Relationships between Obesity, Cardiorespiratory Fitness, and Cardiovascular Function

Background. Obesity and low cardiorespiratory fitness (CRF) have been shown to independently increase the risk of CVD mortality. The aim of this study was to investigate the relationship between CRF, body fatness and markers of arterial function. Method and Results. Obese (9 male, 18 female; BMI 35.3 ± 0.9 kg·m−2) and lean (8 male, 18 female; BMI 22.5 ± 0.3 kg·m−2) volunteers were assessed for body composition (DXA), cardiorespiratory fitness (predicted V˙O2max), blood pressure (BP), endothelial vasodilatator function (FMD), and arterial compliance (AC) (via radial artery tonometry). The obese group had more whole body fat and abdominal fat (43.5 ± 1.2% versus 27.2 ± 1.6%; P < .001 and 48.6 ± 0.9% versus 28.9 ± 1.8%; P < .001, resp.), and lower FMD (3.2 ± 0.4% versus 5.7 ± 0.7%; P < .01) than the lean subjects, but there was no difference in AC. AC in large arteries was positively associated with CRF (R = 0.5; P < .01) but not with fatness. Conclusion. These results indicate distinct influences of obesity and CRF on blood vessel health. FMD was impaired with obesity, which may contribute to arterial and metabolic dysfunction. Low CRF was associated with reduced elasticity in large arteries, which could result in augmentation of aortic afterload

A Mediterranean Diet and Walking Intervention to Reduce Cognitive Decline and Dementia Risk in Independently Living Older Australians:The MedWalk Randomized Controlled Trial Experimental Protocol, Including COVID-19 Related Modifications and Baseline Characteristics.

Background:Several clinical trials have examined diet and physical activity lifestyle changes as mitigation strategies for risk factors linked to cognitive decline and dementias such as Alzheimer’s disease. However, the ability to modify these behaviors longer term, to impact cognitive health has remained elusive.Objective:The MedWalk trial’s primary aim is to investigate whether longer-term adherence to a Mediterranean-style diet and regular walking, delivered through motivational interviewing and cognitive-behavioral therapy (MI-CBT), can reduce age-associated cognitive decline and other dementia risk factors in older, independently living individuals without cognitive impairment.Methods:MedWalk, a one-year cluster-randomized controlled trial across two Australian states, recruited 60–90-year-old people from independent living retirement villages and the wider community. Participants were assigned to either the MedWalk intervention or a control group (maintaining their usual diet and physical activity). The primary outcome is 12-month change in visual memory and learning assessed from errors on the Paired Associates Learning Task of the Cambridge Neuropsychological Test Automated Battery. Secondary outcomes include cognition, mood, cardiovascular function, biomarkers related to nutrient status and cognitive decline, MI-CBT effectiveness, Mediterranean diet adherence, physical activity, quality of life, cost-effectiveness, and health economic evaluation.Progress and Discussion:Although COVID-19 impacts over two years necessitated a reduced timeline and sample size, MedWalk retains sufficient power to address its aims and hypotheses. Baseline testing has been completed with 157 participants, who will be followed over 12 months. If successful, MedWalk will inform interventions that could substantially reduce dementia incidence and ameliorate cognitive decline in the community.<br/

Effects of exercise and cocoa flavanol supplementation on cardiometabolic function.

The link between excess adipose tissue and an increased risk of developing various pathologies, including cardiovascular (CV) diseases and type 2 diabetes, is now well accepted. There is increasing evidence supporting impaired arterial function (AF) as a causal link in this process. It can therefore be postulated that interventions aimed at improving AF may attenuate or prevent this progression from overweight/obesity to CV and metabolic disease. Exercise has been shown to improve AF in various pathologies. A limitation in the evidence for exercise or increased fitness in an obese population is the differentiation of effects of obesity and fitness or exercise on CV function and risk. To investigate this, a cross sectional study was done to compare cardiorespiratory fitness (CRF; predicted VO₂max) and markers of AF (brachial flow mediated dilatation (FMD), arterial compliance (AC) and blood pressure (BP)) in sedentary obese (N=27) and sedentary lean (N=26) volunteers. The obese group had more whole body fat and abdominal fat (43.5 ± 1.2% vs. 27.2 ± 1.6%; p<0.001 and 48.6 ± 0.9% vs. 28.9 ± 1.8%; p<0.001 respectively) and lower FMD (3.2 ± 0.4% vs. 5.7 ± 0.7%; p<0.01) than the lean subjects but there was no difference in AC. FMD correlated with whole body fat (R = 0.28; p<0.05) and abdominal fat (R = 0.34; p<0.05) but not with CRF. By comparison AC in large arteries was positively associated with CRF (R = 0.5; p<0.01) but not with fatness. These results suggest a differential influence of fitness and fatness on AF. Flavanols from cocoa have been shown to positively influence AF in a variety of CV risk groups, however this effect has not been investigated in obese subjects or in long term studies. This question was addressed by conducting a 2x2 factorial, randomised controlled trial comparing a high flavanol (HF; 902mg/day) and low flavanol (LF; 36mg/day) cocoa drink, with or without a moderate exercise program for 12 weeks in 49 overweight/obese volunteers. Compared with LF, HF increased FMD acutely (2 hrs post dose) by 2.42% (p < 0.01) and chronically (over 12 weeks; p < 0.01) by 1.63% and reduced insulin resistance by 0.31 (p < 0.05), diastolic BP by 1.57mmHg and mean BP by 1.17mmHg (p < 0.05), independent of exercise. Regular exercise increased fat oxidation during exercise by 0.10g.m⁻¹ (p < 0.01) and reduced abdominal fat by 0.92% (p < 0.05), independent of cocoa consumption. This study provides the first evidence for a sustained improvement in CV and metabolic function with HF cocoa in an overweight/obese population. To expand upon these potential benefits of cocoa in overweight/obesity a further study was conducted to compare the acute effects of HF (701mg) to LF (22mg) cocoa on BP during exercise in 21 overweight/obese volunteers. Results of this study showed a significant attenuation of the exercise induced rise in BP with the HF compared to LF cocoa. The antihypertensive effects of cocoa flavanols were further examined by 24 hour ambulatory monitoring in 52 untreated hypertensive volunteers consuming 1 of 4 doses (state doses) of cocoa flavanols for 6 weeks. There were significant reductions in 24-hour systolic (5.3 ± 0.8 mmHg; p = 0.001), diastolic (3 ± 0.7 mmHg; p = 0.002) and mean arterial blood pressure (3.8 ± 0.8 mmHg; p = 0.0004) at the highest dose only (1052 mg/d). No reduction in BP was seen at any other dose. These results support the previous evidence for a BP lowering effect of HF cocoa but indicate that the effective dose may be higher than previously indicated. Collectively these results provide considerable support for the potential use of cocoa flavanols to resist the progressive decline in AF leading from obesity to metabolic syndrome.Thesis (Ph.D.) -- University of Adelaide, School of Medical Sciences, 201

Potential implications of dose and diet for the effects of eocoa flavanols on cardiometabolic function

The metabolic syndrome is a pathological state whereby cardiovascular and metabolic dysfunction coexist and typically progress in a mutual feed-forward manner to further dysfunction and ultimately disease. The health and function of the vascular endothelium is integral in this phenomenon and thus represents a logical target for intervention. Consumption of foods high in cocoa flavanols has demonstrated a capacity to markedly improve endothelial function and key markers of the metabolic syndrome including blood pressure and insulin sensitivity. The typically high energy content of foods containing sufficient doses of cocoa flavanols has caused some reservations around its therapeutic use, but this is dependent upon the particulars of the food matrix used. Further to this, the food matrix appears to influence the dose response curve of cocoa flavanols, particularly on blood pressure, with dark chocolate appearing to be 8 times more effective in systolic blood pressure reduction than a cocoa powder drink for the equivalent dose of flavanol. Cocoa flavanol consumption conclusively demonstrates a positive impact on cardiometabolic function; however, more research is needed to understand how best to consume it to maximize the benefit while avoiding excessive fat and sugar consumption

Type 2 diabetes and the medicine of exercise: The role of general practice in ensuring exercise is part of every patient's plan

BACKGROUND: The benefit of exercise in the prevention and management of type 2 diabetes (T2D) has a strong evidence base, so it is important to ensure exercise is part of every patient's management plan. OBJECTIVE: This article reviews the evidence for exercise in T2D and the factors affecting a patient's willingness to commence and sustain enough exercise to gain benefit. The article offers tips about how to safely and effectively prescribe the 'medicine' of exercise for all, even the frailest patients; who to stabilise before an exercise program should begin; and how to use the skills of an accredited exercise physiologist (AEP) to deliver the best 'prescription' possible. DISCUSSION: General practitioners and their teams, along with other healthcare providers such as AEPs, can increase the amount of exercise medicine a patient receives. This is the case for those at risk of developing T2D, those with T2D and those with the many comorbidities associated with T2D.</p

The Effect of Anthocyanin-Rich Foods or Extracts on Vascular Function in Adults: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Anthocyanins are of interest due to their anti-oxidative and vasodilatory properties. Earlier reviews have shown that berries and other anthocyanin rich foods or extracts can improve vascular health, however the effect of anthocyanins on vascular function has not yet been reviewed. To address this gap in the literature, we conducted a systematic review and meta-analysis of randomised-controlled trials examining anthocyanin-rich foods or extracts on measures of vascular reactivity and/or stiffness in adults. Data from 24 studies were pooled as standardized mean difference (SMD) with 95% confidence intervals (CI). Anthocyanin consumption significantly improved flow-mediated dilation (FMD) following acute (SMD: 3.92%, 95% CI: 1.47, 6.38, p = 0.002; I2 = 91.8%) and chronic supplementation (SMD: 0.84%, 95% CI: 0.55, 1.12, p = 0.000; I2 = 62.5%). Pulse wave velocity was improved following acute supplementation only (SMD: −1.27 m/s, 95% CI: −1.96, −0.58, p = 0.000; I2 = 17.8%). These results support the findings of previous reviews that anthocyanin rich foods or extracts may indeed improve vascular health, particularly with respect to vascular reactivity measured by FMD. More research is required to determine the optimal dosage, and the long-term effects of consumption

An evaluation of a novel biomarker feedback intervention on smoking cesation; a pilot study

Cessation is the single most important decision smokers can make to improve their health. The aim of this study was to investigate the effects of a novel biomarker feedback intervention on smoking cessation. Participants (n = 14) were block matched into two groups - biomarker feedback and standard care (control) - and encouraged to stop smoking without the support of any pharmacological aids. All participants received standard smoking cessation advice and also had physiological measures collected during both rest and sub-maximal exercise testing at baseline, week 6 and week 12. The standard care group only received the smoking cessation advice as their intervention, whereas the biomarker feedback group were also given individual feedback in relation to their physiological results. Cessation rates were not significantly different between groups (p = 0.56) at week 12 follow-up; however, a calculation of odds ratios (OR) suggests that the biomarker feedback group was more likely to be successful when compared to standard care (OR = 4.5). Results suggest that targeting health motivations may positively influence cessation rates. Future research is needed to verify this result with a larger group