Effects of dietary fat modification on fibrinogen, factor VII, and plasminogen activator inhibitor-1 activity in subjects with impaired glucose tolerance

Abstract

Our aim was to assess the impact of a monounsaturated fat—enriched (Mono) diet and a diet recommended by the National Cholesterol Education Program (NCEP) on plasma levels of fibrinogen and activities of factor VII (FVII:C) and plasminogen activator inhibitor-1 (PAl-1) and the impact of genetic polymorphisms of these variables ( HaeIII, Mspl, and 4G 5G polymorphisms, respectively) in 28 subjects with impaired glucose tolerance ([IGT] 17 men and 11 women; mean age, 55.6 ± 5.5 years). A diet rich in fat and saturated fatty acids served as a baseline diet for 3 weeks. Thereafter, subjects were randomized for the next 8 weeks to either the Mono diet (n = 12) or NCEP diet (n = 16). Fibrinogen levels or PAl-1 activities did not change with either of the diets, but fibrinogen levels were higher (3.4 ± 0.5 v 4.0 ± 0.6 g/L, P = .007 at baseline) throughout the study in heterozygous subjects with respect to HaeIII polymorphism. This polymorphism and age accounted for 38% of the variation of fibrinogen levels. Mspl polymorphism together with body mass index explained 51% of the variation of FVII:C, which was higher in subjects with the M1M1 genotype compared with M1M2 M2M2 genotypes (127% ± 21% v 90% ± 12%, P < .001). FVII:C showed a decrease with the NCEP diet ( P < .05), but the decline was confined to M1M1 subjects. PAl-1 activity did not differ significantly between the genotypes. The insulin sensitivity index (S 1) obtained by the minimal model method was the main explanatory variable of PAl-1 activity. To conclude, despite good compliance, the fat-modified diet did not alter plasma levels of fibrinogen or PAl-1 in white subjects with IGT. FVII:C levels decreased with the NCEP diet, but this was confined to subjects with the M1M1 genotype.