AGE, HYPERTENSION AND TYPE-I DIABETES IND UCE OPPOSITE MODIFICATIONS IN STORAGE CAPACITY OF MEDIUM-SIZE ARTERIES

Objective : to study the structural modifications of a muscular and me dium-size radial artery as regards age, in normal subjects (NT) and HT and DTI. Material and methods : transverse study with 39 NT aged 48 1 6 years, were compared to 22 HT, aged 50 +/- 11 years, and to 22 DT ag ed 37 +/- 12 years. An echo-tracking system (NIUS 01, Asulabs, Neuchat el, Switzerland) were used to measure the systolic (Ds) and diastolic diameter (Dd) and derive three indices of compliance and storage capac ity : systolo-diastolic variation of cross sectional area VSCA = pi [( Ds2/4) - (Dd2/4)] mm2, operative arterial compliance CA = pi Dd (Ds - Dd) / 2 (PAS - PAD) in mm2/mmHg. Results : 1-degree In NT, Ds and Dd i ncreased significantly with age (p < 0.01), likewise the VSCA, and CA (p < 0.002). 2-degrees In HT and DTI, when age was taken into account, the Ds and Dd were significantly greater than in control but VCSA and CA were higher in HT and lower in DT. Conclusion : similar to ageing changes in NT, HT lead to increase in medium-size radial artery the di ameter and storage capacity, while to decrease in DT. This suggests th at opposite cardiovascular load induce opposite modifications in arter ial wall structure leading to reduce the wall stress.