The prevalence of type 2 diabetes in patients with COVID-19: a systematic review and meta-analysis

Background. A strong link between morbidity and mortality from COVID-19 and diabetes mellitus is reported by many studies. The present study estimated the pooled prevalence of diabetes in patients with COVID-19. Material and methods. International scientific databases were searched until 15 April 2020. There was no limitation in time and language of the published papers. Quality assessment of studies was performed using the Newcastle-Ottawa Scale (NOS) checklist. The random effects model was used to report the pooled prevalence with 95% confidence interval (CI). Results. The pooled prevalence of diabetes in patients with COVID-19 was 14% (95% CI: 11.17). Due to high heterogeneity (I-2 of 93.4%, P < 0.001), three subgroups were analyzed based on study location, age and sex. The prevalence of diabetes (P) was higher among male patients (P = 16%, 95% CI: 0.12, 0.20), patients aged >= 65 years (P = 19%, 95% CI: 0.08, 0.31). The prevalence of diabetes was 15% (95% CI: 0.10, 0.20) among patients in Wuhan, China and 10% in patients in other cities in China (95% CI: 0.06, 0.15), and 39% in patients from other countries (95% CI: 0.04, 0.74). Conclusion. According to the results of this systematic review, the prevalence of diabetes in patients with COVID-19 is higher in other countries compared to China. The prevalence of diabetes among COVID-19 patients was also significantly higher in men and elderlies. This evidence may be useful for health policymakers to design suitable preventive and therapeutic interventions in patients with diabetes and COVID-19.