Short-term aerobic exercise improves arterial stiffness in type 2 diabetes

Objective: To investigate whether: (1) aerobic exercise decreases arterial stiffness and (2) reduction in arterial stiffness is associated with improvement in insulin resistance in type 2 diabetes. Methods: Common carotid and femoral arterial stiffness was ultrasonographically evaluated using stiffness index β in 23 type 2 diabetic subjects before and after a 3-week exercise protocol including ergometer and walking. Insulin sensitivity (Clamp-IR) was assessed using euglycemic-hyperinsulinemic clamp before and after the protocol. Arterial stiffness was also examined in steady hyperinsulinemic state during clamp. Results: Anthropometrical factors did not change following exercise. Clamp-IR tended to increase after exercise protocol (P=0.061). Stiffness index β decreased following exercise in both common carotid and femoral arteries (P=0.020 and P<0.001, respectively). ΔClamp-IR was significantly correlated with the changes in stiffness index β of both common carotid (P=0.040) and femoral artery (P=0.016). Divided into tertiles according to ΔClamp-IR, decreases in stiffness index β for both common carotid (P=0.009) and femoral (P=0.037) arteries was greater in tertile group with a higher ΔClamp-IR. Hyperinsulinemia during clamp decreased stiffness index β in both common carotid (P=0.031) and femoral (P=0.025) arteries before exercise, but these effects disappeared after the exercise protocol. Conclusions: Short-term aerobic exercise significantly decreased arterial stiffness in both common carotid and femoral arteries, and the reduction of stiffness was associated with improvement of insulin resistance in type 2 diabetes.