Diabetes and Mortality among Patients with Chronic Kidney Disease and COVID-19: A Systematic Review, Meta-analysis, and Meta-regression

INTRODUCTION: Patients with kidney disease and COVID-19, whether on hemodialysis (HD) or not, have a higher risk of contracting COVID-19 accompanied by a higher mortality rate due to suppressed immune functions. Diabetes, one of the ubiquitous etiology of kidney disease, is also associated with a composite of poor outcomes. METHODS: Meta-analysis and meta-regression of 13 articles on COVID-19 patients with chronic kidney disease, with information on diabetes and mortality were performed using Review Manager 5.4 and OpenMetaAnalyst. RESULTS: The meta-analysis of a pooled subject of 18,822 patients showed that the presence of diabetes in CKD patients with COVID-19 was associated with an increased risk of mortality (RR 1.41 (1.15, 1.72); P < 0.001; I2 70%, P < 0.001). Subgroup analysis showed that diabetes was not associated with mortality in the HD group (RR 1.27 (1.06, 1.54); P = 0.01; I2 0%, P = 0.70) but showed a significant association in the non-HD group (RR 1.66 (1.59, 1.73); P < 0.001; I2 85%, P < 0.001). Male gender (P = 0.070) contributed to the effect size differences (age: P < 0.001; hypertension: P = 0.007; CVD: P < 0.001; lung disease: P < 0.001). CONCLUSIONS: Diabetes was associated with higher mortality risk among CKD patients, primarily those who did not need RRT.