Coagulation factor 7 in elderly people : genetic disposition and diet

In elderly people an increase in thrombotic tendency may lead to a increase in the risk of a coronary event. Coagulation factor VII affects this thrombotic tendency and has been recognised as a risk indicator for coronary heart disease. It is not known whether the level of factor VII can be influenced at older age. From studies in young subjects it is clear that dietary fat and the R/Q353 polymorphism (alleles R and Q) are the main determinants of factor VII. We studied the relation of factor VII with diet in elderly men and women, taking the R/Q353 polymorphism into account.

In a cross-sectional study among 1158 elderly men and women (>55 y) factor VII coagulant activity (FVII:C) and total factor VII (FVIIt) were investigated in relation to serum-triglycerides, the R/Q353 polymorphism and the habitual diet. FVII:C was inversely associated with dietary fibre and protein and positively with saturated fat intake and serum-triglycerides. These associations were much stronger in subjects with the RR genotype compared to those carrying the Q allele; if the mean intake of dietary fibre would increase with 10 g a day, FVII:C would be expected to decrease with 7.6 % in elderly people homozygous for the R allele versus only 1.9 % decrease in those carrying the Q allele. FVIIt was inversely related to intake of dietary fibre and positively to serumtriglycerides, again the associations being stronger in subjects with the RR genotype. In a cross-over study among elderly women (>60 y, 35 RQ/QQ, 56RR) the postprandial response of activated factor VII (FVIIa) to several fat-rich (50 g) breakfasts was evaluated. The response of (FVIIa) was very similar for meals rich in palmitic acid, rich in stearic acid or rich in linoleic/linolenic acid with a ratio of 3:1 or 15:1. The increase in FVIIa ranged from 14.9 (95% CI: 10.6,19.2) IUmL after the stearic rich breakfast to 21.1 (16.6,25.6) IU/mL after the linoleic/linolenic 15:1 rich breakfasts. After the fat-free control breakfast FVIIa decreased with 8.7 (6.3,11.1) IU/mL. The mean absolute total response to the fatrich breakfasts combined was 37 IU/mL in subjects with the RR genotype and 16.1 IU/mL in subjects carrying the Q allele. Also the response relative to the fasting (FVIIa) level differed significantly between the genotype groups (RR: 42%, RQ/QQ: 32%). Serumtriglycerides concentration was not associated with FVIIa.

In elderly people, factor VII is influenced by dietary fibre, total dietary fat and serumtriglycerides and not by fat type. The R/Q353 polymorphism strongly modifies these effects. This indicates that an increase in dietary fibre and a decrease in dietary fat intake may reduce the risk of a coronary event by reducing the level of factor VII particularly in elderly people with the RR genotype.