Paeds · endocrinology-diabetes-and-growth
Hypoglycaemia in diabetes
Also known as Insulin-induced hypoglycaemia · Severe hypoglycaemia · Impaired awareness of hypoglycaemia · Nocturnal hypoglycaemia · Hypoglycaemia-associated autonomic failure · HAAF · Dead-in-bed syndrome
A fellowship approach to hypoglycaemia in children and adolescents with diabetes: recognise the autonomic-to-neuroglycopenic slide and the silent nocturnal event as the single greatest barrier to safe intensive therapy, classify severity by the ISPAD/ADA levels, understand why the glucagon and adrenaline counter-regulation fails in type 1 diabetes and produces impaired awareness (HAAF), and deliver the rule of 15 for mild events and glucagon or intravenous dextrose for severe events — then prevent recurrence with continuous glucose monitoring, hybrid closed-loop delivery, structured education, and insulin-adjustment skills.
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- Any child or adolescent with diabetes who becomes confused, drowsy, uncoordinated, or behaves oddly — check a glucose immediately and treat on suspicion, never waiting for a confirmatory laboratory value
- A seizure or loss of consciousness in a child with type 1 diabetes is hypoglycaemia until proven otherwise — give glucagon or intravenous dextrose without delay
- Impaired awareness of hypoglycaemia — the loss of the autonomic warning of sweating, tremor and palpitations — is present in around one in four children and adolescents and is the strongest predictor of a future severe event
- Nocturnal hypoglycaemia is usually asymptomatic; an unexplained early-morning headache, lethargy, raised ketones, or a wet bed should trigger review of overnight glucose patterns
- Repeated severe events erode the adrenaline response and deepen the cycle of hypoglycaemia-associated autonomic failure (HAAF), raising the risk of further severe and silent hypoglycaemia
- The rare but catastrophic 'dead-in-bed' syndrome — an unexpected overnight death in a young person with type 1 diabetes — is linked to profound nocturnal hypoglycaemia and QT prolongation
- A child who cannot articulate symptoms (toddlers, children with disability or neurodivergence) depends entirely on caregiver observation, so unexplained irritability, pallor, or behavioural change demand a glucose check
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- Recognition and emergency treatment of severe hypoglycaemia in a child with diabetes
- The rule of 15 for mild-to-moderate hypoglycaemia
- Impaired awareness of hypoglycaemia and its prevention
- Counter-regulatory physiology and hypoglycaemia-associated autonomic failure (HAAF)
- Continuous glucose monitoring and hybrid closed-loop insulin delivery to prevent hypoglycaemia
- Glucagon (intramuscular and intranasal) and intravenous dextrose for severe events
- Managing a severe hypoglycaemic seizure at school or home
- Advising on exercise-related and nocturnal hypoglycaemia
- Adjusting insulin after a hypoglycaemic event without abandoning glycaemic targets
- Acute short case of an adolescent found unconscious with type 1 diabetes
- Long case of a child with recurrent severe hypoglycaemia and impaired awareness discussing CGM, hybrid closed-loop, and structured education
- Acute complications of diabetes therapy
- Continuous glucose monitoring and insulin-pump technology
- Adolescent diabetes and risk-taking behaviours
- Physiology of glucose counter-regulation and ketogenesis
- Severity classification and emergency management of hypoglycaemia
- Pharmacology of glucagon and fast-acting carbohydrate
- Resuscitation of the hypoglycaemic collapse
- Communicating a hypoglycaemia-prevention plan to a family and school
- Recognition and treatment of hypoglycaemia in diabetes
- Impaired awareness and recurrent severe hypoglycaemia
- Diabetes technology and prevention of hypoglycaemia
- Acute hypoglycaemic emergencies
- Diabetes technology including CGM and hybrid closed-loop systems
- Multidisciplinary diabetes education and prevention
- Emergency management of hypoglycaemia in children with diabetes
- Counter-regulatory failure and impaired awareness
- Long-term neurocognitive outcomes of recurrent hypoglycaemia
The unifying teaching point is that hypoglycaemia is the single greatest barrier to safe intensive insulin therapy. The Diabetes Control and Complications Trial proved that intensive control prevents long-term microvascular complications, but at the price of a threefold increase in severe hypoglycaemia — a finding that reshaped paediatric diabetes care into a constant negotiation between lowering the HbA1c and protecting the brain. [4] [1]
Overview & Definition
Hypoglycaemia in diabetes is a low blood glucose produced by the imbalance between insulin action and available substrate — too much insulin, too little food, too much exercise, or a combination of all three. The threshold at which harm begins is lower than the threshold at which symptoms appear, which is why the ISPAD guidelines define a glucose below 3.9 millimoles per litre (70 milligrams per decilitre) as an alert value that should prompt review, and below 3.0 millimoles per litre (54 milligrams per decilitre) as a clinically important event that demands action. A severe event is defined not by a number but by the child's functional state: any hypoglycaemia associated with altered mental or physical status that requires another person to administer treatment. [1]
Clinically, the condition matters because the brain depends on glucose as its obligate fuel, and a child with type 1 diabetes has lost the insulin arm of the body's glucose-defence system and partially lost the glucagon arm as well. The result is that each episode is both an immediate emergency — a starved brain can seize and injure itself — and a signal that the therapy has outrun the physiology. The framing matters because it dictates management: the priority is to treat first and analyse the cause afterwards, because the recovery of the brain is time-critical and the analysis can wait. [3] [2]
References12ShowHide
- [1]Abraham MB, Karges B, Dovc K, et al. ISPAD Clinical Practice Consensus Guidelines 2022: Assessment and management of hypoglycemia in children and adolescents with diabetes Pediatr Diabetes, 2022.PMID 36537534
- [2]McCrimmon RJ, Sherwin RS. Hypoglycemia in type 1 diabetes Diabetes, 2010.PMID 20876723
- [3]Cryer PE. Hypoglycemia, functional brain failure, and brain death J Clin Invest, 2007.PMID 17404614
- [4]Nathan DM, Genuth S, Lachin J, et al. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus N Engl J Med, 1993.PMID 8366922
- [5]Tamborlane WV, Beck RW, Bode BW, et al. Continuous glucose monitoring and intensive treatment of type 1 diabetes N Engl J Med, 2008.PMID 18779236
- [6]Bergenstal RM, Klonoff DC, Garg SK, et al. Threshold-based insulin-pump interruption for reduction of hypoglycemia N Engl J Med, 2013.PMID 23789889
- [7]Haynes A, Hermann JM, Clapin H, et al. Decreasing Trends in Mean HbA1c Are Not Associated With Increasing Rates of Severe Hypoglycemia in Children: A Longitudinal Analysis of Two Contemporary Population-Based Pediatric Type 1 Diabetes Registries From Australia and Germany/Austria Between 1995 and 2016 Diabetes Care, 2019.PMID 31213467
- [8]Ly TT, Gallego PH, Davis EA, Jones TW. Impaired awareness of hypoglycemia in a population-based sample of children and adolescents with type 1 diabetes Diabetes Care, 2009.PMID 19587370
- [9]Cameron FJ, Northam EA, Ryan CM. The effect of type 1 diabetes on the developing brain Lancet Child Adolesc Health, 2019.PMID 30987935
- [10]Jones J, James S, Brown F, et al. Dead in bed - A systematic review of overnight deaths in type 1 diabetes Diabetes Res Clin Pract, 2022.PMID 36007797
- [11]Pontiroli AE, Tagliabue E. Intranasal versus injectable glucagon for hypoglycemia in type 1 diabetes: systematic review and meta-analysis Acta Diabetol, 2020.PMID 32025860
- [12]Northam EA, Lin A. Hypoglycaemia in childhood onset type 1 diabetes--part villain, but not the only one Pediatr Diabetes, 2010.PMID 19538515