BOSTON — Nonfasting lipid status may be a better marker for impaired lipid metabolism than fasting lipids, according to a prospective study.
The findings suggest that patients need not deny themselves a good breakfast or lunch before having their blood drawn for plasma lipid testing.
Dr. István Reiber and Dr. Izabella Mezõ from the Szent György Hospital in Székesfehérvár, Hungary, compared fasting and postprandial lipid levels among 102 nondiabetic patients (44 men), and found that the only significant differences in any lipid parameters were between fasting and nonfasting triglycerides.
It is well known that there are no significant changes in total cholesterol and HDL cholesterol levels between the fasting and postprandial state. In addition, recent study findings suggest that nonfasting triglyceride concentrations in plasma are more predictive of cardiovascular events than are conventional measures of fasting triglycerides, the investigators wrote in a scientific poster presented at a symposium sponsored by the International Atherosclerosis Society.
The study participants had never received lipid-lowering drugs. They underwent separate venous blood draws following an overnight fast, 3 hours after eating their usual breakfasts, and 3 hours after their usual lunches.
Overall, total cholesterol in the fasting state was 5.51 mmol/L, 5.48 mmol/L after breakfast, and 5.69 mmol/L after lunch, a difference that was not significant.
HDL levels also were comparable between the fasting and postprandial states, at 1.12 mmol/L, 1.14 mmol/L (breakfast), and 1.20 mmol/L (lunch), respectively. Triglyceride levels, however, were significantly higher after eating, rising from 2.21 mmol/L in the fasting state, to 2.31 mmol/L after breakfast, and 2.94 mmol/L after lunch.
The researchers also found that both postprandial triglyceride measures correlated significantly with fasting triglycerides. All volunteers who had fasting triglyceride levels below 1.5 mmol/L had postprandial triglyceride levels below 2.0 mmol/L.
In addition to being more convenient, allowing patients to have their lipids measured in a nonfasting state is preferable because after all, “atherosclerosis is a postprandial story,” the researchers wrote, referring to the fact that people are in a postprandial state at least 20 hours daily.
Lipid measures 2-4 hours after meals provide a better early predictor for cardiovascular disease than do fasting lipids, concluded the investigators, who advised intervention whenever a patient has triglycerides higher than 2.0 mmol/L with elevated LDL and decreased HDL. Their suggested triglyceride treatment targets are fasting triglycerides lower than 1.0 mmol/L, or 2-4 hour postprandial triglycerides lower than 3.0 mmol/L.
Neither investigator disclosed relevant conflicts of interest.