New Study Suggests That Non-Fasting Lipid Levels May Be Used Instead of Fasting Lipid Levels in Cardiovascular Disease Risk Screening and Treatment

In a study published in JAMA Internal Medicine showed that both fasting and non-fasting lipid levels were associated with incident coronary and atherosclerotic cardiovascular disease (ASCVD) risk and yielded similar results. The study led by Dr. Samia Mora suggests that routine measurement of non-fasting lipid levels may help in ASCVD risk screening and treatment.

Although most people are in the non-fasting state, fasting samples have been the standard for measuring lipid profiles. There has been evidence to suggest that the post-prandial state may actually strengthen the association between lipid levels and the occurrence of cardiovascular disease. However, there have been no recent studies that simultaneously examined the association between both fasting and non-fasting lipid levels and ASCVD risk prospectively in a single population. To address this knowledge gap, Dr. Mora and her team used data from from the large-scale randomized clinical Anglo-Scandinavian Cardiac Outcomes Trial–Lipid Lowering Arm (ASCOT-LLA) to compare the association between fasting and non-fasting lipid levels and cardiovascular disease risk.

ASCOT-LLA was a randomized, placebo-controlled trial that tested whether atorvastatin would reduce the rate of incident coronary events in patients at high risk of cardiovascular disease. A total of 10,305 participants were randomized to atorvastatin or placebo. In this post-hoc analysis, 8,270 patients out of the 10,305 patients had both fasting and non-fasting lipid levels available and were included in the secondary analysis. The primary endpoint of the trial consisted of a composite of nonfatal myocardial infarction and fatal coronary heart disease. The investigators also designated a composite of myocardial infarction, stroke, and ASCVD death as a secondary endpoint.

In the 8,270 patients included in the sub-analysis, the investigators found that the association between fasting lipid levels and the outcome did not differ based on whether the patient was fasting. In both states, higher levels of low-density lipoprotein (LDL) and lower levels of high-density lipoprotein (HDL) were associated with the outcome. Additionally, there was no evidence of significant interaction by fasting state noted on the association between lipid levels and the outcome. For example, adjusted HRs per 40 mg/dL for LDL cholesterol were 1.32 (95% CI 1.08-1.61, p = 0.007) for when not fasting and 1.28 (95% CI 1.07-1.55, p = 0.008) for fasting levels. Results were similar when only patients with no prior history of coronary heart disease were assessed (HR 1.42, 95% CI 1.13-1.78, p = 0.003 for nonfasting levels; HR 1.37, 95% CI 1.11-1.69, p = 0.003 for fasting levels). Also, results were consistent in both the atorvastatin and placebo group. Finally, concordance of fasting and non-fasting lipid profiles when patients were classified into appropriate ASCVD risk categories was similar between the two groups (94.8% concordance).

Dr. Mora and her team demonstrated that there was no difference in the association between both fasting and non-fasting lipid profiles and cardiovascular outcomes. The results suggest that adapting non-fasting lipid measurements into routine clinical practice is possible in a way that is consistent with the current guidelines for fasting lipid profiles. Dr. Mora highlights one of the major strengths of this study. While previous studies have shown that there was no difference in fasting and non-fasting lipid measurements and the outcome, it was not done in the same individual. This study was one of the first to have both measurements available. Dr. Mora said that the “association with cardiovascular risk was at least as good for nonfasting as for fasting lipid levels measured in the same individuals, and lipid level measurements had very high concordance for cardiovascular risk categorization regardless of fasting status. These results are consistent with prior population-level studies that examined fasting and nonfasting lipid levels and support the recent change in US guidelines to more broadly adopt nonfasting lipids for routine cardiovascular risk assessment.”