Apolipoprotein B gene polymorphisms and serum lipids: meta-analysis of therole of genetic variation in responsiveness to diet

Background: The genetic variance determining plasma lipid and lipoprotein c oncentrations may modify individual responsiveness to alterations in dietar y fat and cholesterol content. Objective: The aim was to examine the role of apolipoprotein (apo) B DNA po lymorphisms in responsiveness of plasma lipids and lipoproteins to diet. Design: A controlled dietary intervention study was conducted in 44 healthy , middle-aged subjects with a 3-mo baseline, a 1-mo fat-controlled, a 1-mo high-fat, and a 1-mo habitual diet period. We also conducted a meta-analysi s of all published dietary trials, including our own. Results: In our own dietary study, the apo B XbaI restriction-site polymorp hism affected the responsiveness to diet of the plasma LDL-cholesterol conc entration (P < 0.05, repeated-measures analysis of variance). Especially du ring the high-fat diet, homozygous absence of the XbaI restriction site (X- /X-) was associated with a greater increase in LDL cholesterol (44 +/- 5%) than was X+/X+ (27 +/- 7%) or X+/X- (40 +/- 5%). The high-fat diet also ind uced a larger increase in plasma LDL cholesterol in subjects with the R-/R- genotype (homozygous absence of the EcoRI restriction site) (59 +/- 10%) t han in those with the R+/R-(39 +/- 6%) or R+/R+ (36 +/- 4%) genotype. The M +/M+,genotype (homozygous presence of the MspI restriction site) was also m ore responsive (41 +/- 3% increase in LDL cholesterol) than the M+/M- genot ype (27 +/- 10% increase). The meta-analysis supported the finding of the s ignificant role of the EcoRI and MspI polymorphisms, but not that of the Xb aI polymorphism. Conclusions: The present study indicated that the apo B EcoRI and MspI poly morphisms are associated with responsiveness to diet.