the prevalence of AF were investigated in total cohort, low and high groups using multivariate logistic regression analysis.

Results: Of the total 52,448 participants (median age, 72 years; range, 65-78 years; 17,980 men), AF prevalence was 2.2% (1161/52,448). After classifying all participants by HbA1c level, the proportion of participants with AF was 2.2% (1073/49,498) in the low group and 3.0% (88/2950) in high group (p=0.005). AF was significantly associated with cardiac disease (OR, 5.78; 95%CI, 5.07-6.58; p<0.001), elevating HbA1c (OR, 1.57; 95%CI, 1.33-1.84; p<0.001), increasing age (OR, 1.40; 95%CI, 1.30-1.51; p<0.001), and male sex (OR, 1.27; 95%CI, 1.10-1.47; p=0.001) in low group and was related to cardiac disease (OR, 4.85; 95%CI, 3.08-7.62; p<0.001) and age (OR, 1.45; 95%CI, 1.09-1.93; p=0.010) in high group. After adjusted age, gender, vascular risk factors, cardiac disease, and eGFR, elevating HbA1c (OR, 1.18; 95%CI, 1.09-1.28; p<0.001) was the factor in association with AF.

Conclusions: The presence of AF appears to be associated with the level of HbA1c, especially in patients with HbA1c <6.5%.