The effect of increased egg consumption on plasma cholesteryl ester transfer activity in healthy subjects.

BACKGROUND

Plasma cholesteryl ester transfer activity influences the distribution of cholesterol among plasma lipoproteins and changes in its activities may influence the response of plasma lipoprotein cholesterol levels to increased cholesterol intake in the form of eggs.

OBJECTIVE

The aim of the study was to determine the effect of increased egg intake on plasma newly synthesized cholesteryl ester transfer (NCET) activity and plasma lipids and lipoprotein levels in free-living men and women.

DESIGN

The study was longitudinal and included a 12 d intervention arm and a similar control period immediately prior to the intervention to account for any changes in variables with time.

SUBJECTS

Thirty two healthy subjects aged 20-57 y and consuming self-selected diets were recruited. Twelve men and 14 women were entered into the intervention arm of the study. Twelve of these subjects and six others were in the control group.

INTERVENTIONS

Subjects who participated in the intervention phase received one additional egg per day.

RESULTS

Plasma NCET activity decreased significantly (P = 0.05) in the 26 subjects who consumed an extra egg, mainly due to a significant (P = 0.02) decrease (-13.4%) in the activity in the women. Plasma cholesterol and apolipoprotein B-containing lipoprotein cholesterol increased significantly (P < 0.05) in the intervention group and in men (P = 0.02) but not in women. Age was correlated significantly (r = 0.519, P < 0.01) with the change in plasma NCET activity in all subjects and in men (r = -0.644, P < 0.05). The decrease in plasma NCET activity was significantly (P = 0.02) less in the lowest tertile compared with other tertiles of self-reported habitual dietary cholesterol intake independent of age and gender.

CONCLUSIONS

These data suggest that an increase in dietary cholesterol reduces plasma NCET activity particularly in women and older men and individuals with higher habitual intakes of cholesterol. Furthermore, a reduction in plasma NCET activity may tend to limit the increase in apoB-containing lipoprotein cholesterol in women during increased egg consumption.