Lipid

Hypercholesterolemia

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Hypercholesterolemia, Hyperlipidemia, Familial Hypercholesterolemia, Familial Hyperlipidemia

  • See Also
  1. Hypertriglyceridemia
  2. CAD Risk Management
  3. Hyperlipidemia Management
  • Causes
  • Familial Hypercholesterolemia
  1. General Findings
    1. LDL Cholesterol >190 mg/dl
    2. Premature, early onset coronary event (age <50 years)
      1. Coronary events may occur as early as age 17 years in males, and 25 years in females
  2. Homozygous Familial Hypercholesterolemia
    1. Corneal arcus senilis
    2. Xanthomas
  3. Heterozygous Familial Hypercholesterolemia
    1. Worldwide Prevalence: 1 in 250 to 350
    2. Silent severe Hyperlipidemia (LDL Cholesterol >190 mg/dl)
    3. No physical findings until premature cardiovascular events occur
  4. References
    1. Hu (2020) Circulation 141(22): 1742-59 [PubMed]
  • Causes
  • Other Secondary Causes of Hypercholesterolemia
  1. Genetic Cholesterol disorder findings
    1. See Familial Hypercholesterolemia as above
    2. LDL Cholesterol >190-200 mg/dl
    3. Serum Triglycerides > 1000 mg/dl
    4. HDL Cholesterol < 30 mg/dl
  2. Hypothyroidism
  3. Nephrotic Syndrome
  4. Chronic Liver Disease (Primary Biliary Cirrhosis)
  5. Dysglobulinemia
  6. Cushing's Syndrome
  7. Hyperparathyroidism
  8. Acute Intermittent Porphyria
  9. Medications
    1. Protease Inhibitors
  • Screening
  • Guidelines
  1. General counseling for all patients
    1. Low Fat Diet
    2. Exercise Program
  2. Criteria for age to start screening
    1. NIH as of 2011 recommends screening all ages 9-11 and again at 17-21years
      1. Treat patients only with significant LDL increase (e.g. >190)
      2. Goal to identify Familial Hypercholesterolemia
    2. Age over 20 years (ATP III Guidelines)
      1. Screen at age 20 and then every 5 years
      2. Prior guidelines for age to start screening
        1. Age >34 years in men
        2. Age >44 years in women
    3. Ages 2 to 20 years
      1. Family History of Total Cholesterol >300 mg/dl
      2. Family History Premature Coronary Artery Disease
        1. Age under 56 years in men
        2. Age under 66 years in women
  3. Screening protocol (repeated every 5 years)
    1. Full Fasting lipid profile preferred (ATP III guide)
    2. Alternative protocol: Non-Fasting lipid screening
      1. NCEP reasoning for non-Fasting lipid screening
        1. Non-Fasting screening improves compliance
        2. Postprandial Triglyceride rise can be evaluated
          1. Related to atherosclerosis risk
      2. Protocol
        1. Obtain non-Fasting Total Cholesterol with HDL
      3. Criteria to perform Fasting full lipid panel
        1. No Cardiac Risk Factors: Cholesterol >240 mg/dl
        2. Cardiac Risk Factors: Cholesterol >200 mg/dl
        3. HDL Cholesterol <40 mg/dl
    3. Alternative protocol: Non-Fasting Non-HDL Cholesterol
      1. Non-HDL Cholesterol = VLDL + IDL + LDL
      2. Correlates very well with outcomes
      3. Convenient (Patient does not need to fast)
      4. Goal Non-HDL Cholesterol is 30 higher than LDL goal
  1. http://www.nhlbi.nih.gov/about/framingham/riskabs.htm
  2. NCEP Framingham Online Calculator
    1. http://hin.nhlbi.nih.gov/atpiii/calculator.asp
  3. Results of lowering LDL Cholesterol
    1. Relative CAD risk reduced 1% per 1% LDL decrease
  • Management
  • General
  1. See Hyperlipidemia Management
  2. Coronary Artery Disease Risk Factors
    1. Positive Risk Factors
      1. See Cardiac Risk Factors
    2. Negative Risk Factors (Protective)
      1. HDL Cholesterol over 60 mg/dl
  3. Available lipid lowering modalities
    1. Dietary changes
      1. Low Fat Diet
      2. Phytosterols (Plant Stanols) lower LDL Cholesterol
    2. Weight loss for Obesity
      1. Lowers LDL Cholesterol
      2. Improves Insulin sensitivity
    3. Aerobic Exercise
      1. Raises HDL Cholesterol
      2. Lowers Triglycerides
    4. Anti-hyperlipidemic Medications
    5. Tobacco Cessation (Increases HDL by 30%)
  1. Cholesterol Management
    1. Goal if LDL Cholesterol below 160 mg/dl (ideally <130)
    2. Low Fat Diet if LDL Cholesterol over 160 mg/dl
    3. Anti-hyperlipidemic if LDL Cholesterol over 190 mg/dl
  2. Monitoring
    1. Desirable lipids: Repeat Lipid panel in 5 years
    2. Borderline lipids: Repeat lipid panel in 1 year
    3. Elevated lipids: Repeat lipid panel in 3-6 months
  1. Cholesterol Management
    1. Goal LDL Cholesterol below 130 mg/dl
    2. Low Fat Diet if LDL Cholesterol over 130 mg/dl
    3. Anti-hyperlipidemic indications
      1. LDL Cholesterol over 130 (FRS 10 year risk <20%)
      2. LDL Cholesterol over 160 (FRS 10 year risk <10%)
  2. Monitoring
    1. Desirable lipids: Repeat Lipid panel in 1-2 years
    2. Borderline lipids: Repeat lipid panel in 6 months
    3. Elevated lipids: Repeat lipid panel in 2-3 months
  1. Coronary Artery Disease equivalents
    1. Diabetes Mellitus
    2. Ten year Framingham Risk Score (FRS) 20% or higher
    3. Abdominal Aortic Aneurysm
    4. Peripheral Vascular Disease (e.g. Claudication)
    5. Symptomatic Carotid Artery disease
  2. Cholesterol Management
    1. Goal LDL Cholesterol below 100 (ideally <70 mg/dl)
    2. Low Fat Diet if LDL Cholesterol above 100 mg/dl
    3. Anti-hyperlipidemic if LDL Cholesterol over 130 mg/dl
  3. Monitoring
    1. Desirable lipids: Repeat Lipid panel in 6-12 months
    2. Borderline lipids: Repeat lipid panel in 2-3 months
    3. Elevated lipids: Repeat lipid panel in 6 weeks
  • Management
  • CAD with multiple uncontrolled risks
  1. Goal LDL Cholesterol below 70 mg/dl
  2. Low Fat Diet if LDL Cholesterol above 70 mg/dl
  3. Anti-hyperlipidemic if LDL Cholesterol over 100 mg/dl
  • References
  1. (2001) JAMA 285:2486-97 [PubMed]
  2. Ahmed (1998) Am Fam Physician 57(9):2192-203 [PubMed]
  3. Grundy (1997) Circulation 95:2329-31 [PubMed]
  4. Grundy (1997) Am Fam Physician 55(6): 2250-8 [PubMed]
  5. Mosca (2002) Am Fam Physician 65(2):217-26 [PubMed]
  6. Safeer (2002) Am Fam Physician 65(5):871-80 [PubMed]
  7. Yeshuran (1995) South Med J 88:379-91 [PubMed]