Acta Diabetologica

, Volume 52, Issue 5, pp 845–853 | Cite as

Incidence and risk factors for severe and symptomatic hypoglycemia in type 1 diabetes. Results of the HYPOS-1 study

  • Carlo B. Giorda
  • Alessandro Ozzello
  • Sandro Gentile
  • Alberto Aglialoro
  • Anna Chiambretti
  • Fabio Baccetti
  • Francesco M. Gentile
  • Giuseppe Lucisano
  • Antonio Nicolucci
  • Maria Chiara Rossi
  • HYPOS-1 Study Group of AMD
Original Article



Hypoglycemia is common in type 1 diabetes mellitus (T1DM). We aimed to update the incidence of severe and symptomatic hypoglycemia and investigate several correlated factors.


In this multicenter, observational retrospective study, the data of 206 T1DM patients from a sample of 2,229 consecutive patients seen at 18 diabetes clinics were analyzed. Sociodemographic and clinical characteristics, severe hypoglycemia in the past 12 months, and symptomatic hypoglycemia in the past 4 weeks were recorded with a self-report questionnaire and a clinical form during a routine visit. Poisson multivariate models were applied.


A minority of patients accounted for the majority of both severe and symptomatic episodes. The incidence rate (IR) of severe hypoglycemia was 0.49 (0.40–0.60) events/person-years. The incidence rate ratio (IRR) was higher in patients with previous severe hypoglycemia (3.71; 2.28–6.04), neuropathy (4.16; 2.14–8.05), long duration (>20 years, 2.96; 1.60–5.45), and on polypharmacy (1.24; 1.13–1.36), but it was lower when a complication was present. The IR of symptomatic hypoglycemia was 53.3 events/person-years, with an IRR significantly higher among women or patients with better education, or shorter duration or on pumps. The IRR was lower in patients with higher BMI or neuropathy or aged more than 50 years.


Fewer than 20 % of T1DM patients are free from hypoglycemia, with one in six having experienced at least one severe episode in the last year. The distribution is uneven, with a tendency of episodes to cluster in some patients. Severe and symptomatic episodes have different correlates and reflect different conditions.


Type 1 diabetes Hypoglycemia Incidence Risks factors 



This study was organized and funded by the AMD Foundation Rome, with an unrestricted grant from Novo Nordisk.

Conflict of interest

Carlo B Giorda, Alessandro Ozzello, Sandro Gentile, Alberto Aglialoro, Anna Chiambretti, Fabio Baccetti, Francesco M. Gentile, Giuseppe Lucisano, Antonio Nicolucci and Maria Chiara Rossi declare that they have no conflict of interest.

Ethical standard

This study was approved by Institutional Interdipartimental Ethics Committee S. Luigi Hospital of Orbassano, Italy.

Human and animal rights

All procedures were carried out in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 [5].

Informed consent

Informed consent was obtained from all patients for being included in the study.


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Copyright information

© Springer-Verlag Italia 2015

Authors and Affiliations

  • Carlo B. Giorda
    • 1
  • Alessandro Ozzello
    • 2
  • Sandro Gentile
    • 3
  • Alberto Aglialoro
    • 4
  • Anna Chiambretti
    • 5
  • Fabio Baccetti
    • 6
  • Francesco M. Gentile
    • 7
  • Giuseppe Lucisano
    • 8
  • Antonio Nicolucci
    • 8
  • Maria Chiara Rossi
    • 8
  • HYPOS-1 Study Group of AMD
  1. 1.Metabolism and Diabetes UnitASL TO5ChieriItaly
  2. 2.Departmental Service of Diabetology and Metabolic DiseasesASL TO3PineroloItaly
  3. 3.Department of Clinical and Experimental MedicineSecond University of NaplesNaplesItaly
  4. 4.Metabolism and Diabetes Unit Hospital St. MartinGenoaItaly
  5. 5.Metabolism and Diabetes UnitASL TO4ChivassoItaly
  6. 6.Metabolism and Diabetes UnitASL 1Massa CarraraItaly
  7. 7.Metabolism and Diabetes UnitASL di BariRutiglianoItaly
  8. 8.Laboratory of Clinical Epidemiology of Diabetes and Chronic DiseasesFondazione Mario Negri SudSanta Maria ImbaroItaly

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