Arterial stiffness, wave reflection amplitude and left ventricular afterload are increased in overweight individuals

Background: Reflected pressure waves from the lower body to the heart in overweight subjects return early and augment aortic systolic pressure and increase left ventricular (LV) afterload and wasted energy.Methods: Central aortic pressure waves were generated from radial artery pressure waves recorded non-invasively in 176 subjects (age 52 Æ 18 years).Augmentation index (Alx), an estimate of wave reflection, and LV wasted energy (Ew) were calculated from the generated aortic pressure wave.Data were collected in 88 non-diabetic, non-renal disease normotensive overweight (BMI 30 Æ 5.0 kg/m 2 ) subjects and compared to data collected from 88 normotensive normal weight (BMI 23 Æ 2.1, P < 0.01) control subjects matched for gender, age, height, heart rate and ejection duration.Results: Compared to controls, overweight subjects had higher aortic systolic (124 Æ 17 vs 114 Æ 14 mmHg, P < 0.001) and pulse (44 Æ 16 vs 37 Æ 12 mmHg, P < 0.001) blood pressures.Also, increased BMI was associated with an increase in Alx (28 Æ 9.3 vs 20 Æ 12%, P < 0.001), reflected wave duration (176 Æ 28 vs 159 Æ 30 msec, P < 0.004) and Ew (2527 Æ 1732 vs 1498 Æ 1375 dsc À2 , P < 0.001) and a decrease in pressure wave travel time (133 Æ 14 vs 143 Æ 15 msec, P < 0.001).These modifications in wave reflection characteristics in overweight subjects were associated with a decrease in pulse pressure amplification (1.3 Æ 0.14 vs 1.5 Æ 0.29, P < 0.01).Conclusions: Overweight subjects have a stiffer arterial system which decreases wave propagation time and causes the reflected pressure wave to arrive earlier at the heart with