Global diabetes prevalence in COVID-19 patients and contribution to COVID-19-related severity and mortality: a systematic review and meta-analysis
BACKGROUND: COVID-19 and diabetes both contribute to large global disease burdens.
PURPOSE: To quantify the prevalence of diabetes in various COVID-19 disease stages and calculate the population attributable fraction (PAF) of diabetes to COVID-19-related severity and mortality
DATA SOURCES: Systematic review identified 729 studies with 29,874,938 COVID-19 patients.
STUDY SELECTION: Studies detailed the prevalence of diabetes in subjects with known COVID-19 diagnosis and severity.
DATA EXTRACTION: Study information, COVID-19 disease stages and diabetes prevalence were extracted.
DATA SYNTHESIS: The pooled prevalence of diabetes in stratified COVID-19 groups was 14.7% (95%CI: 12.5–16.9) among confirmed cases, 10.4% (7.6–13.6) among non-hospitalized cases, 21.4% (20.4–22.5) among hospitalized cases, 11.9% (10.2–13.7) among non-severe cases, 28.9% (27.0–30.8) among severe cases and 34.6% (32.8–36.5) among deceased subjects, respectively. Multivariate meta-regression analysis explained 53–83% heterogeneity of the pooled prevalence. Based on a modified version of the comparative risk assessment model, we estimated that the overall PAF of diabetes was 9.5% (7.3–11.7) for the presence of severe disease in COVID-19 individuals and 16.8% (14.8–18.8) for COVID-19-related deaths. Subgroup analyses demonstrated that countries with high-income levels, high healthcare access and quality index (HAQ) and low diabetes disease burden had lower PAF of diabetes contributing to COVID-19 severity and death.
LIMITATIONS: Most studies had a high risk of bias.
CONCLUSIONS: The prevalence of diabetes increases with COVID-19 severity and diabetes accounts for 9.5% of severe COVID-19 cases and 16.8% of deaths, with disparities according to country income, HAQ, and diabetes disease burden.