The effects of submaximal exercise on a treadmill on the recovery of the stiffness index and reflection index in men with untreated hypertension

Abstract

Aim. Increased arterial stiffness is a risk factor for cardiovascular disease (CVD). Adult men with untreated hypertension are at risk of future CVD. The study aimed to compare the effects of a submaximal exercise on the recovery of the two descriptors of arterial pressure waveform, i.e. stiffness index (SI) and reflection index (RI), between men with untreated hypertension (HA) and healthy peers. Material and Methods. The study included 70 Caucasian men with untreated primary HA and 30 normotensive men. Blood pressure, SI and RI were determined by photoplethysmography before and 6 minutes after a submaximal (up to 85% of age-predicted maximal heart rate) exercise on a treadmill. Results. Baseline SI was higher in HA than control men (6.06 [0.66] vs. 6.61 [0.84] m/s; p=0.0019) and remained significantly increased during post-exercise recovery only in HA men (7.59 [1.6] vs. 6.18 [0.85] m/s; p<0.0001). Pre-exercise RI did not differ between HA and healthy men (50.74 [14.17] vs 48.9 [14.86]%). Six minutes after the exercise, RI higher in HA patients than in healthy men (45.26[15.33] vs 36.2 [13.18]%; p=0.0058). Conclusions. Arterial stiffness is higher in men with HA both at rest and 6 minutes after exercise. Compared with healthy men, those with HA have more increased arterial tone and impaired vasodilation but only during the recovery. It suggests that untreated HA patients have abnormal mechanical properties of arterial pressure waveforms during the post-exercise recovery.