Interaction between smoking and the Sstl polymorphism of the apo C-III gene determines plasma lipid response to diet.

BACKGROUND

It has recently been demonstrated that the lipid profile of smokers improves if they follow a Mediterranean diet.

AIM

To establish whether the Sstl polymorphism of the apo C-III gene interacts with smoking and determines the lipid response to diet in healthy subjects.

METHODS AND RESULTS

Fifty-nine volunteers (18 smokers: 8 with the S1S1 genotype, and 10 with the S2 allele; 41 non-smokers: 29 with the S1S1 genotype and 12 with the S1S2 genotype) consecutively followed three different diets: a diet enriched in saturated fatty acids (SFA) (38% fat, 20% SFA) followed by a randomised, cross-over period during which they ate a diet enriched in carbohydrates (NCEP-1) (30% fat, 10% SFA, 55% carbohydrates) and a diet enriched in monounsaturated fatty acids (MUFA) (8% fat, 22% MUFA). Cholesterol, triacylglycerol, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) levels were measured at the end of each dietary period. The smokers carrying the S1S1 genotype were not influenced by any of the diets, but the atherogenic ratio decreased in the carriers of the S2 allele when they changed from the diet rich in SFA to a diet rich in olive oil or carbohydrates (p < 0.039). No significant difference was observed when the non-smoking carriers of the S2 allele changed from one diet to another, but there was a decrease in the LDL-C/HDL-C ratio when the subjects with the S1S1 genotype changed from the saturated diet to either of the other diets (p < 0.001).

CONCLUSIONS

Smoking interacts with the apo CM polymorphism and determines the level of lipid response to dietary changes.