PROGRESSION OF SUBCLINICAL ATHEROSCLEROSIS IN 6 YEARS - ULTRASOUND EVALUATION OF THE AVERAGE, COMBINED FEMORAL AND CAROTID BIFURCATION INTIMA-MEDIA THICKNESS

The intima-media complex thickness (IMT) was evaluated in 472 asymptom atic subjects in a 6-year follow-up study. Four age groups were includ ed (40-45, 46-50, 51-55 and 56-60) with the aim of obtaining a random equal number of men and women sample. The baseline IMT ranged from 0.4 2 to 2.12 mm (mean 0.63 mm, SD 0.14 mm). In 4.66% subjects completing the 6-year follow-up, the IMT decreased by more than 0.1 mm and in 18% there was no significant IMT change (> 0.1 mm). In the remaining indi viduals (77.33%) the IMT increased by at least 0.1 mm. The IMT increas e in the 56-60 age group was significantly higher than in the remainin g age groups (p < 0.02). A significantly higher percentage of smokers was also observed in the 56-60 age group(p < 0.05). However the IMT in crease in the smoker subgroups was not significantly different from th e mean IMT increase observed in the whole group or from the IMT increa se observed in the non-smoker group. Blood pressure variations were no t associated with change of IMT over six years. The main difference be tween the four groups was an average weight 5.7% higher in the oldest age group at the end of the study (4.44% higher at inclusion). in conc lusion the increase in IMT appeared to be greater in older subjects an d the effect of smoking did not apparently affect IMT increase. The me thod of IMT measurements is able to demonstrate the age-related evolut ion of intima-media in a population.