Glucose levels at hospital admission are associated with 5 year mortality

Aim: We aimed to determine if hospital admission hyperglycaemia and hypoglycaemia are associated with increased long-term mortality. 

Methods: A post-hoc analysis of data from a trial of glucose screening in the emergency department was conducted. Data were linked with a death registry up to 5 years after admission. The relationship between admission glucose and mortality was examined by cox regression. Further analyses of people who survived the admission and subsequent 28 days was performed. 

Results: There were 131,322 patients, of whom 38,712 (29.5 %) died. Mean follow-up was 3·3 ± 1·5 years. Compared to the reference glucose band of 6·1-8·0 mmol/L, there was increased mortality in higher bands, reaching a hazard ratio (HR) of 1·44 (95 %CI 1·34-1·55, p < 0·001) for people with glucose > 20·0 mmol/L. The HR was 1·56 (95 %CI 1·46-1·68, p < 0·001) for people with glucose ≤ 4·0 mmol/L. Similar relationships were observed among 28-day survivors. The relationships were attenuated among people with known diabetes. Among 4867 subjects with glucose ≥ 14·0 mmol/L, those diagnosed with diabetes during the admission had lower mortality compared to subjects where the diagnosis was not made (HR 0·53, 95 %CI 0·40-0·72, p < 0·001). This was attenuated among 28-day survivors. 

 Conclusion: Hyperglycaemia and hypoglycaemia on hospital admission are associated with increased long-term mortality.