Objective: To assess the effect of spontaneous nocturnal hypoglycemia on quality of life and mood the subsequent days in type 1 diabetes.

Research Design and Methods: A total of 153 persons with type 1 diabetes participated in 6 days of blinded continuous glucose monitoring (CGM) while daily documenting hypoglycemic symptoms, quality of life and mood. Hypoglycemia was defined by interstitial glucose ≤ 70 mg/dl (IG70) and ≤ 54 mg/dl (IG54) for > 15 minutes and was classified as asymptomatic if no hypoglycemic symptoms were reported in the diary.

Results: Self-estimated quality of life assessed by the EQ-5D VAS (but not by the WHO Well-Being Index) was higher the day after an asymptomatic (but not after a symptomatic) hypoglycemic night as compared with non-hypoglycemic nights (IG70: p = 0.021 and IG54: p = 0.048). The effect increased with longer duration and lower glucose nadir of nocturnal hypoglycemia (IG70: p = 0.04). The finding was confined to participants with reduced hypoglycemia awareness. There was no effect on mood of nocturnal hypoglycemia.

Conclusions: Individuals with type 1 diabetes and impaired awareness report higher quality of life following nights with asymptomatic - but not symptomatic - hypoglycemia. The effect was amplified by lower glucose nadir and longer duration of the episodes and may contribute to explain resistance to implementation of interventions against hypoglycemia in many people with impaired hypoglycemia awareness.


M.M. Henriksen: None. H.U. Andersen: Advisory Panel; Self; Abbott Laboratories, AstraZeneca, Novo Nordisk A/S. Speaker's Bureau; Self; Nordic Infucare. Stock/Shareholder; Self; Novo Nordisk Inc. B. Thorsteinsson: None. U. Pedersen-Bjergaard: Advisory Panel; Self; AstraZeneca, Sanofi-Aventis, Zealand Pharma A/S. Speaker's Bureau; Self; Novo Nordisk A/S.


Nordsjællands Hospital; Jascha Foundation; Danish Medical Research Grant; The Toyota Foundation, Denmark

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