EFFECT OF AGE AND SEX ON THE PLATELET FATTY ACID (FA) COMPOSITION AND IN ITS MODULATION BY PLASMA FA

Age, sex and platelet hyperactivity are factors that condition the development of coronary heart disease (CHD). Platelet function is believed to be influenced by its FA pattern, which can be modulated by the FA composition of plasma lipid fractions. Therefore, it seemed of interest to evaluate the effect of age and sex on platelet FA and ascertain whether the plasma influence on platelet FA is modified by age and sex. The study has been performed in 98 subjects, 49 couples, men (M) and women (W), living together and with the same dietary habits. The subjects were divided into three age groups : G I:16-40, GII:40-60,and G III: 60. Plasma and platelet FA of phospholipids (PL), triglycerides, and free FA fractions were evaluated by gas-chromatography. The results showed scarce differences in platelet FA in relation to sex. With respect to age, the percentages of 18:2 and 20:5 in most platelet lipid fractions both in M and in W decrease with age. More interesting are the differences in correlation found between plasma and platelet FA, particularly in the PL fraction, with age and sex. In this respect an increase in the correlation coefficient was found for 16:0,18:0 and 20:4 and a decrease for 20:5 in middle aged men and postmenopausic women (Table). The similarity between these two groups of subjects may have a physiopathological meaning, if we take into account that both are more susceptible to CHD and that an increase in 16:0, 18:0 and 20:4 as well as a decrease in 20:5 may condition a platelet hyperfuntion, circumstance that may be more easily produced by plasma influence in those subjects.The results of the present study also confirm that that in general plasma greately influences the platelet content in 18:1, 18:2 and to a lower extent the saturated FA.