Influence of apolipoprotein A-1 promoter polymorphism on lipid levels and responses to dietary change in Finnish adults

Objectives. To analyse the association between the G/A polymorphism in the apolipoprotein A-1 (apo A-1) promoter region and plasma lipid levels, as well as their responses to dietary change, in Finnish adults.
Subjects and design. Blood samples from 86 subjects (42 men, 44 women) who attended a dietary intervention study carried out in North Karelia in 1993 were available for the current analysis. The diet study consisted of a 2-week baseline period, followed by an 8-week intervention period, and an 8-week switchback period.
Intervention. Diet was modified to a low-fat, low-cholesterol diet during the dietary intervention.
Main outcome measures. Fasting plasma lipid, lipoprotein and apolipoprotein levels were determined.
Results. At baseline, the high-density lipoprotein (HDL) cholesterol and apo A-1 levels were higher ( P <0.01) and the triglyceride levels were lower ( P <0.05) in men, but not in women, with the A allele. The differences in HDL cholesterol and apo A-1 levels between genotypes remained during the low-fat, low-cholesterol diet and switchback periods. Apart from the difference between responses in apo A-1 during switchback to the original diet, lipid responses to dietary change did not differ significantly between genotypes.
Conclusion. Our findings indicate a significant association between the apo A-1 promoter polymorphism and plasma apo A-1 and HDL-cholesterol in men. In theory, the higher plasma HDL-cholesterol and apo A-1 levels in the GA/AA group may confer some protection against coronary artery disease. The differences in HDL-cholesterol and apo A-1 levels between genotypes persisted during different diets suggesting that the possible benefit is independent of fat and cholesterol intake.