Association of atrial fibrillation with diabetic nephropathy

Background: Many studies have provided evidence for an increased risk of atrial fibrillation among diabetic patients as compared to the nondiabetic population. It is also well known that diabetes predisposes a person to an increased risk of diabetic nephropathy. A few reviews and studies have hinted towards an increased risk of atrial fibrillation among diabetic nephropathy patients; however, there is no concrete evidence at present. Aim: To conduct a meta-analysis to explore if there is an association between diabetic nephropathy and atrial fibrillation. Methods: The available literature was searched for relevant studies from the period of January 1995 to November 2020. The following quality assessment criteria were considered for study shortlisting: clearly defined comparison groups, same outcome measured in both comparison groups, known confounders addressed, and a sufficiently long and complete (more than 80%) follow-up of patients. Two independent reviewers searched the databases, formed their search strategies, and finalized the studies. The data were analyzed to obtain a summary odds ratio along with a forest plot by Cochrane's RevMan 5.3. Results: Only four studies were found to meet the inclusion criterion for this meta-analysis (total number of study participants: 307330, diabetic nephropathy patients: 22855). Of these, two were retrospective cross-sectional studies, one was a prospective cohort study, and one was a case-control study. Three studies had provided the odds ratio as the measure of effect (two retrospective cross-sectional studies and one case-control study), with the one cohort study reporting the hazards ratio as the measure of effect. Therefore, the meta-analysis was done excluding the cohort study. The summary odds ratio in the present study was 1.32 (0.80-2.18), which was not statistically significant. Due to large heterogeneity among the included studies and their small sample sizes, it was found that the summary estimate shifted towards the null value. Conclusion: The present meta-analysis found no significant association between atrial fibrillation and diabetic nephropathy. However, more studies with large sample sizes are required to strengthen the evidence for an association.