The influence of acute exercise on bone biomarkers: protocol for a systematic review with meta-analysis.

BACKGROUND: Bone is a plastic tissue that is responsive to its physical environment. As a result, exercise interventions represent a potential means to influence the bone. However, little is currently known about how various exercise and participant characteristics interact to influence bone metabolism. Acute, controlled, interventions provide an in vivo model through which the acute bone response to exercise can be investigated, typically by monitoring circulating bone biomarkers. Currently, substantial heterogeneity in factors such as study design, quality, exercise, and participant characteristics render it difficult to synthesize and evaluate the available evidence. Using a systematic review and meta-analytic approach, the aim of this investigation is to quantify the effect of an acute exercise bout on circulating bone biomarkers as well as examine the potential factors that may moderate this response, e.g., variation in participant, exercise, and sampling characteristics. METHODS: This protocol was designed in accordance with the PRISMA-P guidelines. Seven databases (MEDLINE, Embase, Sport Discus, Cochrane CENTRAL, PEDro, LILACS, and Ibec) will be systematically searched and supplemented by a secondary screening of the reference lists of all included articles. The PICOS (Population, Intervention, Comparator, Outcomes and Study Design) approach was used to guide the determination of the eligibility criteria. Participants of any age, sex, training, or health status will be considered for inclusion. We will select studies that have measured the bone biomarker response before and after an acute exercise session. All biomarkers considered to represent the bone metabolism will be considered for inclusion, and sensitivity analyses will be conducted using reference biomarkers for the measurement of bone resorption and formation (namely ß-CTX-1 and P1NP). Multi-level, meta-regression models within a Bayesian framework will be used to explore the main effect of acute exercise on bone biomarkers as well as potential moderating factors. The risk of bias for each individual study will be evaluated using a modified version of the Downs and Black checklist while certainty in resultant outcomes will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. DISCUSSION: A better understanding of the bone metabolic response to an acute bout of exercise has the potential to advance our understanding of the mechanisms through which this stimulus impacts bone metabolism, including factors that may moderate this response. Additionally, we will identify current gaps in the evidence base and provide recommendations to inform future research. SYSTEMATIC REVIEW REGISTRATION: This protocol was prospectively registered in the Open Science Framework Registry ( https://osf.io/6f8dz ).

DNA methylation pattern changes following a short-term hypocaloric diet in women with obesity.

BACKGROUND/OBJECTIVES: We aimed to investigate the effects of short-term hypocaloric diet-induced weight loss on DNA methylation profile in leukocytes from women with severe obesity. METHODS: Eleven women with morbid obesity (age: 36.9 ± 10.3 years; BMI: 58.5 ± 10.5 kg/m2) were assessed before and after 6 weeks of a hypocaloric dietary intervention. The participants were compared with women of average weight and the same age (age: 36.9 ± 11.8 years; BMI: 22.5 ± 1.6 kg/m2). Genome-wide DNA methylation analysis was performed in DNA extracted from peripheral blood leukocytes using the Infinium Human Methylation 450 BeadChip assay. Changes (Δß) in the methylation level of each CpGs were calculated. A threshold with a minimum value of 10%, p < 0.001, for the significant CpG sites based on Δß and a false discovery rate of <0.05 was set. RESULTS: Dietary intervention changed the methylation levels at 16,064 CpG sites. These CpGs sites were related to cancer, cell cycle-related, MAPK, Rap1, and Ras signaling pathways. However, regardless of hypocaloric intervention, a group of 878 CpGs (related to 649 genes) remained significantly altered in obese women when compared with normal-weight women. Pathway enrichment analysis identified genes related to the cadherin and Wnt pathway, angiogenesis signaling, and p53 pathways by glucose deprivation. CONCLUSION: A short-term hypocaloric intervention in patients with severe obesity partially restored the obesity-related DNA methylation pattern. Thus, the full change of obesity-related DNA methylation patterns could be proportional to the weight-loss rate in these patients after dietary interventions.

A Comparative Study of Hummingbirds and Chickens Provides Mechanistic Insight on the Histidine Containing Dipeptide Role in Skeletal Muscle Metabolism.

Histidine containing dipeptides (HCDs) have numerous ergogenic and therapeutic properties, but their primary role in skeletal muscle remains unclear. Potential functions include pH regulation, protection against reactive oxygen/nitrogen species, or Ca2+ regulation. In recognition of the challenge of isolating physiological processes in-vivo, we employed a comparative physiology approach to investigate the primary mechanism of HCD action in skeletal muscle. We selected two avian species (i.e., hummingbirds and chickens), who represented the extremes of the physiological processes in which HCDs are likely to function. Our findings indicate that HCDs are non-essential to the development of highly oxidative and contractile muscle, given their very low content in hummingbird skeletal tissue. In contrast, their abundance in the glycolytic chicken muscle, indicate that they are important in anaerobic bioenergetics as pH regulators. This evidence provides new insights on the HCD role in skeletal muscle, which could inform widespread interventions, from health to elite performance.

Effects of health at every size® interventions on health-related outcomes of people with overweight and obesity: a systematic review.

CONTEXT: The growing use of interventions based on the Health at Every Size® (HAES®) in obesity management. OBJECTIVE: This study aimed to summarize the health-related effects of HAES®-based interventions on people with overweight and obesity. DATA SOURCES: MEDLINE (via PubMed), EMBASE, Cochrane Library, LILACS, Google Scholar, OpenGrey and Grey Literature Report. STUDY SELECTION: A systematic review of studies published until January 2017 reporting on HAES®-based randomized and non-randomized controlled trials in people with overweight and/or obesity. DATA EXTRACTION: Fourteen papers met the inclusion criteria. The assessed studies included the following tests: blood profile, blood pressure, anthropometry, eating behaviour, energy intake, diet quality, psychological and qualitative evaluations. RESULTS: The HAES® interventions benefited both the psychological and physical activity outcomes, besides promoting behavioural and qualitative changes in eating habits. On the other hand, the results regarding cardiovascular responses, body-image perception and total energy intake were inconsistent. CONCLUSIONS: Despite improving the cardiovascular status, eating behaviours, quality of life and psychological well-being in participants, other large long-term clinical trials should be performed to establish the effectiveness of HAES®-based interventions in improving health for people with overweight and obesity. PROSPERO registration 2017: CRD42017054857.

Objectively measured physical activity and its influence on physical capacity and clinical parameters in patients with primary Sjögren's syndrome.

Objective The objectives of this paper are to objectively measure habitual physical activity levels in patients with primary Sjögren's syndrome (pSS) with mild disease activity and to determine to which extent it may be associated with physical capacity and function and clinical features. Methods In this cross-sectional study, 29 women with pSS were objectively assessed for habitual physical activity levels (using accelerometry) and compared with 20 healthy women (CTRL) frequency-matched for physical activity levels, age, body mass index, and body fat percentage with regard to physical capacity and function, fatigue, depression, pain, and health-related quality of life. Results pSS showed 8.5 min/day of moderate-to-vigorous physical activity (MVPA) when only MVPA accumulated in bouts ≥ 10 min was considered; when considering total MVPA (including bouts < 10 min), average levels were 26.3 min/day, with 62% of pSS patients achieving the recommendation (≥ 21.4 min/day). Moreover, pSS showed lower VO2peak, lower muscle strength and function, higher fatigue, and poorer health-related quality of life when compared with CTRL ( p < 0.05). These differences (except for aerobic capacity) were sustained even when only individuals achieving the minimum of 21.4 min/day of total MVPA in both groups were compared. Finally, MVPA time was significantly correlated with aerobic conditioning, whereas total counts and sedentary time were associated with lower-body muscle strength and the bodily-pain domain of SF-36 in patients with pSS. Conclusion When compared to physical activity-matched healthy controls, pSS patients showed reduced physical capacity and function, increased fatigue and pain, and reduced health-related quality of life. Except for aerobic conditioning, these differences were sustained when only more physically active participants were compared, indicating that minimum recommended levels of physical activity for the general population may not be sufficient to counteract pSS comorbidities.

Placebo in sports nutrition: a proof-of-principle study involving caffeine supplementation.

We investigated the effects of supplement identification on exercise performance with caffeine supplementation. Forty-two trained cyclists (age 37 ± 8 years, body mass [BM] 74.3 ± 8.4 kg, height 1.76 ± 0.06 m, maximum oxygen uptake 50.0 ± 6.8 mL/kg/min) performed a ~30 min cycling time-trial 1 h following either 6 mg/kgBM caffeine (CAF) or placebo (PLA) supplementation and one control (CON) session without supplementation. Participants identified which supplement they believed they had ingested ("caffeine", "placebo", "don't know") pre- and post-exercise. Subsequently, participants were allocated to subgroups for analysis according to their identifications. Overall and subgroup analyses were performed using mixed-model and magnitude-based inference analyses. Caffeine improved performance vs PLA and CON (P ≤ 0.001). Correct pre- and post-exercise identification of caffeine in CAF improved exercise performance (+4.8 and +6.5%) vs CON, with slightly greater relative increases than the overall effect of caffeine (+4.1%). Performance was not different between PLA and CON within subgroups (all P > 0.05), although there was a tendency toward improved performance when participants believed they had ingested caffeine post-exercise (P = 0.06; 87% likely beneficial). Participants who correctly identified placebo in PLA showed possible harmful effects on performance compared to CON. Supplement identification appeared to influence exercise outcome and may be a source of bias in sports nutrition.

Chronic lactate supplementation does not improve blood buffering capacity and repeated high-intensity exercise.

Since there is conflicting data on the buffering and ergogenic properties of calcium lactate (CL), we investigated the effect of chronic CL supplementation on blood pH, bicarbonate, and high-intensity intermittent exercise performance. Sodium bicarbonate (SB) was used as a positive control. Eighteen athletes participated in this double-blind, placebo-controlled, crossover, fully counterbalanced study. All participants underwent three different treatments: placebo (PL), CL, and SB. The dose was identical in all conditions: 500 mg/kg BM divided into four daily individual doses of 125 mg/kg BM, for five consecutive days, followed by a 2-7-day washout period. On the fifth day of supplementation, individuals undertook four 30-s Wingate bouts for upper body with 3-min recovery between bouts. Total mechanical work (TMW) for the overall protocol and for the initial (1st+2nd) and final (3rd+4th) bouts was determined at each session. Blood pH, bicarbonate, and lactate levels were determined at rest, immediately and 5 min after exercise. CL supplementation did not affect performance (P > 0.05 for the overall TMW as well for initial and final bouts), nor did it affect blood bicarbonate and pH prior to exercise. SB supplementation improved performance by 2.9% for overall TMW (P = 0.02) and 5.9% in the 3rd+4th bouts (P = 0001). Compared to the control session, SB also promoted higher increases in blood bicarbonate than CL and PL (+0.03 ± 0.04 vs +0.009 ± 0.02 and +0.01 ± 0.03, respectively). CL supplementation was not capable of enhancing high-intensity intermittent performance or changing extracellular buffering capacity challenging the notion that this dietary supplement is an effective buffering agent.

Resistance Training and Co-supplementation with Creatine and Protein in Older Subjects with Frailty.

BACKGROUND: Studies assessing the effects co-supplementation with creatine and protein, along with resistance training, in older individuals with frailty are lacking. OBJECTIVES: This is an exploratory trial from the Pro-Elderly study ("Protein Intake and Resistance Training in Aging") aimed at gathering knowledge on the feasibility, safety, and efficacy of co-supplementation with creatine and protein supplementation, combined with resistance training, in older individuals with frailty. DESIGN: A 14-week, double-blind, randomized, parallel-group, placebo controlled exploratory trial. SETTING, PARTICIPANTS: The subjects were randomly assigned to whey protein and creatine co-supplementation (WHEY+CR) or whey protein supplementation (WHEY) group. All subjects undertook a supervised exercise training program and were assessed at baseline and after 14 weeks. MEASUREMENTS: Muscle function, body composition, blood parameters, and self-reported adverse events were assessed. RESULTS: No interaction effects (between-group differences) were observed for any dependent variables (p > 0.05 for all). However, there were main time-effects in handgrip (WHEY+CR = 26.65 ± 31.29; WHEY = 13.84 ± 14.93 Kg; p = 0.0005), timed-up-and-go (WHEY+CR = -11.20 ± 9.37; WHEY = -17.76 ± 21.74 sec; p = 0.006), and timed-stands test (WHEY+CR = 47.50 ± 35.54; WHEY = 46.87 ± 24.23 reps; p = 0.0001), suggesting that WHEY+CR and WHEY were similarly effective in improving muscle function. All of the subjects showed improvements in at least two of the three functional tests, regardless of their treatments. Body composition and blood parameters were not changed (p > 0.05). No severe adverse effects were observed. CONCLUSIONS: Co-supplementation with creatine and whey protein was well-tolerable and free of adverse events in older subjects with frailty undertaking resistance training. Creatine supplementation did not augment the adaptive effects of resistance training along with whey protein on body composition or muscle function in this population. Clinicaltrials.gov: NCT01890382.

Effects of acute aerobic exercise on leukocyte inflammatory gene expression in systemic lupus erythematosus.

UNLABELLED: Systemic lupus erythematosus (SLE) is an autoimmune disease with a persistent systemic inflammation. Exercise induced inflammatory response in SLE remains to be fully elucidated. The aim of this study was to assess the effects of acuteexercise on leukocyte gene expression in active (SLEACTIVE) and inactive SLE (SLEINACTIVE) patients and healthy controls(HC). METHODS: All subjects (n = 4 per group) performed a 30-min single bout of acute aerobic exercise (~70% of VO2peak) on a treadmill, and blood samples were collected for RNA extraction from circulating leukocyte at baseline, at the end of exercise, and after three hours of recovery. The expression of a panel of immune-related genes was evaluated by a quantitative PCR array assay. Moreover, network-based analyses were performed to interpret transcriptional changes occurring after the exercise challenge. RESULTS: In all groups, a single bout of acute exercise led to the down-regulation of the gene expression of innate and adaptive immunity at the end of exercise (e.g., TLR3, IFNG, GATA3, FOXP3, STAT4) with a subsequent up-regulation occurring upon recovery. Exercise regulated the expression of inflammatory genes in the blood leukocytes of the SLE patients and HC, although the SLE groups exhibited fewer modulated genes and less densely connected networks (number of nodes: 29, 40 and 58; number of edges: 29, 60 and 195; network density: 0.07, 0.08 and 0.12, for SLEACTIVE, SLEINACTIVE and HC, respectively). CONCLUSION: The leukocytes from the SLE patients, irrespective of disease activity, showed a down-regulated inflammatory geneexpression immediately after acute aerobic exercise, followed by an up-regulation at recovery. Furthermore, less organized gene networks were observed in the SLE patients, suggesting that they may be deficient in triggering a normal exercised-induced immune transcriptional response.

Exploratory studies of the potential anti-cancer effects of creatine.

Two experiments were performed, in which male Wistar Walker 256 tumor-bearing rats were inoculated with 4 × 10(7) tumor cells subcutaneously and received either creatine (300 mg/kg body weight/day; CR) or placebo (water; PL) supplementation via intragastric gavage. In experiment 1, 50 rats were given PL (n = 22) or CR (n = 22) and a non-supplemented, non-inoculated group served as control CT (n = 6), for 40 days, and the survival rate and tumor mass were assessed. In experiment 2, 25 rats were given CR or PL for 15 days and sacrificed for biochemical analysis. Again, a non-supplemented, non-inoculated group served as control (CT; n = 6). Tumor and muscle creatine kinase (CK) activity and total creatine content, acidosis, inflammatory cytokines, and antioxidant capacity were assessed. Tumor growth was significantly reduced by approximately 30 % in CR when compared with PL (p = 0.03), although the survival rate was not significantly different between CR and PL (p = 0.65). Tumor creatine content tended to be higher in CR than PL (p = 0.096). Tumor CK activity in the cytosolic fraction was higher in CR than PL (p < 0.0001). Blood pCO2 was higher in CT and CR than PL (p = 0.0007 and p = 0.004, respectively). HCO3 was augmented in CT compared to PL (p = 0.03) and CR (p = 0.001). Plasma IL-6 was lower and IL-10 level was higher in CR than PL (p = 0.03 and p = 0.0007, respectively) and TNF-alpha featured a tendency of decrease in CR compared to PL (p = 0.08). Additionally, total antioxidant capacity tended to be lower in CT than PL (p = 0.07). Creatine supplementation was able to slow tumor growth without affecting the overall survival rate, probably due to the re-establishment of the CK-creatine system in cancer cells, leading to attenuation in acidosis, inflammation, and oxidative stress. These findings support the role of creatine as a putative anti-cancer agent as well as help in expanding our knowledge on its potential mechanisms of action in malignancies.

Inflammatory cytokine kinetics to single bouts of acute moderate and intense aerobic exercise in women with active and inactive systemic lupus erythematosus.

The aim of this study was to evaluate changes in the cytokines INF-γ, IL-10, IL-6, TNF-α and soluble TNF receptors (sTNFR1 and sTNFR2) in response to single bouts of acute moderate and intense exercise in systemic lupus erythematosus women with active (SLE(ACTIVE)) and inactive (SLE(INACTIVE)) disease. Twelve SLE(INACTIVE) women (age: 35.3 ± 5.7 yrs; BMI: 25.6±3.4 kg/m2), eleven SLE(ACTIVE) women (age: 30.4 ± 4.5 yrs; BMI: 26.1±4.8 kg/m2), and 10 age- and BMI-matched healthy control women (HC) performed 30 minutes of acute moderate (~50% of VO(2)peak) and intense (~70% of VO(2)peak) exercise bout. Cytokines and soluble TNF receptors were assessed at baseline, immediately after, every 30 minutes up to three hours, and 24 hours after both acute exercise bouts. In response to acute moderate exercise, cytokines and soluble TNF receptors levels remained unchanged in all groups (P>0.05), except for a reduction in IL-6 levels in the SLE(ACTIVE) group at the 60th and 180th minutes of recovery (P<0.05), and a reduction in sTNFR1 levels in the HC group at the 90th, 120th, 150th, 180th minutes of recovery (P<0.05). The SLE(INACTIVE) group showed higher levels of TNF-α, sTNFR1, and sTNFR2 at all time points when compared with the HC group (P<0.05). Also, the SLE(ACTIVE) group showed higher levels of IL-6 at the 60th minute of recovery (P<0.05) when compared with the HC group. After intense exercise, sTNFR1 levels were reduced at the 150th (P=0.041) and 180th (P=0.034) minutes of recovery in the SLE(INACTIVE) group, whereas the other cytokines and sTNFR2 levels remained unchanged (P>0.05). In the HC group, IL-10, TNF-α, sTNFR1, and sTNFR2 levels did not change, whilst INF-γ levels decreased (P=0.05) and IL-6 levels increased immediately after the exercise (P=0.028), returning to baseline levels 24 hours later (P > 0.05). When compared with the HC group, the SLE(INACTIVE) group showed higher levels of TNF-α and sTNFR2 in all time points, and higher levels of sTNFR1 at the end of exercise and at the 30th minute of recovery (P<0.05). The SLE(ACTIVE) group also showed higher levels of TNF-α at all time points when compared with the HC group (P<0.05), (except after 90 min, 120 min and 24 hours of recovery) (P>0.05). Importantly, the levels of all cytokine and soluble TNF receptors returned to baseline 24 hours after the end of acute exercise, irrespective of its intensity, in all three groups (P>0.05). This study demonstrated that both the single bouts of acute moderate and intense exercise induced mild and transient changes in cytokine levels in both SLE(INACTIVE) and SLE(ACTIVE) women, providing novel evidence that acute aerobic exercise does not trigger inflammation in patients with this disease.

Exercise training, creatine supplementation, and bone health in ovariectomized rats.

UNLABELLED: Evidence suggests that creatine may have some beneficial effects on bone. The study aimed to investigate the effects of exercise alone or combined with creatine on bone health in ovariectomized rats. Findings show that exercise, but not creatine, has an important role in improving bone health. INTRODUCTION: The aim of this study was to investigate the effects of exercise training alone or combined with creatine supplementation on bone health parameters in ovariectomized rats. METHODS: Wistar rats were randomly allocated into one of five groups: (i) sham-operated, (ii) ovariectomized non-trained placebo-supplemented, (iii) ovariectomized non-trained creatine-supplemented, (iv) ovariectomized exercise-trained placebo-supplemented, and (v) ovariectomized exercise-trained creatine-supplemented. Downhill running training and/or creatine supplementation (300 mg/kg body weight) were administered for 12 weeks. Bone mineral content (BMC), bone mineral density (BMD), and biomechanical and histomorphometric parameters were assessed. RESULTS: No interaction effects were observed for BMC and BMD at whole body, femur, and lumbar spine (p > 0.05). Importantly, a main effect of training was detected for whole body BMC and BMD (p = 0.003 and p < 0.001, respectively), femoral BMC and BMD (p = 0.005 and p < 0.001, respectively), and lumbar spine BMC and BMD (p < 0.001 and p < 0.001, respectively), suggesting that the trained animals had higher bone mass, irrespective of creatine supplementation. Main effects of training were also observed for maximal load (p < 0.001), stiffness (p < 0.001), and toughness (p = 0.046), indicating beneficial effects of exercise training on bone strength. Neither a main effect of supplementation nor an interaction effect was detected for biomechanical parameters (p > 0.05). No main or interaction effects were observed for any of the histomorphometric parameters evaluated (p > 0.05). CONCLUSIONS: Exercise training, but not creatine supplementation, attenuated ovariectomy-induced bone loss in this rat model.

Efficacy and safety of creatine supplementation in childhood-onset systemic lupus erythematosus: a randomized, double-blind, placebo-controlled, crossover trial.

INTRODUCTION: Creatine supplementation has emerged as a promising non-pharmacological therapeutic strategy to counteract muscle dysfunction and low lean mass in a variety of conditions, including in pediatric and rheumatic diseases. The objective of this study was to examine the efficacy and safety of creatine supplementation in childhood systemic lupus erythematosus (C-SLE). METHODS: C-SLE patients with mild disease activity (n = 15) received placebo or creatine supplementation in a randomized fashion using a crossover, double-blind, repeated-measures design. The participants were assessed at baseline and after 12 weeks in each arm, interspersed by an eight-week washout period. The primary outcomes were muscle function, as assessed by a battery of tests including one-maximum repetition (1-RM) tests, the timed-up-and-go test, the timed-stands test, and the handgrip test. Secondary outcomes included body composition, biochemical markers of bone remodeling, aerobic conditioning, quality of life, and physical capacity. Possible differences in dietary intake were assessed by three 24-hour dietary recalls. Muscle phosphorylcreatine content was measured through phosphorus magnetic resonance spectroscopy (31 P-MRS). The safety of the intervention was assessed by laboratory parameters, and kidney function was measured by (51)Cr-EDTA clearance. Additionally, self-reported adverse events were recorded throughout the trial. RESULTS: Intramuscular phosphorylcreatine content was not significantly different between creatine and placebo before or after the intervention (creatine-Pre: 20.5 ± 2.6, Post: 20.4 ± 4.1, placebo-Pre: 19.8 ± 2.0; Post: 20.2 ± 3.2 mmol/kg wet muscle; p = 0.70 for interaction between conditions). In addition, probably as a consequence of the lack of change in intramuscular phosphorylcreatine content, there were no significant changes between placebo and creatine for any muscle function and aerobic conditioning parameters, lean mass, fat mass, bone mass, and quality of life scores (p > 0.05). The (51)Cr-EDTA clearance was not altered by creatine supplementation and no side effects were noticed. CONCLUSION: A 12-week creatine supplementation protocol at 0.1 g/kg/d is well tolerated and free of adverse effects but did not affect intramuscular phosphorylcreatine, muscle function, free-fat mass or quality of life in non-active C-SLE patients. TRIAL REGISTRATION: Clinicaltrials.gov number: NCT01217320.

Blood flow restricted resistance training attenuates myostatin gene expression in a patient with inclusion body myositis.

UNLABELLED: Inclusion body myositis is a rare idiopathic inflammatory myopathy that produces extreme muscle weakness. Blood flow restricted resistance training has been shown to improve muscle strength and muscle hypertrophy in inclusion body myositis. OBJECTIVE: The aim of this study was to evaluate the effects of a resistance training programme on the expression of genes related to myostatin (MSTN) signalling in one inclusion body myositis patient. METHODS: A 65-year-old man with inclusion body myositis underwent blood flow restricted resistance training for 12 weeks. The gene expression of MSTN, follistatin, follistatin-like 3, activin II B receptor, SMAD-7, MyoD, FOXO-3, and MURF-2 was quantified. RESULTS: After 12 weeks of training, a decrease (25%) in MSTN mRNA level was observed, whereas follistatin and follistatin-like 3 gene expression increased by 40% and 70%, respectively. SMAD-7 mRNA level was augmented (20%). FOXO-3 and MURF-2 gene expression increased by 40% and 20%, respectively. No change was observed in activin II B receptor or MyoD gene expression. CONCLUSIONS: Blood flow restricted resistance training attenuated MSTN gene expression and also increased expression of myostatin endogenous inhibitors. Blood flow restricted resistance training evoked changes in the expression of genes related to MSTN signalling pathway that could in part explain the muscle hypertrophy previously observed in a patient with inclusion body myositis.

Impaired aerobic exercise capacity and cardiac autonomic control in primary antiphospholipid syndrome.

Primary antiphospholipid syndrome (PAPS) is associated with increased risk of cardiovascular disease and mortality. Aerobic capacity and cardiac autonomic control are also associated with these risks. The aim of our study was to assess aerobic capacity and cardiac autonomic control in PAPS patients. Thirteen women with PAPS and 13 healthy controls matched for age, gender, and body mass index were enrolled for the study. Both groups were sedentary and were not under chronotropic, antidepressants and hypolipemiant drugs. All subjects performed a treadmill-graded maximal exercise. Aerobic capacity was assessed by peak oxygen uptake (VO2peak), time at anaerobic ventilatory threshold (VAT) and respiratory compensation point (RCP) and time-to-exhaustion, whereas cardiac autonomic control was assessed by chronotropic reserve (CR) and heart rate recovery at the first and second minutes after graded exercise (HRR1min and HRR2min, respectively). All aerobic capacity indexes were reduced more in PAPS patients than in healthy subjects: VO2peak (30.2 ± 4.7 vs 34.6 ± 4.3 ml.kg(-1).min(-1), p = 0.021), time at VAT (3.0 ± 1.5 vs 5.0 ± 2.0 min, p = 0.016), time at RCP (6.5 ± 2.0 vs 8.0 ± 2.0 min, p = 0.050), time-to-exhaustion (8.5 ± 2.0 vs 11.0 ± 2.5 min, p = 0.010). HRR1min (22 ± 9 vs 30 ± 7 bpm, p = 0.032) and HRR2min (33 ± 9 vs 46 ± 8 bpm, p = 0.002) were delayed in PAPS patients compared to healthy controls but CR was not significantly different (p = 0.272). In conclusion, an impaired aerobic capacity and cardiac autonomic control was identified in PAPS.

Incidence of adverse events associated with percutaneous muscular biopsy among healthy and diseased subjects.

The development of the percutaneous muscle biopsy technique is recognized as one of the most important scientific contributions in advancing our understanding of skeletal muscle physiology. However, a concern that this procedure may be associated with adverse events still exists. We reported the incidence of adverse outcomes associated with percutaneous muscle biopsy in healthy and diseased subjects. Medical records of 274 volunteers (496 muscle biopsies) were reviewed. This included 168 healthy subjects (330 muscle biopsies) as well as 106 chronically ill patients (166 muscle biopsies). This latter group encompassed patients with type II diabetes (n=28), osteoarthritis (n=39), inclusion body myositis (n=4), polymyositis (n=4), and chronic heart failure (n=31). The most common occurrences were pain (1.27%), erythema (1.27%), and ecchymosis (1.27%). Panic episode, bleeding, and edema were also reported (0.21%, 0.42%, and 0.84%, respectively), while infection, hematoma, inflammation, denervation, numbness, atrophy, and abnormal scarring were not verified. The percent of incidents did not differ between healthy and ill individuals. In conclusion, the incidence of complications associated with percutaneous muscle biopsy is scarce and of minor clinical relevance. Additionally, the rate of adverse events is comparable between healthy and chronically ill subjects.

Abnormal chronotropic reserve and heart rate recovery in patients with SLE: a case-control study.

Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case-control study, 22 women with SLE (age 29.5 ± 1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5 ± 1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (ΔHRR) was defined as the difference between HR at peak exercise and at both first (ΔHRR1) and second (ΔHRR2) minutes after exercising. SLE patients presented lower peak VO(2) when compared with healthy subjects (27.6 ± 0.9 vs. 36.7 ± 1.1 ml/kg/min, p = 0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8 ± 2.4 vs. 98.2 ± 2.6%, p = 0.001), ΔHRR1 (22.1 ± 2.5 vs. 32.4 ± 2.2%, p = 0.004) and ΔHRR2 (39.1 ± 2.9 vs. 50.8 ± 2.5%, p = 0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed ΔHRR.

Erratic control of breathing during exercise in patients with systemic lupus erythematosus: a pilot-study.

PURPOSE: The aim of this study was to provide a comprehensive evaluation of the pattern and timing of breathing during incremental exercise in a sample of women living with systemic lupus erythematosus (SLE). METHODS: In this cross-sectional study, 20 women with SLE without pulmonary involvement were compared with 20 gender-, body mass index- (BMI), and age-matched healthy individuals. By using a cardiopulmonary incremental exercise test, the following parameters were assessed: tidal volume (VT); breathing frequency (BF); total respiratory time (TOT); inspiratory time (TI); expiratory time (TE); inspiratory time to total time (TI/TOT); mean inspiratory flow (VT/TI); ventilatory equivalent for carbon dioxide (VE/VCO2) and end-tidal carbon dioxide pressure (PETCO2). RESULTS: BF and BF/VT were significantly higher in patients with SLE versus controls, whereas VT, TE, TI and TOT were significantly lower in the former group ( p<0.05). Additionally, patients with SLE presented higher VE/VCO2 and lower PETCO2 than controls ( p<0.05), suggesting a ventilatory inefficiency. CONCLUSION: We reported compelling evidence of abnormal pattern and timing of breathing during incremental exercise in SLE. Considering that an erratic control of breathing may play an important role in exercise intolerance and fatigue, respiratory exercises emerge as a potential treatment for these symptoms in patients with SLE.

Development, validity and reliability of a questionnaire designed to evaluate rapid weight loss patterns in judo players.

The aim of this study was to develop a questionnaire to evaluate rapid weight loss patterns of competitive judo players and to assess its validity and reliability. We evaluated the reliability (n=94), content validity (evaluation by 10 experts), discriminant validity (differences in scores between athletes with body weight below and above their weight class; n=100) and convergent validity (correlation with Restraint Scale; n=60). No item was considered unclear or ambiguous by more than 20% of the experts. The intraclass Coefficient Correlation was above 0.90 for all questions whose answers were parametric (P<0.001; n=94) and no significant differences were found between test and retest scores (n=94--Wilcoxon's signed rank test). Cronbach's alpha was 0.98 for scores obtained between test and retest. Non-numerical questions showed proportions of agreement >80%; Spearman's Correlation between the Restraint Scale and the Rapid Weight Loss Questionnaire was 0.62 (P<0.001; n=60). Athletes below their weight class (n=50) had a significantly lower score compared with athletes above the weight class (n=50; P<0.001--Mann-Whitney U test). In conclusion, the questionnaire showed good validity and reliability and could be used accurately to assess weight loss patterns of judo players.