Patients with diabetes are at higher risk of developing severe COVID-19 infection with a two-fold increased risk of mortality. This study described the risk factors affecting clinical outcomes of confirmed COVID-19 patients with diabetes mellitus at the University of Santo Tomas Hospital, Manila, Philippines.

This retrospective study included 204 patients with COVID-19 (34 with known type 2 diabetes and 2 with new-onset diabetes) from March to October 2020. Clinical characteristics and laboratory parameters were collected and analyzed in subjects with diabetes. A univariate logistic regression was used to calculate the odds ratios and 95% confidence interval (CI) for the patient’s risk factors associated with mortality or poor prognosis.

Moderate COVID-19 infection occurred in 52.8% of type 2 diabetes mellitus (T2DM) patients and critical COVID-19 infection in 27.8%. All patients with critical COVID-19 infection presented with acute respiratory distress syndrome, half had concomitant septic shock and respiratory failure was observed in 27.8%. The average length of hospital stay was approximately 17.5 days. T2DM patients with established atherosclerotic cardiovascular disease (ASCVD) are 5.1 times (95% CI 1.2 to 21.4) more likely to develop severe or critical COVID-19 infection, and more likely to stay in the hospital for more than 14 days. HbA1c >8.5% is a potential risk (OR = 3.7, 0.6 to 21.6) for severe to critical disease. T2DM patients with concomitant coronary artery disease are 7.6 times (95% CI 1.3 to 43.4) more likely to stay longer (more than 14 days) as compared to those without existing coronary artery disease. Prior statin use was a significant risk factor for ICU admission (p-value 0.0341). Other potential risk factors affecting clinical outcomes are obesity (OR 3, 0.4 to 22.7), prior use of thiazolidinedione (OR 7.8, 0.5 to 126.7) or sodium-glucose transporter 2 (SGLT2) inhibitors (OR 7.5, 0.4 to 145) and prior use of anti-thrombotic (OR 4.6, 0.4 to 56.8). The recovery rate of T2DM patients hospitalized for COVID-19 infection was 86.1%.

Patients with T2DM are more vulnerable to COVID-19 infection. The presence of established ASCVD increases the likelihood of severe COVID-19 disease as well as longer length of hospital stay for more than 14 days. Early recognition and prompt treatment led to a favorable recovery rate.