The association between glycaemic control during hospitalization and risk of adverse events: A retrospective cohort study

INTRODUCTION: Hyperglycaemia is common during hospitalization; glycaemic targets in non‐critical care settings have not been well studied. We assessed associations between inpatient glycaemic control and adverse events. METHODS: We conducted a retrospective cohort study on non‐critically ill medical patients hospitalized in a tertiary care hospital between 2015 and 2018. Mean glycaemia during the first four days of hospitalization was categorized as 4.0–7.0 mmol/L, 7.1–10.0 mmol/L and >10.0 mmol/L. The primary outcome was a composite of adverse events including mortality, infections, acute kidney injury, thromboembolic and cardiovascular events. The secondary outcome was hypoglycaemia, defined as any glycaemia <4.0 mmol/L. Logistic regression was used to assess adverse events, and a Cox proportional hazards model was used to estimate hypoglycaemia risk. RESULTS: Our cohort included 1,368 patients, of whom 407 (29.8%) experienced an adverse event. We did not find associations between glycaemia of 4.0–7.0 mmol/L (adjusted odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.63–1.23) or glycaemia of >10.0 mmol/L (adjusted OR: 0.98, 95% CI: 0.75–1.28) and the occurrence of adverse events, compared to a glycaemia of 7.1–10.0 mmol/L. Glycaemia of >10.0 mmol/L was associated with an increased risk of hypoglycaemia (adjusted hazard ratio [HR]: 1.72, 95% CI: 1.21–2.45). Hypoglycaemia was associated with adverse events (adjusted OR 1.85, 95% CI 1.31–2.60). CONCLUSIONS: Neither glycaemia of 4.0–7.0 mmol/L nor glycaemia of >10.0mmol/L during non‐critical care hospitalization was associated with increased adverse events. Glycaemia of >10.0 mmol/L was associated with increased hypoglycaemia, likely due to aggressive glucose lowering. These findings highlight the need for further studies to discern optimal inpatient glycaemic targets.