Haemoglobin concentration and mass as determinants of exercise performance and of surgical outcome

Parenteral Iron Therapy: Examining Current Evidence for Use in Athletes

A high prevalence of iron deficiency exists in athlete populations. Various mechanisms, including increased losses through sweat, haemolysis, haematuria, and gastrointestinal micro-ischemia; inadequate dietary intake; and transient exercise-induced increases in the regulatory hormone, hepcidin, contribute to the increased prevalence in athletes. Indeed, hepcidin has been shown to peak around 3-6 hours post-exercise, limiting iron absorption from the gut. As the practitioner's ability to control losses is limited, the key to treatment of iron deficiency in athletes is optimal timing of dietary and oral iron supplementation around these periods of reduced gut absorption. While timing and dosing schedule strategies might be sufficient to treat iron deficiency non-anaemia, the significant lag to impact iron status is relatively long. Therefore, in iron deficiency anaemia, the use of parenteral iron has the benefit of rapid repletion of iron stores and normalisation of haemoglobin status, while bypassing the action of hepcidin at the gut. Furthermore, newer intravenous formulations can be administered as a single total dose over 15-60 min and have a similar safety profile to oral treatment. This review discusses the existing evidence for parenteral iron use in athletes and the unique context for consideration when choosing the parenteral route in this population.

Peak Exercise Capacity and Angina Threshold Improvement after Cardiac Rehabilitation in a Patient with Stable Angina and Low Hemoglobin

Cardiac rehabilitation (CR) is recommended for all patients with stable angina (SA) as an effective treatment. Hemoglobin (Hgb) levels predict exercise performance and may affect symptom threshold in SA patients. A multidisciplinary CR intervention was individually tailored for a 72-year-old patient with a diagnosis of SA, low Hgb (<10 g/dL), and typical chest pain at light-to-moderate exercise (<5 metabolic equivalent task), who was stratified as at high risk for cardiac events during exercise. Two symptom-limited exercise tests were performed before and after 36 sessions of supervised exercise training producing near-optimal accumulated total volume load and chronic training load. In this case report, we show that an individually tailored CR intervention in a patient with SA and low Hgb is feasible, effective, and safe at reducing the burden of symptoms while increasing peak exercise capacity, health-related quality of life, and physical activity engagement.

Physiological and performance effects of live high train low altitude training for elite endurance athletes: A narrative review

Altitude training has become an important training application for athletes due its potential for altering physiology and enhancing performance. This practice is commonly used by athletes, with a popular choice being the live high - train low approach. This model recommends that athletes live at high altitude (1250-3000 m), but train at low altitude or sea-level (0-1200 m). Exposure to altitude often leads to hypoxic stress and in turn stimulates changes in total haemoglobin mass, erythropoietin, and soluble transferrin receptors, which alter further underlying physiology. Through enhanced physiology, improved exercise performance may arise through enhancement of the oxygen transport system which is important for endurance events. Previous investigations into the effects of altitude training on exercise performance have been completed in a range of contexts, including running, cycling, swimming, and triathlon. Often following a LHTL altitude intervention, athletes realise improvements in maximal oxygen consumption capacity, time trial performance and peak power outputs. Although heterogeneity exists among LHTL methodologies, i.e., exposure durations and altitude ranges, we synthesised this data into kilometre hours, and found that the most common hypoxic doses used in LHTL interventions ranged from ∼578-687 km h. As this narrative review demonstrates, there are potential advantages to using altitude training to enhance physiology and improve performance for endurance athletes.

Fourteen-Days Spirulina Supplementation Increases Hemoglobin, but Does Not Provide Ergogenic Benefit in Recreationally Active Cyclists: A Double-Blinded Randomized Crossover Trial

Spirulina supplementation has been reported to increase hemoglobin concentration as well as a variety of cardiorespiratory and lactate-based performance parameters during maximal and submaximal states of exercise. This study investigates the efficacy of supplementing a 6 g/day dosage of spirulina for 14-days in recreationally active individuals, analyzing cardiorespiratory parameters during maximal and submaximal cycling as well as the potential mechanistic role of hemoglobin augmentation. 17 recreationally active individuals (Male = 14, Female = 3, Age 23 ± 5 years, V̇O2max 43.3 ± 8.6 ml/min·kg) ingested 6 g/day of spirulina or placebo for 14-days in a double-blinded randomized crossover study, with a 14-day washout period between trials. Participants completed a 20-min submaximal cycle at 40% maximal power output (WRmax), followed by a V̇O2max test. Hemoglobin (g/L), WRmax (watts), time to fatigue (seconds), heart rate (bpm), oxygen uptake (ml/min·kg), RER and blood lactate response (mmol/L) were measured and compared between conditions. Cardiorespiratory variables were recorded at 5-min intervals and lactate was measured at 10-min intervals during the submaximal exercise. There was a significant 3.4% increase in hemoglobin concentration after spirulina supplementation in comparison to placebo (150.4 ± 9.5 g/L Vs 145.6 ± 9.4 g/L, p = 0.047). No significant differences existed between either condition in both testing protocols for V̇O2max, WRmax, time to fatigue, heart rate, oxygen uptake, RER and blood lactate response (p > 0.05). 14-days of spirulina supplementation significantly improved hemoglobin concentration but did not lead to any considerable ergogenic improvements during maximal or submaximal exercise at a 6 g/day dosage in recreationally active individuals whilst cycling.

Smartwatch-Based Maximum Oxygen Consumption Measurement for Predicting Acute Mountain Sickness: Diagnostic Accuracy Evaluation Study

BACKGROUND

Cardiorespiratory fitness plays an important role in coping with hypoxic stress at high altitudes. However, the association of cardiorespiratory fitness with the development of acute mountain sickness (AMS) has not yet been evaluated. Wearable technology devices provide a feasible assessment of cardiorespiratory fitness, which is quantifiable as maximum oxygen consumption (VO2max) and may contribute to AMS prediction.

OBJECTIVE

We aimed to determine the validity of VO2max estimated by the smartwatch test (SWT), which can be self-administered, in order to overcome the limitations of clinical VO2max measurements. We also aimed to evaluate the performance of a VO2max-SWT-based model in predicting susceptibility to AMS.

METHODS

Both SWT and cardiopulmonary exercise test (CPET) were performed for VO2max measurements in 46 healthy participants at low altitude (300 m) and in 41 of them at high altitude (3900 m). The characteristics of the red blood cells and hemoglobin levels in all the participants were analyzed by routine blood examination before the exercise tests. The Bland-Altman method was used for bias and precision assessment. Multivariate logistic regression was performed to analyze the correlation between AMS and the candidate variables. A receiver operating characteristic curve was used to evaluate the efficacy of VO2max in predicting AMS.

RESULTS

VO2max decreased after acute high altitude exposure, as measured by CPET (25.20 [SD 6.46] vs 30.17 [SD 5.01] at low altitude; P<.001) and SWT (26.17 [SD 6.71] vs 31.28 [SD 5.17] at low altitude; P<.001). Both at low and high altitudes, VO2max was slightly overestimated by SWT but had considerable accuracy as the mean absolute percentage error (<7%) and mean absolute error (<2 mL·kg-1·min-1), with a relatively small bias compared with VO2max-CPET. Twenty of the 46 participants developed AMS at 3900 m, and their VO2max was significantly lower than that of those without AMS (CPET: 27.80 [SD 4.55] vs 32.00 [SD 4.64], respectively; P=.004; SWT: 28.00 [IQR 25.25-32.00] vs 32.00 [IQR 30.00-37.00], respectively; P=.001). VO2max-CPET, VO2max-SWT, and red blood cell distribution width-coefficient of variation (RDW-CV) were found to be independent predictors of AMS. To increase the prediction accuracy, we used combination models. The combination of VO2max-SWT and RDW-CV showed the largest area under the curve for all parameters and models, which increased the area under the curve from 0.785 for VO2max-SWT alone to 0.839.

CONCLUSIONS

Our study demonstrates that the smartwatch device can be a feasible approach for estimating VO2max. In both low and high altitudes, VO2max-SWT showed a systematic bias toward a calibration point, slightly overestimating the proper VO2max when investigated in healthy participants. The SWT-based VO2max at low altitude is an effective indicator of AMS and helps to better identify susceptible individuals following acute high-altitude exposure, particularly by combining the RDW-CV at low altitude.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200059900; https://www.chictr.org.cn/showproj.html?proj=170253.

Implications of gender-affirming endocrine care for sports participation

Many transgender (trans) individuals utilize gender-affirming hormone therapy (GAHT) to promote changes in secondary sex characteristics to affirm their gender. Participation rates of trans people in sport are exceedingly low, yet given high rates of depression and increased cardiovascular risk, the potential benefits of sports participation are great. In this review, we provide an overview of the evidence surrounding the effects of GAHT on multiple performance-related phenotypes, as well as current limitations. Whilst data is clear that there are differences between males and females, there is a lack of quality evidence assessing the impact of GAHT on athletic performance. Twelve months of GAHT leads to testosterone concentrations that align with reference ranges of the affirmed gender. Feminizing GAHT in trans women increases fat mass and decreases lean mass, with opposite effects observed in trans men with masculinizing GAHT. In trans men, an increase in muscle strength and athletic performance is observed. In trans women, muscle strength is shown to decrease or not change following 12 months of GAHT. Haemoglobin, a measure of oxygen transport, changes to that of the affirmed gender within 6 months of GAHT, with very limited data to suggest possible reductions in maximal oxygen uptake as a result of feminizing GAHT. Current limitations of this field include a lack of long-term studies, adequate group comparisons and adjustment for confounding factors (e.g. height and lean body mass), and small sample sizes. There also remains limited data on endurance, cardiac or respiratory function, with further longitudinal studies on GAHT needed to address current limitations and provide more robust data to inform inclusive and fair sporting programmes, policies and guidelines.

Factors associated with high-level endurance performance: An expert consensus derived via the Delphi technique

There is little agreement on the factors influencing endurance performance. Endurance performance often is described by surrogate variables such as maximum oxygen consumption, lactate threshold, and running economy. However, other factors also determine success and progression of high-level endurance athletes. Therefore, the aim was to identify the relevant factors for endurance performance assessed by international experts by adhering to a structured communication method (i.e., Delphi technique). Three anonymous evaluation rounds were conducted initiated by a list of candidate factors (n = 120) serving as baseline input variables. The items that achieved ≥70% of agreement in round 1 were re-evaluated in a second round. Items with a level of agreement of ≥70% in round 2 reached consensus and items with a level of agreement of 40-69% in round 2 were re-rated in a third round followed by a consensus meeting. Round 1 comprised of 27 panellists (n = 24 male) and in round 2 and 3 18 (n = 15 male) of the 27 panellists remained. Thus, the final endurance expert panel comprised of 18 international experts (n = 15 male) with 20 years of experience on average. The consensus report identified the following 26 factors: endurance capacity, running economy, maximal oxygen consumption, recovery speed, carbohydrate metabolism, glycolysis capacity, lactate threshold, fat metabolism, number of erythrocytes, iron deficiency, muscle fibre type, mitochondrial biogenesis, hydrogen ion buffering, testosterone, erythropoietin, cortisol, hydration status, vitamin D deficiency, risk of non-functional overreaching and stress fracture, healing function of skeletal tissue, motivation, stress resistance, confidence, sleep quality, and fatigue. This study provides an expert-derived summary including 26 key factors for endurance performance, the "FENDLE" factors (FENDLE = Factors for ENDurance Level). This consensus report may assist to optimize sophisticated diagnostics, personalized training strategies and technology.

Aerobic Training With Blood Flow Restriction for Endurance Athletes: Potential Benefits and Considerations of Implementation

ABSTRACT

Smith, NDW, Scott, BR, Girard, O, and Peiffer, JJ. Aerobic training with blood flow restriction for endurance athletes: potential benefits and considerations of implementation. J Strength Cond Res 36(12): 3541-3550, 2022-Low-intensity aerobic training with blood flow restriction (BFR) can improve maximal oxygen uptake, delay the onset of blood lactate accumulation, and may provide marginal benefits to economy of motion in untrained individuals. Such a training modality could also improve these physiological attributes in well-trained athletes. Indeed, aerobic BFR training could be beneficial for those recovering from injury, those who have limited time for training a specific physiological capacity, or as an adjunct training stimulus to provide variation in a program. However, similarly to endurance training without BFR, using aerobic BFR training to elicit physiological adaptations in endurance athletes will require additional considerations compared with nonendurance athletes. The objective of this narrative review is to discuss the acute and chronic aspects of aerobic BFR exercise for well-trained endurance athletes and highlight considerations for its effective implementation. This review first highlights key physiological capacities of endurance performance. The acute and chronic responses to aerobic BFR exercise and their impact on performance are then discussed. Finally, considerations for prescribing and monitoring aerobic BFR exercise in trained endurance populations are addressed to challenge current views on how BFR exercise is implemented.

Remote Monitoring of Vital and Activity Parameters in Chronic Transfusion-Dependent Patients: A Feasibility Pilot Using Wearable Biosensors

Introduction

Little is known if, and to what extent, outpatient red blood cell (RBC) transfusions benefit chronic transfusion-dependent patients. Costs, labour, and potential side effects of RBC transfusions cause a restrictive transfusion strategy to be the standard of care. However, effects on the actual performance and quality of life of patients who require RBCs on a regular basis are hardly studied. The aim of this study was to assess if new technologies and techniques like wearable biosensor devices and web-based testing can be used to measure physiological changes, functional activity, and hence eventually better assess quality of life in a cohort of transfusion-dependent patients.

Methods

We monitored 5 patients who regularly receive transfusions during one transfusion cycle with the accelerateIQ biosensor platform, the Withings Steel HR, and web-based cognitive and quality of life testing.

Results

Data collection by the deployed devices was shown to be feasible; the AccelerateIQ platform rendered data of which 97.8% was of high quality and usable; of the data the Withings Steel HR rendered, 98.9% was of high quality and usable. Furthermore, heart rate decreased and cognition improved significantly following RBC transfusions. Activity and quality of life measures did not show transfusion-induced changes.

Conclusion

In a 5-patient cohort of transfusion-dependent patients, we found that the accelerateIQ, Withings Steel HR, and CANTAB platforms enable acquisition of high-quality data. The collected data suggest that RBC transfusions significantly and reversibly decrease heart rate and increase sustained attention in this cohort. This feasibility study justifies larger validation trials to confirm that these wearables can indeed help to determine personalized RBC transfusion strategies and thus optimization of each patient's quality of life.

Analysis of the Sustainability of Long-Term Detraining Caused by COVID-19 Lockdown: Impact on the Maximal Aerobic Speed of Under-16 Soccer Players

This retrospective cohort study aimed to analyze the effect of a 9-week detraining caused by COVID-19 lock-down on the maximal aerobic speed (MAS) of youth soccer players. The study included twenty-two under-16 male players competing at the national league level (15.4 ± 0.7 years old) who were analyzed pre and post the detraining period. The MAS was estimated using the Bronco’s test. Moreover, the self-regulated physical exercise performed by the players during the lockdown was monitored using a questionnaire. Considering the training volume per week, the players were grouped into those working more (>180 min/week) and those working less (<180 min/week) during the lockdown. Within-group changes revealed no significant differences (p = 0.122; d = 0.381) in the group that self-trained less than 180 min/week started (pre-lockdown) at 3.97 ± 0.29 m/s and ended (post-lockdown) at 3.85 ± 0.34 m/s, corresponding to a decrease of 3.02%. For those who self-trained more than 180 min/week during the lockdown, they started with 4.33 ± 0.28 m/s and decreased by 1.62% for 4.26 ± 0.28 m/s (p = 0.319; d = 0.250). The team as a whole (pooled data, all players included) decreased 2.27% from 4.15 ± 0.34 to 4.06 ± 0.37 m/s (p = 0.077; d = 0.321). Between group analysis revealed that the group of players that trained more than 180 min/weeks were significantly better than players working below 180 min/week in both pre-lockdown moment (+9.01%; p = 0.007; d = 1.263) and post-lockdown moment (10.6%; p = 0.006; d = 1.323). Home-based training can be a good strategy to mitigate the detraining effects caused by a lockdown.

Tailoring prehabilitation to address the multifactorial nature of functional capacity for surgery

Mounting evidence suggests that recovery begins before the surgical incision. The pre-surgery phase of recovery - the preparation for optimal surgical recovery - can be reinforced with prehabilitation. Prehabilitation is the approach of enhancing the functional capacity of the individual to enable them to withstand a stressful event. With this narrative review, we apply the Wilson & Cleary conceptual model of patient outcomes to specify the complex and integrative relationship of health factors that limit functional capacity before surgery. To have the greatest impact on patient outcomes, prehabilitation programs require individualized and coordinated care from medical, nutritional, psychosocial, and exercise services. This article is protected by copyright. All rights reserved.

Relationships between Fitness Status and Blood Biomarkers in Professional Soccer Players

Background

Physical conditions are recognized to be optimal after the pre-season (PS) phase in professional sports. Given that blood measures may also reveal variations, which in turn, may present associations with fitness changes.

Objective

The aim of this study is to test the changes of blood markers and physical fitness outcomes at the beginning and following the PS phase. Additionally, we aimed also to analyze the associations of training adaptations between blood markers and the physical fitness measures. Methodology. 25 professional male soccer players (28.1 ± 4.6 years old, 2.0 ± 7.8 kg, and 176.7 ± 4.9 cm) were assessed for hematological and biochemical parameters, and physical fitness measures in the baseline and after the phase of PS.

Results

Increases in platelets were observed after the PS phase (p = 0.001, η2 = 0.39). Regarding the biochemical parameters, significant increases between PS were found for creatinine (Cre) (p = 0.001, η2 = 0.66), alkaline phosphatase (ALP) (p = 0.001, η2 = 0.79), C-Reactive Protein (CRP) (p = 0.001, η2 = 0.74), cortisol (C) (p = 0.001, η2 = 0.63), and testosterone (T) (p = 0.001, η2 = 0.76), whereas significant decreases were found for albumin (Alb) (p = 0.004, η2 = 0.29), and calcium corrected (Ca Corr.) (p = 0.002, η2 = 0.32). Moderate correlations were found between albumin and the 5-meter linear sprint split (r = -0.44 (95%CI: -0.71; -0.05)) and CRP (r = -0.48 (95%CI: -0.74; -0.10)). Moderate correlations were found between VAMEVAL and hemoglobin (r = 0.44 (95%CI: 0.05; 0.71)).

Conclusions

The overall physical fitness measures improved after the PS phase. Also, significant variations (decreases/increases) were observed for the case of biomchemical and hematological outcomes. Coaches should carefully consider the adaptative changes observed in blood parameters as the changes in whole organism and metabolism after specific critical phases as the PS in professional players. Thus, optimal management of stimulus/recovery can be warranted to minimize illness and injury rate and to follow the direction and dynamics of adaptative changes.

Six weeks of static apnea training does not affect Hbmass and exercise performance

PURPOSE

Acute apnea is known to induce decreases in oxyhemoglobin desaturation (SpO₂) and increases in erythropoietin concentration ([EPO]). This study examined the potential of an apnea training program to induce erythropoiesis and increase hematological parameters and exercise performance.

METHODS

Twenty-two male subjects were randomly divided into an apnea and control group. The apnea group performed a 6-week apnea training program consisting of a daily series of 5 maximal static apneas. Before and after training, subjects visited the lab on three test days to perform 1) a ramp incremental test measuring V̇O_2peak, 2) CO-rebreathing for Hb mass determination and a 3-km time trial and 3) an apnea test protocol with continuous finger SpO₂ registration. Venous blood samples were drawn before and 180 minutes after the apnea test for analysis of [EPO].

RESULTS

Minimal SpO₂ reached during the apnea test protocol was 91 ±7% pre and 82 ±7% post apnea training. The apnea test protocol did not elicit an acute increase in [EPO] (p=0.685) before nor after the training program. Consequently, resting [EPO] (p=0.170), Hbmass (p=0.134), V̇O_2peak (p=0.796) and 3-km cycling time trial performance (p=0.509) were not affected either.

CONCLUSION

The apnea test and training protocol, consisting of 5 maximal static apneas, did not induce a sufficiently strong hypoxic stimulus to cause erythropoiesis and therefore did not result in an increase in resting [EPO], Hbmass, V̇O_2peak or time trial performance. Longer and/or more intense training sessions inducing a stronger hypoxic stimulus are probably needed to obtain changes in hematological and exercise parameters.

Exploring the Anthropometric, Cardiorespiratory, and Haematological Determinants of Marathon Performance

Aim

We aimed to investigate the main anthropometric, cardiorespiratory and haematological factors that can determine marathon race performance in marathon runners.

Methods

Forty-five marathon runners (36 males, age: 42 ± 10 years) were examined during the training period for a marathon race. Assessment of training characteristics, anthropometric measurements, including height, body weight (n = 45) and body fat percentage (BF%) (n = 33), echocardiographic study (n = 45), cardiopulmonary exercise testing using treadmill ergometer (n = 33) and blood test (n = 24) were performed. We evaluated the relationships of these measurements with the personal best marathon race time (MRT) within a time frame of one year before or after the evaluation of each athlete.

Results

The training age regarding long-distance running was 9 ± 7 years. Training volume was 70 (50-175) km/week. MRT was 4:02:53 ± 00:50:20 h. The MRT was positively associated with BF% (r = 0.587, p = 0.001). Among echocardiographic parameters, MRT correlated negatively with right ventricular end-diastolic area (RVEDA) (r = -0.716, p < 0.001). RVEDA was the only independent echocardiographic predictor of MRT. With regard to respiratory parameters, MRT correlated negatively with maximum minute ventilation indexed to body surface area (VEmax/BSA) (r = -0.509, p = 0.003). Among parameters of blood test, MRT correlated negatively with haemoglobin concentration (r = -0.471, p = 0.027) and estimated haemoglobin mass (Hbmass) (r = -0.680, p = 0.002). After performing multivariate linear regression analysis with MRT as dependent variable and BF% (standardised β = 0.501, p = 0.021), RVEDA (standardised β = -0.633, p = 0.003), VEmax/BSA (standardised β = 0.266, p = 0.303) and Hbmass (standardised β = -0.308, p = 0.066) as independent variables, only BF% and RVEDA were significant independent predictors of MRT (adjusted R² = 0.796, p < 0.001 for the model).

Conclusions

The main physiological determinants of better marathon performance appear to be low BF% and RV enlargement. Upregulation of both maximum minute ventilation during exercise and haemoglobin mass may have a weaker effect to enhance marathon performance.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT04738877.

Physiology, pathophysiology and (mal)adaptations to chronic apnoeic training: a state-of-the-art review

Breath-hold diving is an activity that humans have engaged in since antiquity to forage for resources, provide sustenance and to support military campaigns. In modern times, breath-hold diving continues to gain popularity and recognition as both a competitive and recreational sport. The continued progression of world records is somewhat remarkable, particularly given the extreme hypoxaemic and hypercapnic conditions, and hydrostatic pressures these athletes endure. However, there is abundant literature to suggest a large inter-individual variation in the apnoeic capabilities that is thus far not fully understood. In this review, we explore developments in apnoea physiology and delineate the traits and mechanisms that potentially underpin this variation. In addition, we sought to highlight the physiological (mal)adaptations associated with consistent breath-hold training. Breath-hold divers (BHDs) are evidenced to exhibit a more pronounced diving-response than non-divers, while elite BHDs (EBHDs) also display beneficial adaptations in both blood and skeletal muscle. Importantly, these physiological characteristics are documented to be primarily influenced by training-induced stimuli. BHDs are exposed to unique physiological and environmental stressors, and as such possess an ability to withstand acute cerebrovascular and neuronal strains. Whether these characteristics are also a result of training-induced adaptations or genetic predisposition is less certain. Although the long-term effects of regular breath-hold diving activity are yet to be holistically established, preliminary evidence has posed considerations for cognitive, neurological, renal and bone health in BHDs. These areas should be explored further in longitudinal studies to more confidently ascertain the long-term health implications of extreme breath-holding activity.

How does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation

Objectives

We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT).

Design

Systematic review.

Data sources

Four databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020.

Eligibility criteria for selecting studies

Eligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English.

Results

Twenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy.

Conclusion

In transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.

The effects of normoxic endurance exercise on erythropoietin (EPO) production and the impact of selective β1 and non-selective β1 + β2 adrenergic receptor blockade

PURPOSE

Habitual endurance exercise results in increased erythropoiesis, which is primarily controlled by erythropoietin (EPO), yet studies demonstrating upregulation of EPO via a single bout of endurance exercise have been equivocal. This study compares the acute EPO response to 30 min of high versus 90 min of moderate-intensity endurance exercise and whether that response can be upregulated via selective adrenergic receptor blockade.

METHODS

Using a counterbalanced, cross-over design, fifteen participants (age 28 ± 8) completed two bouts of running (30-min, high intensity vs 90-min, moderate intensity) matched for overall training stress. A separate cohort of fourteen participants (age 31 ± 6) completed three bouts of 30-min high-intensity cycling after ingesting the preferential β₁-adrenergic receptor (AR) antagonist bisoprolol, the non-preferential β₁ + β₂ antagonist nadolol or placebo. Venous blood was collected before, during, and after exercise, and serum EPO levels were determined by ELISA.

RESULTS

No detectable EPO response was observed during or after high intensity running, however, in the moderate-intensity trial EPO was significantly elevated at both during-exercise timepoints (+ 6.8% ± 2.3% at 15 min and + 8.7% ± 2.2% at 60 min). No significant change in EPO was observed post-cycling or between the trials involving βAR blockade.

CONCLUSION

Neither training mode (running or cycling), nor beta-blockade significantly influenced the EPO response to 30 min of high-intensity exercise, however, 90 min of moderate-intensity running elevated EPO during exercise, returning to baseline immediately post-exercise. Identifying the optimal mode, duration and intensity required to evoke an EPO response to exercise may help tailor exercise prescriptions designed to maximize EPO response for both performance and clinical applications.

Relationships Between Aerobic Performance, Hemoglobin Levels, and Training Load During Small-Sided Games: A Study in Professional Soccer Players

The purposes of this study were (1) to analyze between-session variations of external and internal load measures during small-sided games (SSGs) and (2) to test the relationships between the maximum speed reached (VIFT) during the last stage of the 30-15 Intermittent Fitness Test, hemoglobin levels, and training load measures during SSG intervals among professional soccer players. Sixteen professional soccer players (mean ± SD; age 27.2 ± 3.4 years, height 174.2 ± 3.6 cm, body mass 69.1 ± 6.4 kg, and body fat 10.4 ± 4.1%) participated in this study. Hemoglobin and aerobic performance were first tested, and then a 3-week SSG program was applied using a 3 vs. 3 format. During those 3 weeks, internal and external load of entire sessions were also monitored for all training sessions. Trivial-to-small, standardized differences were observed between sessions for external and internal measures during SSGs. Total distance (TD) and mechanical work (MW) were the only variables that indicated small changes. Large-to-very-large relationships were found between VIFT and external loads: TD (r range: 0.69; 0.87), high-intensity running (HIR; r range: 0.66; 0.75), and MW (r range: 0.56; 0.68). Moderate-to-large negative relationships were found between hemoglobin levels and internal loads: Edwards' TRIMP (r range: -0.36; -0.63), %HRmax (r range: -0.50; -0.61), and red zone (r range: -0.50; -0.61). VIFT had unclear relationships with overall internal loads, while hemoglobin levels presented unclear relationships with overall external loads. In conclusion, no meaningful changes were found between sessions considering the format of play used. Additionally, the detected relationships indicate that VIFT and hemoglobin levels are good indicators of the performance capacity and physiological profile of players during SSGs. Also, the use of SSGs protocols as a monitoring complement of the 30-15IFT is suggested.

Effects of Ashwagandha (Withania somnifera) on Physical Performance: Systematic Review and Bayesian Meta-Analysis

Ashwagandha (Withania somnifera) is considered a potent adaptogen and anti-stress agent that could have some potential to improve physical performance. This preferred reporting items for systematic reviews and meta-analyses (PRISMA)-based comprehensive systematic review and Bayesian meta-analysis aimed to evaluate clinical trials up to 2020 from PubMed, ScienceDirect, and Google Scholar databases regarding the effect of Ashwagandha supplementation on physical performance in healthy individuals. Besides implementing estimation statistics analysis, we developed Bayesian hierarchical models for a pre-specified subgroup meta-analysis on strength/power, cardiorespiratory fitness and fatigue/recovery variables. A total of 13 studies met the requirements of this systematic review, although only 12 were included in the quantitative analysis. A low-to-moderate overall risk of bias of the trials included in this study was detected. All Bayesian hierarchical models converged to a target distribution (Ȓ = 1) for both meta-analytic effect size (μ) and between-study standard deviation (τ). The meta-analytic approaches of the included studies revealed that Ashwagandha supplementation was more efficacious than placebo for improving variables related to physical performance in healthy men and female. In fact, the Bayesian models showed that future interventions might be at least in some way beneficial on the analyzed outcomes considering the 95% credible intervals for the meta-analytic effect size. Several practical applications and future directions are discussed, although more comparable studies are needed in exercise training, and athletic populations are needed to derive a more stable estimate of the true underlying effect.

Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage

Males enjoy physical performance advantages over females within competitive sport. The sex-based segregation into male and female sporting categories does not account for transgender persons who experience incongruence between their biological sex and their experienced gender identity. Accordingly, the International Olympic Committee (IOC) determined criteria by which a transgender woman may be eligible to compete in the female category, requiring total serum testosterone levels to be suppressed below 10 nmol/L for at least 12 months prior to and during competition. Whether this regulation removes the male performance advantage has not been scrutinized. Here, we review how differences in biological characteristics between biological males and females affect sporting performance and assess whether evidence exists to support the assumption that testosterone suppression in transgender women removes the male performance advantage and thus delivers fair and safe competition. We report that the performance gap between males and females becomes significant at puberty and often amounts to 10-50% depending on sport. The performance gap is more pronounced in sporting activities relying on muscle mass and explosive strength, particularly in the upper body. Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 12 months of treatment. Thus, the muscular advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations should consider this evidence when reassessing current policies regarding participation of transgender women in the female category of sport.

Impact of Combined Photo-Biomodulation and Aerobic Exercise on Cognitive Function and Quality-of-Life in Elderly Alzheimer Patients with Anemia: A Randomized Clinical Trial

Purpose

Few data are available on the positive impact of photo-biomodulation (PBM) using low-level laser therapy as a complementary treatment for improving the cognitive function and optimizing the hemoglobin (Hb) level and oxygen carrying capacity in anemic elderly patients and consequently improving the quality-of-life. The present study aimed to evaluate a new, safe, and easy therapeutic approach to improve Alzheimer’s disease-related symptoms that interfere with the whole life activities and social interaction of elderly patients.

Patients and Methods

In this placebo-controlled clinical trial, 60 elderly patients suffering from anemia and mild cognitive dysfunction were randomly assigned into two equal groups to receive active or placebo low-level laser in addition to a moderate-intensity aerobic exercise over a 12-week period. Hb level as well as cognitive and functional tests were reassessed for any change after 12 weeks of intervention.

Results

By the end of this study, both groups showed significant improvements in Hb level, Montreal Cognitive Assessment Scale (MoCa – B basic), Quality-of-Life for Alzheimer’s Disease scale, and Berg Balance scale scores along with significant reduction in body mass index (BMI) and waist–hip ratio (WHR) (P<0.0001). The experimental group which received active low-level laser in addition to moderate-intensity aerobic exercise showed more significant results compared to the control group which received placebo low-level laser in addition to moderate-intensity aerobic exercise in all the measured outcomes (P<0.001).

Conclusion

Combined low-level laser therapy and moderate-intensity aerobic exercises are more effective in improving the cognitive function and quality-of-life of Alzheimer’s disease patients.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT04496778.

Seasonal variability of the vitamin D effect on physical fitness in adolescents

Studies investigating the relationship between vitamin D and physical fitness in youth have provided inconsistent findings. Recent evidence indicates that the expression of receptors and vitamin D-modulated genes in young subjects has a seasonal profile. Therefore, we investigated the role of vitamin D on physical fitness across seasons in a total of 977 male adolescents. Anthropometrics, lifestyle, dietary habits, biochemical profiles and physical fitness were studied. Multiple linear regression models, including pairwise interaction terms involving total 25-OH-vitamin D, were fitted. The interacting effect of season and total 25-OH-vitamin D had a significant influence on physical fitness performance (spring and total 25-OH-vitamin D: ß 0.19, SE 0.07, p = 0.007; summer and total 25-OH-vitamin D: ß 0.10, SE 0.06, p = 0.11; autumn and total 25-OH-vitamin D: ß 0.18, SE 0.07, p = 0.01), whereas the main effect of total 25-OH-vitamin D alone was not significant (p = 0.30). Body fat percentage, recreational physical activity level, time spent per day gaming/TV-watching, smoking, and hemoglobin levels were also related to the physical fitness performance score. Future studies should further explore the role of seasonal-dependent effects of vitamin D on health.

Spirulina supplementation improves oxygen uptake in arm cycling exercise

PURPOSE

Spirulina has previously been reported to improve high-intensity exercise performance and hemoglobin. However, spirulina's effect on arm cycling exercise has yet to be investigated. The purpose of this study was to investigate the responses of spirulina supplementation on hemoglobin and on oxygen uptake, RER and HR during seated arm cycling exercise.

METHODS

In a double-blinded randomized crossover design, eleven males untrained in arm cycling ingested 6 g/day of spirulina or placebo for seven days. Seated on the Arm Crank Ergometer, each participant performed a baseline V̇O2max test, and then after supplementation, 2 × 30-min submaximal exercise bouts corresponding to 55% of their V̇O2max, followed by an incremental test to fatigue. A seven-day wash-out period was required between conditions. Oxygen uptake, RER and HR were measured continuously during exercise and hemoglobin measured prior to exercise after both conditions.

RESULTS

Spirulina significantly (p < 0.05) increased Hb in comparison to Placebo (144.1 g/l ± 10.5 Vs 154.5 g/l ± 6.9). After spirulina supplementation, during the 30-min exercise bouts, oxygen uptake and HR were significantly lower (2170 ml/min ± 173 Vs 2311 ml/min ± 189 and 154 bpm ± 14 Vs 149 bpm ± 17), RER was not significantly different. In comparison to placebo, Spirulina significantly increased oxygen uptake at time of fatigue (34.10 ml/min/kg ± 6.03 Vs 37.37 ml/min/kg ± 5.98). Time taken to fatigue was not different.

CONCLUSION

Spirulina supplementation significantly reduces oxygen uptake and HR during arm cycling submaximal exercise, allowing for an increased oxygen uptake during an incremental test to fatigue.

Dietary intake of heme iron is associated with ferritin and hemoglobin levels in Dutch blood donors: results from Donor InSight

Whole blood donors, especially frequently donating donors, have a risk of iron deficiency and low hemoglobin levels, which may affect their health and eligibility to donate. Lifestyle behaviors, such as dietary iron intake and physical activity, may influence iron stores and thereby hemoglobin levels. We aimed to investigate whether dietary iron intake and questionnaire-based moderate-to-vigorous physical activity were associated with hemoglobin levels, and whether ferritin levels mediated these associations. In Donor InSight-III, a Dutch cohort study of blood and plasma donors, data on heme and non-heme iron intake (mg/day), moderate-to-vigorous physical activity (10 minutes/day), hemoglobin levels (mmol/L) and ferritin levels (μg/L) were available in 2,323 donors (1,074 male). Donors with higher heme iron intakes (regression coefficients (β) in men and women: 0.160 and 0.065 mmol/L higher hemoglobin per 1 mg of heme iron, respectively) and lower non-heme iron intakes (β: -0.014 and -0.017, respectively) had higher hemoglobin levels, adjusted for relevant confounders. Ferritin levels mediated these associations (indirect effect (95% confidence interval) in men and women respectively: 0.074 (0.045; 0.111) and 0.061 (0.030; 0.096) for heme and -0.003 (-0.008;0.001) and -0.008 (-0.013;-0.003) for non-heme). Moderate-to-vigorous physical activity was negatively associated with hemoglobin levels in men only (β: -0.005), but not mediated by ferritin levels. In conclusion, higher heme and lower non-heme iron intake were associated with higher hemoglobin levels in donors, via higher ferritin levels. This indicates that donors with high heme iron intake may be more capable of maintaining iron stores to recover hemoglobin levels after blood donation.

Preoperative erythropoietin within a patient blood management program decreases both blood transfusion and postoperative anemia: a prospective observational study

BACKGROUND

In orthopedic surgery, a patient blood management program (PBM) has been proposed to reduce blood transfusion. The aim of this observational study was to assess, within a PBM, the specific efficacy of preoperative erythropoietin (EPO).

STUDY DESIGN AND METHODS

In a single hospital, 723 patients undergoing elective primary hip or knee arthroplasty were prospectively studied. The PBM included EPO if preoperative hemoglobin was lower than 13 g/dL, intraoperative administration of tranexamic acid, use of recommended transfusion thresholds, and postoperative infusion of iron. Blood transfusion and hemoglobin were noted until discharge. Major thromboembolic or cardiovascular events were assessed during admission and 1 month after discharge.

RESULTS

Transfusion was noted in 2.5% patients with EPO. Transfusion rate was higher in patient for whom EPO was not indicated (13.6% transfusion rate; odds ratio [OR], 13.7; 95% confidence interval [CI], 2.6-66; p = 10^-3 ) or if erythropoietin was indicated but not administrated (36.8% transfusion rate; OR, 18.2; 95% CI, 3.9-84.5; p < 10^-3 ). Hemoglobin was significantly higher during the postoperative period in patients with erythropoietin. At hospital discharge, 57% of patients were anemic if EPO was used compared to 88% when EPO was not indicated and 87% when EPO was indicated but not administered (p < 10^-6 ). There were no significant differences in the odds of major complications between patients with or without EPO.

CONCLUSIONS

Within a PBM, preoperative treatment of anemia with EPO decreased both the rate of blood transfusion and postoperative anemia. Further studies are necessary to confirm these results.

Association of preoperative anaemia with cardiopulmonary exercise capacity and postoperative outcomes in noncardiac surgery: a substudy of the Measurement of Exercise Tolerance before Surgery (METS) Study

BACKGROUND

Preoperative anaemia is associated with elevated risks of postoperative complications. This association may be explained by confounding related to poor cardiopulmonary fitness. We conducted a pre-specified substudy of the Measurement of Exercise Tolerance before Surgery (METS) study to examine the associations of preoperative haemoglobin concentration with preoperative cardiopulmonary exercise testing performance (peak oxygen consumption, anaerobic threshold) and postoperative complications.

METHODS

The substudy included a nested cross-sectional analysis and nested cohort analysis. In the cross-sectional study (1279 participants), multivariate linear regression modelling was used to determine the adjusted association of haemoglobin concentration with peak oxygen consumption and anaerobic threshold. In the nested cohort study (1256 participants), multivariable logistic regression modelling was used to determine the adjusted association of haemoglobin concentration, peak oxygen consumption, and anaerobic threshold with the primary endpoint (composite outcome of death, cardiovascular complications, acute kidney injury, or surgical site infection) and secondary endpoint (moderate or severe complications).

RESULTS

Haemoglobin concentration explained 3.8% of the variation in peak oxygen consumption and anaerobic threshold (P<0.001). Although not associated with the primary endpoint, haemoglobin concentration was associated with moderate or severe complications after adjustment for peak oxygen consumption (odds ratio=0.86 per 10 g L^-1 increase; 95% confidence interval, 0.77-0.96) or anaerobic threshold (odds ratio=0.86; 95% confidence interval, 0.77-0.97). Lower peak oxygen consumption was associated with moderate or severe complications without effect modification by haemoglobin concentration (P=0.12).

CONCLUSION

Haemoglobin concentration explains a small proportion of variation in exercise capacity. Both anaemia and poor functional capacity are associated with postoperative complications and may therefore be modifiable targets for preoperative optimisation.

Effect of Delayed Cord Clamping on Cerebral Oxygenation in Very Preterm Infants

BACKGROUND AND OBJECTIVE

The mechanism of reported benefits of delayed cord clamping (DCC) are unclear. We aimed to determine whether DCC compared to immediate cord clamping (ICC) in very preterm infants improves cerebral oxygenation in the first 24 h.

STUDY DESIGN

This is a prospective study of a subset of infants at < 30 weeks of gestation who were randomised to DCC (≥60 s) or ICC (< 10 s) and required an indwelling arterial catheter. Regional cerebral oxygenation (rScO2), blood pressure, PI, and peripheral saturation were measured and cerebral fractional tissue oxygen extraction (cFTOE) calculated for the following 3 time intervals: 3-6, 6-12, and 12-28 h of age. Functional ultrasound measures including superior vena cava flow, right ventricular output, ductus arteriosus size and shunt and anterior cerebral artery resistive index were determined.

RESULTS

The mean (±SD) gestation and birth weight of the 51 study infants were 27 ± 1 weeks and 1,046 ± 241 g respectively. Twenty infants received DCC and 31 received ICC. Baseline demographics were similar between the 2 groups. Comparing DCC and ICC infants, there was no difference in rScO2 or cFTOE at any time point. Three out of 20 infants did not receive DCC due to clinical concerns. A sensitivity analysis revealed that cord clamping ≥30 s was significantly associated with increased rScO2 and decreased cFTOE at all 3 time points after adjusting for gestation.

CONCLUSION

Although DCC was not associated with changes in cerebral oxygenation overall, sensitivity analysis suggested a possible effect of an increased rScO2 and a decreased cFTOE with ≥30 s of DCC.

The impact of supplementation with pomegranate fruit (Punica granatum L.) juice on selected antioxidant parameters and markers of iron metabolism in rowers

Background

The aim of this study was to analyse the effect of pomegranate juice (POM) supplementation on the levels of selected pro-inflammatory cytokines, hepcidin and markers of iron metabolism in well-trained rowers.

Method

The double-blind placebo-controlled study included 19 members of the Polish Rowing Team. The athletes were randomised into the supplemented group (n = 10), receiving 50 ml of standardised POM daily for two months, or the placebo group (n = 9). The subjects performed a 2000 m test on the rowing ergometer at the start of the project (baseline) and end of follow-up period. Blood samples from the antecubital vein were obtained three times during each trial: prior to the exercise, one minute after the test, and following a 24 h recovery.

Results

The study documented the beneficial effect of supplementation with pomegranate fruit juice on TAC (P < 0.002). During the resting period, TAC level in the supplemented group was significantly higher than in the placebo group (x ± SD, 2.49 ± 0.39 vs. 1.88 ± 0.45, P < 0.05). The ergometric test conducted at baseline demonstrated a significant post-exercise increase in the concentrations of soluble transferrin receptors (P < 0.04), iron (P < 0.002) and IL-6 (P < 0.02), and to a significant post-exercise decrease in TAC. A significant increase in IL-6 concentration was also observed 24 h post-exercise. The exercise test conducted at the end of the follow-up period resulted in a significant decrease in TBIC and a significant increase in UIBC (P < 0.001), observed in both groups, both immediately post-exercise and after the resting period.

Conclusion

Supplementation with POM contributed to a significant strengthening of plasma antioxidant potential in the group of well-trained rowers, but had no effect on iron metabolism markers.

Delayed vs early umbilical cord clamping for preterm infants: a systematic review and meta-analysis

BACKGROUND

The effects of delayed cord clamping of the umbilical cord in preterm infants are unclear.

OBJECTIVE

We sought to compare the effects of delayed vs early cord clamping on hospital mortality (primary outcome) and morbidity in preterm infants using Cochrane Collaboration neonatal review group methodology.

STUDY DESIGN

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Chinese articles, cross-referencing citations, expert informants, and trial registries to July 31, 2017, for randomized controlled trials of delayed (≥30 seconds) vs early (<30 seconds) clamping in infants born <37 weeks' gestation. Before searching the literature, we specified that trials estimated to have cord milking in >20% of infants in any arm would be ineligible. Two reviewers independently selected studies, assessed bias, and extracted data. Relative risk (ie, risk ratio), risk difference, and mean difference with 95% confidence intervals were assessed by fixed effects models, heterogeneity by I² statistics, and the quality of evidence by Grading of Recommendations, Assessment, Development, and Evaluations.

RESULTS

Eighteen randomized controlled trials compared delayed vs early clamping in 2834 infants. Most infants allocated to have delayed clamping were assigned a delay of ≥60 seconds. Delayed clamping reduced hospital mortality (risk ratio, 0.68; 95% confidence interval, 0.52-0.90; risk difference, -0.03; 95% confidence interval, -0.05 to -0.01; P = .005; number needed to benefit, 33; 95% confidence interval, 20-100; Grading of Recommendations, Assessment, Development, and Evaluations = high, with I² = 0 indicating no heterogeneity). In 3 trials in 996 infants ≤28 weeks' gestation, delayed clamping reduced hospital mortality (risk ratio, 0.70; 95% confidence interval, 0.51-0.95; risk difference, -0.05; 95% confidence interval, -0.09 to -0.01; P = .02, number needed to benefit, 20; 95% confidence interval, 11-100; I² = 0). In subgroup analyses, delayed clamping reduced the incidence of low Apgar score at 1 minute, but not at 5 minutes, and did not reduce the incidence of intubation for resuscitation, admission temperature, mechanical ventilation, intraventricular hemorrhage, brain injury, chronic lung disease, patent ductus arteriosus, necrotizing enterocolitis, late onset sepsis or retinopathy of prematurity. Delayed clamping increased peak hematocrit by 2.73 percentage points (95% confidence interval, 1.94-3.52; P < .00001) and reduced the proportion of infants having blood transfusion by 10% (95% confidence interval, 6-13%; P < .00001). Potential harms of delayed clamping included polycythemia and hyperbilirubinemia.

CONCLUSION

This systematic review provides high-quality evidence that delayed clamping reduced hospital mortality, which supports current guidelines recommending delayed clamping in preterm infants. This review does not evaluate cord milking, which may also be of benefit. Analyses of individual patient data in these and other randomized controlled trials will be critically important in reliably evaluating important secondary outcomes.

Antihypoxic activities of constituents from Arenaria kansuensis

BACKGROUND

In previous investigation, we have identified antioxidative effects of water-soluble ethanolic extracts (named as AKE) from Arenaria kansuensis and inferred that these extracts or their constituents may also have antihypoxic activity. A. kansuensis has been widely used in traditional Tibetan medicine for altitude sickness (AS) and has been known as the herb of anti-inflammatory and hypoxia resistance for a long time.

PURPOSE

The purpose of this study is to evaluate protective effects of AKE and its major constituents against hypoxia-induced lethality in mice and RSC96 cells.

STUDY DESIGN AND METHODS

Hypoxia-induced lethality in mice was investigated by 3 experimental animal models of hypoxia. Meanwhile, we established a RSC96 cell model of hypoxia which applied to screen and assess the anti-hypoxic activity of compounds isolated from A. kansuensis.

RESULTS

Results indicated that AKE dose-dependently prolonged survival time of hypoxia induced lethality in mice compared to vehicle group and exhibited significantly anti-hypoxic effect. AKE also enhanced the number of red blood cells (RBC) and the concentration of hemoglobin (HB). 8 compounds were bio-guided separated and purified from AKE based on the animal model and cell model of hypoxia. Among which pyrocatechol (C16) and tricin 7-O-β-d-glucopyranoside (C13) were confirmed to express better protective effects on cell damage induced by hypoxia, suggesting that these two compounds are major active constituents of AKE for anti-hypoxia.

CONCLUSION

This study demonstrated that pyrocatechol and tricin 7-O-β-d-glucopyranoside could be therapeutic candidates for treatment of AS. It is the first time to find the major active constituents of AKE for anti-hypoxia. Meanwhile, a RSC96 cell model of hypoxia was established to screen anti-hypoxic activity of compounds for the first time.

The UK Cardiac and Vascular Surgery Interventional Anaemia Response (CAVIAR) Study: protocol for an observational cohort study to determine the impact and effect of preoperative anaemia management in cardiac and vascular surgical patients

INTRODUCTION

Preoperative anaemia is linked to poor postsurgical outcome, longer hospital stays, greater risk of complications and mortality. Currently in the UK, some sites have developed anaemia clinics or pathways that use intravenous iron to correct iron deficiency anaemia prior to surgery as their standard of care. Although intravenous iron has been observed to be effective in a variety of patient settings, there is insufficient evidence in its use in cardiac and vascular patients. The aim of this study is to observe the impact and effect of anaemia and its management in patients undergoing cardiac and vascular surgery. In addition, the UK Cardiac and Vascular Surgery Interventional Anaemia Response (CAVIAR) Study is also a feasibility study with the aim to establish anaemia management pathways in the preoperative setting to inform the design of future randomised controlled trials.

METHODS AND ANALYSIS

The UK CAVIAR Study is a multicentre, stepped, observational study, in patients awaiting major cardiac or vascular surgery. We will be examining different haematological variables (especially hepcidin), functional capacity and patient outcome. Patients will be compared based on their anaemia status, whether they received intravenous iron in accordance to their hospital's preoperative pathway, and their disease group. The primary outcomes are the change in haemoglobin levels from baseline (before treatment) to before surgery; and the number of successful patients recruited and consented (feasibility). The secondary outcomes will include changes in biomarkers of iron deficiency, length of stay, quality of life and postoperative recovery.

ETHICS AND DISSEMINATION

The study protocol was approved by the London-Westminster Research Ethics Committee (15/LO/1569, 27 November 2015). NHS approval was also obtained with each hospital trust. The findings of the study will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Clinical Trials registry (NCT02637102) and the ISRCTN registry (ISRCTN55032357).

Anesthesia for Patients with Anemia

Anemia is a common and often ignored condition in surgical patients. Anemia is usually multifactorial and iron deficiency and inflammation are commonly involved. An exacerbating factor in surgical patients is iatrogenic blood loss. Anemia has been repeatedly shown to be an independent predictor of worse outcomes. Patient blood management (PBM) provides a multimodality framework for prevention and management of anemia and related risk factors. The key strategies in PBM include support of hematopoiesis and improving hemoglobin level, optimizing coagulation and hemostasis, use of interdisciplinary blood conservation modalities, and patient-centered decision making throughout the course of care.

Gender disparities in the functional significance of anemia among apparently healthy adults

BACKGROUND

Data on the functional impact of anemia on cardiorespiratory fitness (CRF) and survival in healthy individuals are limited. Our aim was to evaluate the association between anemia thresholds, low CRF, and survival in otherwise healthy adults.

METHODS

Study population included 16 334 apparently healthy subjects attending annual periodic health screening examinations (71 200 annual visits), including exercise stress testing (EST). Anemia was defined by the World Health Organization (WHO) or Beutler and Waalens' (BW) criteria. Low CRF was defined as the lowest fitness quintile according to the Bruce protocol.

RESULTS

The mean age was 46±10 years, and 70% were men. Mean Hb levels were 13±1 and 15±1 among women and men, respectively, with higher proportion of anemia among women. The majority of anemic subjects had mild anemia. When analyzing repeated annual visits, anemia was associated with a significant 39% and 64% increased risk of low CRF according the WHO and BW criteria only in women (n=18 672). Baseline anemia at first visit was associated with 2.6- and 1.9-fold increased risk of all-cause mortality using the WHO and BW criteria, exclusively in men (n=11 511).

CONCLUSIONS

Overall, the functional and prognostic impact of anemia is gender dependent, based on the WHO and BW arbitrary criteria, suggesting differing mechanism and responses.

The use of biomarkers to describe plasma-, red cell-, and blood volume from a simple blood test

Plasma volume and red cell mass are key health markers used to monitor numerous disease states, such as heart failure, kidney disease, or sepsis. Nevertheless, there is currently no practically applicable method to easily measure absolute plasma or red cell volumes in a clinical setting. Here, a novel marker for plasma volume and red cell mass was developed through analysis of the observed variability caused by plasma volume shifts in common biochemical measures, selected based on their propensity to present with low variations over time. Once a month for 6 months, serum and whole blood samples were collected from 33 active males. Concurrently, the CO-rebreathing method was applied to determine target levels of hemoglobin mass (HbM) and blood volumes. The variability of 18 common chemistry markers and 27 Full Blood Count variables was investigated and matched to the observed plasma volume variation. After the removal of between-subject variations using a Bayesian model, multivariate analysis identified two sets of 8 and 15 biomarkers explaining 68% and 69% of plasma volume variance, respectively. The final multiparametric model contains a weighting function to allow for isolated abnormalities in single biomarkers. This proof-of-concept investigation describes a novel approach to estimate absolute vascular volumes, with a simple blood test. Despite the physiological instability of critically ill patients, it is hypothesized the model, with its multiparametric approach and weighting function, maintains the capacity to describe vascular volumes. This model has potential to transform volume management in clinical settings. Am. J. Hematol. 92:62-67, 2017. © 2016 Wiley Periodicals, Inc.

Risks of Anemia in Cardiac Surgery Patients

Anemia is an common condition in patients undergoing cardiac surgery, and it is often present in one quarter to half of patients at admission. Several studies have indicated that anemia is a major risk factor for worse outcomes, including increased risk of mortality and major morbidity and prolonged hospitalization. Anemia is a leading reason for use of allogeneic blood transfusions. Harmful effects of anemia are often attributed to the reduced oxygen carrying capacity of blood, reduced viscosity and the resulting impaired rheologic characteristics of blood, underlying comorbidities, and the side effects of treatments given for anemia, namely, allogeneic blood transfusions. Patients undergoing cardiac surgery may be at increased risk of anemia given the often-existing cardiac comorbidities and the negative impacts of cardiopulmonary bypass. However, whether less restrictive transfusion practices are justified in patients undergoing cardiac surgery is still a matter of debate. The prevalence of anemia often increases during hospital stay, and it can persist for a long time beyond hospital discharge. Given the associated risks and available management strategies, clinicians should remain vigilant to detect and treat anemia throughout the course of care for patients undergoing cardiac surgery.

'Blood doping' from Armstrong to prehabilitation: manipulation of blood to improve performance in athletes and physiological reserve in patients

Haemoglobin is the blood’s oxygen carrying pigment and is encapsulated in red blood corpuscles. The concentration of haemoglobin in blood is dependent on both its total mass in the circulation (tHb-mass) and the total plasma volume in which it is suspended. Aerobic capacity is defined as the maximum amount of oxygen that can be consumed by the body per unit time and is one measure of physical fitness. Observations in athletes who have undergone blood doping or manipulation have revealed a closer relationship between physical fitness (aerobic capacity) and total haemoglobin mass (tHb-mass) than with haemoglobin concentration ([Hb]). Anaemia is defined by the World Health Organisation (WHO) as a haemoglobin concentration of <130 g/L for men and <120 g/L for women. Perioperative anaemia is a common problem and is associated with increased mortality and morbidity following surgery. Aerobic capacity is also associated with outcome following major surgery, with less fit patients having a higher incidence of mortality and morbidity after surgery. Taken together, these observations suggest that targeted preoperative elevation of tHb-mass may raise aerobic capacity both directly and indirectly (by augmenting preoperative exercise initiatives- ‘prehabilitation’) and thus improve postoperative outcome. This notion in turn raises a number of questions. Which measure ([Hb] or tHb-mass) has the most value for the description of oxygen carrying capacity? Which measure has the most utility for targeting therapies to manipulate haemoglobin levels? Do the newer agents being used for blood manipulation (to increase tHb-mass) in elite sport have utility in the clinical environment? This review explores the literature relating to blood manipulation in elite sport as well as the relationship between perioperative anaemia, physical fitness and outcome following surgery, and suggests some avenues for exploring this area further.

Effects of aerobic exercise on hematologic indices of women with rheumatoid arthritis: A randomized clinical trial

Background:

To investigate the effects of moderate aerobic exercise on the hemoglobin, hematocrit, and red blood cell (RBC) mass of women with rheumatoid arthritis (RA).

Materials and Methods:

This randomized clinical trial was conducted at the Specialized Clinic of Physical Medicine and Rehabilitation, Al-Zahra Hospital of Isfahan, during a 4-month period in 2014. We included patients with RA who did not have any malignancy and hematologic disorder. Two groups — one group receiving aerobic therapy along with medical therapy (N = 16) and the other group receiving medical therapy alone (N = 17) both for a period of 8 weeks. The levels of RBC mass, Hb, and HCT were measured before and after the intervention. The changes in these parameters were compared between the two study groups.

Results:

There was no significant difference between the two study groups regarding the baseline characteristics. The aerobic exercise resulted in increased RBC mass (P < 0.001), Hb (P < 0.001), and HCT (P < 0.001). However, those who received medical therapy alone did not experience any significant changes in these parameters. We found that the RBC mass (P = 0.581), Hb (P = 0.882), and HCT (P = 0.471) were comparable between the two study groups after 8 weeks of intervention.

Conclusion:

Although the aerobic exercise results in increased Hb, HCT, and RBC mass in patients with RA, the increase was not significant when compared to that in controls. Thus, the increase in the HB, HCT, and RBC could not be attributable to aerobic exercise.

Pre-operative anaemia

Pre-operative anaemia is a relatively common finding, affecting a third of patients undergoing elective surgery. Traditionally associated with chronic disease, management has historically focused on the use of blood transfusion as a solution for anaemia in the peri-operative period. Data from large series now suggest that anaemia is an independent risk associated with poor outcome in both cardiac and non-cardiac surgery. Furthermore, blood transfusion does not appear to ameliorate this risk, and in fact may increase the risk of postoperative complications and hospital length of stay. Consequently, there is a need to identify, diagnose and manage pre-operative anaemia to reduce surgical risk. Discoveries in the pathways of iron metabolism have found that chronic disease can cause a state of functional iron deficiency leading to anaemia. The key iron regulatory protein hepcidin, activated in response to inflammation, inhibits absorption of iron from the gastrointestinal tract and further reduces bioavailability of iron stores for red cell production. Consequently, although iron stores (predominantly ferritin) may be normal, the transport of iron either from the gastrointestinal tract or iron stores to the bone marrow is inhibited, leading to a state of 'functional' iron deficiency and subsequent anaemia. Since absorption from the gastrointestinal tract is blocked, increasing oral iron intake is ineffective, and studies are now looking at the role of intravenous iron to treat anaemia in the surgical setting. In this article, we review the incidence and impact of anaemia on the pre-operative patient. We explain how anaemia may be caused by functional iron deficiency, and how iron deficiency anaemia may be diagnosed and treated.

Mean platelet volume (MPV) predicts middle distance running performance

BACKGROUND

Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners.

METHODS

The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75-85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection.

RESULTS

The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly associated with running performance.

CONCLUSION

The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance.