Obesity and Metabolic Syndrome

Basics & Causes - Weighty Who, Why

• Pediatric Obesity:
  • BMI ≥ 95th percentile for age/sex.
  • Overweight: BMI 85th-94th percentile.
• Metabolic Syndrome (MetS) in Children:
  • Cardiovascular risk factor cluster.
  • Criteria (≥3/5, adapted IDF/AHA):
    • Abdominal obesity (Waist Circumference ≥ 90th %ile)
    • ↑ Triglycerides (TG ≥ 150 mg/dL)
    • ↓ HDL-C (< 40 mg/dL)
    • ↑ Blood Pressure (BP ≥ 90th %ile or ≥ 130/85 mmHg)
    • ↑ Fasting Glucose (FG ≥ 100 mg/dL) or T2DM
• Causes (Etiology):
  • Multifactorial: Gene-environment interplay.
  • Genetic: Polygenic; Syndromic (e.g., Prader-Willi, Bardet-Biedl).
  • Environmental:
    • Diet: ↑Calorie-dense foods, sugary drinks.
    • Activity: ↓Physical activity, ↑screen time.
  • Endocrine (Rare): Hypothyroidism, Cushing’s syndrome.
  • Medications: Corticosteroids, some antipsychotics.
  • Early Life Factors: Maternal obesity/GDM; SGA with rapid catch-up.

⭐ Leptin deficiency is a rare monogenic cause of severe early-onset obesity, treatable with recombinant leptin_._

Evaluation & Diagnosis - Spotting the Signs

• Key History & Physical Exam:
  • Diet, activity, family Hx (Obesity, DM, CVD).
  • Anthropometry:
    • BMI: >85th %ile (Overweight), >95th %ile (Obese).
    • WC: >90th %ile. WHtR: >0.5.
  • BP: >90th %ile for age/sex/height.
  • Clinical signs: Acanthosis nigricans, striae, hepatomegaly.
• Metabolic Syndrome (MetS) Criteria (Pediatric, e.g., IDF-like for ≥10 yrs):
  • WC >90th %ile PLUS ≥2 of:
    • TG ≥150 mg/dL.
    • HDL-C <40 mg/dL.
    • BP ≥130/85 mmHg or Rx.
    • FPG ≥100 mg/dL or T2DM.
• Core Lab Investigations:
  • Fasting lipids & glucose/HbA1c.
  • LFTs (ALT for NAFLD).
  • TSH (rule out hypothyroidism).

⭐ Acanthosis nigricans is a key cutaneous marker of insulin resistance in obese children.

Health Impacts - Beyond the Bulk

• Cardiovascular: Hypertension (↑BP), dyslipidemia (↑TG, ↓HDL-C), endothelial dysfunction, early atherosclerosis, LVH.
• Endocrine/Metabolic: Insulin resistance → Type 2 DM, Polycystic Ovary Syndrome (PCOS), NAFLD/NASH, dysmetabolic syndrome, early/precocious puberty.

  ⭐ Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in obese children.

• Respiratory: Obstructive Sleep Apnea (OSA), asthma exacerbation, exercise intolerance.
• Musculoskeletal: Slipped Capital Femoral Epiphysis (SCFE), Blount's disease (tibia vara), ↑fracture risk, flat feet.
• Gastrointestinal: GERD, cholelithiasis (gallstones).
• Neurological: Idiopathic Intracranial Hypertension (IIH/Pseudotumor cerebri).
• Psychosocial: Depression, anxiety, low self-esteem, bullying, eating disorders.
• Renal: Glomerulosclerosis, proteinuria. ​

Treatment & Thwarting - Action Plan Attack

• Cornerstone: Lifestyle Modification (LSM)
  • Diet: Balanced, calorie-controlled; ↓sugary drinks, ↑fiber.
  • Activity: ≥60 min/day moderate-vigorous; screen time <2 hr/day.
  • Behavioral: Family-based, goal-setting.
• Pharmacotherapy (If LSM fails after 6-12 months)
  • Criteria: BMI ≥95th centile + comorbidities, or BMI ≥97th centile.
  • Agents:
    • Orlistat (≥12 yrs)
    • Metformin (≥10 yrs for T2DM/insulin resistance)
    • Liraglutide (≥12 yrs)
    • Setmelanotide (specific genetic obesity)
• Bariatric Surgery (Severe cases, failed LSM/pharma)
  • Criteria: BMI ≥40, or ≥35 + severe comorbidities; skeletal maturity.
• Prevention (Thwarting)
  • Early life: Promote breastfeeding, healthy weaning.
  • School & community programs.
  • Limit obesogenic environment.

⭐ For pediatric obesity with insulin resistance or T2DM, Metformin (≥10 yrs) is a key pharmacological option post-LSM failure.

High‑Yield Points - ⚡ Biggest Takeaways

• Childhood Obesity: BMI ≥95th percentile. Severe: BMI ≥120% of 95th or ≥35 kg/m².
• Metabolic Syndrome (Peds): Central obesity + ≥2 factors (↑TG, ↓HDL, ↑BP, ↑Glucose).
• Insulin Resistance: Core defect. Acanthosis Nigricans is a key sign.
• Screen for: Dyslipidemia, HTN, T2DM, NAFLD, PCOS (girls).
• Management: Intensive lifestyle modification (diet, exercise, behavior) is primary.
• Pharmacotherapy (e.g., Metformin, Liraglutide) for severe cases/comorbidities in adolescents.