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Effectiveness of HIIT compared to moderate continuous training in improving vascular parameters in inactive adults.
Ramírez-Vélez, R, Hernández-Quiñones, PA, Tordecilla-Sanders, A, Álvarez, C, Ramírez-Campillo, R, Izquierdo, M, Correa-Bautista, JE, Garcia-Hermoso, A, Garcia, RG
Lipids in health and disease. 2019;(1):42
Abstract
BACKGROUND Strong evidence shows that physical inactivity increases the risk of many adverse health conditions, including major non-communicable diseases, such as cardiovascular disease (CVD), metabolic syndrome, and breast and colon cancers, and shortens life expectancy. We aimed to determine the effects of moderate (MCT)- versus high-intensity interval training (HIT) on vascular function parameters in physically inactive adults. We hypothesized that individualized HIT prescription would improve the vascular function parameters more than the MCT in a greater proportion of individuals. METHODS Twenty-one inactive adults were randomly allocated to receive either MCT group (60-75% of their heart rate reserve, [HRR] or HIT group (4 min at 85-95% of peak HRR), 3 days a week for 12 weeks. Vascular function (brachial artery flow-mediated dilation, FMD [%], normalized brachial artery flow-mediated dilation, FMDn [%], aortic pulse wave velocity, PWV [m·s- 1], AIx, augmentation index: aortic and brachial [%]), were measured at baseline and over 12 weeks of training. In order for a participant to be considered a responder to improvements in vascular function parameters (FMDn and PWV), the typical error was calculated in a favorable direction. RESULTS FMD changed by - 1.0% (SE 2.1, d = 0.388) in the MCT group, and + 1.8% (SE 1.8, d = 0.699) in the HIT group (no significant difference between groups: 2.9% [95% CI, - 3.0 to 8.8]. PWV changed by + 0.1 m·s- 1 (SE 0.2, d = 0.087) in the MCT group but decreased by - 0.4 m·s- 1 in the HIT group (SE 0.2, d = 0.497), with significant difference between groups: - 0.4 [95% CI, - 0.2 to - 0.7]. There was not a significant difference in the prevalence of no-responder for FMD (%) between the MCT and HIT groups (66% versus 36%, P = 0.157). Regarding PWV (m·s- 1), an analysis showed that the prevalence of no-responder was 77% (7 cases) in the MCT group and 45% (5 cases) in the HIT group (P = 0.114). CONCLUSIONS Under the conditions of the present study, both groups experienced changed in vascular function parameters. Compared to MCT group, HIT is more efficacious for improving FMD and decreasing PWV, in physically inactive adults. TRIAL REGISTRATION ClinicalTrials.gov NCT02738385 registered on 23 March 2016.
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Preceding exercise and postprandial hypertriglyceridemia: effects on lymphocyte cell DNA damage and vascular inflammation.
Brown, M, McClean, CM, Davison, GW, Brown, JCW, Murphy, MH
Lipids in health and disease. 2019;(1):125
Abstract
BACKGROUND Exercise has proved effective in attenuating the unfavourable response normally associated with postprandial hypertriglyceridemia (PHTG) and accompanying oxidative stress. Yet, the acute effects of prior exercise and PHTG on DNA damage remains unknown. The purpose of this study was to examine if walking alters PHTG-induced oxidative damage and the interrelated inflammatory mechanisms. METHODS Twelve apparently healthy, recreationally active, male participants (22.4 ± 4.1 years; 179.2 ± 6 cm; 84.2 ± 14.7 kg; 51.3 ± 8.6 ml·kg- 1·min- 1) completed a randomised, crossover study consisting of two trials: (1) a high-fat meal alone (resting control) or (2) a high-fat meal immediately following 1 h of moderate exercise (65% maximal heart rate). Venous blood samples were collected at baseline, immediately post-exercise or rest, as well as at 2, 4 and 6 h post-meal. Biomarkers of oxidative damage (DNA single-strand breaks, lipid peroxidation and free radical metabolism) and inflammation were determined using conventional biochemistry techniques. RESULTS DNA damage, lipid peroxidation, free radical metabolism and triglycerides increased postprandially (main effect for time, p < 0.05), regardless of completing 1 h of preceding moderate intensity exercise. Plasma antioxidants (α-tocopherol and γ-tocopherol) also mobilised in response to the high-fat meal (main effect for time, p < 0.05), but no changes were detected for retinol-binding protein-4. CONCLUSION The ingestion of a high fat meal induces postprandial oxidative stress, inflammation and a rise in DNA damage that remains unaltered by one hour of preceding exercise.
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Effect of chronic nitrate and citrulline supplementation on vascular function and exercise performance in older individuals.
Le Roux-Mallouf, T, Pelen, F, Vallejo, A, Halimaoui, I, Doutreleau, S, Verges, S
Aging. 2019;(10):3315-3332
Abstract
Increased nitric oxide (NO) bioavailability may improve exercise performance and vascular function. It remains unclear whether older adults who experience a decreased NO bioavailability may benefit from chronic NO precursor supplementation. This randomised, double-blind, trial aims to assess the effect of chronic NO precursor intake on vascular function and exercise performance in older adults (60-70 years old). Twenty-four healthy older adults (12 females) performed vascular function assessment and both local (knee extensions) and whole-body (incremental cycling) exercise tests to exhaustion before and after one month of daily intake of a placebo (PLA) or a nitrate-rich salad and citrulline (N+C, 520mg nitrate and 6g citrulline) drink. Arterial blood pressure (BP) and stiffness, post-ischemic, hypercapnic and hypoxic vascular responses were evaluated. Prefrontal cortex and quadriceps oxygenation was monitored by near-infrared spectroscopy. N+C supplementation reduced mean BP (-3.3mmHg; p=0.047) without altering other parameters of vascular function and oxygenation kinetics. N+C supplementation reduced heart rate and oxygen consumption during submaximal cycling and increased maximal power output by 5.2% (p<0.05), but had no effect on knee extension exercise performance. These results suggest that chronic NO precursor supplementation in healthy older individuals can reduce resting BP and increase cycling performance by improving cardiorespiratory responses.
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Effect of Metformin on Vascular Function in Children With Type 1 Diabetes: A 12-Month Randomized Controlled Trial.
Anderson, JJA, Couper, JJ, Giles, LC, Leggett, CE, Gent, R, Coppin, B, Peña, AS
The Journal of clinical endocrinology and metabolism. 2017;(12):4448-4456
Abstract
CONTEXT Children with type 1 diabetes have vascular dysfunction preceding atherosclerosis. Early interventions are needed to reduce cardiovascular disease. OBJECTIVE To evaluate the effect of metformin on vascular function in children with type 1 diabetes. DESIGN Twelve-month double-blind, randomized, placebo-controlled trial. SETTING Tertiary pediatric diabetes clinic. PARTICIPANTS Ninety children (8 to 18 years of age), >50th percentile body mass index (BMI), with type 1 diabetes. INTERVENTION Metformin (up to 1 g twice a day) or placebo. MAIN OUTCOME MEASURE Vascular function measured by brachial artery ultrasound [flow-mediated dilatation/glyceryl trinitrate-mediated dilatation (GTN)]. RESULTS Ninety participants were enrolled [41 boys, 13.6 (2.5) years of age, 45 per group], 10 discontinued intervention, and 1 was lost to follow-up. On metformin, GTN improved, independent of glycosylated hemoglobin (HbA1c), by 3.3 percentage units [95% confidence interval (CI) 0.3, 6.3, P = 0.03] and insulin dose reduced by 0.2 U/kg/d (95% CI 0.1, 0.3, P = 0.001) during 12 months, with effects from 3 months. Metformin had a beneficial effect on HbA1c at 3 months (P = 0.001) and difference in adjusted HbA1c between groups during 12 months was 1.0%; 95% CI 0.4, 1.5 (10.9 mmol/mol; 95% CI 4.4, 16.4), P = 0.001. There were no effects on carotid/aortic intima media thickness, BMI, lipids, blood pressure, or other cardiovascular risk factors. Median (95% CI) adherence, evaluated by electronic monitoring, was 75.5% (65.7, 81.5), without group differences. More gastrointestinal side effects were reported on metformin (incidence rate ratio 1.65, 95% CI 1.08, 2.52, P = 0.02), with no difference in hypoglycemia or diabetic ketoacidosis. CONCLUSIONS Metformin improved vascular smooth muscle function and HbA1c, and lowered insulin dose in type 1 diabetes children. These benefits and good safety profile warrant further consideration of its use.
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Consuming a balanced high fat diet for 16 weeks improves body composition, inflammation and vascular function parameters in obese premenopausal women.
Silver, HJ, Kang, H, Keil, CD, Muldowney, JA, Kocalis, H, Fazio, S, Vaughan, DE, Niswender, KD
Metabolism: clinical and experimental. 2014;(4):562-73
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Abstract
OBJECTIVE Inflammation, insulin resistance and vascular dysfunction characterize obesity and predict development of cardiovascular disease (CVD). Although women experience CVD events at an older age, vascular dysfunction is evident 10years prior to coronary artery disease. Questions remain whether replacing SFA entirely with MUFA or PUFA is the optimal approach for cardiometabolic benefits. This study tested the hypotheses that: a) body composition, inflammation and vascular function would improve with a high fat diet (HFD) when type of fat is balanced as 1/3 SFA, 1/3 MUFA and 1/3 PUFA; and b) body composition, inflammation and vascular function would improve more when balanced HFD is supplemented with 18C fatty acids, in proportion to the degree of 18C unsaturation. METHODS Obese premenopausal women were stabilized on balanced HFD and randomized to consume 9g/d of encapsulated stearate (18:0), oleate (18:1), linoleate (18:2) or placebo. RESULTS Significant improvements occurred in fat oxidation rate (↑6%), body composition (%fat: ↓2.5±2.1%; %lean: ↑2.5±2.1%), inflammation (↓ IL-1α, IL-1β, 1L-12, Il-17, IFNγ, TNFα, TNFβ) and vascular function (↓BP, ↓PAI-1, ↑tPA activity). When compared to HFD+placebo, HFD+stearate had the greatest effect on reducing IFNγ (↓74%) and HFD+linoleate had the greatest effect on reducing PAI-1 (↓31%). CONCLUSIONS Balancing the type of dietary fat consumed (SFA/MUFA/PUFA) is a feasible strategy to positively affect markers of CVD risk. Moreover, reductions in inflammatory molecules involved in vascular function might be enhanced when intake of certain 18C fatty acids is supplemented. Long term effects need to be determined for this approach.
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The impact of the catechol-O-methyltransferase genotype on vascular function and blood pressure after acute green tea ingestion.
Miller, RJ, Jackson, KG, Dadd, T, Mayes, AE, Brown, AL, Lovegrove, JA, Minihane, AM
Molecular nutrition & food research. 2012;(6):966-75
Abstract
SCOPE Evidence for the benefits of green tea catechins on vascular function is inconsistent, with genotype potentially contributing to the heterogeneity in response. Here, the impact of the catechol-O-methyltransferase (COMT) genotype on vascular function and blood pressure (BP) after green tea extract ingestion are reported. METHODS AND RESULTS Fifty subjects (n = 25 of the proposed low-activity [AA] and of the high-activity [GG] COMT rs4680 genotype), completed a randomized, double-blind, crossover study. Peripheral arterial tonometry, digital volume pulse (DVP), and BP were assessed at baseline and 90 min after 1.06 g of green tea extract or placebo. A 5.5 h and subsequent 18.5 h urine collection was performed to assess green tea catechin excretion. A genotype × treatment interaction was observed for DVP reflection index (p = 0.014), with green tea extract in the AA COMT group attenuating the increase observed with placebo. A tendency for a greater increase in diastolic BP was evident at 90 min after the green tea extract compared to placebo (p = 0.07). A genotypic effect was observed for urinary methylated epigallocatechin during the first 5.5 h, with the GG COMT group demonstrating a greater concentration (p = 0.049). CONCLUSION Differences in small vessel tone according to COMT genotype were evident after acute green tea extract.
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Oral vitamin C enhances the adrenergic vasoconstrictor response to local cooling in human skin.
Yamazaki, F
Journal of applied physiology (Bethesda, Md. : 1985). 2012;(10):1689-97
Abstract
Local administration of ascorbic acid (Asc) at a supraphysiological concentration inhibits the cutaneous vasoconstrictor response to local cooling (LC). However, whether orally ingesting Asc inhibits the LC-induced vasoconstrictor response remains unknown. The purpose of the present study was to examine the acute influence of oral Asc on the adrenergic vasoconstrictor response to LC in human skin. In experiment 1, skin blood flow (SkBF) was measured by laser-Doppler flowmetry at three sites (forearm, calf, palm). The three skin sites were locally cooled from 34 to 24°C at -1°C/min and maintained at 24°C for 20 min before (Pre) and 1.5 h after (Post) oral Asc (2-g single dose) or placebo supplementation. Cutaneous vascular conductance (CVC) was calculated as the ratio of SkBF to blood pressure and expressed relative to the baseline value before LC. Oral Asc enhanced (P < 0.05) the reductions in CVC in the forearm (Pre, -50.3 ± 3.3%; Post, -57.8 ± 2.2%), calf (Pre, -52.6 ± 3.7%; Post, -66.1 ± 4.3%), and palm (Pre, -46.2 ± 6.2%; Post, -60.4 ± 5.6%) during LC. The placebo did not change the responses at any site. In experiment 2, to examine whether the increased vasoconstrictor response caused by oral Asc is due to the adrenergic system, the release of neurotransmitters from adrenergic nerves in forearm skin was blocked locally by iontophoresis of bretylium tosylate (BT). Oral Asc enhanced (P < 0.05) the reductions in CVC at untreated control sites but did not change the responses at BT-treated sites during LC. In experiment 3, to further examine whether adrenergically mediated vasoconstriction is enhanced by oral Asc, 0.1 mM tyramine was administered using intradermal microdialysis in the forearm skin at 34°C in the Pre and Post periods. Oral Asc increased (P < 0.05) the tyramine-induced reduction in CVC. These findings suggest that oral Asc acutely enhances the cutaneous vasoconstrictor responses to LC through the modification of adrenergic sympathetic mechanisms.
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Acute effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight postmenopausal women.
Pal, S, Ellis, V
The British journal of nutrition. 2011;(10):1512-9
Abstract
Previous evidence indicates that chronic consumption of dairy whey proteins has beneficial effects on CVD risk factors. The present study investigated the postprandial effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight and obese postmenopausal women. This was a randomised, three-way cross-over design study where twenty overweight and obese postmenopausal women consumed a breakfast meal in conjunction with one of three supplements: 45 g whey protein isolate, 45 g sodium caseinate or 45 g of a glucose control. Fasting and postprandial blood samples, blood pressure and pulse wave analysis readings were taken for up to 6 h. After consumption of the meal, both systolic and diastolic blood pressure, and augmentation index (AI) decreased initially for all interventions and gradually returned to baseline levels by 6 h. However, there were no significant differences in AI, systolic or diastolic blood pressure within or between the glucose control, casein or whey groups. There were also no significant group effects on plasma inflammatory markers (IL-6, TNF-α and C-reactive protein). The health effects previously seen with chronic whey protein ingestion were not seen in the acute 6 h postprandial period in relation to blood pressure, vascular function or inflammatory markers when compared with casein and a glucose control. This suggests that such effects are better observed from the long-term consumption of whey proteins.
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Substitution of standard soybean oil with olive oil-based lipid emulsion in parenteral nutrition: comparison of vascular, metabolic, and inflammatory effects.
Siqueira, J, Smiley, D, Newton, C, Le, NA, Gosmanov, AR, Spiegelman, R, Peng, L, Osteen, SJ, Jones, DP, Quyyumi, AA, et al
The Journal of clinical endocrinology and metabolism. 2011;(10):3207-16
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CONTEXT Soybean oil-based lipid emulsions are the only Food and Drug Administration-approved lipid formulation for clinical use in parenteral nutrition (PN). Recently concerns with its use have been raised due to the proinflammatory effects that may lead to increased complications because they are rich in ω-6 polyunsaturated fatty acids. METHODS This was a prospective, randomized, controlled, crossover study comparing the vascular, metabolic, immune, and inflammatory effects of 24-h infusion of PN containing soybean oil-based lipid emulsion (Intralipid), olive oil-based (ClinOleic), lipid free, and normal saline in 12 healthy subjects. RESULTS Soybean oil-PN increased systolic blood pressure compared with olive oil-PN (P < 0.05). Soybean oil PN reduced brachial artery flow-mediated dilatation from baseline (-23% at 4 h and -25% at 24 h, both P < 0.01); in contrast, olive oil PN, lipid free PN, and saline did not change either systolic blood pressure or flow-mediated dilatation. Compared with saline, soybean oil PN, olive oil PN, and lipid free PN similarly increased glucose and insulin concentrations during infusion (P < 0.05). There were no significant changes in plasma free fatty acids, lipid profile, inflammatory and oxidative stress markers, immune function parameters, or sympathetic activity between soybean oil- and olive oil-based lipid emulsions. CONCLUSION The 24-h infusion of PN containing soybean oil-based lipid emulsion increased blood pressure and impaired endothelial function compared with PN containing olive oil-based lipid emulsion and lipid-free PN in healthy subjects. These vascular changes may have significant implications in worsening outcome in subjects receiving nutrition support. Randomized controlled trials with relevant clinical outcome measures are needed in patients receiving PN with olive oil-based and soybean oil-based lipid emulsions.
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Effects of carnitine supplementation on flow-mediated dilation and vascular inflammatory responses to a high-fat meal in healthy young adults.
Volek, JS, Judelson, DA, Silvestre, R, Yamamoto, LM, Spiering, BA, Hatfield, DL, Vingren, JL, Quann, EE, Anderson, JM, Maresh, CM, et al
The American journal of cardiology. 2008;(10):1413-7
Abstract
Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.