Risk analysis of PR interval prolongation in type 2 diabetes mellitus

Objective To evaluate the relationship between PR interval prolongation and diabetic retinopathy (DR), diabetic kidney disease (DKD) and carotid intima-media thickness (CIMT). Methods A total of 857 inpatients with type 2 diabetes mellitus (T2DM), from May 2014 to March 2016 at the Department of Endocrinology and Metabolism of Xijing Hospital affiliated to the Fourth Military Medical University were selected and divided into two groups according to their electrocardiogram results: PR≤ 200 ms (Group 1, n=812) and PR>200 ms (Group 2, n=45). The demographic data and biochemical markers including the age, gender, diabetic duration, fasting blood glucose (FPG), blood lipid, albumin creatinine rate, glomerular filtration rate and the prevalence of DR, prevalence of DKD, prevalence of CIMT were compared and analyzed among two groups. Statistical comparisons were performed using the Student t test or Nonparametric Tests. Logistic regression analysis were used to study the influencing factors for PR interval prolongation. Results The mean PR interval of all patients was (162±23) ms. The prevalence of DR and DKD in patients with PR>200 ms were significantly more than those in patients with PR≤200 ms (69% vs 39%, 46.7% vs 23.4%, χ2=15.75,12.44, all P<0.01). Logistic regression analysis showed that the risk of PR interval prolongation for T2DM patients with DR was 2.168 times higher than those with non-DR (OR=2.168, 95%CI 1.055-4.455, P<0.05), and the risk of PR interval prolongation for T2DM patients with DKD was 2.317 times higher than those with non-DKD (OR=2.317, 95%CI 1.160-4.628, P<0.05), PR interval length was not correlated with CIMT in T2DM patients. Conclusion PR interval length is positively correlated with DR, and DKD, but no correlated with CIMT in type 2 diabetic patients. Key words: Diabetes mellitus, type 2; PR interval; Diabetic retinopathy; Diabetic kidney disease; Carotid intima-media thickness