Body-size phenotypes and cardiometabolic risk in Rheumatoid Arthritis

Objectives: Obesity is a significant contributor to metabolic complications. However, such complications are not uniform in people with similar body-size. The existence of normal-weight individuals with and obese individuals without metabolic complications has been described in the general population and is important in the context of cardiovascular disease (CVD). This has not been investigated in rheumatoid arthritis (RA), a condition associated with increased cardiometabolic risk. This study aims to identify the prevalence and predictors of body-size phenotypes in RA and investigate their associations with CVD risk. Methods: Body mass index (BMI: kg/m2), body fat (BF) and fat free mass (FFM), RA characteristics and CVD risk factors were assessed in 363 (262 females) volunteers with RA. Abnormal cardiometabolic status was defined as the presence of >1 of the following: hypertension, increased triglycerides or increased Low or reduced High Density Lipoprotein, high glucose, insulin resistance. Results: Among normal-weight, overweight, and obese participants 25%, 45.8%, 57.1% respectively were metabolically abnormal. Old age (B= 1.032, err=0.011; p= 0.005), waist circumference (B= 1.057, err= 0.011; p= 0.000), and smoking cessation (B= 1.425, err= 0.169; p=0.036) were significant predictors for metabolic abnormality. Conclusions: A significant number of RA patients present with different body-size and metabolic phenotypes. BMI alone is not a sufficient indicator of cardiometabolic risk in RA; this may have significant implications in their CVD risk evaluation. Body fat distribution seems to be a significant contributor to such abnormalities. Further research is needed, focusing on the metabolic properties of specific adipose depots of RA patient

ACSM pre-participation health screening guidelines: a UK university cohort perspective.

PURPOSE: Pre-participation health screening is recommended to detect individuals susceptible to serious adverse cardiovascular complications during exercise. Although expert opinion and best available scientific evidence have informed recent modifications, there remains limited experimental data to support or refute current practice. We therefore aimed to quantify the impact of change to the ACSM pre-participation health screening guidelines on risk classification and referral for medical clearance in a large cohort of undergraduate university students. METHODS: Participants attended the laboratory on a single occasion to undergo pre-participation health screening. Information concerning health status was obtained via self-report questionnaire and objective physiological assessment with all data recorded electronically and evaluated against ACSM screening guidelines (9 and 10 Edition). RESULTS: Five-hundred and fifty-three students completed the study. The 9th Edition screening guidance resulted in eighty-two (15%) subjects classified as high-risk, almost one quarter (24%) classified as moderate-risk, and almost two-thirds (61%) classified as low-risk. In comparison, the updated 10 Edition screening guidance resulted in a significant reduction in those previously classified as either high-risk (5%) or moderate risk (2%), respectively. The majority of subjects (93%) were therefore cleared to begin a structured exercise programme. Taken together, approximately one-third (32%) fewer medical referrals were required when applying the updated 10 Edition guidance (χ (4) = 247.7, P<0.001). CONCLUSION: The updated ACSM 10 Edition pre-participation screening guidance reduces medical referrals by approximately one-third. These findings are in keeping with previous reports and thus serve to consolidate and justify recent modification - particularly when applied to young adult or adolescent populations. The findings and arguments presented should be used to refine and inform future guidance

Vascular Structure and Functional Responses to Consecutive High-Fat Feeding between Insulin Treatment Regimens in Adults with Type 1 Diabetes and Matched Controls.

Background Impaired vascular health is prevalent in type 1 diabetes (T1D); however, it remains unknown whether di!erent insulin treatment regimens mediate indices of vascular structure or function. Methods Sixteen individuals with T1D receiving either multiple daily injection therapy (MDI; n=8; age: 32±13years; BMI:26.0±5.9kg.m2; HbA1c:53.7±11.2mmol/mol [7.1±3.2%]) or continuous subcutaneous insulin infusion (CSII; n=8; age:35±18years; BMI:26.3±4.6kg.m2; HbA1c: 58.6±9.7mmol/mol [7.5±3.0%]) and ten matched controls (CON; age:31±13years; BMI: 24.3±2.9kg.m2) consumed two high fat (HF) meals at 4-hour intervals. Carotid artery intima-media thickness (CIMT) and flow mediated dilation (FMD) was assessed at baseline, with further FMD assessment at 3-hrs following the ingestion of each meal using high resolution B-mode ultrasound. Bolus insulin dose was standardised using the carbohydrate-counting method. Results CIMT was significantly higher in individuals with T1D compared to controls (p=0.039); treatment stratification within T1D revealed MDI mediated this e!ect (MDI vs. CON: p=0.049; CSII vs. CON: p=0.112). FMD remained unchanged following the first meal (p=0.204) but was significantly impaired following the second meal (p=<0.001); post- hoc analysis revealed MDI mediated this e!ect of impaired FMD after the second meal (MDI vs. CON: p=0.048; CSII vs. CON: p=0.416). Conclusions Our findings indicate that patients treated with MDI therapy have higher CIMT (a structural marker of subclinical atherosclerosis) compared to controls but not CSII therapy. FMD was impaired following a second HF meal irrespective of a diabetes status. Considering the pre-existing heightened cardiovascular disease risk in T1D therapeutic strategies to reduce postprandial risk warrants further research

The Effect of High-Fat Diet on Intramyocellular Lipid Content in Healthy Adults: A Systematic Review, Meta-Analysis, and Meta-Regression

\ua9 2024 The AuthorsFatty acids are stored within the muscle as intramyocellular lipids (IMCL). Some, but not all, studies indicate that following a high-fat diet (HFD), IMCL may accumulate and affect insulin sensitivity. This systematic review and meta-analysis aimed to quantify the effects of an HFD on IMCL. It also explored the potential modifying effects of HFD fat content and duration, IMCL measurement technique, physical activity status, and the associations of IMCL with insulin sensitivity. Five databases were systematically searched for studies that examined the effect of ≥3 d of HFD (&gt;35% daily energy intake from fat) on IMCL content in healthy individuals. Meta-regressions were used to investigate associations of the HFD total fat content, duration, physical activity status, IMCL measurement technique, and insulin sensitivity with IMCL responses. Changes in IMCL content and insulin sensitivity (assessed by hyperinsulinemic-euglycemic clamp) are presented as standardized mean difference (SMD) using a random effects model with 95% confidence intervals (95% CIs). Nineteen studies were included in the systematic review and 16 in the meta-analysis. IMCL content increased following HFD (SMD = 0.63; 95% CI: 0.31, 0.94, P = 0.001). IMCL accumulation was not influenced by total fat content (P = 0.832) or duration (P = 0.844) of HFD, physical activity status (P = 0.192), or by the IMCL measurement technique (P &gt; 0.05). Insulin sensitivity decreased following HFD (SMD = –0.34; 95% CI: –0.52, –0.16; P = 0.003), but this was not related to the increase in IMCL content following HFD (P = 0.233). Consumption of an HFD (&gt;35% daily energy intake from fat) for ≥3 d significantly increases IMCL content in healthy individuals regardless of HFD total fat content and duration of physical activity status. All IMCL measurement techniques detected the increased IMCL content following HFD. The dissociation between changes in IMCL and insulin sensitivity suggests that other factors may drive HFD-induced impairments in insulin sensitivity in healthy individuals. This trial was registered at PROSPERO as CRD42021257984

Evaluating the validity of a smartphone step-counter in adults with asthma: a proof-of-concept study

Introduction: Regular physical activity and structured exercise are often reported to be associated with improved asthma control - however the majority of published evidence is limited by short-term studies employing subjective measures of assessment (i.e. self-report / questionnaires). Modern smartphones typically include built-in activity sensors (i.e. possess the capability to monitor daily step-count) and thus may offer a cost-effective and pragmatic solution to the assessment of physical activity in clinical practice and/or research trials. The primary aim of this proof-of-concept study was therefore to evaluate the validity of the iPhone® (Apple Inc, USA) step-counter in adults with asthma and healthy controls. Methods: The study was conducted as a cross-sectional laboratory based-trial. Ten healthy adults with no prior history of respiratory disease and ten adults with a prior physician diagnosis of asthma were enrolled. All completed baseline clinical assessment followed by a standardised walking treadmill challenge consisting of 3 x 3-minute stages at pre-determined speeds: 2.5kph, 5.0kph and 7.5kph. Steps were recorded using the following devices: (i) Yamax Digiwalker™ SW-200 Pedometer (Yamax, UK), (ii) iPhone® step-counter (upper body arm-band), (iii) iPhone® step-counter (lower body trouser pocket) - and evaluated against a video-verified manual step-count (i.e. gold-standard comparator) conducted by the investigator (CR). Results: No difference was observed in manual total step-count between individuals with asthma (1018 steps) and healthy controls (1038 steps) (P=0.44). The iPhone® step-counter (both upper and lower body) provided close agreement with video-verified manual step-count, and importantly, outperformed the Yamax Digiwalker® SW-200 Pedometer across the majority of test stages. Specifically, the iPhone® (lower body) correlated strongly (r = 0.96; P<0.006) and produced the highest level of agreement with video-verified total step-count (mean bias: -11; limits of agreement: -43 to 21) (Table 1). Conclusion: Our findings indicate that the iPhone® provides an accurate estimate of step-count in adults with asthma and healthy controls completing a standardised laboratory-based treadmill test. Prior to implementation, further research is required to determine the validity and reliability of this approach during daily active / free living conditions

The role of microRNAs in regulating inflammation and exercise-induced adaptations in rheumatoid arthritis.

MicroRNAs (miRNAs) are endogenously generated single-stranded RNAs that play crucial roles in numerous biological processes, such as cell development, proliferation, differentiation, metabolism and apoptosis. They negatively regulate target gene expression by repressing translation of messenger RNA into a functional protein. Several miRNAs have been implicated in the development and progression of RA. They are involved in inflammatory and immune processes and are associated with susceptibility to RA and disease activity. They are also considered to be potential markers of disease activity or even therapeutic targets. Likewise, several miRNAs are affected acutely by exercise and regulate exercise-related adaptations in the skeletal muscle and cardiovascular system and aerobic fitness. Interestingly, some miRNAs affected by exercise are also important in the context of RA. Investigating these might increase our understanding of the effects of exercise in RA and improve exercise prescription and, potentially, disease management. In this review, we focus on the miRNAs that are associated with both RA and exercise and discuss their roles in (and potential interactions between) RA and exercise-induced adaptations

Participation in physical activity decreased more in people with rheumatoid arthritis than the general population during the COVID-19 lockdown: a cross-sectional study

The COVID-19 pandemic and social distancing restrictions have significantly reduced population-wide physical activity (PA) levels. However, the impact of the pandemic and relevant restrictions on PA participation, and any potential barriers to it, in people with rheumatoid arthritis (RA) are not clear. Furthermore, we are unsure if any such PA changes have affected their body weight, mental wellbeing, and/or quality of life (QoL). Thus, the aim of this study was to examine the impact of the lockdown on PA participation in people with RA, versus people without RA. Participants (n = 128; RA = 27, non-RA = 101) completed a self-administered online survey, which included questions on PA, body weight, mental wellbeing and QoL. PA participation during lockdown was significantly lower among RA versus non-RA participants (p < 0.001). Additionally, a similar profile of results was found where more RA participants vs non-RA participants reported reduced habitual PA (59% vs 33%) and increased body weight (59% vs 35%). Mental wellbeing scores were similarly low in both groups during lockdown (RA: 20.8 ± 4.2; non-RA: 22.2 ± 3.4, p = 0.080). Matched group comparisons identified similar trends to full sample analyses. In the first months of the lockdown, more people with RA reported decreased PA participation and increased body weight than their non-RA counterparts. Access to exercise equipment and facilities appears to be the main cause for these results. Looking beyond COVID-19, specific PA promotion for people with RA will be required to prevent a pandemic of inactivity

The role of microRNAs in regulating inflammation and exercise-induced adaptations in rheumatoid arthritis.

MicroRNAs (miRNAs) are endogenously generated single-stranded RNAs that play crucial roles in numerous biological processes, such as cell development, proliferation, differentiation, metabolism and apoptosis. They negatively regulate target gene expression by repressing translation of messenger RNA into a functional protein. Several miRNAs have been implicated in the development and progression of RA. They are involved in inflammatory and immune processes and are associated with susceptibility to RA and disease activity. They are also considered to be potential markers of disease activity or even therapeutic targets. Likewise, several miRNAs are affected acutely by exercise and regulate exercise-related adaptations in the skeletal muscle and cardiovascular system and aerobic fitness. Interestingly, some miRNAs affected by exercise are also important in the context of RA. Investigating these might increase our understanding of the effects of exercise in RA and improve exercise prescription and, potentially, disease management. In this review, we focus on the miRNAs that are associated with both RA and exercise and discuss their roles in (and potential interactions between) RA and exercise-induced adaptations

Smartphone pedometers in adults with asthma: a practical approach to physical activity assessment? A pilot validation study

OBJECTIVE: The aim of this pilot validation study was to determine the accuracy of a smartphone (iPhone®) pedometer in adults with and without asthma. METHODS: : Ten adults with asthma and ten healthy controls underwent clinical assessment prior to completing two separate trials. Phase 1. standardized treadmill and self-paced walking tests. Total steps were recorded via: (i) Yamax Digiwalker™ SW800 pedometer positioned on the waistband, (ii) iPhone® pedometer positioned on the upper body, (iii) iPhone® pedometer positioned on the lower body and evaluated against a video-verified manual step-count. Phase 2. step-count was evaluated over seven-days during habitual free-living conditions via Yamax Digiwalker™ SW800 and iPhone® pedometers. RESULTS: : During treadmill walking, the iPhone® positioned on the lower body correlated strongly (r = 0.96) and produced the highest level of agreement (mean bias: -11 steps, LOA: -43 to 21 steps) in comparison to video-verified manual step-count. During self-paced walking, all devices provided an excellent step-count estimate. During free-living conditions, no difference was observed between the Yamax Digiwalker™ SW800 pedometer and iPhone® (P = 0.10) and a strong correlation (r = 0.94) and acceptable agreement (mean bias: -343, LOA: -1963 to 1276 steps) was observed. CONCLUSION: : Our findings indicate that an in-built iPhone® pedometer offers a practical approach to physical activity assessment in adults with and without asthma. Future research is now required to further validate the precision of this approach and evaluate the efficacy and effectiveness of smartphone pedometers to monitor and promote physical activity when employed during medical consultation and/or clinical research trials