Lipid screening: is it enough to measure total cholesterol concentration?

Area of Science:

• Cardiovascular Medicine
• Clinical Biochemistry
• Public Health Screening

Background:

• Coronary heart disease (CHD) is a leading cause of mortality.
• Accurate identification of patients at risk is crucial for effective prevention strategies.
• Lipoprotein abnormalities, including cholesterol and triglyceride levels, are key indicators of CHD risk.

Purpose of the Study:

• To evaluate if total cholesterol measurement alone is sufficient for identifying patients at risk of CHD.
• To determine the necessity of measuring triglyceride and high-density lipoprotein (HDL) cholesterol alongside total cholesterol.

Main Methods:

• A cross-sectional screening program was conducted across six general practices in Oxfordshire.
• Data were collected from 1901 men and 2068 women aged 25-59.
• Cardiovascular risk was assessed using fasting plasma concentrations of total cholesterol, triglyceride, and HDL cholesterol.

Main Results:

• Among 2931 patients, 74% had total cholesterol < 6.5 mmol/l. Isolated hypertriglyceridemia was missed in 185 patients without triglyceride measurement.
• Only 18 patients (0.6%) had both high triglycerides (≥ 2.3 mmol/l) and low HDL cholesterol (< 0.9 mmol/l).
• In patients with hypercholesterolemia (total cholesterol ≥ 6.5 mmol/l), HDL measurement refined risk assessment, identifying 9% with moderately increased risk (total:HDL ratio < 4.5) and 3.5% with low risk (ratio < 3.5).

Conclusions:

• Fasting triglyceride and HDL cholesterol measurements identify few additional at-risk patients when total cholesterol is below 6.5 mmol/l.
• These lipid parameters are crucial for patients with total cholesterol exceeding 6.5 mmol/l for precise risk stratification.
• Full lipoprotein assessment, including HDL cholesterol, is recommended before initiating lipid-lowering drug therapy.