The differential impact of aerobic and isometric handgrip exercise on blood pressure variability and central aortic blood pressure.

BACKGROUND: Blood pressure variability and central SBP are independent markers of cardiovascular risk. Data on lifestyle-interventions to reduce these parameters are sparse. The present work reports the differential effects of aerobic vs. isometric handgrip exercise on blood pressure variability and central SBP in a prospective randomized trial. METHODS: Seventy-five hypertensive patients were randomized to one of the following 12-week programs: isometric handgrip training five times weekly; 'Sham-handgrip training' five times weekly; aerobic exercise training (30 min three to five times/week). Blood pressure variability was assessed by the coefficient of variation in 24-h ambulatory blood pressure monitoring (ABPM). Central SBP was measured noninvasively by the SphygmoCor device (AtCor Medical, Australia). RESULTS: The aerobic exercise program significantly decreased systolic daytime variability (12.1 ±â€Š2.5 vs. 10.3 ±â€Š2.8, P = 0.04), whereas diastolic daytime blood pressure variability was not significantly altered (P = 0.14). Night-time variability was not significantly affected (P > 0.05). Central SBP was reduced from 145±15 to 134 ±â€Š19 mmHg (P = 0.01). Isometric handgrip and sham-handgrip exercise did not significantly affect blood pressure variability (P > 0.05 each). Isometric exercise tended to reduce central SBP (142 ±â€Š19 to 136 ±â€Š17 mmHg, P = 0.06). ANCOVA revealed significant intergroup differences for the change of daytime SBP and DBP variability (P = 0.048 and 0.047, respectively). CONCLUSION: Aerobic exercise reduces blood pressure variability and central SBP. Isometric handgrip exercise does not reduce blood pressure variability but tends to lower central SBP in this hypertensive population.

The impact of aerobic and isometric exercise on different measures of dysfunctional high-density lipoprotein in patients with hypertension.

BACKGROUND: Exercise training increases high-density lipoprotein (HDL) cholesterol, but its effect on HDL function is unclear. In hypertensives, exercise improves endothelial dysfunction, which is related to HDL function. In the present study, we assess for the first time the effects of different exercise modalities on two cell-free assays of HDL function. DESIGN: The study was conducted as a prospective randomized controlled trial in 75 hypertensive patients. METHODS: Patients were randomized in three groups: (a) handgrip isometric training five times weekly; (b) placebo-handgrip; and (c) aerobic exercise training at least three times per week. HDL function was assessed in serum samples at baseline and after 12 weeks of training by two independent assays that determine the proinflammatory phenotype (haptoglobin content) of a specific amount of HDL (Haptoglobin-HDL [HPHDL]) and oxidized HDL (HDLox) as a measure of reduced antioxidant function of HDL. HDL function measures were normalized by the measures of a pooled control of sera from healthy participants and by HDL-C levels (normalized ratio, no units). RESULTS: Aerobic exercise led to significant reduction of the HDLox from 0.99 ± 0.27 to 0.90 ± 0.29 (no units, p = 0.03). The HPHDL did not change in any training group. Changes of HDLox correlated with reduction of the systolic blood pressure only after aerobic exercise (R = 0.64, p = 0.03). CONCLUSIONS: Aerobic but not isometric exercise improves the antioxidant function of HDL in patients with hypertension. This improvement correlates positively with reductions of blood pressure.

Aerobic versus isometric handgrip exercise in hypertension: a randomized controlled trial.

OBJECTIVES: Aerobic dynamic exercise reduces blood pressure (BP) and is broadly recommended by current American and European hypertension guidelines. Isometric exercise is currently not recommended, since data from only a few studies are available. We compare for the first time the effects of isometric handgrip training and aerobic exercise in a randomized controlled trial. METHODS: A total of 75 hypertensive patients were randomized to one of the following 12-week programmes: Isometric handgrip training five times weekly (two contractions of 2 min at 30% of maximal power with each arm); 'Sham-handgrip training' five times weekly (two contractions of 2 min at 5% of maximal power with each arm); Aerobic exercise training of 30 min three to five times per week. All patients underwent office BP measurement, 24-h ambulatory BP measurement and noninvasive assessment of arterial compliance and systemic vascular resistance at baseline and after 12 weeks. RESULTS: Baseline epidemiological and hemodynamic characteristics did not differ between groups. Aerobic exercise led to a significant reduction of systolic 24-h BP (P = 0.025), office SBP (P = 0.03), systemic vascular resistance (P = 0.001) and small artery elasticity index (P = 0.005). There were no statistical significant changes of these parameters in the isometric exercise and the 'sham exercise' groups (P > 0.05 each). CONCLUSION: Isometric handgrip training, performed according to a typical protocol, did not reduce BP in hypertensive patients. Aerobic exercise, even as an uncontrolled and unsupervised exercise regimen, led to a significant reduction of ambulatory and office BP.