Objective: The augmentation index (AI) derived from central arteries is generally defined as an index of augmentation of central blood pressure in systole derived from the return of pressure waves reflected from the periphery and is an index of arterial stiffness. There is controversy with respect to how to affect AI.
Methods: In a cross-sectional study of 4985 subjects (2417 men and 2568 women) aged 18 - 96 years (50.94 +/- 14.73 years, mean +/- SD), AI was measured in the left radial artery using tonometry Colin HEM-9000AI.
Results: Among the subjects, 39.4% were diagnosed as hypertensive, 11.2% as diabetes mellitus, and 48.7% as hyperlipidemia. Stepwise regression analysis revealed that age, diastolic blood pressure, smoking, heart rate, height, waist circumference and fasting blood glucose were independent determinants of radial AI in women;while in men, it was also determined by total cholesterol. Radial AI was significantly higher in women than in men [(83.18 +/- 12.36)% vs. (71.93 +/- 15.22)%, P < 0.01].
Conclusion: Our findings indicate that AI is determined by arterial stiffness, distance to the reflection point and reflection coefficient. It is necessary to take into account these confounding factors when assessing AI is used as an index for atherosclerosis.