High-density lipoprotein functionality in cholesterol efflux in early childhood is related to the content ratio of triglyceride to cholesterol.

Cholesterol efflux capacity (CEC), commonly measured as a useful risk marker of atherosclerotic cardiovascular disease, depends on high-density lipoprotein (HDL) functionality and its concentration. We defined the relative HDL functionality in cholesterol efflux, not influenced by HDL concentration, as the ratio of measured CEC to standardized CEC (stCEC) based on HDL-cholesterol (HDL-C) of each individual using the curve regression equation obtained from the correlation. HDL-C, CEC, and CEC/stCEC levels in the < 28-day-old participants (neonates) were significantly low compared to those of the ≥ 28-day-old participants, indicating that the low CEC levels in the neonates depend on not only lower HDL-C but also lower HDL functionality. The low level of CEC/stCEC was remarkable in neonates born at < 34 weeks of gestation and did not improved to the reference level (1.000) until the infantile period. The relatively low or high CEC/stCEC ratios in neonates and infants were associated with lower or higher HDL-TG and HDL-TG/HDL-C ratio, respectively. However, no apparent effect of HDL-TG and HDL-TG/HDL-C ratio on CEC/stCEC was observed in the ≥ 1-year-old participants, indicating that HDL functionality in cholesterol efflux could be associated with the various HDL particles with various lipid compositions, but not just with HDL-TG and HDL-TG/HDL-C ratio.