Mastery imagery ability moderates the relationship between heart rate reactivity to acute psychological stress and perceptions of stress and physiological arousal.

Imagery has been associated with cardiovascular and psychological responses to stress; however, the mechanisms underlying this association are not fully understood. The present study examined if the ability to image mastering challenging or difficult situations moderated the relationship between heart rate reactivity and perceptions of stress and physiological arousal experienced during acute stress. Four hundred and fifty-eight participants completed a standardized laboratory stress protocol with heart rate being measured throughout. After completing an acute psychological stress task, participants rated how stressed and physiologically aroused they felt (i.e., intensity) and whether they perceived the stress and physiological arousal as being helpful/unhelpful to performance (i.e., interpretation). Mastery imagery ability was assessed by questionnaire. Moderation analyses controlling for gender demonstrated that imagery ability moderated the relationship between heart rate reactivity and interpretation of stress (ß = 0.015, p = .003) and perceived physiological arousal (ß = 0.013, p = .004). Simple slope analysis indicated that in those with higher imagery ability, heart rate reactivity was associated with stress and arousal being perceived as more positive toward performance. Imagery ability did not moderate the relationship between heart rate reactivity and perceived stress intensity or physiological arousal intensity (p's > .05), but imagery ability did predict lower perceived stress intensity (ß = -0.217, p < .001) and perceived physiological arousal intensity (ß = -0.172, p < .001). Higher mastery imagery ability may possibly help individuals perceive responses to stress as more beneficial for performance and thus be an effective coping technique.

Examining the associations between physical activity, self-esteem, perceived stress, and internalizing symptoms among older adolescents.

INTRODUCTION: In older adolescence, stress has been found to be prevalent. It has been seen that higher physical activity (PA) relates to lower stress levels, which, in turn, relates to fewer anxiety and depressive symptoms (internalizing symptoms). However, how these associations function is not fully understood. PA is strongly associated with greater self-esteem in adolescents. As greater self-esteem is thought to aid better coping with stress and has been seen as beneficial for mental health in adolescents, PA may be associated with lower stress and better mental health through self-esteem and more adaptive stress appraisals. Therefore, the aim of the study was to examine the relationships between PA, self-esteem, stress, and mental health. METHODS: A cross-sectional design was employed, and path analysis was implemented. PA, self-esteem, stress appraisals, distress tolerance, perceived stress, anxiety, and depression were assessed using online questionnaires from 244 adolescent participants from the United Kingdom (aged 15-19, M = 16.75 [SD = 0.82], 145 female). RESULTS: Path analysis revealed that PA was associated with lower perceived stress through increased self-esteem, adaptive appraisals, and higher distress tolerance (total standardized indirect effect; p = .007 (-0.25 to -0.11). Moreover, lower perceived stress was associated with lower anxiety (standardized direct effect; p < .001 [2.65-4.0] and depressive symptoms (standardized direct effect; p < .001 [0.33-0.63]). CONCLUSIONS: Findings suggest that higher PA could be effective in improving mental health among older adolescents, due to its association with perceived stress through higher self-esteem and more adaptive appraisals of stress.

Pain and fatigue are longitudinally and bi-directionally associated with more sedentary time and less standing time in rheumatoid arthritis.

OBJECTIVES: The aims of this study were to examine the longitudinal and bi-directional associations of pain and fatigue with sedentary, standing and stepping time in RA. METHODS: People living with RA undertook identical assessments at baseline (T1, n = 104) and 6-month follow-up (T2, n = 54). Participants completed physical measures (e.g. height, weight, BMI) and routine clinical assessments to characterize RA disease activity (DAS-28). Participants also completed questionnaires to assess physical function (HAQ), pain (McGill Pain Questionnaire) and fatigue (Multidimensional Assessment of Fatigue Scale). Participants' free-living sedentary, standing and stepping time (min/day) were assessed over 7 days using the activPAL3µ™. For the statistical analysis, hierarchical regression analysis was employed to inform the construction of path models, which were subsequently used to examine bi-directional associations of pain and fatigue with sedentary, standing and stepping time. Specifically, where significant associations were observed in longitudinal regression analysis, the bi-directionality of these associations was further investigated via path analysis. For regression analysis, bootstrapping was applied to regression models to account for non-normally distributed data, with significance confirmed using 95% CIs. Where variables were normally distributed, parametric, non-bootstrapped statistics were also examined (significance confirmed via ß coefficients, with P < 0.05) to ensure all plausible bi-directional associations were examined in path analysis. RESULTS: Longitudinal bootstrapped regression analysis indicated that from T1 to T2, change in pain, but not fatigue, was positively associated with change in sedentary time. In addition, change in pain and fatigue were negatively related to change in standing time. Longitudinal non-bootstrapped regression analysis demonstrated a significant positive association between change in fatigue with change in sedentary time. Path analysis supported the hypothesized bi-directionality of associations between change in pain and fatigue with change in sedentary time (pain, ß = 0.38; fatigue, ß = 0.44) and standing time (pain, ß = -0.39; fatigue, ß = -0.50). CONCLUSION: Findings suggest pain and fatigue are longitudinally and bi-directionally associated with sedentary and standing time in RA.

Different types of physical activity are positively associated with indicators of mental health and psychological wellbeing in rheumatoid arthritis during COVID-19.

Nationwide lockdowns during SARS-CoV-2 (COVID-19) can compromise mental health and psychological wellbeing and limit opportunities for physical activity (PA), particularly in clinical populations, such as people with rheumatoid arthritis (RA), who are considered at risk for COVID-19 complications. This study aimed to investigate associations between PA and sedentary time (ST) with indicators of mental health and wellbeing in RA during COVID-19 lockdown, and examine the moderation effects of self-isolating. 345 RA patients completed an online questionnaire measuring PA (NIH-AARP Diet and Health Study Questionnaire), ST (International Physical Activity Questionnaire-Short Form), pain (McGill Pain Questionnaire and Visual Analogue Scale), fatigue (Multidimensional Fatigue Inventory), depressive and anxious symptoms (Hospital Anxiety and Depression Scale), and vitality (Subjective Vitality Scale) during the United Kingdom COVID-19 lockdown. Associations between PA and ST with mental health and wellbeing were examined using hierarchical multiple linear regressions. Light PA (LPA) was significantly negatively associated with mental fatigue (ß = - .11), depressive symptoms (ß = - .14), and positively with vitality (ß = .13). Walking was negatively related to physical fatigue (ß = - .11) and depressive symptoms (ß = - .12) and positively with vitality (ß = .15). Exercise was negatively associated with physical (ß = - .19) and general (ß = - .12) fatigue and depressive symptoms (ß = - .09). ST was positively associated with physical fatigue (ß = .19). Moderation analyses showed that LPA was related to lower mental fatigue and better vitality in people not self-isolating, and walking with lower physical fatigue in people self-isolating. These findings show the importance of encouraging PA for people with RA during a lockdown period for mental health and wellbeing.

Social media use informing behaviours related to physical activity, diet and quality of life during COVID-19: a mixed methods study.

BACKGROUND: This mixed methods study explored how social media use informed physical activity and diet-related behaviours, and self-perceived Quality of Life (QoL) during COVID-19, and assessed the contextual factors that drive social media use for health-related behaviour change in diverse groups. During the COVID-19 lockdown periods there were reported changes to social media use and health behaviours, and this gave an opportunity to investigate potential relationships. METHODS: An explanatory sequential research design of two parts was used: (1) An online survey that assessed social media use in relation to physical activity levels, diet quality and QoL (n = 786; Mage 45.1 ± 19.1 (range 16-88) years; Female =69%); (2) 20 purposive focus groups (n = 69; Mage = 52.88 ± 18.45 years, Female n = 68%) to understand the contextual factors that drive social media use for health-related behaviour change. Descriptive and thematic analysis were conducted. RESULTS: Participants in this study reported that social media facilitated the self-management of behaviours related to physical activity, diet and QoL, through access to information to inform workouts and dietary quality, and the opportunities for interaction with peers, family members and within social groups. Contextual factors including work, home and lifestyle arrangements, pre-existing health-related knowledge and behaviours, and the perceived value of social media for health influenced the relationship between social media use and self-reported outcomes. Social media influencers, peers/family members, and official organisations influenced the application of health-related information accessed via social media. CONCLUSIONS: The evidence shows that participants were critical users of social media and were able to use social media to derive benefit for their health and wellbeing. Detailed guidance for those who use social media, as well as those who recommend and endorse social media content is required to maximise the potential of social media to support health behaviours. Future public health strategies and social media interventions should acknowledge diversity in contextual factors driving social media use for health behaviour change.

Measurement of sedentary time and physical activity in rheumatoid arthritis: an ActiGraph and activPAL™ validation study.

Accurate measurement of sedentary time and physical activity (PA) is essential to establish their relationships with rheumatoid arthritis (RA) outcomes. Study objectives were to: (1) validate the GT3X+ and activPAL3µ™, and develop RA-specific accelerometer (count-based) cut-points for measuring sedentary time, light-intensity PA and moderate-intensity PA (laboratory-validation); (2) determine the accuracy of the RA-specific (vs. non-RA) cut-points, for estimating free-living sedentary time in RA (field-validation). Laboratory-validation: RA patients (n = 22) were fitted with a GT3X+, activPAL3µ™ and indirect calorimeter. Whilst being video-recorded, participants undertook 11 activities, comprising sedentary, light-intensity and moderate-intensity behaviours. Criterion standards for devices were indirect calorimetry (GT3X+) and direct observation (activPAL3µ™). Field-validation: RA patients (n = 100) wore a GT3X+ and activPAL3µ™ for 7 days. The criterion standard for sedentary time cut-points (RA-specific vs. non-RA) was the activPAL3µ™. Results of the laboratory-validation: GT3X-receiver operating characteristic curves generated RA-specific cut-points (counts/min) for: sedentary time = ≤ 244; light-intensity PA = 245-2501; moderate-intensity PA ≥ 2502 (all sensitivity ≥ 0.87 and 1-specificity ≤ 0.11). ActivPAL3µ™-Bland-Altman 95% limits of agreement (lower-upper [min]) were: sedentary = (- 0.1 to 0.2); standing = (- 0.7 to 1.1); stepping = (- 1.2 to 0.6). Results of the field-validation: compared to the activPAL3µ™, Bland-Altman 95% limits of agreement (lower-upper) for sedentary time (min/day) estimated by the RA-specific cut-point = (- 42.6 to 318.0) vs. the non-RA cut-point = (- 19.6 to 432.0). In conclusion, the activPAL3µ™ accurately quantifies sedentary, standing and stepping time in RA. The RA-specific cut-points offer a validated measure of sedentary time, light-intensity PA and moderate-intensity PA in these patients, and demonstrated superior accuracy for estimating free-living sedentary time, compared to non-RA cut-points.

Loneliness in healthy young adults predicts inflammatory responsiveness to a mild immune challenge in vivo.

The established link between loneliness and poor health outcomes may stem from aberrant inflammatory regulation. The present study tested whether loneliness predicted the inflammatory response to a standardised in vivo immune challenge. Using a within-subjects double blind placebo-controlled design, 40 healthy men (mean age = 25, SD = 5) received a Salmonella Typhi vaccination (0.025 mg; Typhim Vi, Sanofi Pasteur, UK) and placebo (saline) on two separate occasions. Loneliness was assessed using the R-UCLA loneliness scale. Regression analyses showed that those that reported feeling more lonely exhibited an elevated interleukin-6 response (ß = 0.564, 95% confidence interval [0.003, 0.042], p < .05). This association withstood adjustment for potentially confounding variables, including age, sleep quality, socio-emotional factors, and health factors. The present findings are in line with evidence that loneliness may shift immune system responsivity, suggesting a potential biobehavioural pathway linking loneliness to impaired health.

Comparison of the effects of exercise and anti-TNF treatment on cardiovascular health in rheumatoid arthritis: results from two controlled trials.

People with rheumatoid arthritis (RA) are at increased risk for cardiovascular disease (CVD). Both pharmacological treatment and exercise are suggested in the management of CVD risk in RA. This study explored the effects of exercise and anti-TNF treatment on CVD risk in RA. Twenty RA patients (70% female, 50 (10) years) completed a 3-month exercise intervention and 23 RA patients (65% female, 54 (15) years) started anti-TNF treatment. Markers of disease activity, CVD risk, and vascular function were assessed before and after 3-months of intervention/treatment. Both exercise and anti-TNF treatment improved functional ability and fatigue, anti-TNF treatment was more successful in improving inflammation, disease activity, functional ability and pain. Exercise induced a reduction in overall CVD risk and improvement in vascular function, which was significantly different from anti-TNF treatment where no such changes were found. These findings showed that exercise and anti-TNF had differential effects on CVD risk in RA, and should be combined for optimal CVD risk reduction. Whereas anti-TNF treatment is likely to impact on CVD risk through reducing the systemic inflammatory load, exercise should be recommended to people with RA as an effective self-management strategy to reduce CVD risk further. Once RA patients have responded successfully to anti-TNF treatment, increasing exercise should be encouraged to reduce the risk for CVD. Thus, supporting exercise programmes when the disease is controlled, is likely to enhance the uptake and the maintenance of exercise, which will result in additional benefits to cardiovascular health and wellbeing in people with RA.

Acute hydrocortisone administration reduces cardiovagal baroreflex sensitivity and heart rate variability in young men.

KEY POINTS: A surge in cortisol during acute physiological and pathophysiological stress may precipitate ventricular arrhythmia and myocardial infarction. Reduced cardiovagal baroreflex sensitivity and heart rate variability are observed during acute stress and are associated with an increased risk of acute cardiac events. In the present study, healthy young men received either a single iv bolus of saline (placebo) or hydrocortisone, 1 week apart, in accordance with a randomized, placebo-controlled, cross-over study design. Hydrocortisone acutely increased heart rate and blood pressure and reduced cardiovagal baroreflex sensitivity and heart rate variability in young men. These findings suggest that, by reducing cardiovagal baroreflex sensitivity and heart rate variability, acute surges in cortisol facilitate a pro-arrhythmic milieu and provide an important mechanistic link between stress and acute cardiac events ABSTRACT: Surges in cortisol concentration during acute stress may increase cardiovascular risk. To better understand the interactions between cortisol and the autonomic nervous system, we determined the acute effects of hydrocortisone administration on cardiovagal baroreflex sensitivity (BRS), heart rate variability (HRV) and cardiovascular reactivity. In a randomized, placebo-controlled, single-blinded cross-over study, 10 healthy males received either a single iv bolus of saline (placebo) or 200 mg of hydrocortisone, 1 week apart. Heart rate (HR), blood pressure (BP) and limb blood flow were monitored 3 h later, at rest and during the sequential infusion of sodium nitroprusside and phenylephrine (modified Oxford Technique), a cold pressor test and a mental arithmetic stress task. HRV was assessed using the square root of the mean of the sum of the squares of differences between successive R-R intervals (rMSSD). Hydrocortisone markedly increased serum cortisol 3 h following infusion and also compared to placebo. In addition, hydrocortisone elevated resting HR (+7 ± 4 beats min-1 ; P < 0.001) and systolic BP (+5 ± 5 mmHg; P = 0.008); lowered cardiovagal BRS [geometric mean (95% confidence interval) 15.6 (11.1-22.1) ms/mmHg vs. 26.2 (17.4--39.5) ms/mmHg, P = 0.011] and HRV (rMSSD 59 ± 29 ms vs. 84 ± 38 ms, P = 0.004) and increased leg vasoconstrictor responses to cold pressor test (Δ leg vascular conductance -45 ± 20% vs. -23 ± 26%; P = 0.023). In young men, an acute cortisol surge is accompanied by increases in HR and BP, as well as reductions in cardiovagal BRS and HRV, potentially providing a pro-arrhythmic milieu that may precipitate ventricular arrhythmia or myocardial infarction and increase cardiovascular risk.

Sedentary behaviour in rheumatoid arthritis: definition, measurement and implications for health.

RA is a chronic autoimmune disease characterized by high grade-inflammation, and associated with elevated cardiovascular risk, rheumatoid-cachexia and functional impairment. Sedentary behaviour (SB) is linked to heightened inflammation, and is highly pervasive in RA, likely as a result of compromised physical function and persistent fatigue. This high sedentarity may exacerbate the inflammatory process in RA, and hold relevance for disease-related outcomes. The aim of this narrative review is to provide an overview of the definition, measurement and health relevance of SB in the context of RA. Contradictions are highlighted with regard to the manner in which SB is operationalized, and the significance of SB for disease outcomes in RA is outlined. The advantages and disadvantages of SB measurement approaches are also discussed. Against this background, we summarize studies that have reported SB and its health correlates in RA, and propose directions for future research.

Sitting time is negatively related to microvascular endothelium-dependent function in rheumatoid arthritis.

BACKGROUND: Sedentary behaviour is linked to increased cardiovascular disease risk in Rheumatoid Arthritis (RA), but the biological processes underlying this relationship are not understood. OBJECTIVES: To investigate the cross-sectional associations of habitual sedentary behaviour, with endothelial function in RA. METHODS: Sixty-eight RA patients (Mage = 55 ±â€¯12 years) underwent Laser Doppler Imaging with iontophoresis, to assess microvascular endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside, SNP) function. Large-vessel endothelium-dependent and endothelium-independent functions were measured via flow-mediated dilation (FMD) and glyceryl trinitrate dilation (GTN), respectively. Habitual sedentary behaviour (hours/week sitting) was self-reported (International Physical Activity Questionnaire). RESULTS: Regressions revealed sitting time significantly negatively predicted microvascular endothelium-dependent function (ACh, unstandardizedß = -3.25, p = .02, 95% CI [-6.07, -.42], R2 = 0.06), but did not associate with other endothelial function outcomes (SNP, FMD, GTN). CONCLUSION: Habitual sedentary behaviour (sitting time) appears to be adversely linked to microvascular endothelium-dependent function among people living with RA.

Low-grade inflammation decreases emotion recognition - Evidence from the vaccination model of inflammation.

The ability to adequately interpret the mental state of another person is key to complex human social interaction. Recent evidence suggests that this ability, considered a hallmark of 'theory of mind' (ToM), becomes impaired by inflammation. However, extant supportive empirical evidence is based on experiments that induce not only inflammation but also induce discomfort and sickness, factors that could also account for temporary social impairment. Hence, an experimental inflammation manipulation was applied that avoided this confound, isolating effects of inflammation and social interaction. Forty healthy male participants (mean age = 25, SD = 5 years) participated in this double-blind placebo-controlled crossover trial. Inflammation was induced using Salmonella Typhi vaccination (0.025 mg; Typhim Vi, Sanofi Pasteur, UK); saline-injection was used as a control. About 6 h 30 m after injection in each condition, participants completed the Reading the Mind in the Eyes Test (RMET), a validated test for assessing how well the mental states of others can be inferred through observation of the eyes region of the face. Vaccination induced systemic inflammation, elevating IL-6 by +419% (p < .001), without fever, sickness symptoms (e.g., nausea, light-headedness), or mood changes (all p's > .21). Importantly, compared to placebo, vaccination significantly reduced RMET accuracy (p < .05). RMET stimuli selected on valence (positive, negative, neutral) provided no evidence of a selective impact of treatment. By utilizing an inflammation-induction procedure that avoided concurrent sicknesses or symptoms in a double-blinded design, the present study provides further support for the hypothesis that immune activation impairs ToM. Such impairment may provide a mechanistic link explaining social-cognitive deficits in psychopathologies that exhibit low-grade inflammation, such as major depression.

The Role of Physical Activity and Sedentary Behavior in Predicting Daily Pain and Fatigue in Older Adults: a Diary Study.

Background: Little attention has been paid to within-person daily associations among light physical activity (PA), moderate-to-vigorous physical activity (MVPA), and sedentary behavior (SB) with subsequent bodily pain and fatigue. Daily reports of pain and fatigue are less likely to be affected by recall bias and to conflate days of high and low pain/ fatigue into one overall score. Purpose: The purpose of this study was to examine daily within-person associations between pain, fatigue, and physical health and ascertain whether such associations are moderated by individual differences in these variables. Methods: Participants were 63 community-living older adults (female n = 43, mean age = 70.98 years). Questionnaires measured typical levels of PA, SB, bodily pain, fatigue, and physical health. Subsequently, on a daily basis over a 1-week period, participants' levels of light PA, MVPA, and SB were measured using accelerometers. Participants completed a questionnaire rating their pain and fatigue at the end of each day. Results: Multilevel modeling revealed positive within-person associations between daily light PA, dailyMVPA, and pain, as well as negative within-person associations between daily SB and pain. For individuals with higher typical levels of fatigue, there was a negative association between daily light PA, MVPA, and fatigue. For individuals with better levels of physical health, there was also a negative association between daily MVPA and fatigue. For those with higher typical levels of fatigue and better levels of physical health, there was a positive association between daily SB and fatigue. No such interaction effects were found between high levels of typical pain and PA or SB. Conclusions: Our findings indicate that efforts to promote daily PA in older adults might be more effective for those who report high typical levels of fatigue and physical health, compared to those who report high levels of daily physical pain.

Sedentary behaviour is associated with increased long-term cardiovascular risk in patients with rheumatoid arthritis independently of moderate-to-vigorous physical activity.

BACKGROUND: Rheumatoid Arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD). The physical dysfunction symptomatic of RA means people living with this disease spend large periods of the day sedentary, which may further elevate their risk of CVD. The primary aim of this study was to investigate relationships between objectively assessed sedentary behaviour patterns and light physical activity (LPA) with 10-year risk of CVD. Secondary aims were to explore the role of sedentary behaviour patterns and LPA for individual CVD risk factors and functional disability in RA. The extent to which associations were independent of moderate-to-vigorous physical activity (MVPA) engagement was also examined. METHODS: Baseline data from a subsample of participants recruited to the Physical Activity in Rheumatoid Arthritis (PARA) study were used to answer current research questions. Sixty-one patients with RA (mean age (± SD) = 54.92 ± 12.39 years) provided a fasted blood sample and underwent physical assessments to evaluate factors associated with their cardiovascular health. Sedentary behaviour patterns (sedentary time, sedentary bouts, sedentary breaks), LPA and MVPA were measured via 7-days of accelerometry. Ten-year CVD risk was computed (Q-risk-score2), and functional disability determined via questionnaire. RESULTS: Regressions revealed significant positive associations between sedentary time and the number of sedentary bouts per day ≥20 min with 10-year CVD risk, with the reverse true for LPA participation. Associations were independent of MVPA engagement. CONCLUSIONS: Promoting LPA participation and restricting sedentary bouts to <20 min may attenuate long-term CVD risk in RA, independent of MVPA engagement. TRIAL REGISTRATION: ISRCTN04121489 (retrospectively registered 19/10/2012).

Factors associated with parasympathetic activation following exercise in patients with rheumatoid arthritis: a cross-sectional study.

BACKGROUND: Patients with rheumatoid arthritis (RA) have an increased risk for cardiovascular disease (CVD) with poor parasympathetic function being implicated as an underlying factor. Factors related to parasympathetic function, commonly assessed by heart rate recovery (HRR) following maximal exercise, are currently not known in RA. We aimed to explore the association between HRR with CVD risk factors, inflammatory markers, and wellbeing in patients with RA. METHODS: Ninety-six RA patients (54.4 ± 12.6 years, 68 % women) completed a treadmill exercise test, during which heart rate (HR) was monitored. HRR1 and HRR2 were defined as the absolute change from HR peak to HRR 1 min post HR peak and 2 min post HR peak, respectively. Cardiorespiratory fitness, CVD risk factors, and serological markers of inflammation were measured in all patients. The Framingham Risk Score (FRS) was used as an assessment of global risk for CVD events, and wellbeing was assessed by questionnaires. RESULTS: Mean HRR1 and HRR2 were 29.1 ± 13.2 bpm and 46.4 ± 15.3 bpm, respectively. CVD risk factors as well as most inflammatory markers and measures of wellbeing were inversely correlated with HRR1 and HRR2. Multivariate regression analyses revealed that 27.9 % of the variance in HRR1 and 37.9 % of the variance in HRR2 was explained collectively by CVD risk factors, measures of inflammation, and wellbeing (p = 0.009, p = 0.001 respectively), however no individual measure was independently associated with HRR1 or HRR2. CONCLUSION: Parasympathetic activation was associated with overall CVD risk, arthritis-related burden and wellbeing in patients with RA. TRIAL REGISTRATION: [Exercise, cardiovascular disease and rheumatoid arthritis, ISRCTN04121489 ].

Cardiorespiratory fitness levels and their association with cardiovascular profile in patients with rheumatoid arthritis: a cross-sectional study.

OBJECTIVE: The aim of this study was to investigate the association of different physical fitness levels [assessed by the maximal oxygen uptake (VO2max) test] with cardiovascular disease (CVD) risk factors in patients with RA. METHODS: A total of 150 RA patients were assessed for cardiorespiratory fitness with a VO2max test and, based on this, were split in three groups using the 33rd (18.1 ml/kg/min) and 66th (22.4 ml/kg/min) centiles. Classical and novel CVD risk factors [blood pressure, body fat, insulin resistance, cholesterol, triglycerides, high-density lipoprotein (HDL), physical activity, CRP, fibrinogen and white cell count], 10-year CVD risk, disease activity (DAS28) and severity (HAQ) were assessed in all cases. RESULTS: Mean VO2max for all RA patients was 20.9 (s.d. 5.7) ml/kg/min. The 10-year CVD risk (P = 0.003), systolic blood pressure (P = 0.039), HDL (P = 0.017), insulin resistance and body fat (both at P < 0.001), CRP (P = 0.005), white blood cell count (P = 0.015) and fibrinogen (P < 0.001) were significantly different between the VO2max tertiles favouring the group with the higher VO2max levels. In multivariate analyses of variance, VO2max was significantly associated with body fat (P < 0.001), HDL (P = 0.007), insulin resistance (P < 0.003) and 10-year CVD risk (P < 0.001), even after adjustment for DAS28, HAQ and physical activity. CONCLUSION: VO2max levels are alarmingly low in RA patients. Higher levels of VO2max are associated with a better cardiovascular profile in this population. Future studies need to focus on developing effective behavioural interventions to improve cardiorespiratory fitness in RA.

Individualised exercise improves endothelial function in patients with rheumatoid arthritis.

BACKGROUND: We investigated the effects of individualised combined resistance and aerobic exercise on microvascular and macrovascular function in rheumatoid arthritis (RA) patients. METHODS: Forty age-matched, gender-matched and body mass index (BMI)-matched patients were allocated to either an exercise group, receiving a 6 months tailored aerobic and resistance exercise intervention, or controls receiving only information about the benefits of exercise. Participants were assessed for microvascular (acetylcholine (Ach) and sodium nitroprusside (SNP)) and macrovascular (flow-mediated dilatation (FMD) and glyceryl trinitrate (GTN)) endothelial function, maximal oxygen uptake, disease activity and severity (C-reactive protein (CRP), disease activity score 28 and health assessment questionnaire). Data were collected at baseline, 3 months and at the end of the intervention (6 months). RESULTS: At baseline, demographic, anthropometric, disease-related characteristics and endothelial function parameters were similar between the exercise and control groups (p>0.05). Repeated measures analysis of variance revealed a significant improvement in endothelial function parameters at 3 (GTN: p<0.001) or 6 months (Ach: p=0.016, SNP: p=0.045, FMD: p=0.016) in the exercise but not in the control group. Generalised estimated equations detected that maximal oxygen uptake was a strong predictor for the observed changes in Ach (p=0.009) and GTN (p<0.001) whereas logCRP for SNP (p=0.017) and GTN (p=0.008). CONCLUSIONS: An exercise programme designed to meet individual needs and physical abilities significantly improves microvascular and macrovascular function in parallel with disease-related characteristics in RA patients. The potential long-term beneficial effects of such interventions at reducing cardiovascular risk in these patients merit further exploration. CLINICAL TRIAL REGISTRATION: ISRCTN50861407.

Underlying inflammation has no impact on the oxidative stress response to acute mental stress.

INTRODUCTION: Mental stress is considered to be a trigger for acute myocardial infarction (MI), with inflammation thought to provide a mechanism. Inflammation is reciprocally linked to oxidative stress, which has also been implicated in MI. The purpose of this study was to assess the effects of experimentally-induced inflammation on the oxidative stress response to mental stress in healthy participants. METHODS: Healthy males undertook one of two inflammatory stimuli: typhoid vaccination (Vaccination paradigm, N=17) or eccentric exercise (Eccentric exercise paradigm, N=17). All participants completed a mental arithmetic stress task twice (within-subject design): 6h after the inflammatory stimulus, and during a control non-inflammation condition. Blood samples were taken before, immediately and 30min after the stress task. Plasma was assessed for interleukin-6 (IL-6), protein carbonyls (PC), lipid hydroperoxides (LOOH), total antioxidant capacity (TAC) and nitric oxide metabolites (NOx). RESULTS: Vaccination paradigm: IL-6, PC and NOx were significantly higher in the vaccination condition, relative to the control condition (p<.05). PC, TAC, LOOH and NOx were unchanged in response to mental stress in both the vaccination and control conditions. Eccentric Exercise paradigm: IL-6 and TAC were significantly higher in the eccentric exercise condition (p<.05), relative to the control condition. PC, TAC and NOx were unchanged in response to mental stress in both the eccentric exercise and control conditions. CONCLUSIONS: Two different inflammatory paradigms were successful in increasing selective plasma markers of inflammation and oxidative stress prior to a mental stress task. However, experimentally induced transient inflammation had no impact on mental stress-induced changes in plasma LOOH, PC, TAC or NOx in young healthy participants.

Three months of moderate-intensity exercise reduced plasma 3-nitrotyrosine in rheumatoid arthritis patients.

PURPOSE: Rheumatoid arthritis (RA) patients display high levels of oxidative stress. Transient exercise-induced increases in oxidative stress are thought to be adaptive in healthy populations. This study investigated the effect of exercise on markers of oxidative stress in RA, following acute exercise and a period of exercise training. METHODS: Acute exercise study: RA patients (N = 12, age: 56 ± 11) undertook a bout of exercise (30-40 min, 70 % VO2MAX), and blood samples were taken before and after exercise to assess markers of oxidative stress. Training study: RA patients (N = 19, age: 56 ± 10) were randomised into either a control or exercise group, who undertook 3 exercise sessions per week (30-40 min @70 % VO2MAX) for 3 months. Plasma markers of oxidative stress (protein carbonyls (PC), lipid hydroperoxides (LOOH), 3-nitrotyrosine (3-NT), total antioxidant capacity (TAC) and catalase (CAT) activity), inflammation (interleukin-8 (IL-8) and C-reactive protein (CRP)) and nitric oxide metabolites (NOx) were assessed before and after training. RESULTS: Acute exercise study: Protein carbonyls (PC) (+18 %) and NOx (+27 %) were significantly increased following exercise. Training study: 3-nitrotyrosine (3-NT) decreased (2.18 ± 1.78 to 1.10 ± 0.93 µM) in the exercise group only, alongside increases in aerobic fitness (24.45 ± 4.98 to 27.10 ± 4.51 ml/kg/min(-1)) and reductions in disease activity score (DAS: 3.47 ± 1.17 to 2.88 ± 0.76). PC, LOOH, TAC, IL-8, CRP and NOx concentrations, and CAT activity were unchanged in both groups. CONCLUSIONS: Aerobic exercise training did not increase markers of oxidative stress in RA patients. 3-Nitrotyrosine and disease activity were decreased following exercise training.

Fostering autonomous motivation, physical activity and cardiorespiratory fitness in rheumatoid arthritis: protocol and rationale for a randomised control trial.

BACKGROUND: People with rheumatoid arthritis are at greater risk of morbidity and mortality from cardiovascular disease than the general population. Sustained physical activity increases cardio-respiratory fitness and reduces cardiovascular disease risk factors. However, little is known about how we can effectively promote long-term participation in physical activity in patients with rheumatoid arthritis. The literature consistently calls for physical activity interventions, and their implementation, to be theoretically-grounded. METHODS/DESIGN: This paper documents the protocol of a randomised control trial that investigates whether a Self-determination Theory-based intervention fosters the adoption and maintenance of physical activity (3, 6 and 12 months) sufficient to provide sustained cardiovascular and personal well-being benefits in patients with rheumatoid arthritis. The cost effectiveness of the intervention will also be determined. The trial is registered as Current Controlled Trials ISRCTN04121489. DISCUSSION: Results from this trial will provide guidance regarding key social environmental factors that can be manipulated to support motivational processes conducive to positive health behaviour change and optimal functioning in patients with Rheumatoid Arthritis.