Effects of glycemic control on COVID-19 outcomes in patients with diabetes mellitus

Objective

Diabetes mellitus is reportedly associated with mortality, intensive care unit (ICU) admission, and other poor outcomes in COVID-19 patients. Although there have been studies examining the relationship between glycemic control and COVID-19 outcome in other countries, there have been few reports from Japan. This study aims to clarify the relationship between outcome and glycemic control in COVID-19 patients with diabetes.

Methods

A single-center retrospective cohort study was conducted for COVID-19 patients with diabetes who were admitted to St. Luke's International Hospital. We analyzed the association between inpatient glycemic control status and death and intensive care unit (ICU) admission as primary endpoints, and the periods of hospitalization as a secondary endpoint.

Results

Of the 275 patients, 37 were in the poor outcome group who died or were admitted to the ICU; these patients had a significantly higher mean blood glucose level during hospitalization (164.3 [100-343] mg/dL) than the 238 patients in the good outcome group (123.4 [69-401] mg/dL, p<0.001). The mean blood glucose cutoff for the two groups was 122.2 mg/dL. A multivariate logistic regression analysis showed a significant association between a higher mean blood glucose level and a poor outcome (odds ratio [OR]: 14.0, 95% confidence interval [CI]: 1.73-114, p<0.05). Furthermore, patients with a lower mean blood glucose level of <122.2 mg/dL had a significantly shorter periods of hospitalization (7.5 [7-8] days) than those with a higher level of ≥122.2 mg/dL (11.0 [9-13] days, p<0.001).

Conclusion

A lower mean blood glucose level during hospitalization was associated with significantly lower mortality and ICU admission rates and shorter periods of hospitalization.