LMCC/Dyslipidemia

• abnormal elevation of plasma cholesterol or triglycerides
• this disorder increases the risks associated with obesity, diabetes and alcohol use

Assessment

Signs of Hyperlipidemia

• atheromata - plaques in blood vessel walls
• xanthoma - plaques or nodules composed of lipid laden histiocystes in the skin and eyelids
• tendinous xanthoma - lipid deposits in tendons
• corneal arcus (arcus senillis) - lipid deposits in corena

• levels should be measured every five years in those > age 20
• prior to labs, also assess for coronary artery disease risk factors
• labs drawn are:
  • total cholesterol
  • LDL-C (bad cholesterol)
    • Note: LDL-C cannot be calculated if triglyceride levels are >4.5mmol/L
  • HDL-C (good cholesterol)
  • triglyceride levels

Risk Category

Emerging risk factors for hypertriglyceridemia

• lipoprotein a
• genetic risk
• hormone replacement therapy
• infectious agents
• metabolic syndrome

• must also estimate 10 year risk for developing coronary artery disease using the Framingham heart data

Risk Factors for CAD

Major

1. Smoking

2. Diabetes

3. Hypertension

4. Hyperlipidemia

5. Family History of CAD

Minor

1. Obesity

2. Sedentary lifestyle

3. Hyperhomoysteinemia

Target Lipid Values for Primary Prevention of CAD

• once risk is established, target levels can be set

Risk Category	LDL-C(mmol/L)	Total-cholesterol:HDL-C ratio
High 10 year risk of CAD > 20%/history of DM/history of atherosclerotic disease	<2.5	<4
Moderate 10 year risk 11%-19%	<3.5	<5
Low 10 year risk < 10%	<4.5	<6

• note: There are no longer any target triglyceride levels

Management

• use risk level as a guide for treatment
• use dietary/lifestyle modification for 3 months before initiating drug therapy:
  • weight loss
  • exercise
  • avoid EtOH and smoking
  • blood glucose control
  • increase omega-3 fatty acid intake

• after the initiation of drug therapy, lipids should be measured after 6 weeks and 3 months.
  • if adequate reevaluate in 6 months
  • monitor ALT, AST and CK every 6 months for signs of transaminitis or myositis, a potential side effect of using lipid lowering agents.

Pharmacology: Lipid Lowering Agents

• statins: HMG-CoA reductase inhibitors
  • Atorastatin (Lipitor)
  • Lovostatin (Mevacor)
  • Pravastatin (Pravachol)
  • Simvastatin (Zocor)
  • Rosuvastatin (Crestor)
• bile acid sequestrants
• nicotinic acid
• fibrates
• psyllium
• cholesterol absorption inhibitors (ie. ezetimibe)

Isolated hypertriglyceridemia

• normal HDL-C and total cholesterol with elevated triglycerides
  • mild: TG > 2.0mmol/L
  • marked: TG > 4.5mmol/L
• principal therapy is lifestyle modification
• drug therapy is nicotinic acid or fibrates

References

Toronto Notes 2005

Additional Reading

Statin use in treating high cholesterol