This systematic review and meta-analysis shows that diabetes mellitus (DM) is associated with mortality, severe COVID-19, acute respiratory distress syndrome (ARDS), and disease progression in patients with COVID-19.

The authors examined 6452 patients from 30 studies assessing DM, COVID-19, and outcomes including mortality, severe COVID-19, ARDS, need for intensive care unit (ICU) care, and disease progression. Their meta-analysis showed that DM was significantly associated with composite poor outcome (RR 2.38 [1.88, 3.03]), as well as mortality (RR 2.12 [1.44, 3.11]), severe COVID-19 (RR 2.45 [1.79, 3.35]), ARDS (RR 4.64 [1.86, 11.58]), and disease progression (RR 3.31 [1.08, 10.14]). Moreover, the association with composite poor outcome was positively influenced by age (p = 0.003) and hypertension (p < 0.001).

In subgroup analysis, the authors showed that the association was of DM and composite poor outcomes was weaker in studies with median age ≥55 years-old (RR 1.92) compared to <55 years-old (RR 3.48), and in prevalence of hypertension ≥25% (RR 1.93) compared to <25% (RR 3.06). Subgroup analysis on median age <55 years-old and prevalence of hypertension <25% showed strong association (RR 3.33).