High-intensity interval training improves blood pressure and adropin plasma levels in elderly with hypertensive treatment

Adropin is a newly identified bioactive protein that is important in energy hemostasis and vascular endothelial function. The purpose of the present study was to investigate plasma levels of adropin and nitrite/nitrate (NO), in elderly treated hypertensive subjects at baseline and follow-up after 6 weeks of high-intensity interval training (HIIT). Forty-four elderly participants with treated hypertensives (age 61.09±5.82 years, 25 male and 19 female, BMI= 25.7±1.31 kg/m2) were randomly assigned to either the high-intensity interval training (HIIT) or control group. The HIIT group received an intervention consisting of 10 intervals of 1.5 min at 85% to 90% of their heart rate reserve (HRR), separated by 2 min of rest at 50% to 55% of their HRR, in three sessions per week for a duration of six weeks. Plasma levels of adropin and NO were measured using enzyme-linked immunosorbent assay. The statistical analysis was performed by two-way repeated ANOVA to determine differences between groups and Pearson’s correlation coefficient to determine correlation. The results showed that, following the six-week HIIT intervention, the plasma levels of adropin and NO significantly increased when compared to both control group (P= 0.0016) and the baseline (P= 0.0003) measurements. Peak oxygen consumption was increased after exercise training compared to the control group (P=0.005). Δ adropin in the HIIT group showed a positive correlation with increased Δ NO (r= 0.707, P= 0.002) and Δ VO2peak (r= 0.836, P= 0.001), and a negative correlation with Δ DBP (r= 0.643, P= 0.025) and Δ SBP (r= 0.691, P= 0.013). The study findings suggests that HIIT can enhance both blood pressure and cardiorespiratory fitness. The observed increase in plasma level of adropin may have contributed to reduction of blood pressure by promoting nitric oxide production.