Diabetes Mellitus in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Diabetes mellitus is a metabolic disorder characterised by chronic hyperglycaemia due to either insufficient insulin production (Type 1 diabetes) or insulin resistance (Type 2 diabetes). In children, Type 1 diabetes is more common, while Type 2 diabetes is increasingly being diagnosed due to rising obesity rates. Both types of diabetes can lead to serious complications if not properly managed.

Aetiology

• Type 1 Diabetes Mellitus: An autoimmune condition where the immune system destroys insulin-producing beta cells in the pancreas. It is influenced by genetic and environmental factors.
• Type 2 Diabetes Mellitus: Characterised by insulin resistance, often associated with obesity, physical inactivity, and a strong family history of diabetes.

Pathophysiology

The pathophysiology of diabetes in children depends on the type:

• Type 1 Diabetes: The autoimmune destruction of pancreatic beta cells results in a lack of insulin. Insulin is essential for glucose uptake into cells, and its absence leads to hyperglycaemia. Without insulin, cells are starved of glucose, leading to the breakdown of fat for energy and production of ketones, which can result in diabetic ketoacidosis (DKA).
• Type 2 Diabetes: Insulin resistance means that although insulin is produced, the body's cells do not respond properly. As a result, the pancreas compensates by producing more insulin, but over time, this can lead to beta cell exhaustion and reduced insulin production, causing hyperglycaemia.

Risk Factors

• Type 1 Diabetes:
  • Family history of Type 1 diabetes or other autoimmune conditions.
  • Genetic factors (e.g., HLA gene mutations).
  • Viral infections such as enterovirus.
• Type 2 Diabetes:
  • Obesity.
  • Family history of Type 2 diabetes.
  • Sedentary lifestyle.
  • Ethnicity (increased risk in Afro-Caribbean and South Asian children).
  • Polycystic ovary syndrome (PCOS) in adolescent girls.

Signs and Symptoms

Children with diabetes may present with the following symptoms, often referred to as the classic “4 Ts”:

• Thirst: Increased thirst (polydipsia).
• Toilet: Frequent urination (polyuria), including bed-wetting.
• Tired: Fatigue and lethargy.
• Thinner: Weight loss, despite an increased appetite.

In Type 1 diabetes, children may also present with diabetic ketoacidosis (DKA), a life-threatening complication characterised by vomiting, abdominal pain, rapid breathing, and confusion.

Investigations

• Capillary blood glucose: A finger-prick test to check blood glucose levels. Hyperglycaemia (>11 mmol/L) is suggestive of diabetes.
• HbA1c: A blood test measuring average blood glucose levels over the past 2-3 months. A level ≥48 mmol/mol (6.5%) confirms a diagnosis of diabetes.
• Urine ketones: To check for the presence of ketones, which can indicate DKA in Type 1 diabetes.
• Autoantibody testing: In Type 1 diabetes, tests for specific antibodies can confirm autoimmune destruction of beta cells.
• Oral Glucose Tolerance Test (OGTT): Used to diagnose Type 2 diabetes, particularly in obese children.

Management

Management of diabetes in children focuses on controlling blood glucose levels to prevent both acute complications (e.g., hypoglycaemia, DKA) and long-term complications (e.g., retinopathy, nephropathy). Treatment differs between Type 1 and Type 2 diabetes.

Type 1 Diabetes Management:

• Insulin therapy: Children with Type 1 diabetes require lifelong insulin therapy. This may be delivered via multiple daily injections or an insulin pump. Basal (long-acting) and bolus (short-acting) insulin are used to mimic natural insulin production.
• Blood glucose monitoring: Frequent monitoring of blood glucose levels is essential to adjust insulin doses. Continuous glucose monitors (CGMs) may be recommended.
• Carbohydrate counting: To calculate the amount of insulin required based on carbohydrate intake.
• DKA management: In cases of DKA, children require urgent hospitalisation for intravenous fluids, insulin, and electrolyte correction.

Type 2 Diabetes Management:

• Lifestyle modifications: First-line treatment includes weight loss, regular physical activity, and a healthy diet to improve insulin sensitivity.
• Metformin: The first-line oral medication for children with Type 2 diabetes to reduce insulin resistance.
• Insulin therapy: In more severe cases or when oral medications fail, insulin therapy may be required.

Monitoring and Follow-up:

• Regular monitoring of HbA1c to assess long-term glucose control.
• Annual screening for complications such as retinopathy, nephropathy, and neuropathy.
• Psychosocial support for both the child and family, including education on managing diabetes.

When to Refer:

• All children with suspected diabetes should be urgently referred to a paediatric diabetes specialist for diagnosis and management.
• Refer children with Type 1 diabetes presenting in DKA to the emergency department for immediate treatment.

References

1. NICE (2024). Diabetes (Type 1 and Type 2) in Children: Diagnosis and Management Guidelines. Available at: NICE Guidance
2. Diabetes UK (2023). Managing Diabetes in Children. Available at: Diabetes UK
3. British Medical Journal (2023). Paediatric Diabetes: Clinical Guidelines. Available at: BMJ