Makindo Medical Notes

Lipid disorders are categorized into three main types: predominant hypercholesterolemia, predominant hypertriglyceridemia, and mixed lipid disorders.

About Hypertriglyceridemia (HTG)

• Defined as elevated triglyceride (TG) levels in the blood, which can increase the risk of cardiovascular disease and, in severe cases, pancreatitis.

Aetiology

• Genetic Causes:
  • Lipoprotein Lipase Deficiency: Autosomal recessive disorder with extremely high TG levels.
  • Apolipoprotein C-II Deficiency: Leads to similar lipid profiles as lipoprotein lipase deficiency.
  • Polygenic Hypertriglyceridemia: The most common cause, influenced by multiple genetic factors.
  • Familial Hypertriglyceridemia: Inherited disorder with elevated triglycerides due to genetic factors.
• Secondary (Acquired) Causes:
  • Excess Alcohol Consumption and Type 2 Diabetes Mellitus: Commonly associated with elevated TG levels.
  • Other risk factors include obesity, poor diet, and lack of physical activity.

Severity of Hypertriglyceridemia

• Moderate: TG levels between 2.3 and 5 mmol/L.
• Severe: TG levels between 5 and 10 mmol/L.
• Very Severe: TG levels above 10 mmol/L.
• There is a significant risk of acute pancreatitis when TG levels exceed 12 mmol/L.

Causes of Hypertriglyceridemia

• Acquired Causes:
  • Excessive alcohol consumption.
  • Uncontrolled diabetes (especially type 2).
  • Medications: Thiazide diuretics, corticosteroids, and estrogens.
• Familial Causes:
  • Familial Combined Hypertriglyceridemia: Genetic disorder with elevated triglycerides and sometimes elevated LDL.
  • Remnant Dyslipidemia: Mixed elevation of TG and cholesterol.
  • Chylomicronemia Syndrome: Characterized by very high TG levels due to chylomicrons in the blood.

Clinical Features

• Pancreatitis: Increased risk in severe hypertriglyceridemia.
• Lipaemia Retinalis: Milky appearance of retinal blood vessels seen in extremely high TG levels.
• Hepatosplenomegaly: Enlarged liver and spleen in some cases.
• Eruptive Xanthomas: Small yellowish-red bumps on the skin, often on the back and buttocks, seen with very high TG levels.
• Massive Hypertriglyceridemia: Observed with lipoprotein lipase deficiency.

Management

• Comprehensive Risk Assessment: Evaluate cardiovascular risk factors, including smoking, hypertension, and diabetes, not solely focusing on lipid levels.
• Medications: Treatment targets triglyceride levels:
  • Fibrates: Effective in lowering TG levels by increasing lipoprotein lipase activity.
  • Nicotinic Acid (Niacin): Reduces TG and LDL levels while raising HDL levels.
  • Omega-3 Fatty Acids (Fish Oil): Helps lower TG levels and may be prescribed in high doses.
• Lifestyle Modifications: Encourage a low-fat diet, regular physical activity, and limited alcohol intake.