Diabetes Mellitus in Children

DM Overview & Types - Sugar Rush Intro

• Diabetes Mellitus (DM): Chronic hyperglycemia from defects in insulin secretion, action, or both.
• Key Pediatric Types:
  • Type 1 DM (T1DM): Most common (~90%). Autoimmune β-cell destruction; absolute insulin deficiency. Often presents with DKA.
  • Type 2 DM (T2DM): ↑ incidence. Insulin resistance & relative deficiency. Strong obesity link.
  • MODY (Maturity Onset Diabetes of the Young): Monogenic (autosomal dominant). Non-ketotic.
  • Neonatal DM: Onset <6 months. Genetic defects (e.g., KCNJ11, ABCC8).

⭐ T1DM accounts for over 90% of childhood diabetes cases.

Pathophys & Clinical Picture - The Sweet Sickness

• Pathophysiology:
  • T1DM: Autoimmune β-cell destruction → absolute insulin deficiency. HLA-DR3/DR4 link. Viral triggers.
  • T2DM: Insulin resistance & relative insulin deficiency. Obesity is a key risk factor.
• Clinical Picture:
  • Classic "3 Ps": Polyuria, Polydipsia, Polyphagia (📌).
  • Weight loss (T1DM), fatigue, blurred vision.
  • Recurrent infections (e.g., candidiasis).
  • DKA: Common T1DM presentation (~25-40%): abdominal pain, vomiting, Kussmaul breathing, fruity breath, dehydration.
  • Acanthosis nigricans (T2DM insulin resistance marker).

⭐ DKA is the initial presentation in up to 40% of children with new-onset T1DM.

Diagnosis & Investigations - Cracking the Code

• Suspect DM: Polyuria, polydipsia, unexplained weight loss.
• Diagnostic Criteria (any one):
  • RPG ≥ 200 mg/dL + symptoms
  • FPG ≥ 126 mg/dL
  • 2-hr PG (OGTT) ≥ 200 mg/dL (1.75g/kg)
  • HbA1c ≥ 6.5% (📌 Caution: rapid onset)
• Further Investigations:
  • Urine: Glucosuria, Ketonuria
  • Blood: Glucose, HbA1c
  • T1DM Markers: Autoantibodies (GAD65, IA-2, IAA, ZnT8)
  • C-peptide: ↓ T1DM, normal/↑ T2DM

⭐ DKA is the initial presentation in 20-40% of children with new-onset T1DM.

Management Principles - Sugar Control Central

• Insulin Therapy:
  • Regimen: Basal-bolus (long + rapid-acting pre-meals) standard.
  • Dosing: Initial TDD $0.5-1 \text{ U/kg/day}$. Puberty/DKA $1-1.5 \text{ U/kg/day}$. Honeymoon $<0.5 \text{ U/kg/day}$.
• Monitoring:
  • SMBG: 4-6x/day. Pre-meal target 90-130 mg/dL, post-meal <180 mg/dL.
  • HbA1c: Target <7.0% (ADA) / <7.5% (ISPAD), individualized.
• DKA Management: (Flowchart below)
  • Key: Fluids, Insulin, K+ (📌 "FIK", fluids first).
  • Fluids: NS $10-20 \text{ ml/kg}$ (1hr); deficit + maintenance over 48hrs.
  • Insulin: IV Reg $0.05-0.1 \text{ U/kg/hr}$ (1-2h post-fluids).
  • K+: Add if K+ < 5.5 mEq/L & UOP.
• Hypoglycemia:
  • Mild/Moderate: Rule of 15 (15g simple carbs, recheck BG in 15 min).
  • Severe: Glucagon IM/SC.

⭐ In DKA, start insulin 1-2h after fluids to prevent rapid osmotic shifts & cerebral edema.

Complications & Special Forms - Beyond the Basics

• Chronic Complications:
  • Microvascular: Retinopathy, nephropathy, neuropathy. Annual screening from puberty or 5 yrs post-diagnosis.
  • Macrovascular: Accelerated atherosclerosis risk.
• Associated Autoimmune: Thyroid disease, celiac disease.
• Special Forms:
  • MODY: Genetic (AD), non-ketotic, family history.
  • Neonatal DM (NDM): Onset <6 months; genetic testing vital.
  • Cystic Fibrosis-Related Diabetes (CFRD): Screen annually from age 10.

⭐ NDM presenting in the first 6 months of life is unlikely to be autoimmune Type 1 DM; suspect monogenic diabetes. ​

High‑Yield Points - ⚡ Biggest Takeaways

• Type 1 DM (autoimmune β-cell destruction) is most common in children.
• Presents with polyuria, polydipsia, weight loss; DKA is a frequent initial emergency.
• Diagnosis: RBS ≥200 mg/dL (symptomatic), FBS ≥126 mg/dL, or HbA1c ≥6.5%.
• DKA management: Prioritize IV fluids, insulin infusion, careful potassium replacement.
• Honeymoon period: Temporary remission after initiating insulin therapy.
• Long-term: Lifelong insulin, glucose monitoring, HbA1c target <7.0-7.5%, screen for complications.
• MODY: Monogenic, autosomal dominant, non-ketotic familial hyperglycemia.