Low normal fasting glucose and risk of accidental death in Korean adults: A prospective cohort study.

AIM: This study aimed to prospectively examine whether low normal glucose levels and hypoglycaemia are associated with increased mortality due to external causes, especially unintentional accidents.

METHODS: A total of 345,318 normoglycaemic Korean adults who had undergone health examinations during 2002-2003 were followed-up to 2013. To avoid potential biases related to glucose-lowering medication use, those with known diabetes or hyperglycaemia were excluded.

RESULTS: During 3.6 million person-years of follow-up, 1293 participants died because of unintentional accidents. Hazard ratios (HRs) for these accidental deaths were 1.26 (95% CI: 1.11-1.42), 1.60 (1.21-2.11) and 3.07 (1.37-6.85) for fasting serum glucose (FSG) levels of 70-79, 55-69 and <55mg/dL (3.9-4.4, 3.05-3.83 and <3.05mmol/L), respectively, compared with 80-99mg/dL (4.44-5.5mmol/L). FSG levels<80mg/dL were associated with an approximately 30% higher mortality due to accidents: specifically, 40% were non-fall-related injury; 50% were automobile-related; and 80% were motorcycle-related. The associations were weak (approximately 10% higher mortality, with P>0.05 for each cause) for deaths due to traffic accidents (pedestrians, pedal cyclists), falls, intentional self-harm and physical assault. The population attributable risks for FSG levels <80mg/dL were 10% (95% CI: 2-18%) for non-fall-related injury, 11% (6-17%) for car accidents and 17% (6-27%) for motorcycle accidents.

CONCLUSION: FSG levels of 70-79mg/dL (3.9-4.4mmol/L) as well as <70mg/dL are risk factors for accidental death. Appropriate management of the impact of FSG levels <80mg/dL might reduce unintended deaths due to non-fall-related injury, and automobile and motorcycle accidents, by ≥10%.