|RICHARD, CAROLINE - Laval University|
|COUTURE, PATRICK - Laval University|
|OOI, ESTHER M - University Of Western Australia|
|TREMBLAY, ANDRE - Laval University|
|DESROCHES, SOPHIE - Laval University|
|CHAREST, AMELIE - Laval University|
|LICHTENSTEIN, ALICE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|LAMARCHE, BENOIT - Laval University|
Submitted to: Arteriosclerosis Thrombosis and Vascular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2013
Publication Date: 11/21/2013
Citation: Richard, C., Couture, P., Ooi, E.M., Tremblay, A.J., Desroches, S., Charest, A., Lichtenstein, A.H., Lamarche, B. 2013. Effect of Mediterranean diet with and without weight loss on apolipoprotein B100 metabolism in men with metabolic syndrome. Arteriosclerosis Thrombosis and Vascular Biology. 34(2):433-438.
Interpretive Summary: The objective of this study was to assess the effect of a Mediterranean-style diet (MedDiet) with and without weight loss on the metabolism of the major protein, apolipoprotein B100 (apoB100), and on low density lipoprotein cholesterol (LDL), the ‘bad’ cholesterol. The diet of 19 men, ages 24-62 years, with metabolic syndrome was first standardized to a North American isoenergetic (constant energy) control diet for 5 weeks, followed by an isoenergetic MedDiet for an additional 5 weeks under full-feeding conditions. Participants next underwent a 20-week supervised weight loss program which resulted in a 10.2 +/- 2.9% loss of body weight and then they consumed the MedDiet for 5 weeks under weight-stabilizing feeding conditions. The metabolic behavior of apoB100 was assessed in the fasted state at the end of the 3 controlled diet phases using a stable isotope labeled amino acid, leucine. Compared with the control diet, the MedDiet without weight loss reduced low LDL-apoB100 pool size primarily by increasing the amount of this protein lost by the body per unit of time (fractional catabolic rate) and increasing the LDL particle size. The MedDiet with weight loss had no further effect on LDL-apoB100 pool size and fractional catabolic rate but further increased the LDL particle size. These data suggest that a MedDiet has favorable effects on heart disease risk by increasing LDL particle size and reducing LDL-apoB100 concentrations even in the absence of weight loss in men with metabolic syndrome.
Technical Abstract: The objective of this study was to assess the effect of a Mediterranean diet (MedDiet) with and without weight loss (WL) on apolipoprotein B100 (apoB100) metabolism in men with metabolic syndrome. The diet of 19 men with metabolic syndrome (age, 24–62 years) was first standardized to a North American isoenergetic control diet for 5 weeks, followed by an isoenergetic MedDiet for an additional 5 weeks under full-feeding conditions (MedDiet-WL). Participants next underwent a 20-week supervised WL program under free-living conditions (-10.2+/-2.9% body weight; P<0.01) and finally consumed the MedDiet (5 weeks) under weight-stabilizing feeding conditions (MedDiet+WL). In vivo kinetic of apoB100 was assessed in the fasted state at the end of the 3 controlled diets using a bolus of D3-leucine. Compared with the control diet, MedDiet-WL reduced low-density lipoprotein (LDL)-apoB100 pool size (-14.2%, P<0.01) primarily through an increase in LDL-apoB100 fractional catabolic rate (+30.4%, P=0.02) and increased LDL particle size (P<0.01) but had no effect on very-LDL (VLDL)-apoB100 pool size or triglyceride concentrations, despite a significant increase in VLDL-apoB100 fractional catabolic rate (+25.6%; P=0.03). MedDiet+WL had no further effect on LDL-apoB100 pool size and fractional catabolic rate but further increased LDL particle size and reduced VLDL-apoB100 pool size versus the control diet primarily through an increase in VLDLapoB 100 fractional catabolic rate (+30.7%; P<0.01). Consumption of MedDiet increases LDL size and reduces LDL-apoB100 concentrations primarily by increasing the catabolism of LDL even in the absence of WL in men with metabolic syndrome. MedDiet seems to have a trivial effect on VLDL concentrations and kinetics unless accompanied by significant WL.