Admission Glucose Number (AGN): A Point of Admission Score Associated With Inpatient Glucose Variability, Hypoglycemia, and Mortality.

Aims: We investigated a point of admission metric of glycemia, the Admission Glucose Number (AGN), and its relationship with both high risk inpatient glucose patterns and mortality in hospital inpatients with type 2 diabetes (T2DM).

Methods: Inpatient capillary blood glucose (CBG) data for patients with T2DM in our health board were identified for a 5-year period and associated with most recent preadmission HbA1c. AGN was calculated as first CBG measured during admission (mmol/L), subtracted from most recent preadmission HbA1c (converted to estimated median glucose mmol/l) within 15 months preadmission. The association between AGN and CBG variability (interquartile range), hypoglycemia free survival (HR) and both inpatient and 100-day mortality (HR) were investigated.

Results: A total of 21 045 first admissions with available HbA1c data were identified. A positive correlation between AGN and glycemic variability was described (partial correlation coefficient 0.25, P < .001), which was stronger than the correlation of either of AGNs' individual components: adjusted CBG1 = 0.07 ( P < .001), eAG = 0.08 ( P < .001). The hazard ratio for time to first recorded CBG < 3 mmol/L for high AGN versus low AGN was 1.74 (95% CI 1.55-1.96), P < .001. A high AGN was associated with increased 100-day mortality (HR 1.26, P = .005), however not with in-hospital mortality (HR = 1.31, P = .08).

Conclusion: AGN is a simple metric that combines 2 readily available measures associated with adverse outcome in T2DM. AGN may be a useful tool to stratify patients for risk of hypoglycemia and postdischarge death.