Neurohumoral and ambulatory haemodynamic adaptations following isometric exercise training in unmedicated hypertensive patients

OBJECTIVE: Hypertension remains the leading modifiable risk factor for cardiovascular disease. Isometric exercise training (IET) has been shown to be a useful nonpharmacological intervention for reducing resting blood pressure (BP). This study aimed to measure alterations in office BP, ambulatory BP, cardiac autonomic modulation and inflammatory and vascular biomarkers following a programme of IET in unmedicated hypertensive patients. METHODS: Twenty-four unmedicated stage 1 hypertensive patients (age 43.8 ± 7.3 years; height, 178.1 ± 7 cm; weight 89.7 ± 12.8 kg) were randomly assigned in a cross-over study design, to 4-weeks of home-based IET and control period, separated by a 3-week washout period. Office and ambulatory BP, cardiac autonomic modulation, and inflammatory and vascular biomarkers were recorded pre and post-IET and control periods. RESULTS: Clinic and 24-h ambulatory BP significantly reduced following IET by 12.4/6.2 and 11.8/5.6 mmHg in SBP/DBP, respectively (P < 0.001 for both), compared with the control. The BP adaptations were associated with a significant (P = 0.018) reduction in the average real variability of 24-h ambulatory BP following IET, compared with control. Cardiac autonomic modulation improved by 11% (P < 0.001), baroreceptor reflex sensitivity improved by 47% (P < 0.001), and IL-6 and asymmetric dimethylarginine reduced by 10% (P = 0.022) and 19% (P = 0.023), respectively, which differed significantly to the control period. CONCLUSION: This is the first evidence of durable BP reduction and wider cardiovascular disease risk benefits of IET in a relevant patient population. Our findings support the role of IET as a safe and viable therapeutic and preventive intervention in the treatment of hypertension.