Hemodilution is not the only reason of difference: Comparison of fasting and non-fasting lipoproteins in paired samples.

INTRODUCTION

Low-density lipoprotein cholesterol (LDL) is an important risk factor for cardiovascular disease (CVD) and generally measured after 8-12 h fasting. However, some recent studies have pointed that non-fasting lipoproteins, especially LDL concentrations, are better indicators for demonstrating CVD risk and atherosclerosis. They asserted that nutrition is a negligible factor on changes in lipoprotein concentrations and claimed this difference as a result of hemodilution effect, caused from fluid intake and can be eliminated by applying some adjustments. We aimed to compare the fasting and non-fasting LDL values of the same individuals and discuss whether non-fasting and fasting LDL results can be used in place of each other, directly or after applying hemodilution correction models.

MATERIAL AND METHODS

Fasting and non-fasting blood samples of 248 apparently healthy participants were collected. Lipid panel tests, albumin and hemoglobin levels were studied in each sample. Results were evaluated in seven different models which were recommended to correct the hemodilution effect on fasting and non-fasting lipid concentrations of the same individual. Concordance of fasting and non-fasting risk group of the individual were calculated according to the National Cholesterol Education Program classification.

RESULTS

Fasting and non-fasting LDL and non-high density lipoprotein cholesterol (non-HDL) concentrations were significantly different in every model (p < 0.001). Concordance results of fasting and non-fasting LDL and non-HDL risk groups were 63.8% and 77.9% respectively.

CONCLUSIONS

Our results demonstrated that fasting and non-fasting LDL and non-HDL concentrations could not be used in place of each other even when the results were adjusted for elimination of the hemodilution effect.