Strong independent association between third-degree AV-block and diabetes mellitus using a large database

Background Recent data suggests an association between DM and third-degree AV- Block. The goal of this study was to evaluate the independent association between diabetes and third-degree AV-Block using a very large database. Method We used ICD-9 Codes for DM and third-degree AV-block from the Nationwide Inpatient Sample (NIS) database. We randomly selected the 1992 and 2002 databases which are 10 years apart as two independent samples. We used uni- and multi-variate analysis to evaluate this association. Results 1992 database contained a total of 6,195,744 patients. Diabetes occurred in (0.5%) of patients with third-degree AV-block vs. (0.2%) of the control (OR: 2.15, CI 2.06-2.25, p<0.0001). 2002 database contained a total of 7,853,982 patients. Diabetes occurred in (0.4%) of patients with third-degree AV-block vs. (0.2%) of the control (OR: 1.86, CI: 1.80-1.93, p<0.0001). Using Multivariate analysis adjusting for age, congestive heart failure, and coronary artery disease, DM remained independently associated with third-degree AV block in both databases. (for 1999: OR: 2.54, CI 2.51-2.57, p<0.0001 and for 2002 OR: 1.56, CI 1.55-1.57, p<0.0001) Conclusion DM is independently associated with third-degree AV-block with persistent association over a period of 10 years. The cause of this association warrants further investigation.