Association between baseline insulin resistance and hospital mortality in moderate to severe coronavirus disease 2019 patients without diabetes mellitus: An observational study

Background: Insulin resistance is often implicated as a risk factor of cell-mediated immune dysfunction in sepsis patients and results in poor clinical outcome. However, it is unclear whether early insulin resistance is contributory to T-cell dysfunction and poor clinical outcome in coronavirus disease 2019 (COVID-19) patients. Methods: Adult patients with moderate-to-severe or critically ill COVID-19 infection were included in this study. Serum samples were collected at the time of diagnosis for fasting plasma glucose, serum insulin, serum cortisol, and serum glucagon measurements, and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) score was calculated. Results: One hundred and twenty-six subjects with a mean (standard deviation) age of 49.6 (16.3) years were recruited in this study, and 62.4% (78 of 125 patients) were male. HOMA-IR was a predictor of inhospital mortality with the area under the receiver operating characteristics curve (AUROC) (95% confidence interval [CI] of 0.61 [0.49-0.73]). With a cutoff value of 1.91, sensitivity was 75.5% and specificity was 45.2%. Higher serum insulin was associated with higher survival with AUROC (95% CI) of 0.65 (0.53-0.76), and the best cutoff was 7.15, with a sensitivity and specificity of 62.1% and 64.5%. Serum cortisol was also a predictor of inhospital mortality with an AUROC (95% CI) of 0.67 (0.56-0.77). Conclusion: An independent association between baseline serum cortisol and poor outcome in moderate-to-severe COVID-19 patients was observed. Hyperglycemia and HOMA-IR can also predict poor outcome in these patients with some accuracy.