Identifying patients with hypercholesterolemia. More than one blood sample is needed

Area of Science:

• Clinical Chemistry
• Preventive Cardiology
• Family Medicine

Background:

• Hypercholesterolemia is a significant risk factor for cardiovascular disease.
• Accurate diagnosis is crucial for timely intervention and management.
• Current diagnostic practices may rely on single measurements, potentially leading to misclassification.

Purpose of the Study:

• To compare the diagnostic accuracy of using one versus two blood samples for hypercholesterolemia.
• To evaluate the reliability of single total cholesterol (TC) measurements in classifying cholesterol risk categories.

Main Methods:

• A test-retest substudy within a randomized control trial involving 142 patients with moderate hypercholesterolemia.
• Two blood samples for TC level determination were collected from each participant at different times.
• Classification into normal, moderate, or high cholesterol risk categories was based on single and average TC values.

Main Results:

• The overall misclassification rate using a single TC level was 22.5%, with a high false-positive rate of 50% for those initially in the high-risk category.
• The false-negative rate was 3.5%.
• Misclassification rates were not significantly influenced by patient demographics, clinical factors, or fasting status.

Conclusions:

• Single total cholesterol measurements are unreliable for diagnosing hypercholesterolemia.
• Family physicians should utilize the average of two cholesterol readings, taken 1-8 weeks apart, for diagnostic and treatment decisions.