Association between decreasing estimated glomerular filtration rate and risk of cardiac conduction defects in patients with type 2 diabetes

AIM: We aimed to assess the association between decreasing estimated glomerular filtration rate (eGFR) or abnormal albuminuria and the risk of certain cardiac conduction defects in patients with type 2 diabetes mellitus (T2DM). METHODS: We examined a hospital-based sample of 923 patients with T2DM discharged from our Division of Endocrinology over the years 2007-2014. Standard electrocardiograms (ECGs) were performed in all patients. eGFR was estimated by using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, whilst albuminuria was measured by an immuno-nephelometric method on morning spot urine samples. RESULTS: A total of 253 (27.4%) patients had some type of cardiac conduction defects on standard ECGs (defined as at least one heart block among first-degree atrioventricular block, second-degree block, third-degree block, left bundle branch block, right bundle branch block, left anterior hemi-block or left posterior hemi-block). Prevalence of patients with eGFRCKD-EPI < 30 mL/min/1.73 m2, eGFRCKD-EPI 59-30 mL/min/1.73 m2 or abnormal albuminuria (i.e. urinary albumin-to-creatinine ratio ≥ 30 mg/g) were 7.0%, 29.4% and 41.3%, respectively. After adjustment for known cardiovascular risk factors, diabetes-related variables and potential confounders, there was a significant, graded association between decreasing eGFR values and risk of any cardiac conduction defects [adjusted-odds ratios of 2.05 (95% CI: 1.2-3.5), 2.85 (95% CI: 1.6-5.1) and 3.62 (95% CI: 1.6-8.1) for eGFRCKD-EPI 89-60, eGFRCKD-EPI 59-30 and eGFRCKD-EPI < 30 mL/min/1.73 m2, respectively]. Conversely, abnormal albuminuria was not independently associated with an increased risk of any conduction defects (adjusted-odds ratio: 1.09, 95% CI: 0.7-1.6). CONCLUSION: Decreasing eGFR is independently associated with an increased risk of cardiac conduction defects in hospitalized patients with T2DM.