Fasting or Non-fasting Lipids for Atherosclerotic Cardiovascular Disease Risk Assessment and Treatment?

Dyslipidemia is a major modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD); however, lipid testing for risk assessment and treatment surveillance has been underutilized. Several factors likely account for this, including the common practice of measuring lipid levels in the fasting state, which often necessitates that patients return for an additional visit. In this review, we evaluate potential advantages and cautions associated with measuring lipids in the non-fasting state.

There is similar performance with the use of either fasting or non-fasting total cholesterol and HDL cholesterol in ASCVD risk assessment. Observational studies demonstrate that in comparison to fasting levels, non-fasting triglycerides are approximately 20% higher on average, although the magnitude of difference is subject to substantial inter-patient variability. Higher triglycerides can lead to the under-estimation of low-density lipoprotein cholesterol (LDL-C) by approximately 10 mg/dL or more when calculated using the Friedewald equation. This is especially clinically relevant at low LDL-C levels, although a novel validated algorithm for LDL-C estimation largely overcomes this limitation. Non-fasting lipid assessment is reasonable in many clinical circumstances given that ASCVD risk prediction is similar using fasting or non-fasting lipid values and because LDL-C can be accurately estimated using modern methods. Allowing the option for non-fasting lipid assessment can reduce a barrier to lipid testing and can facilitate a more convenient assessment of ASCVD risk with the ultimate potential effect of reducing the global burden of ASCVD. However, certain patients such as those with severe hypertriglyceridemias or high-risk patients being treated to low LDL-C levels may still need fasting lipid panels performed for precise diagnosis and to standardize therapeutic monitoring.