Effects of diet and/or low-intensity resistance exercise training on arterial stiffness, adiposity, and lean mass in obese postmenopausal women.

BACKGROUND: Obesity and aging are associated with increased arterial stiffness as indicated by an increased pulse-wave velocity (PWV). We evaluated the independent and combined effects on PWV and body composition of a hypocaloric diet and low-intensity resistance exercise training (LIRET) with slow movement. METHODS: Forty-one postmenopausal women (mean age, 54±6 years; body mass index (BMI), 33.8±0.5kg/m(2)) were randomly assigned to LIRET (n = 14), diet (n = 13), or diet + LIRET (n = 14) for 12 weeks. The women's PWV, mean arterial pressure (MAP), body composition by dual-en ergy x-ray absorptiometry (DXA), and plasma adipokine and insulin levels were measured before and after the interventions. RESULTS: Body weight (P = 0.0001), trunk-fat mass (FM, P = 0.0001), and the serum concentration of leptin (P = 0.02 and P = 0.004) decreased similarly with diet and diet + LIRET, but not with LIRET alone. Leg lean mass (LM) decreased (P = 0.02) with diet, but did not change with diet + LIRET or with LIRET alone. Leg muscle strength increased similarly with LIRET (P = 0.001) and diet + LIRET (P = 0.0001), but did not change with diet alone. Brachial-ankle PWV (baPWV) decreased with diet (P = 0.04) and diet + LIRET (P = 0.01), whereas femoral-ankle PWV (legPWV) decreased only with diet (P = 0.01). Mean arterial pressure (MAP) decreased after LIRET (P = 0.03), diet (P = 0.04), and diet + LIRET (P = 0.004). Carotid-femoral PWV, serum adiponectin concentration, and insulin were not significantly affected by the interventions examined in the study. The reductions in baPWV and legPWV were correlated with one another (r = 0.73, P = 0.0001), and the reductions in legPWV and trunk FM were also correlated with one another (r = 0.36, P = 0.03). CONCLUSIONS: A hypocaloric diet decreases baPWV mainly by reducing legPWV, and this reduction is related to the loss of truncal fat. Although LIRET alone does not affect PWV or body composition, LIRET combined with diet improves baPWV and muscle strength while preventing loss of lean body mass in obese postmenopausal women.

Whole-body vibration training reduces arterial stiffness, blood pressure and sympathovagal balance in young overweight/obese women.

Obesity is associated with early cardiovascular dysfunction and reduced muscle strength. Whole-body vibration (WBV) training may improve arterial function and muscle strength. The effects of WBV training on arterial stiffness (brachial-ankle pulse wave velocity, baPWV), wave reflection (augmentation index, AIx), brachial systolic blood pressure (bSBP), aortic systolic blood pressure (aSBP), heart rate variability, and muscle strength (one-repetition maximum, 1RM) were examined in 10 young (21 ± 2 year) overweight/obese women (body mass index, BMI = 29.9 ± 0.8 kg m(-2)). Participants were randomized to a 6-week WBV training or non-exercising control (CON) period in a crossover design. WBV training (3 days × week) consisted of static and dynamic squats and calf raises with vibration intensity at 25-30 Hz and 1-2 mm amplitude (2.83-4.86 G). There were significant (P<0.05) decreases in baPWV (-0.9 ± 0.3 m s(-1)), AIx (-8.0 ± 2.2 %), bSBP (-5.3 ± 1.5 mm Hg), aSBP (-5.2 ± 2.1 mm Hg), low-frequency power (-0.13 ± 0.05 nu) and sympathovagal balance (LF/HF, -0.42 ± 0.16) after WBV training compared with CON. Significant (P<0.05) increases in high-frequency power (HF, 0.19 ± 0.04 nu) and leg extension 1RM (8.2 ± 2.3 kg) occurred after WBV training compared with CON. Six weeks of WBV training decreased systemic arterial stiffness and aSBP via improvements in wave reflection and sympathovagal balance in young overweight/obese normotensive women. WBV training may benefit arterial function and muscle strength in deconditioned individuals who cannot perform conventional exercise.

Creatine supplementation attenuates hemodynamic and arterial stiffness responses following an acute bout of isokinetic exercise.

Arterial stiffness and hemodynamics may be increased following a bout of resistance exercise. Oral creatine supplementation (Cr) may attenuate cardiovascular responses after exercise via improved anaerobic metabolism. This study was aimed to determine the effect of Cr on hemodynamic and arterial stiffness responses after acute isokinetic exercise. Sixteen healthy males (22.6 ± 0.6 year) were randomly assigned to either placebo (Pl, n = 8) or Cr (n = 8) (2 × 5 g/day) for 3 weeks. Brachial systolic blood pressure (SBP), heart rate (HR), brachial-ankle pulse wave velocity (baPWV), and leg PWV were measured in the supine position at rest before and after the interventions. After the supplementation period, parameters were also measured 5 min (PE5) and 15 min (PE15) after two sets of leg isokinetic exercise. There was no difference between the groups in resting measurements before and after the supplementation. Compared with the Pl group, the Cr group had attenuated (P < 0.05) increases in SBP at PE5 (Pl 14.0 ± 2.5, Cr 5.6 ± 2.3 mmHg), HR at both P5 (Pl 28 ± 4 vs. Cr 16 ± 2 beats/min) and PE15 (Pl 21 ± 3, Cr 11 ± 2 beats/min) and rate pressure product at P5 (Pl 45.8 ± 6.4, Cr 24.8 ± 2.2) and P15 (Pl 34.2 ± 5.0, Cr 15.9 ± 6.0). Compared with the Pl group, the Cr group had suppressed increases in baPWV at PE5 (Pl 1.5 ± 0.4, Cr -0.1 ± 0.4 m/s) and PE15 (Pl 1.1 ± 0.2, Cr -0.3 ± 0.3 m/s) and returned SBP to pre-exercise values at PE15 (Pl 10.6 ± 2.8, Cr 2.1 ± 2.6 mmHg). PWV in the exercised leg decreased at PE5 in both groups. These findings suggest that Cr supplementation attenuates the hemodynamic and baPWV responses after acute isokinetic exercise.

Acute exercise with whole-body vibration decreases wave reflection and leg arterial stiffness.

AIM: Whole-body vibration exercise (WBV) acutely decreases brachial-ankle pulse wave velocity (baPWV), an index of systemic arterial stiffness. However, the effect of WBV on segmental PWV and aortic hemodynamics is unknown. We examined the acute effects of WBV on arterial function. METHODS: Fifteen young men performed ten 1-min sets of static squat with WBV (40 Hz, 1 mm, 5.37 G) and without WBV (no-WBV). Brachial and aortic blood pressure (BP), heart rate (HR), augmentation index (AIx), baPWV, carotid-femoral PWV (cfPWV), and femoral-ankle (faPWV), were recorded before and 5, 15, and 30 min after both trials. RESULTS: Brachial and aortic SBP (P < 0.01), and HR (P < 0.01) were increased only at 5 min after both exercise trials. AIx was elevated through the recovery after no-WBV while decreased at 15 and 30 min after WBV exercise. FaPWV was decreased (P < 0.01) at 5 min after both trials, but returned to baseline at 15 min after no-WBV exercise and was maintained decreased at 15 and 30 min after WBV exercise. There were no significant changes in brachial and aortic diastolic BP, cfPWV and baPWV after both trials. CONCLUSIONS: Our findings indicate that regardless of WBV, static squat causes a small transient increase in hemodynamic responses during early recovery. WBV counteracts the increase in AIx induced by static squat and reduces wave reflection magnitude through a local effect on arterial stiffness.

Oral L-citrulline supplementation attenuates blood pressure response to cold pressor test in young men.

BACKGROUND: Oral L-citrulline is efficiently converted to L-arginine, which has been shown to decrease brachial blood pressure (BP) at rest and during the cold pressor test (CPT). However, aortic BP may better reflect cardiovascular risk than brachial BP. The purpose of this study was to test the hypothesis that oral L-citrulline supplementation attenuates brachial BP and aortic hemodynamic responses to CPT. METHODS: Brachial BP, aortic BP, stroke volume (SV), and wave reflection at rest and during CPT were evaluated in 17 young (21.6 +/- 0.9 years) normotensive men. Subjects were randomly assigned to 4 weeks of oral L-citrulline (6 g/day) or placebo in a crossover design. Hemodynamic responses to CPT were reevaluated after each treatment. RESULTS: During CPT, there were significant (P < 0.05) increases in brachial and aortic BP [systolic (SBP), diastolic (DBP), and pulse pressure (PP)], augmentation index (AIx), SV, and a decrease in transit time of the reflected wave (Tr) from baseline. Compared to placebo, oral L-citrulline treatment decreased (P < 0.05) brachial SBP (-6 +/- 11 mm Hg), aortic SBP (-4 +/- 10 mm Hg), and aortic PP (-3 +/- 6 mm Hg) during CPT but not at rest. There was an inverse correlation (r = -0.40, P < 0.05) between changes in aortic SBP and Tr during CPT after L-citrulline supplementation. CONCLUSIONS: We conclude that oral L-citrulline supplementation attenuates the brachial SBP, aortic SBP, and aortic PP responses to CPT in young normotensive men. Increased wave reflection time contributes to the reduction in aortic SBP response to CPT.