Lipid Panel (Cholesterol & Triglycerides)
Definition
A lipid panel measures blood fats that affect cardiovascular risk: - Total Cholesterol - Sum of all cholesterol types - LDL-C (Low-Density Lipoprotein) - "Bad" cholesterol; drives atherosclerosis - HDL-C (High-Density Lipoprotein) - "Good" cholesterol; protective - Triglycerides - Blood fats affected by diet and metabolism - Non-HDL-C - Total minus HDL; comprehensive atherogenic measure
Why It Matters
Lipids are central to cardiovascular disease: - Atherosclerosis - LDL cholesterol drives plaque formation - Heart attack & stroke risk - Elevated LDL strongly linked to events - Treatable - Lifestyle and medications effectively lower LDL - Mortality reduction - LDL lowering reduces cardiovascular deaths
Key principle: LDL lowering reduces atherosclerotic cardiovascular disease risk proportionally to the absolute reduction in LDL.
Reference Values
LDL Cholesterol
| Level | Interpretation |
|---|---|
| <70 mg/dL | Optimal for very high-risk patients |
| <100 mg/dL | Optimal for high-risk patients |
| 100-129 mg/dL | Near optimal |
| 130-159 mg/dL | Borderline high |
| 160-189 mg/dL | High |
| ≥190 mg/dL | Very high |
HDL Cholesterol
| Level | Interpretation |
|---|---|
| <40 mg/dL (men) | Low (risk factor) |
| <50 mg/dL (women) | Low (risk factor) |
| ≥60 mg/dL | Protective |
Triglycerides
| Level | Interpretation |
|---|---|
| <150 mg/dL | Normal |
| 150-199 mg/dL | Borderline high |
| 200-499 mg/dL | High |
| ≥500 mg/dL | Very high (pancreatitis risk) |
Total Cholesterol
| Level | Interpretation |
|---|---|
| <200 mg/dL | Desirable |
| 200-239 mg/dL | Borderline high |
| ≥240 mg/dL | High |
How It's Measured
- Fasting lipid panel - Traditional (8-12 hour fast)
- Non-fasting - Now acceptable for most screening
- Lab blood draw - Standard method
HealthKit: Can store lipid values from clinical records.
Risk Assessment Context
Lipid targets depend on: - Existing heart disease - Lower targets for secondary prevention - Diabetes - Often treated as high-risk - 10-year ASCVD risk - Calculated using multiple factors - Other risk factors - Smoking, hypertension, family history
Confounders & Limitations
- Fasting status - Mainly affects triglycerides
- Acute illness - Can lower LDL temporarily
- Recent weight loss - Temporarily changes lipids
- Medications - Statins, thyroid drugs, etc.
- Genetics - Familial hypercholesterolemia causes very high LDL
Use Cases
- Cardiovascular risk screening - Routine health assessment
- Treatment monitoring - Assess statin effectiveness
- Lifestyle tracking - Impact of diet and exercise
- Family history concerns - Early screening if family history
Treatment Targets
Individualized based on risk: - Very high risk (existing CVD): LDL <70 mg/dL - High risk (diabetes, high 10-year risk): LDL <100 mg/dL - Moderate risk: LDL <130 mg/dL
Non-Pharmacologic Interventions
- Diet - Reduce saturated fat, increase fiber
- Exercise - Raises HDL, lowers triglycerides
- Weight loss - Improves all lipid parameters
- Smoking cessation - Raises HDL