Christopher JA Pugh

• BSc (Hons), PhD
• Professor (Associate) at Cardiff Metropolitan University

Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for cardiovascular disease (CVD). Endothelial dysfunction is an early manifestation of atherosclerosis and an important prognostic marker for future cardiovascular events. The aim of this study was two-fold: to examine i) the association between liver fat, visceral adipose tiss...

Background and Aims Exercise is recommended for the management of metabolic dysfunction‐associated steatotic liver disease (MASLD), yet effects on liver histology remain unknown, especially without significant weight loss. We aimed to examine changes in surrogate measures of liver histological response with exercise training. Methods We conducted...

Chronic exercise training is associated with an 'athlete's artery' phenotype in young adults and an attenuated age-related decline in endothelium-dependent arterial function. Adolescence is associated with an influx of sex-specific hormones that may exert divergent effects on endothelial function, but whether training adaptations interact with biol...

Purpose Central arterial stiffness, a predictor of cardiovascular risk, attenuates with endurance-exercise in ageing populations. However, in young individuals, this effect is inconsistent and emerging evidence suggests resistance-exercise may increase arterial stiffness. Two-dimensional (2D)-Strain imaging of the common carotid artery (CCA) is mor...

INTRODUCTION: Regular exercise induces recurrent increases in cerebrovascular perfusion. In peripheral arteries, such episodic increases in perfusion are responsible for improvement in arterial function and health. We examined the hypothesis that exercise during water immersion augments cerebral blood flow velocity compared to intensity-matched lan...

The prevalence of centenarians, people who lived 100 years and longer, is steadily growing in the last decades. This exceptional longevity is based on multifaceted processes influenced by a combination of intrinsic and extrinsic factors such as sex, (epi-)genetic factors, gut microbiota, cellular metabolism, exposure to oxidative stress, immune sta...

BACKGROUND The aortic-femoral arterial stiffness gradient, calculated as the ratio of lower-limb pulse-wave velocity (PWV) to central (aortic) PWV, is a promising tool for assessing cardiovascular disease (CVD) risk, but whether it predicts incident CVD is unknown. METHODS We examined the association of the aortic-femoral arterial stiffness gradie...

We participated in the UK and Republic of Ireland May Measurement Month 2021 (MMM21) campaign to raise awareness about blood pressure (BP) measurement and the dangers posed by elevated BP and hypertension. In addition, the campaign aimed to collect and report levels of BP awareness and control in the community setting. The MMM21 campaign set up opp...

Post‐exercise hot (HWI) and cold (CWI) water immersion are popular strategies used by athletes in a range of sporting contexts, such as enhancing recovery or adaptation. However, prolonged heating bouts increase neuroendocrine responses that are associated with perceptions of fatigue. Fourteen endurance‐trained runners performed three trials consis...

Purpose There is emerging evidence that demonstrates the health benefits of hot water immersion including improvements to cardiovascular health and reductions in stress and anxiety. Many commercially available hot tubs offer underwater massage systems which purport to enhance many benefits of hot water immersion, however, these claims have yet to b...

Exercise and passive heating induce some similar vascular hemodynamic, circulating blood marker, and perceptual responses. However, it remains unknown whether post exercise hot water immersion can synergise exercise derived responses and if they differ from hot water immersion alone. This study investigated the acute responses to post moderate‐inte...

Cerebral blood velocity (CBv) increases in response to moderate exercise in humans, but the magnitude of change is smaller in children compared to post-pubertal adolescents and adults. Whether sex differences exist in the anterior or posterior CBv response to exercise across pubertal development remains to be determined. We assessed middle cerebral...

Carotid artery longitudinal wall motion (CALM) is a novel preclinical marker for atherosclerosis that describes the axial anterograde and retrograde motion of the intima–media complex. While regular physical activity and sex are known to independently influence arterial stiffness, their roles on axial arterial wall behaviour are unknown. The purpos...

Vascular ageing, characterized by structural and functional changes in blood vessels of which arterial stiffness and endothelial dysfunction are key components, is associated with increased risk of cardiovascular and other age-related diseases. As the global population continues to age, understanding the underlying mechanisms and developing effecti...

Global cerebral blood flow (gCBF) and cerebrovascular reactivity to hypercapnia (CVRCO2${\mathrm{CV}}{{\mathrm{R}}_{{\mathrm{C}}{{\mathrm{O}}_{\mathrm{2}}}}}$) are modulated by gonadal hormone activity, while insulin‐like growth factor 1 facilitates exercise‐mediated cerebral angiogenesis in adults. Whether critical periods of heightened hormonal a...

Neurovascular coupling (NVC) is mediated via nitric oxide signalling, which is independently influenced by sex hormones and exercise training. Whether exercise training differentially modifies NVC pre- vs. post-puberty, where levels of circulating sex hormones will differ greatly within- and between-sexes, remains to be determined. Therefore, we in...

Central arterial stiffness can influence exercise blood pressure (BP) by increasing the rise in arterial pressure per unit increase in aortic inflow. Whether central arterial stiffness influences the pressor response to isometric handgrip exercise (HG) and post-exercise muscle ischemia (PEMI), two common laboratory tests to study sympathetic contro...

Although physical activity (PA) is crucial in the prevention and clinical management of nonalcoholic fatty liver disease (NAFLD), most individuals with this chronic disease are inactive and do not achieve recommended amounts of PA. There is a robust and consistent body of evidence highlighting the benefit of participating in regular PA, including a...

Background and aims: We present findings from the inaugural American College of Sports Medicine (ACSM) International Multidisciplinary Roundtable, which was convened to evaluate the evidence for physical activity as a means of preventing or modifying the course of NAFLD. Approach and results: A scoping review was conducted to map the scientific...

Hot water immersion improves cardiovascular health and sporting performance, yet its adverse responses are understudied. Thirteen young and 17 middle‐aged adults (n = 30) were exposed to 2 × 30 min bouts of whole‐body 39°C water immersion. Young adults also completed cooling mitigation strategies in a randomized cross‐over design. Orthostatic intol...

Recent research into passive heating has shown that it can enhance performance when used as; a stimulus for heat acclima-tion, part of regular training, or during a warm-up. However, this research is contradictory to established practices such as ice baths in the case of recovery. The current usage and understanding of passive heating within sport...

Purpose We determined the effect of habitual endurance exercise and age on aortic pulse wave velocity (aPWV), augmentation pressure (AP) and systolic blood pressure (aSBP), with statistical adjustments of aPWV and AP for heart rate and aortic mean arterial pressure, when appropriate. Furthermore, we assessed whether muscle sympathetic nerve activit...

There is increasing interest in using neuro-stimulation devices to achieve an ergogenic effect in elite athletes. Although the World Anti-Doping Authority (WADA) does not currently prohibit neuro-stimulation techniques, a number of researchers have called on WADA to consider its position on this issue. Focusing on trans-cranial direct current stimu...

New findings: What is the central question of this study? Endurance athletes demonstrate altered regional right ventricular (RV) wall mechanics in comparison to non-athletic controls at rest, characterised by lower basal deformation. We tested the hypothesis that regional adaptations at the RV base reflects an enhanced functional reserve capacity...

Intermittent claudication (IC) is associated with impairments in quality of life and walking ability. Heat therapy is an emerging cardiovascular therapy, which may improve walking in patients with IC. We undertook a systematic review to establish current evidence for heat therapy for patients with IC. We searched five databases (Ovid Medline / PubM...

We participated in the UK and Republic of Ireland May Measurement Month 2021 (MMM21) campaign to raise awareness about blood pressure (BP) measurement and the dangers posed by elevated BP and hypertension. In addition, the campaign aimed to collect and report levels of BP awareness and control in the community setting. The MMM21 campaign set up opp...

Exercise can induce numerous health benefits that can reduce the risk of chronic diseases and all-cause mortality, yet a significant percentage of the population do not meet minimal physical activity guidelines. Several recent studies have shown that passive heating can induce numerous health benefits, many of which are comparable to exercise, such...

Left ventricular (LV) structural remodeling following athletic training has been evidenced through training-specific changes in wall thickness and geometry. Whether the LV response to changes in hemodynamic load also adapts in a training-specific manner is unknown. Using echocardiography, we examined LV responses of endurance-trained (n=15), resist...

Changes in the arterial baroreflex arc contribute to elevated sympathetic outflow and altered reflex control of blood pressure with human ageing. Utilizing ultrasound and sympathetic microneurography (muscle sympathetic nerve activity; MSNA)we investigated the relationships between aortic and carotid artery wall tension (indices of baroreceptor act...

New findings: What is the central question of this study? Carotid artery peak circumferential strain (PCS) and strain-rate attenuate with age, but appear to be modulated by cardiorespiratory fitness status in young males. However, the relationship between habitual endurance exercise (running) and these parameters has not been studied in young and...

Introduction: The assessment of middle cerebral artery (MCA) haemodynamics is essential for the diagnosis and monitoring of cerebrovascular disease. However, conventional transcranial Doppler (TCD) may not capture the correct flow velocities because of sub-optimal angles of insonation. Conversely, 2-D ultrasound (2D-US) allows for the visualisation...

This study focused on the influence of habitual endurance exercise training (i.e., committed runner or nonrunner) on the regulation of muscle sympathetic nerve activity (MSNA) and arterial pressure in middle-aged (50 to 63 yr, n = 23) and younger (19 to 30 yr; n = 23) normotensive men. Hemodynamic and neurophysiological assessments were performed a...

New findings: What is the central question of this study? Common carotid artery (CCA) two-dimensional strain imaging detects intrinsic arterial wall properties beyond conventional measures of arterial stiffness, but the effect of cardiorespiratory fitness on two-dimensional strain-derived indices of CCA stiffness is unknown. What is the main findi...

Arterial shear stress is a potent stimulus to vascular adaptation in humans. Typically, increases in retrograde shear have been found to acutely impair vascular function while increases in antegrade shear enhance function. We hypothesized that blood flow and shear stress through the brachial and carotid arteries would change in a similar manner in...

An abundance of data unequivocally demonstrates that exercise can be an effective tool in the fight against obesity and its associated comorbidities.1 Indeed, physical activity can be more effective than widely used pharmaceutical interventions. While metformin reduces the incidence of diabetes by 31% (as compared with a placebo) in both men and wo...

Arterial wall mechanics likely play an integral role in arterial responses to acute physiological stress. Therefore, this study aimed to determine the impact of low and moderate intensity double-leg press exercise on common carotid artery (CCA) wall mechanics using 2D vascular strain imaging. Short-axis CCA ultrasound images were collected in 15 he...

Aims: Supervised exercise reduces liver fat and improves endothelial function, a surrogate of cardiovascular disease risk, in non-alcoholic fatty liver disease (NAFLD). We hypothesised that after a 16-week supervised exercise program, patients would maintain longer-term improvements in cardiorespiratory fitness, liver fat and endothelial function....

Non-Alcoholic Fatty Liver Disease (NAFLD) is associated with multi-organ (hepatic, skeletal muscle, adipose tissue) insulin resistance (IR). Exercise is an effective treatment for lowering liver fat but its effect on insulin resistance in NAFLD is unknown. We aimed to determine whether supervised exercise in NAFLD would reduce liver fat and improve...

The objectives of our study were to examine (i) the proportion of 'responders' and 'non-responders' to exercise training in terms of vascular function, (ii) a priori factors related to exercise training-induced changes in conduit artery function, and (iii) the contribution of traditional cardiovascular risk factors to exercise-induced changes in ar...

Non-alcoholic fatty liver disease (NAFLD), characterized by lipid deposition within the liver (intrahepatocellular lipid, IHCL), is associated with insulin resistance and the metabolic syndrome. It has been suggested that impaired skeletal muscle mitochondrial function may contribute to ectopic lipid deposition, and the associated metabolic syndrom...

Introduction. The aim of this study was to examine the contribution of arterial shear to changes in flow mediated dilation (FMD) during sympathetic nervous system activation in healthy humans. Methods. Ten healthy men reported to our laboratory 4 times. Bilateral FMD, shear rate (SR) and catecholamines were examined before/after 10-minutes of -35mm...

Purpose: We performed two experiments to determine whether cutaneous microvascular adaptations in response to repeated core temperature (Tc) elevation are mediated by increases in skin blood flow (SkBF) and/or skin temperature. Methods: Healthy subjects participated for 8 wk in thrice-weekly bouts of 30-min lower limb heating (40°C). In study 1,...

Episodic increases in cerebrovascular perfusion and shear stress may have beneficial impacts on endothelial function that improve brain health. We hypothesised that water immersion to the level of the right atrium in humans would increase cerebral perfusion. We continuously measured, in 9 young (mean±SD, 24.6 ± 2.0 yrs) healthy men, systemic hemody...

Shear stress is a known stimulus to vascular adaptation in humans. However, it is not known whether thermoregulatory reflex increases in blood flow and shear can induce conduit artery adaptation. Ten healthy young volunteers therefore underwent 8 weeks of 3 × weekly bouts of 30 min lower limb heating (40 °C) during which the upper body was not dire...

Introduction: Recent studies from our laboratory have reported that water immersion induces an increase in cerebral artery shear stress and perfusion at rest. Exercise induces recurrent increases in shear stress in peripheral arteries, which have beneficial impacts on cardiovascular function and health. It is therefore plausible that water immersio...

Polycystic ovarian syndrome (PCOS) is associated with an adverse cardiovascular disease (CVD) profile. A surrogate marker for CVD risk is endothelial dysfunction. Limited studies exist examining the cardiovascular and metabolic effects of exercise in PCOS and specifically its impact on endothelial function. Therefore, the aim of the current study w...

Polycystic ovary syndrome (PCOS) is associated with insulin resistance, increased visceral fat and non-alcoholic fatty liver disease (NAFLD) all of which may contribute to endothelial dysfunction, an early marker of cardiovascular disease risk. Our objective was to examine the relationships between endothelial dysfunction in PCOS, the volume of adi...

The leading causes of mortality in non-alcoholic fatty liver disease (NAFLD) relate to cardiovascular disease (CVD). The contribution of nitric oxide (NO) to endothelial function, a surrogate of CVD risk, is currently unknown in NAFLD. We hypothesise that NO-mediated cutaneous microvessel function would be impaired in NAFLD compared with controls a...

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are used for treatment in type 2 diabetes mellitus (T2DM). Little is known about their cardiovascular impact. We sought to determine the effects of chronic treatment on vascular function in T2DM. Brachial artery endothelial-dependent (FMD) and -independent (GTN) function, and carotid intima-media...

Key points Polycystic ovary syndrome (PCOS) is associated with cardiovascular disease. Nitric oxide (NO) is a naturally occurring molecule that possesses anti‐atherogenic properties. The contribution of NO to the dilatation of microvessels in the skin is currently unknown in women with PCOS. In this study, it was found that women with PCOS display...

Context: Nonalcoholic fatty liver disease may be evident in women with polycystic ovary syndrome (PCOS), both conditions being associated with obesity and insulin resistance. However, few studies have accounted for the high prevalence of obesity in PCOS. Objective: The aim of this study was to determine whether PCOS is independently associated w...

Women with polycystic ovary syndrome (PCOS) demonstrate an increased prevalence of cardiovascular disease (CVD) risk factors. Previous researchers have compared flow-mediated dilation (FMD), an early marker of CVD, in women with and without PCOS. Evidence for a PCOS-mediated reduction in FMD remains equivocal, potentially because of study differenc...

PURPOSE Polycystic ovarian syndrome (PCOS) has an adverse cardiovascular disease (CVD) risk profile which infers a ~2 fold increased risk of coronary artery disease. It remains unclear as to whether endothelial dysfunction is evident in PCOS independently, or if co-existing morbidities are independent risk factors for endothelial function in this p...

Aims/Objectives Polycystic ovarian syndrome (PCOS) is associated with an adverse cardiovascular disease (CVD) risk profile coupled with ~2 fold increased risk of coronary artery disease. Limited research exists regarding the cardiometabolic effects of exercise in PCOS, and its impact on endothelial function, an early indicator of CVD risk, has not...

Polycystic ovarian syndrome (PCOS) is associated with abdominal obesity, insulin resistance and elevated hepatic fat. This adverse cardiovascular disease (CVD) risk profile is associated with ~2 fold increased risk of coronary artery disease. Limited research exists regarding the cardiometabolic effects of exercise in PCOS, and its impact on endoth...

Aims A 4-week exercise intervention can reduce hepatic fat independent of weight loss in obese individuals (Johnson et al., 2009). Nevertheless, additional therapeutic benefits could be evident with an increased exercise duration. The aim of this study was to implement a 16-week exercise intervention in overweight and obese NAFLD patients and asses...

Background and aims: Non alcoholic fatty liver disease (NAFLD) is consid- ered the hepatic manifestation of metabolic syndrome and such patients have increased risk of cardiovascular events (myocardial infarction, stroke, coro- nary revascularisation and cardiovascular death). Recent data suggests that patients with NAFLD had a hazard ratio of 2 fo...

Background and aims: Non-Alcoholic Fatty Liver Disease (NAFLD), the hepatic manifestation of the metabolic syndrome is characterised by the accumulation of triglycerides in the liver and is associated with liver-related morbidity and mortality as well as increased cardiovascular risk. Exercise training is recommended as a therapeutic technique to r...

Background and aims: Females with PCOS are at increased risk of cardiovascular disease (CVD). Recent reports suggest that endothelial dysfunction, an early marker of CVD, measured using the flow mediated dilatation (FMD) is evident in PCOS patients. Nevertheless, the supporting evidence remains equivocal, potentially due to differences in obesity a...

Background and aims: It has been suggested that there is a high prevalence of non-alcoholic fatty liver disease (NAFLD) in women with Polycystic Ovary Syndrome (PCOS) as both are associated with obesity and insulin resistance (IR). Furthermore, the mechanism for the peripheral insulin resistance observed in PCOS remains unclear. The aim of this stu...