Arterial stiffness response to exercise in persons with and without Down syndrome

This study compared arterial stiffness and wave reflection at rest and following maximal exercise between individuals with and without Down syndrome (DS), and the influence of body mass index (BMI), peak oxygen uptake (VO₂peak) on changes in arterial stiffness. Twelve people with DS (26.6 ± 2.6 yr) and 15 healthy controls (26.2 ± 0.6 yr) completed this study. Intima-media thickness (IMT) and stiffness of common carotid artery was examined. Hemodynamic and arterial variables were measured before and 3-min after exercise. Persons with DS had higher BMI and lower VO₂peak than controls. IMT did not differ between groups. At rest, carotid β stiffness was significantly higher in persons with DS (P < 0.05) but there was no difference in between groups for any of the other arterial stiffness measures. After exercise, persons with DS exhibited attenuated arterial stiffness responses in AIx-75, carotid β stiffness and Ep in contrast with controls (significant group-by-time interactions). When controlling for BMI and VO₂peak, the interactions disappeared. In both groups combined, BMI was correlated significantly with carotid Ep and β at rest. VO₂peak correlated significantly with AIx-75 and its pre-post change (r = ?0.45, P = 0.029; r = 0.47, P = 0.033, respectively). The arterial stiffness responses to maximal exercise in persons with DS were blunted, potentially reflecting diminished vascular reserve. Obesity and particularly VO₂peak influenced these findings. These results suggest impaired vascular function in people with DS.