Incidence of conduction disturbances in patients with diabetes mellitus: a comparison with age- and sex matched controls from a nationwide observational study

Abstract Background There are uncertainties about diabetes mellitus and the incidences of conduction disturbances regarding their different locations (sinus node disease [SND], atrio-ventricular block located above the His bundle or of infra-Hisian location) and their possible relation to the type of diabetes. We investigated whether diabetes confers higher relative rates of conduction disturbances, and whether this may depend on the type 1 (T1DM) or type 2 (T2DM) of diabetes mellitus. Methods All patients aged ≥18 seen in French hospitals in 2013 with at least 5 years of follow-up were identified and categorized by their diabetes status. A total of 77,499 patients with T1DM (age 60.9±18.3, 52% male) and 506,937 patients with T2DM (age 67.1±14.6, 54% male) were identified. They were matched 1:1 on age and sex with patients with no diabetes and followed over a mean period of 4.3±2.1 years (median 5.3, interquartile 2.8-5.8 years). We calculated incidence rates, incidence rate ratios and adjusted hazard ratios in patients with T1DM and T2DM (compared to age- and sex-matched controls with no diabetes) for the different types of conduction disturbances and for the need of treatment with cardiac implantable electronic device (CIED) such as pacemakers or implantable cardioverter defibrillators (ICD). Hazard ratios were adjusted for comorbidities known or suggested to be directly or indirectly associated with conduction disturbances and for those associated with a high mortality rate and less likely to reach high age with development of conduction disturbances or the need of CIED during follow-up. Results During 3,271,832 million person-years of follow-up, 126,217 patients with new-onset conduction disturbances or CIED implantation were identified. The incidence rates of conduction disturbances were higher in T1DM and T2DM patients than in control patients with no diabetes. This was seen for all-types of conduction disturbances: SND, atrioventricular block, left bundle branch block and right bundle branch block. Treatment with CIEDs were also more frequent in T1DM or T2DM patients than in control patients with no diabetes (see table). The independent associations of T1DM and T2DM with atrioventricular block, right or left bundle branch block and CIED implantation persisted in the multivariable analyses (adjusted HRs ranging from to 1.11 to 1.44, all p<0.0001). Conclusion In this large nationwide study, T1DM and T2DM were both associated with a higher rate of conduction disturbances and CIED implantations compared with age- and sex-matched controls. T1DM and T2DM remained independently associated with AV block after adjustment on comorbidities known to be positively or inversely associated with SND, atrioventricular block or CIED implantation. This also included a higher incidence or left and right bundle branch block, suggesting that the mechanism may not only be related to the influences of the autonomic nervous system or to the use of bradycardic agents.