Initial Diagnostic Work-Up for Hyperlipidemia in a 26-Year-Old Without Known ASCVD
Obtain a lipid profile (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) at the initial evaluation, which can be done either fasting or non-fasting unless specific risk factors are present. 1, 2, 3
When to Screen This Patient
Screen now if any of the following risk factors are present: diabetes mellitus, family history of premature cardiovascular disease (male relatives <50 years or female relatives <60 years), current cigarette smoking, hypertension (BP ≥140/90 mmHg or on antihypertensive medication), obesity, or multiple CHD risk factors 1, 4
Defer screening until age 35 years if male without risk factors or until age 45 years if female without risk factors, as routine screening is not recommended for low-risk young adults in this age group 1, 4
Fasting vs. Non-Fasting Sample
Order a non-fasting lipid panel for initial screening in most cases, as this is adequate for cardiovascular risk assessment and removes a barrier to testing 2, 3, 5
Order a fasting lipid panel instead if:
- Family history of premature ASCVD or genetic hyperlipidemia is present, as fasting helps identify familial lipid disorders more accurately 2, 3
- Non-fasting triglycerides return ≥400 mg/dL, as the Friedewald equation for calculating LDL-C becomes inaccurate at this threshold 2, 3, 5
Components of the Lipid Profile
The standard lipid profile must include 1, 4:
- Total cholesterol
- LDL cholesterol (calculated by Friedewald equation if triglycerides <400 mg/dL, or measured directly if ≥400 mg/dL)
- HDL cholesterol
- Triglycerides
- Non-HDL cholesterol (calculated as total cholesterol minus HDL cholesterol) - this is particularly useful as it can be accurately measured in non-fasting samples 1
Confirming Abnormal Results
Repeat the lipid panel on a separate occasion if initial results are abnormal, and use the average of both measurements for risk assessment and treatment decisions 1, 6
Obtain a fasting lipoprotein analysis if the initial non-fasting test shows borderline or elevated values, particularly if triglycerides are elevated 1
Special Considerations for This Age Group
If familial hypercholesterolemia is suspected (LDL-C ≥190 mg/dL or ≥135 mg/dL with family history of premature cardiovascular disease), refer to a lipid specialist for genetic testing and more intensive evaluation 1
For patients with diabetes diagnosed at this age:
- Obtain lipid profile at the time of diabetes diagnosis, preferably after glycemia has improved 1
- Initial testing may be done with non-fasting non-HDL cholesterol with confirmatory fasting lipid panel 1
- If initial LDL cholesterol is ≤100 mg/dL, repeat testing at 9-11 years of age 1
Follow-Up Testing Intervals
Repeat lipid testing every 5 years if initial results are normal and no risk factors develop 1, 4
Test more frequently (annually or every 1-2 years) if lipid levels are near treatment thresholds or if cardiovascular risk factors are present 4
Common Pitfalls to Avoid
Do not use calculated LDL-C when triglycerides are ≥400 mg/dL - order fasting lipids and consider direct LDL-C measurement instead 2, 3
Do not delay lipid testing because the patient arrives non-fasting - proceed with non-fasting measurement for most clinical scenarios 2, 3
Do not rely on a single lipid measurement for diagnosis or treatment decisions - always confirm with a repeat test 1, 6
Do not screen all young adults regardless of risk factors, as this leads to unnecessary testing in low-risk individuals where absolute benefit is minimal 1