🍬 Type 1 Diabetes Mellitus (T1DM)

1. Definition

Type 1 Diabetes Mellitus (T1DM) is a chronic autoimmune disorder characterized by the destruction of pancreatic beta cells, leading to absolute insulin deficiency.
It results in hyperglycemia, requiring lifelong insulin therapy.
T1DM is the most common form of diabetes in children and adolescents.

2. Causes

Autoimmune destruction of insulin-producing beta cells in the islets of Langerhans
Genetic predisposition with environmental triggers
Associated autoimmune conditions (e.g., celiac disease, autoimmune thyroiditis)

3. Risk Factors

Family history of T1DM
Genetic markers: HLA-DR3, HLA-DR4
Viral infections (e.g., Coxsackie B, enteroviruses)
Early cow’s milk exposure (possible)
Other autoimmune diseases (e.g., Hashimoto's, Addison’s)

4. Types

Type	Description
Type 1A (autoimmune)	Positive for autoantibodies (e.g., anti-GAD, IA2)
Type 1B (idiopathic)	No detectable autoantibodies
Latent Autoimmune Diabetes in Adults (LADA)	Milder, slower-onset autoimmune diabetes in adults

5. Pathogenesis

Autoimmune attack on beta cells → ↓ insulin production → ↑ blood glucose
Without insulin:
- Glucose cannot enter cells → energy deficit → lipolysis
- Ketone body production → metabolic acidosis → diabetic ketoacidosis (DKA)
Hyperglycemia → osmotic diuresis → dehydration, electrolyte loss

6. Clinical Presentation

Symptoms

Polyuria
Polydipsia
Weight loss
Fatigue
Nocturia/bedwetting
Blurred vision

Signs

Dehydration (dry mucous membranes, tachycardia)
Kussmaul breathing (if DKA)
Fruity-smelling breath (ketones)
Lethargy or altered consciousness (if severe)

Physical Examination Findings

Low weight/BMI
Delayed growth/puberty
Possible acanthosis nigricans (if insulin resistance overlaps)

7. Organ & System Complications

System	Complications
Metabolic	Diabetic ketoacidosis (DKA), hypoglycemia
Renal	Microalbuminuria → diabetic nephropathy
Ophthalmologic	Retinopathy, cataracts
Neurologic	Peripheral neuropathy, autonomic dysfunction
Cardiovascular	Early atherosclerosis, hypertension
Psychosocial	Eating disorders, anxiety, school difficulties

8. Diagnostic Investigations

Test	Reason
Blood glucose (random)	≥11.1 mmol/L with symptoms confirms diagnosis
Fasting glucose	≥7.0 mmol/L
HbA1c	≥6.5% (48 mmol/mol)
Urine ketones/glucose	Suggests ketosis and glycosuria
Blood gas, serum ketones	For DKA assessment

9. Other Relevant Investigations

Test	Reason
Autoantibodies (anti-GAD, IA2, ZnT8)	Confirm autoimmune type
C-peptide	Reflects endogenous insulin production
Thyroid function tests	Screen for autoimmune thyroiditis
TTG-IgA	Screen for celiac disease
Lipid profile	Baseline cardiovascular risk

10. Treatment

Curative/Definitive

No cure; requires lifelong insulin therapy

Empirical

Start insulin therapy immediately after diagnosis

Supportive

Insulin regimen: basal-bolus or pump
Blood glucose monitoring (fingerstick or CGM)
Carbohydrate counting and dietary education
Sick day management
Family and school support

Palliative

In cases of severe complications, end-of-life care may be discussed

11. Long-Term Complications of Treatment

Treatment	Complication	Monitoring	Expected Results
Insulin therapy	Hypoglycemia, lipodystrophy, weight gain	SMBG/CGM, injection site rotation, BMI	Stable glucose, HbA1c <7.5%, minimal hypo
Poor compliance	DKA, hyperglycemia, long-term complications	HbA1c every 3 months, ketone testing	HbA1c <7.5%, no DKA episodes

12. Surveillance for the Disease

Domain	Frequency	What to Monitor
HbA1c	Every 3 months	Target <7.5%
Growth & puberty	Every 3–6 months	Height, weight, Tanner staging
Renal	Yearly from age 10 or 5 years after diagnosis	Urine albumin:creatinine ratio
Eyes	Yearly from age 12	Retinal exam (retinopathy screening)
Thyroid function	Yearly	TSH, free T4
Celiac screening	Every 1–2 years	TTG-IgA, total IgA
Lipids	At puberty, then every 5 years	Fasting lipid profile
Mental health	As needed	Mood, anxiety, eating disorder screening

13. Malaysia Support Group for Parents

Support Group	Description	Contact/Link
Diabetes Malaysia	Advocacy, awareness, peer support	www.diabetes.org.my
MySihat (Health Promotion Board)	Educational materials and family resources	www.mysihat.gov.my
Hospital-based diabetes clinics	Dietitian, endocrinologist, diabetic educator	Available at HKL, HUSM, UMMC, Penang GH, etc.
Facebook groups (e.g. T1DM Malaysia)	Parent and adolescent peer-to-peer support	Search “Type 1 Diabetes Malaysia” on Facebook