Dyslipidaemia

“Abnormal blood levels of one or more lipids or lipoproteins”

• Most common forms
  • ↑ LDL
  • ↓ HDL
  • ↑ Triglycerides
  • ↑ Cholesterol

Risk Factors

• Primary dyslipidaemia:
  • Gene mutations eg LDLRAP1 mutation
• Secondary dyslipidaemia:
  • Obesity
  • T2DM
  • Alcoholism

Aetiology

• Primary dyslipidaemia:
  • Inherited
• Secondary dyslipidaemia:
  • Acquired

Pathophysiology

• Primary dyslipidaemia:
  • LDLRAP1 mutation:
    1. ↓ the efficiency of endocytosis of receptor-bound LDL particles
    2. ↓ Clearance of LDL from plasma
    3. ­↑ Macrophage consumption of excess LDL cholesterol
    4. ­↑ Atherosclerosis risk

• Secondary dyslipidaemia:
  • Obesity & T2DM:
    1. Elevated FFA levels
    2. ↑ Hepatic VLDL-TG secretion
  • Alcoholism:
    1. ↑ Hepatic VLDL secretion

Clinical Presentation

• High LDL:
  • Tendinous xanthomas at the Achilles
  • Knee tendons and elbows
  • Xanthelasma
  • Arcus corneae
• High TG:
  • Xanthomas at knees, feet, elbows, and hands

Investigations

• Bloods:
  • Serum lipid profile- including total cholesterol, TG, HDL, LDL, VLDL
• Imaging: n/a
• Special:
  • Screening tests eg if FHx of severe hyperlipidaemia

Management

• Conservative:
  • Lifestyle Management – exercise & dietary changes
• Medical:
  • 1^st line= Statin eg Lovastatin, Pravastatin.
  • If statins fail, niacin/fibrates used (main aim of management: prevent atherosclerotic CVD)
• Surgical: n/a

Complications

• Atherosclerosis
• Myocardial Infarction
• Coronary artery disease
• Acute coronary syndrome
• Stroke