Type 1 Diabetes Mellitus

Definition

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder with beta cell destruction characterised by hyperglycaemia due to absolute insulin deficiency.

Etiology
  • Younger age
  • Genetic predisposition
  • Family history of type 1 or 2 diabetes mellitus
  • Past medical history of gestational diabetes
Clinical Features
  • Classic triad:
    • Polyuria
    • Polydipsia
    • Loss of weight/ fatigue
  • Suspect diabetes in patients with recurrent infections (e.g. cellulitis, UTIs)
  • Commonly first present with diabetic ketoacidosis (DKA):
    • Abdominal pain
    • Nausea
    • Vomiting
    • Tachypnoea
Investigations
  • Positive for 2 separate tests (or same test repeated twice) if asymptomatic; or positive for 1 test if symptomatic:
    • Fasting plasma glucose >7 mmol/L
    • Random plasma glucose >11 mmol/L
    • HbA1c >6.5%
    • 2-hour 75g OGTT >11 mmol/L
Management
  • Insulin injection
  • Eating plan to ensure regular food intake
  • Education on the condition and management
Author