Effects of bench step exercise on arterial stiffness in post-menopausal women: contribution of IGF-1 bioactivity and nitric oxide production

Abstract

Objective: To examine the effect of bench step exercise on arterial pulse wave velocity (PWV) and the associated contribution of insulin-like growth factor (IGF)-1 bioactivity and nitric oxide (NO).

Design: Twenty-six elderly (post-menopausal) women were randomly allocated to a bench step exercise group or a control group. The participants in the bench step exercise group practiced a 12-week home-based bench step exercise for 10-20min, 3 times daily (i.e., for a total of 140min/week at the intensity level of lactate threshold (LT)). In addition to conventional risk factors of atherosclerosis, PWV, IGF-1/IGF binding protein (IGFBP)-3 molar ratio (an index for IGF-1 bioactivity), and urinary nitrite/nitrate (NO(x)) excretion were measured before and after the intervention.

Results: BMI, systolic blood pressure, fasting plasma glucose, low-density lipoprotein cholesterol, LT, and PWV were significantly improved in the bench step exercise group. A significant positive correlation between changes in PWV and IGF-1/IGFBP-3 molar ratio, and a significant negative correlation between changes in IGF-1/IGFBP-3 molar ratio and urinary NO(x) excretion were found in the bench step exercise group.

Conclusion: The bench step exercise leads to improvements in not only the classical risk factors of atherosclerosis but also the arterial stiffness in elderly women, partly through NO production via IGF-1 bioactivity.