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).

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.

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 eGFR_CKD-EPI < 30 mL/min/1.73 m², eGFR_CKD-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 eGFR_CKD-EPI 89–60, eGFR_CKD-EPI 59–30 and eGFR_CKD-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).

Decreasing eGFR is independently associated with an increased risk of cardiac conduction defects in hospitalized patients with T2DM.