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Association of severe hypoglycemia with mortality for people with diabetes mellitus during a 20-year follow-up in Denmark: a cohort study



Severe hypoglycemia has a significant deteriorating effect on quality of life of the individual and has been associated with increased mortality. The aim of this study was to investigate the mortality among people with type 1 and type 2 diabetes suffering from severe hypoglycemia in Denmark in the last two decades.


People diagnosed with type 1 (n = 44,033) and type 2 diabetes (n = 333,581) were extracted from the complete population of Denmark from 1996 to 2017 via ICD-10 diabetes codes and ATC diabetes medication codes. People suffering from severe hypoglycemia (type 1 diabetes n = 8808, type 2 diabetes n = 5605) as identified from ICD-10 codes were then matched 1:1 by year of birth, gender and year of diabetes diagnosis with those without severe hypoglycemia. Cox proportional hazards models were constructed to analyze the effect of severe hypoglycemia on mortality.


For both people with type 1 (HR 1.11, CI 95% 1.06 to 1.17) and type 2 diabetes (HR 1.77, CI 95% 1.67 to 1.87) suffering from hypoglycemia, an increased mortality risk was observed, compared to people without severe hypoglycemia. An investigation of the death causes did not indicate an association between the severe hypoglycemic episodes and death.


In this study, severe hypoglycemic episodes increased the mortality risk for people with type 1 and type 2 diabetes. The risk was higher among people with type 2 diabetes. Whether severe hypoglycemia is a symptom of other underlying illnesses increasing mortality risk or a risk factor itself needs further investigation.

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This study was not funded.

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Corresponding author

Correspondence to Morten Hasselstrøm Jensen.

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Conflict of interest

Author Vestergaard has received unrestricted Grants from MSD and Servier and travel grants from Amgen, Eli Lilly, Novartis, Sanofi Aventis and Servier. Auther Dethlefsen is employed at Novo Nordisk A/S. Author Jensen is former employee at Novo Nordisk A/S and holds shares in the company.

Ethical approval

All data was handled in accordance with the General Data Protection Regulation (EU) 2016/679. No ethical approval is necessary in Denmark when handling registry data only.

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For this study, formal consent was not required.

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Jensen, M.H., Dethlefsen, C., Hejlesen, O. et al. Association of severe hypoglycemia with mortality for people with diabetes mellitus during a 20-year follow-up in Denmark: a cohort study. Acta Diabetol 57, 549–558 (2020).

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  • Severe hypoglycemia
  • Mortality
  • Type 1 diabetes
  • Type 2 diabetes
  • Denmark