Serum Folate and Low-Density Lipoprotein Particle Size

Abstract

Nutritional parameters, such as B-vitamins, have not been studied for an association with low-density lipoprotein (LDL) particle size. The present study explored whether serum vitamin levels, including folate and vitamin B-12, could be associated with LDL particle size. Using a randomly selected population of 255 hospital workers, we collected detailed lipid profiles, including triglyceride (TG), high-density lipoprotein (HDL) cholesterol, and LDL particle sizes. The peak particle size of LDL was measured by density gradient ultracentrifugation and a pore gradient lipoprotein system. Serum folate and vitamin B-12 levels were measured about 1 year later and analyzed. Carotid intima-media thickness (IMT) and hepatic steatosis were diagnosed ultrasonographically, and metabolic syndrome was diagnosed using ATP III criteria. LDL peak particle size was significantly correlated with carotid mean IMT (r=-0.16, p=0.010). Serum folate levels were significantly and positively correlated with HDL cholesterol and negatively with TG, although the latter showed borderline significance. With increasing serum folate levels, the LDL peak particle size showed a gradual independent increase, even when adjusted for age, sex, hepatic steatosis, metabolic syndrome, and the TG/HDL cholesterol ratio. Folate may act to enhance LDL particle size. Future clinical and research work should include a study of the safe application and manipulation of folate levels in order to control LDL particle size.