The efficacy of 'static' training interventions for improving indices of cardiorespiratory fitness in premenopausal females.
ABSTRACT: PURPOSE:Cardiovascular disease (CVD) is the leading cause of death worldwide. Many risk factors for CVD can be modified pharmacologically; however, uptake of medications is low, especially in asymptomatic people. Exercise is also effective at reducing CVD risk, but adoption is poor with time-commitment and cost cited as key reasons for this. Repeated remote ischaemic preconditioning (RIPC) and isometric handgrip (IHG) training are both inexpensive, time-efficient interventions which have shown some promise in reducing blood pressure (BP) and improving markers of cardiovascular health and fitness. However, few studies have investigated the effectiveness of these interventions in premenopausal women. METHOD:Thirty healthy females were recruited to twelve supervised sessions of either RIPC or IHG over 4 weeks, or acted as non-intervention controls (CON). BP measurements, flow-mediated dilatation (FMD) and cardiopulmonary exercise tests (CPET) were performed at baseline and after the intervention period. RESULTS:IHG and RIPC were both well-tolerated with 100% adherence to all sessions. A statistically significant reduction in both systolic (-?7.2 mmHg) and diastolic (-?6 mmHg) BP was demonstrated following IHG, with no change following RIPC. No statistically significant improvements were observed in FMD or CPET parameters in any group. CONCLUSIONS:IHG is an inexpensive and well-tolerated intervention which may improve BP; a key risk factor for CVD. Conversely, our single arm RIPC protocol, despite being similarly well-tolerated, did not elicit improvements in any cardiorespiratory parameters in our chosen population.
Project description:Aerobic exercise reduces blood pressure (BP) on average 5-7?mmHg among those with hypertension; limited evidence suggests similar or even greater BP benefits may result from isometric handgrip (IHG) resistance exercise.We conducted a randomized controlled trial investigating the antihypertensive effects of an acute bout of aerobic compared with IHG exercise in the same individuals. Middle-aged adults (n?=?27) with prehypertension and obesity randomly completed three experiments: aerobic (60% peak oxygen uptake, 30 min); IHG (30% maximum voluntary contraction, 4?×?2 min bilateral); and nonexercise control. Study participants were assessed for carotid-femoral pulse wave velocity pre and post exercise, and left the laboratory wearing an ambulatory BP monitor.SBP and DBP were lower after aerobic versus IHG (4.8?±?1.8/3.1?±?1.3?mmHg, P?=?0.01/0.04) and control (5.6?±?1.8/3.6?±?1.3?mmHg, P?=?0.02/0.04) over the awake hours, with no difference between IHG versus control (P?=?0.80/0.83). Pulse wave velocity changes following acute exercise did not differ by modality (aerobic increased 0.01?±?0.21?ms, IHG decreased 0.06?±?0.15?ms, control increased 0.25?±?0.17?ms, P?>?0.05). A subset of participants then completed either 8 weeks of aerobic or IHG training. Awake SBP was lower after versus before aerobic training (7.6?±?3.1?mmHg, P?=?0.02), whereas sleep DBP was higher after IHG training (7.7?±?2.3?mmHg, P?=?0.02).Our findings did not support IHG as antihypertensive therapy but that aerobic exercise should continue to be recommended as the primary exercise modality for its immediate and sustained BP benefits.
Project description:Six healthy male adults underwent RIPC, consisting of 3x5 min cycles of upper arm ischemia (inflating a blood pressure cuff to >200 mmHg) alternating with 3x5 min reperfusion (bp cuff deflated). Blood samples were collected at baseline and at 1 and 4 min into each reperfusion period. Plasma was isolated and the six reperfusion samples were pooled to one RIPC sample. Both baseline and RIPC samples were depleted, concentrated, trypsin digested, iTRAQ labeled and analyzed by LC and Orbitrap-MS where each RIPC sample was compared to the same individual's baseline sample.
Project description:ABSTRACT:Ischaemic reperfusion (IR) injury is a major cause of graft loss, morbidity and mortality following orthotopic liver transplantation (OLT). Demand for liver transplantation has resulted in increasing use of marginal grafts that are more prone to IR injury. Remote ischaemic preconditioning (RIPC) reduces IR injury in experimental models, but recipient RIPC has not been evaluated clinically. METHODS:A single-centre double-blind randomized controlled trial (RCT) is planned to test the hypothesis that recipient RIPC will reduce IR injury. RIPC will be performed following recipient anaesthetic induction but prior to skin incision. The protocol involves 3 cycles of 5 min of lower limb occlusion with a pneumatic tourniquet inflated to 200 mmHg alternating with 5 min of reperfusion. In the control group, the sham will involve the cuff being placed on the thigh but without being inflated. The primary endpoint is ability to recruit patients to the trial and safety of RIPC. The key secondary endpoint is a reduction in serum aspartate transferase levels on the third post-operative day. DISCUSSION:RIPC is a promising strategy to reduce IR injury in liver transplant recipients as there is a clear experimental basis, and the intervention is both inexpensive and easy to perform. This is the first trial to investigate RIPC in liver transplant recipients. TRIAL REGISTRATION:Clinicaltrials.gov NCT00796588.
Project description:India is undergoing rapid urbanization with simultaneous increases in the prevalence of cardiovascular disease (CVD). As urban areas become home to an increasing share of the world's population, it is important to understand relationships between the built environment and progression towards CVD.We assessed associations between multiple measures of the built environment and biomarkers of early vascular aging (EVA) in the Population Study of Urban, Rural and Semiurban Regions for the Detection of Endovascular Disease and Prevalence of Risk Factors and Holistic Intervention Study (PURSE-HIS) in Chennai, India.We performed a cross-sectional analysis of 3,150 study participants. EVA biomarkers included systolic and diastolic blood pressure (SBP and DBP), central pulse pressure (cPP) and flow-mediated dilatation (FMD). Multiple approaches were used to assign residential exposure to factors of the built environment: Moderate Resolution Imaging Spectroradiometer (MODIS)-derived normalized difference vegetation index (NDVI), a measure of vegetation health and greenness; Landsat-derived impervious surface area (ISA); and Visible Infrared Imaging Radiometer Suite (VIIRS)-derived nighttime lights (NTL). Multivariable regression models were used to assess associations between each built environment measure and biomarkers of EVA, adjusting for age, body mass index (BMI), cooking fuel type, energy intake, sex, physical activity, smoking, socioeconomic status, and stress.Residing in areas with higher ISA or NTL, or lower greenness, was significantly associated with elevated SBP, DBP, and cPP, and with lower FMD, adjusting for age, BMI, sex, smoking status, and other CVD risk factors. An interquartile range decrease in greenness had the largest increase in SBP [4.3?mmHg (95% CI: 2.9, 5.6)], DBP [1.2?mmHg (95% CI: 0.4, 2.0)] and cPP [3.1?mmHg (95% CI: 2.0, 4.1)], and the largest decrease in FMD [-1.5% (95%CI: -2.2%, -0.9%].Greenness, ISA, and NTL were associated with increased SBP, DBP, and cPP, and with reduced FMD, suggesting a possible additional EVA pathway for the relationship between urbanization and increased CVD prevalence in urban India. https://doi.org/10.1289/EHP541.
Project description:We examined the association between the angiotensin I-converting enzyme (ACE) I/D gene polymorphism and isometric handgrip (IHG) training on cardiovascular and muscular responses among normotensive males. Thirty (II = 10, ID = 10, and DD = 10) normotensive untrained males underwent IHG training at 30% of their maximal voluntary contraction 3 days per week for 8 weeks. Cardiovascular and muscular variables were measured before IHG, after a session of IHG and after 8 weeks of IHG. No significant interaction effect was found between ACE I/D genotype and IHG training session on all dependent variables (all p > 0.05). There was a significant main effect of IHG training session on systolic blood pressure (SBP) (p = 0.002), mean arterial pressure (MAP) (p = 0.015) and handgrip strength (HGS) (p = 0.001) scores, while no difference in diastolic blood pressure (DBP), pulse pressure, or heart rate scores was found. A greater improvement in cardiovascular parameters following 8 weeks of IHG training was observed in participants with the D allele than the I allele (SBP reduction: ID+DD genotype group (-5.53 ± 6.2 mmHg) vs. II genotype group (-1.52 ± 5.3 mmHg)); MAP reduction: ID + DD genotype group (-2.80 ± 4.5 mmHg) vs. II genotype group (-1.45 ± 3.5 mmHg). Eight weeks of IHG training improved cardiovascular and muscular performances of normotensive men. Reduction in SBP and MAP scores in D allele carriers compared to I allele carriers indicates that the ACE I/D polymorphism may have an influence on IHG training adaptation in a normotensive population.
Project description:Cocoa flavanol (CF) intake improves endothelial function in patients with cardiovascular risk factors and disease. We investigated the effects of CF on surrogate markers of cardiovascular health in low risk, healthy, middle-aged individuals without history, signs or symptoms of CVD. In a 1-month, open-label, one-armed pilot study, bi-daily ingestion of 450 mg of CF led to a time-dependent increase in endothelial function (measured as flow-mediated vasodilation (FMD)) that plateaued after 2 weeks. Subsequently, in a randomised, controlled, double-masked, parallel-group dietary intervention trial (Clinicaltrials.gov: NCT01799005), 100 healthy, middle-aged (35-60 years) men and women consumed either the CF-containing drink (450 mg) or a nutrient-matched CF-free control bi-daily for 1 month. The primary end point was FMD. Secondary end points included plasma lipids and blood pressure, thus enabling the calculation of Framingham Risk Scores and pulse wave velocity. At 1 month, CF increased FMD over control by 1·2 % (95 % CI 1·0, 1·4 %). CF decreased systolic and diastolic blood pressure by 4·4 mmHg (95 % CI 7·9, 0·9 mmHg) and 3·9 mmHg (95 % CI 6·7, 0·9 mmHg), pulse wave velocity by 0·4 m/s (95 % CI 0·8, 0·04 m/s), total cholesterol by 0·20 mmol/l (95 % CI 0·39, 0·01 mmol/l) and LDL-cholesterol by 0·17 mmol/l (95 % CI 0·32, 0·02 mmol/l), whereas HDL-cholesterol increased by 0·10 mmol/l (95 % CI 0·04, 0·17 mmol/l). By applying the Framingham Risk Score, CF predicted a significant lowering of 10-year risk for CHD, myocardial infarction, CVD, death from CHD and CVD. In healthy individuals, regular CF intake improved accredited cardiovascular surrogates of cardiovascular risk, demonstrating that dietary flavanols have the potential to maintain cardiovascular health even in low-risk subjects.
Project description:Inadequate blood pressure (BP) control is a frequent challenge in general practice. The objective of this study was to determine whether a color-coded BP booklet using a traffic light scheme (red, >180 mmHg systolic BP and/or >110 mmHg diastolic BP; yellow, >140-180 mmHg systolic BP or >90-110 mmHg diastolic BP; green, ≤140 mmHg systolic BP and ≤90 mmHg diastolic BP) improves BP control and adherence with home BP measurement.In this two-group, randomized controlled trial, general practitioners recruited adult patients with a BP >140 mmHg systolic and/or >90 mmHg diastolic. Patients in the control group received a standard BP booklet and the intervention group used a color-coded booklet for daily home BP measurement. The main outcomes were changes in BP, BP control (treatment goal <140/90 mmHg), and adherence with home BP measurement after 6 months.One hundred and twenty-one of 137 included patients qualified for analysis. After 6 months, a significant decrease in systolic and diastolic BP was achieved in both groups, with no significant difference between the groups (16.1/7.9 mmHg in the intervention group versus 13.1/8.6 mmHg in the control group, P=0.3/0.7). BP control (treatment target <140/90 mmHg) was achieved significantly more often in the intervention group (43% versus 25%; P=0.037; number needed to treat of 5). Adherence with home BP measurement overall was high, with a trend in favor of the intervention group (98.6% versus 96.2%; P=0.1).Color-coded BP self-monitoring significantly improved BP control (number needed to treat of 5, meaning that every fifth patient utilizing color-coded self-monitoring achieved better BP control after 6 months), but no significant between-group difference was observed in BP change. A markedly higher percentage of patients achieved BP values in the normal range. This simple, inexpensive approach of color-coded BP self-monitoring is user-friendly and applicable in primary care, and should be implemented in the care of patients with arterial hypertension.
Project description:BACKGROUND:Hypertension is a leading cause of cardiovascular disease (CVD). The purpose of this study was to examine the effectiveness of community healthcare in controlling blood pressure (BP) and mitigating related risk factors after 5 y of follow-up. METHODS:Hierarchical clustering sampling was employed to choose a representative sample of 10 rural and 10 urban community populations (N=4235). The 5y prospective cohort study was completed by the medical group in the community clinical centre. RESULTS:The study included 4235 patients, median age 69 y (range 61-76), with hypertension in 2009; 2533 (59.81%) were female. The rate of BP control increased from 28.33% in 2009 to 64.05% in 2014. The BP control rate was higher in patients with CVD and kidney disease and lower in those with obesity than in those without. Comparing 2009 and 2014 values, the intervention resulted in median systolic BP and diastolic BP reductions of 7.0 mmHg and 6.5 mmHg, respectively. Age, medication treatment, antihypertensive agents, BP at baseline and follow-up, complications of diabetes, CVD, obesity and kidney disease, the aspartate aminotransferase:aminotransferase ratio and smoking were identified as risk factors for BP control. CONCLUSIONS:Community management of hypertension by general practitioners achieved significant BP control over 5 y of intervention.
Project description:BACKGROUND:Hypertension markedly increases the risk of cardiovascular diseases and overall mortality. Lifestyle modifications, such as increased levels of physical activity, are recommended as the first line of anti-hypertensive treatment. A recent systematic review showed that isometric handgrip (IHG) training was superior to traditional endurance and strength training in lowering resting systolic blood pressure (SBP). The average length of previous IHG training studies is approximately 7.5 weeks with the longest being 10 weeks. Therefore, presently it is unknown if it is possible to further lower blood pressure levels beyond the 10-week mark. Recently, we developed a novel method for monitoring handgrip intensity using a standard Nintendo Wii Board (Wii). The primary aim of this study is to explore the effects of a 20-week IHG home training facilitated by a Wii in hypertensive older adults (50 + years of age) on lowering SBP compared to usual care. Secondary aims are to explore if/when a leveling-off effect on SBP will occur during the 20-week intervention period in the training group and to explore adherence and potential harms related to the IHG home training. METHODS/DESIGN:Based on previous evidence, we calculated that 50 hypertensive (SBP between 140 and 179 mmHg), older adults (50 + years of age) are needed to achieve a power of 80% or more. Participants will be randomly assigned to either an intervention >group (IHG home training + hypertension guidelines on lifestyle changes) or to a control group (hypertension guidelines on lifestyle changes). Participants in the intervention group will perform IHG home training (30% of maximum grip strength for a total of 8 min per day per hand) three times a week for 20 weeks. Resting blood pressure and maximal handgrip strength will be obtained by a blinded outcome assessor in both groups at specific time points (baseline, follow-up at 5, 10, 15, and 20 weeks) throughout the study. DISCUSSION:This assessor-blinded, randomized controlled trial will explore the effect of a 20-week IHG home training intervention on resting blood pressure in hypertensive older adults. In addition, the trial will report adherence and potential harms related to the IHG home training. TRIAL REGISTRATION:ClinicalTrials.gov, ID: NCT03069443 . Registered on 3 March 2017.
Project description:The optimal BP level in kidney transplant recipients remains uncertain. This post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial cohort assessed associations of BP with a pooled cardiovascular disease (CVD) outcome and with all-cause mortality. In 3474 prevalent kidney transplant patients, mean age was 52±9 years, 63% were men, 76% were white, 20% had a history of CVD, 40% had a history of diabetes mellitus, and the median time since transplant was 4.1 years (25th to 75th percentiles, 1.7-7.4); mean systolic BP was 136±20 mmHg and mean diastolic BP was 79±12 mmHg. There were 497 CVD events and 406 deaths. After adjustment for demographic and transplant characteristics and CVD risk factors, each 20-mmHg increase in baseline systolic BP associated with a 32% increase in subsequent CVD risk (hazard ratio [HR], 1.32; 95% confidence interval [95% CI], 1.19 to 1.46) and a 13% increase in mortality risk (HR, 1.13; 95% CI, 1.01 to 1.27). Similarly, after adjustment, at diastolic BP levels<70 mmHg, each 10-mmHg decrease in diastolic BP level associated with a 31% increase in CVD risk (HR, 1.31; 95% CI, 1.06 to 1.62) and a 31% increase in mortality risk (HR, 1.31; 95% CI, 1.03 to 1.66). However, at diastolic BP levels>70 mmHg, there was no significant relationship between diastolic BP and outcomes. Higher systolic BP strongly and independently associated with increased risk of CVD and all-cause mortality, without evidence of a J shape, whereas only lower levels of diastolic BP associated with increased risk of CVD and death in this trial.