RESUMO
AIMS/HYPOTHESIS: Attenuated counterregulation after recurrent hypoglycaemia is a major complication of diabetes treatment. As there is previous evidence for the relevance of sleep in metabolic control, we assessed the acute contribution of sleep to the counterregulatory adaptation to recurrent hypoglycaemia. METHODS: Within a balanced crossover design, 15 healthy, normal-weight male participants aged 18-35 years underwent three hyperinsulinaemic-hypoglycaemic clamps with a glucose nadir of 2.5 mmol/l, under two experimental conditions, sleep and sleep deprivation. Participants were exposed to two hypoglycaemic episodes, followed by a third hypoglycaemic clamp after one night of regular 8 h sleep vs sleep deprivation. The counterregulatory response of relevant hormones (glucagon, growth hormone [GH], ACTH, cortisol, adrenaline [epinephrine] and noradrenaline [norepinephrine]) was measured, and autonomic and neuroglycopenic symptoms were assessed. RESULTS: Sleep deprivation compared with sleep dampened the adaptation to recurrent hypoglycaemia for adrenaline (p=0.004), and this pattern also emerged in an overall analysis including adrenaline, GH and glucagon (p=0.064). After regular sleep, the counterregulatory responses of adrenaline (p=0.005), GH (p=0.029) and glucagon (p=0.009) were attenuated during the 3rd clamp compared with the 1st clamp, but were preserved after sleep deprivation (all p>0.225). Neuroglycopenic and autonomic symptoms during the 3rd clamp compared with the 1st clamp were likewise reduced after sleep (p=0.005 and p=0.019, respectively). In sleep deprivation, neuroglycopenic symptoms increased (p=0.014) and autonomic symptoms were unchanged (p=0.859). CONCLUSIONS/INTERPRETATION: The counterregulatory adaptation to recurrent hypoglycaemia is compromised by sleep deprivation between hypoglycaemic episodes, indicating that sleep is essential for the formation of a neurometabolic memory, and may be a potential target of interventions to treat hypoglycaemia unawareness syndrome.