210 research outputs found
Studying the cutaneous microcirculatory response during upper-limb exercise in healthy, older, sedentary people
This study investigated changes incurred in cutaneous skin blood flux (SKBF) in the superficial veins of the lower
limb by upper limb exercise training in the form of arm-cranking in 14 healthy participants over the age of 50 years. Changes in cutaneous microvascular function of the lower leg were assessed using laser Doppler Flowmetry (LDF) during a 30-minute exercise session undertaken over 4-exercise periods. Both SKBF and Time to reach Peak Perfusion (Tmax) were improved significantly during the 2nd (e.g. 121 (±107.2) vs 280 (±269.1) and 171 (±34.4) vs. 247 (±38.3) respectively) when compared to the first exercise period, while values approaching initial levels in the following stages. The results indicate that the thermoregulatory and vasodilation mechanisms observed during exercise in middle-aged and older healthy people are different to the one appearing in younger age groups, suggesting a more extensive effect of the age-related structural changes than it was previously thought
Exploring the feasibility of an exercise programme including aerobic and resistance training in people with limited cutaneous systemic sclerosis.
OBJECTIVES: It is suggested that exercise can improve the vascular function and quality of life (QoL) in people with systemic sclerosis (SSc), potentially offering clinical benefits to this population. Yet the feasibility of such an intervention remains untested. Therefore, the purpose of this study is to examine the feasibility of a combined exercise protocol (aerobic and resistance training) in people with limited cutaneous SSc (lcSSc). METHODS: Thirty-two lcSSc patients (66.5 ± 12 years old) were randomly allocated in two groups (exercise and control group). The exercise group underwent a 12-week exercise programme, twice per week. All patients performed the baseline, three- and six-month follow-up measurements where functional ability, body composition and QoL were assessed. Participants' experiences were explored through interviews. RESULTS: Compliance was 92.6% with no dropouts. The individuals' confidence to participate in the study's exercise protocol for twice per week was 95%. The average value for the physical activity enjoyment scale was 103 ± 10 out of 119 (highest score). The mean values for the intention to engage in exercise twice per week were 6.4 ± 1 (likely) out of 7 (very likely). QoL for the exercise group showed to have a better life satisfaction, less anxiety and Raynaud's phenomenon-accompanied pain. CONCLUSIONS: Our results suggest that a combined exercise protocol was feasible for people with lcSSc, with no adverse events, resulting in high adherence and low attrition rates, high enjoyment levels and intentions for future engagement to this exercise. Thus, the specific protocol is a safe adjunct therapy for people with lcSSc. TRIAL REGISTRATION: ClinicalTrials.gov (NCT number): NCT03058887, February 23, 2017, https://clinicaltrials.gov/ct2/show/NCT03058887?term=NCT03058887&rank=1Key Points• High-intensity interval training in combination with resistance training constitutes a feasible exercise protocol for people with lcSSc.• Overall, the exercise programme demonstrated high adherence and enjoyment levels and low attrition rates.• The exercise protocol was proved to be safe with no adverse events for people with lcSSc
Association between pretreatment haemoglobin levels and morphometric characteristics of the tumour, response to neoadjuvant treatment and long-term outcomes in patients with locally advanced rectal cancers
Aim
The study was carried out to investigate whether
pretreatment haemoglobin (Hb) levels act as a biomar-
ker in the management of patients with locally advanced
rectal cancer.
Method\ud
We prospectively collected data on all patients
within our cancer network with localized low rectal
cancer treated with preoperative radiotherapy/chemora-
diotherapy at Mount Vernon Centre for Cancer Treat-
ment between March 1994 and July 2008. Pretreatment
Hb level was assessed as an independent variable for the
whole study sample and dichotomised at a value of 12 g/dl.
A multivariate analysis of covariance (MANCOVA) was
conducted on parameters that had significant association
on univariate analysis of covariance (ANCOVA) and cor-
relational (Kendall tau/Pearson) analyses. Kaplan
–
Meier
survival analysis and Cox proportional hazard models
were used to determine significant prognostic markers.
Statistical significance was set at 0.05.
Results
463 patients (male/female 2:1; median age
=
66 years, interquartile range
=
56.5
–
73.0) were included
in the analysis. There was significant tumour response of
T stage (
P
<
0.001) and N stage (
P
<
0.001), with
17.6% of patients achieving a pathological complete
response. Pretreatment Hb value was inversely related to
the craniocaudal vertical tumour length (
P
=
0.02) and
pretreatment T stage of the tumour (
P
=
0.01). Patients
with Hb levels of
<
12 g/dl and moderately differenti-
ated adenocarcinoma were less responsive. Local recur-
rence was more common in patients with a pretreatment
Hb of
<
12 g/dl (hazard ratio
=
1.78) over a median
follow up of 24 months, but this was not statistically
significant (
P
=
0.08).
Conclusion
The pretreatment Hb level might be used
as a biomarker of rectal tumour morphology, response
to neoadjuvant chemoradiation and risk of local recur-
renc
Supervised exercise training and increased physical activity to reduce cardiovascular disease risk in women with polycystic ovary syndrome: Study protocol for a randomized controlled feasibility trial
Background: Polycystic ovary syndrome (PCOS) affects up to 20% of women and is characterised by higher amounts of visceral fat, obesity, insulin resistance, dyslipidemia and reproductive and cardiometabolic complications. Increased oxidised low-density lipoprotein (LDL) concentrations have been associated with an increased risk of cardiovascular disease (CVD)-related events. Oxidised LDL is rarely used as a marker for CVD risk in PCOS-related studies despite its widely accepted role in atherogenesis and the increased risk factors associated with PCOS. Additionally, prolonged periods of sedentary behaviour can negatively affect metabolic health. No studies have specifically examined the effects of reducing sedentary behaviour on CVD risk in PCOS with a lifestyle physical activity intervention. The aim of the current study is to measure the feasibility of a randomised controlled trial (RCT) examining the effects of supervised exercise and reducing sedentary behaviour in women with PCOS on CVD risk. Methods/design: A feasibility, exploratory RCT will be conducted. Fifty-one pre-menopausal females will be randomly allocated between an exercise group (EG), a lifestyle physical activity group (LPAG) and a control group. Participants in the EG will undertake a 12-week supervised aerobic exercise programme. The LPAG will aim to increase daily physical activity and reduce sedentary behaviour for 12 weeks. The control group will not take part in any intervention. Primary outcomes are feasibility and acceptability of the intervention and procedures. Secondary outcomes are oxidised LDL, aerobic fitness, blood lipid profile, fasting glucose and insulin, testosterone and inflammatory markers. Discussion: PCOS is associated with various increased risk factors for CVD, including hypertension, dyslipidemia, abdominal obesity, insulin resistance, and inflammation. Whether oxidised LDL has a role in this increased risk is not yet known. The present study aims to measure the feasibility of implementing structured exercise training and/or increased lifestyle physical activity in women with PCOS, so that a subsequent adequately powered RCT can be designed. The results from the study will be used to refine the interventions and determine the acceptability of the study design. A limitation is that some self-monitoring in the lifestyle physical activity group may not be reliable or replicable, for example inputting information about time spent cleaning/gardening
Effects of lower limb angioplasty on endothelial-dependent and -independent microvascular reactivity
Background: Percutaneous Transluminal Angioplasty (PTA) of the lower limb
improves arterial flow and claudication symptoms, but the effects on cutaneous microvascular
perfusion and reactivity have not been previously reported.
Report: Cutaneous microvascular function in the feet was assessed in 12 patients with intermittent
claudication before and after PTA using Laser Doppler Fluximetry (LDF) with transcutaneous
iontophoretic administration of acetylcholine and sodium nitroprusside. Maximum
vasodilator responses to both endothelial-dependent and independent vasodilators were
increased following PTA.
Conclusions: Large vessel intervention to improve macrovascular flow has additional benefits on
the downstreamcutaneous microcirculation to improve vasodilator responsiveness. These effects
may be clinically important to reduce the risk of ischaemic ulceration and tissue breakdown
Physiological effects of a short-term, lifestyle intervention based on the Mediterranean diet - comparison between older and younger healthy, sedentary adults
Objective: To determine whether short-term adherence to the Mediterranean Diet (MD) is associated with improved physiological function.
Research Methods and Procedures: This was a single-centre, cohort pilot study. Twenty-four healthy, sedentary younger (18-35 years) and older (55-75 years) adults took part. Participants were advised and supported to follow the Mediterranean diet for 4 weeks. We took baseline and post-intervention measurements of weight, height, waist and hip circumference, blood pressure, heart rate, as well as microvascular physiological assessments using laser Doppler Fluximetry (LDF) at rest as well as transcutaneous oxygen pressure (TcPO2) during a sub-maximal exercise assessment.
Results: We identified statistically-significant improvements in axon-mediated microvascular vasodilation (2.24 (±0.56) to 3.14 (±0.84), P =0.03) and endothelial-mediated NO synthesis (2.59 (±0.67) to 3.32 (±0.87), P =0.022) in the younger group. Despite the intervention not including an exercise element, the rate of perceived exertion was reduced in both groups (p<0.001), after following the MD for a month.
Conclusions: Improvements in physiological function were observed following a short-term dietary intervention based on the MD in a younger population. These were not matched in a senior group. Our findings suggest that different durations should be applied when designing dietary interventions in different age-groups, with expectations in physiological improvements differing.
Keywords: Mediterranean diet, LDF, Oxygen tension, cardiovascular disease, blood pressure
Comparison of laser speckle contrast imaging with laser Doppler for assessing microvascular function
Objective: To compare the inter-day reproducibility of post-occlusive reactive hyperaemia (PORH) and sympathetic vasomotor reflexes assessed by single-point laser Doppler flowmetry (SP-LDF), integrating-probe LDF (IP-LDF) and laser speckle contrast imaging (LSCI), and the spatial variability of PORH assessed by IP-LDF and LSCI. We also evaluated the relationship between IP-LDF and LSCI perfusion values across a broad range of skin blood flows.
Methods: Eighteen healthy adults (50% male, age 27 ± 4 years) participated in this study. Using SP-LDF, IP-LDF and LSCI, an index of skin blood flow was measured on the forearm during PORH (1-, 5- and 10-min occlusions) and on the finger pad during inspiratory gasp and cold pressor tests. These tests were repeated 3-7 days later. Data were converted to cutaneous vascular conductance (CVC; laser Doppler flow/mean arterial pressure) and expressed as absolute and relative changes from pre-stimulus CVC (ΔCVCABS and ΔCVCREL, respectively), as well as normalised to peak CVC for the PORH tests. Reproducibility was expressed as within-subjects coefficients of variation (CV, in %) and intraclass correlation coefficients.
Results: The reproducibility of PORH on the forearm was poorer when assessed with SP-LDF and IP-LDF compared to LSCI (e.g., CV for 5-min PORH ΔCVCABS = 35, 27 and 19%, respectively), with no superior method of data expression. In contrast, the reproducibility of the inspiratory gasp and cold pressor test responses on the finger pad were better with SP-LDF and IP-LDF compared to LSCI (e.g., CV for inspiratory gasp ΔCVCREL = 13, 7 and 19%, respectively). The spatial variability of PORH responses was poorer with IP-LDF compared to LSCI (e.g., CV ranging 11-35% versus 3-16%, respectively). The association between simultaneous LSCI and IP-LDF perfusion values was non-linear.
Conclusion: The reproducibility of cutaneous PORH was better when assessed with LSCI compared to SP-LDF and IP-LDF; probably due to measuring larger skin areas (lower inter-site variability). However, when measuring sympathetic vasomotor reflexes on the finger pad, reproducibility was better with SP-LDF and IP-LDF, perhaps due to the high sensitivity of LSCI to changes in skin blood flow at low levels
Commentary on: "Implementing a Mediterranean-Style Diet Outside the Mediterranean Region".
Letter to the editor
Validation of an arm crank ergometer test for use in sedentary adults
The maximal oxygen uptake (V̇O2peak) test is an approved pre-operative examination tool, in a clinical setting: Both V̇O2peak and anaerobic threshold indicate a patient's physiological tolerance for major surgery and post-operative mortality, with cycle ergometry being routinely used for V̇O2peak tests in clinical settings, in many European countries. Nevertheless, the opportunities to assess populations with restricted mobility of the lower limbs are limited, as alternative methods (such as an arm-crank test protocol) to assess V̇O2peak are yet to be established. Twelve sedentary middle-aged adults (55.1 ± 5.0 years) performed two incremental protocols on an arm crank and cycle ergometer on separate occasions. During exercise, gas exchange was collected and analysed by an online breath-by-breath analysis system. Regression analysis showed that the model with dependent variable cycle ergometer V̇O2peak (CEV̇O2peak) in ml·kg-1·min-1 and independent variables arm crank V̇O2peak (ACEV̇O2peak) in ml·kg-1·min-1, lean body mass lower limbs (LBMLL) and total lean body mass (TLBM) fitted the population the best, with r2 = 0.87, adj. r2 = 0.82 and SEE = 3.14. The equation estimated with this model is: CE V̇O2peak = 11.776 + 1.418 X ACE V̇O2peak(ml·kg-1·min-) – 1.454 x TLBM + 3.967 X LLLBM. Our study suggests that arm cranking could be an alternative mode of exercise for sedentary middle-aged adults (and potentially in clinical settings) to assess the cardiorespiratory fitness of people with restricted lower-limb mobility.
Key words: Cardiopulmonary test, arm exercise, physiological responses, upper limbs
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