Glycemic Gap Predicts Mortality in a Large Multicenter Cohort Hospitalized With COVID-19

Abstract

Purpose Diabetes or hyperglycemia at admission are established risk factors for adverse outcomes during hospitalization for COVID-19, but the impact of prior glycemic control is not clear. Methods We examined the relationship between clinical predictors including acute and chronic glycemia and clinical outcomes including ICU admission, mechanical ventilation (MV), and mortality among 1,786 individuals with diabetes or hyperglycemia (glucose > 10 mmol/l twice in 24 hrs.) admitted from March 2020 through February 2021 with COVID-19 infection at 5 university hospitals in the eastern U.S. Results The cohort was 51.3% male, 53.3% White, 18.8% Black, 29.0% Hispanic, with age = 65.6 ± 14.4 yrs., BMI = 31.5 ± 7.9 kg/m2, glucose = 12.0 ± 7.5 mmol/l [216 ± 135 mg/dl], and HbA1c = 8.07 ± 2.25%. During hospitalization, 38.9% were admitted to the ICU, 22.9% received MV, and 10.6% died. Age (p < 0.001) and admission glucose (p = 0.014) but not HbA1c were associated with increased risk of mortality. Glycemic gap, defined as admission glucose minus estimated average glucose based on HbA1c, was a stronger predictor of mortality than either admission glucose or HbA1c alone (OR = 1.040 [95% CI: 1.019, 1.061] per mmol/l, p < 0.001). In an adjusted multivariable model, glycemic gap, age, BMI, and diabetic ketoacidosis on admission were associated with increased mortality, while higher eGFR and use of any diabetes medication were associated with lower mortality (p < 0.001). Conclusions Relative hyperglycemia, as measured by the admission glycemic gap, is an important marker of mortality risk in COVID-19.

Predictors of readmission and mortality in adults with diabetes or stress hyperglycemia after initial hospitalization for COVID-19

“…Our consortium previously reported a mortality rate of 10.6% during initial hospitalization in this cohort, with advanced age and elevated glycemic gap being predictors of mortality. 1 Use of any diabetes medications was associated with lower mortality. 1 Our readmission cohort had a mortality rate of 8.0%.…”

“… 1 Use of any diabetes medications was associated with lower mortality. 1 Our readmission cohort had a mortality rate of 8.0%. The small number of deaths in the readmission sample, however, limited our ability to reliably identify risk factors for mortality on readmission.…”

“…Data were collected locally through retrospective reviews of electronic medical records, entered into a Research Electronic Data Capture (REDCap) web-based repository, and de-identified data were analyzed as previously described. 1 Data coordination was performed by investigators at Brigham and Women’s Hospital. 1 The Institutional Review Boards for the Protection of Human Subjects at each institution considered this study “exempt” and not requiring informed consent.…”

“… 1 Data coordination was performed by investigators at Brigham and Women’s Hospital. 1 The Institutional Review Boards for the Protection of Human Subjects at each institution considered this study “exempt” and not requiring informed consent.…”

“…Our consortium previously reported that older age, elevated glycemic gap, higher body mass index (BMI), and diabetic ketoacidosis (DKA) were associated with higher mortality in adults with diabetes or stress hyperglycemia (SH) admitted with COVID-19. 1 Little is known, however, about predictors of readmission after an initial admission due to COVID-19 in adults with diabetes. Our primary objective was to determine predictors of 30-day readmission in our cohort of adults with diabetes or SH initially hospitalized with COVID-19.…”