Objective: To investigate the association between admission blood glucose levels and the risk of in-hospital cardiovascular and renal complications.

Research Design and Methods: A multicentre, prospective cohort study of 36269 adults hospitalised with COVID-19 between 6th February 2020 and 16th March 2021. Logistic regression models explored associations between admission glucose level (mmol/l) and odds of in-hospital heart failure, arrhythmia, cardiac ischaemia, cardiac arrest, coagulation complications, stroke and renal injury. Non-linear associations were investigated using restricted cubic splines. Interaction models further explored whether associations between glucose levels and complications were modified by several clinically relevant characteristics (age, sex, ethnicity, diabetes status).

Results: Cardiovascular and renal complications occurred in 10421 (28.7%) patients; median glucose level on admission was 6.7 mmol/l (IQR:5.8, 8.7) (120.6 mg/dL (104.4, 156.6)). Accounting for confounders, for all outcomes except cardiac ischaemia and stroke there was a non-linear association between glucose and cardiovascular and renal complications. For example the odds of experiencing heart failure, arrhythmia, coagulation complications and renal injury decreased to a nadir at 6.4 (115 mg/dL), 4.9 (88.2 mg/dL), 4.7 (84.6 mg/dL) and 5.8 (104.4 mg/dL) mmol/l, respectively and increased thereafter until 26.0 (468 mg/dL), 50.0 (900 mg/dL), 8.5 (152 mg/dL), and 32.4 (583.2 mg/dL) mmol/l. Compared to 5 mmol/l (90 mg/dL), the odds ratios at these glucose levels were 1.28 (95% CI: 0.96, 1.69) for heart failure, 2.23 (95% CI: 1.03, 4.81) for arrhythmia, 1.59 (95% CI: 1.36, 1.86) for coagulation complications and 2.42 (95% CI: 2.01, 2.92) for renal injury.. For most complications, evidence for a modifying effect of age was observed, with higher odds of experiencing complications at higher glucose levels for patients younger than 69 years. Pre-existing diabetes status had a similar modifying effect on the odds of experiencing a complication, but evidence was strongest for renal injury, cardiac ischaemia and ‘any cardiovascular/renal complication’.

Conclusions: Increased odds of cardiovascular or renal complications were observed for admission glucose levels indicative of both hypo- and hyperglycaemia. In light of findings of increased odds of complications at both high and low glucose levels, optimising glycaemic control is recommended to ameliorate the prognosis for COVID-19 patients.


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Cite as

Norris, T., Razieh, C., Yates, T., Zaccardi, F., Gillies, C., Chudasama, Y., Rowlands, A., Davies, M., McCann, G., Banerjee, A., Docherty, A., Openshaw, P., Baillie, J., Semple, M., Lawson, C., Khunti, K. & ISARIC4C Investigators 2022, 'Admission blood glucose level and its association with cardiovascular and renal complications in patients hospitalised with COVID-19: glucose, cardiovascular outcomes and COVID-19', Diabetes Care, article no: dc211709. https://doi.org/10.2337/dc21-1709

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Last updated: 25 July 2023
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