The athlete's hematological response to hypoxia: A meta-analysis on the influence of altitude exposure on key biomarkers of erythropoiesis.

Altitude training is associated with changes in blood markers, which can confound results of the Athlete?s Biological Passport (ABP). This meta-analysis aims to describe the fluctuations during- and post-altitude in key ABP variables; hemoglobin concentration ([Hb]), square-root transformed reticulocyte percentage (sqrt(retic%)) and the OFF-score. Individual de-identified raw data were provided from 17 studies. Separate linear mixed effects analyses were performed for delta values from baseline for [Hb], sqrt(retic%) and OFF-score, by altitude phase (during and post). Mixed models were fitted with the hierarchical structure: study and subject within study as random effects. Delta values as response variables and altitude dose (in kilometer hours; km.hr = altitude (m) / 1000 x hours), sex, age, protocol and baseline values as fixed effects. Allowances were made for potential autocorrelation. Within two days at natural altitude [Hb] rapidly increased. Subsequent delta [Hb] values increased with altitude dose, reaching a plateau of 0.94 g/dL [95%CI (0.69, 1.20)] at ~1000 km.hr. Delta sqrt(retic%) and OFF-score were the first to identify an erythrocyte response, with respective increases and decreases observed within 100 to 200 km.hr. Post-altitude, [Hb] remained elevated for two weeks. Delta sqrt(retic%) declined below baseline, the magnitude of change was dependent on altitude dose. Baseline values were a significant covariate (p<0.05). The response to altitude is complex resulting in a wide range of individual responses, influenced primarily by altitude dose and baseline values. Improved knowledge of the plausible hematological variations during- and post-altitude provides fundamental information for both the ABP expert and sports physician.

Reliability and accuracy of six hand-held blood lactate analysers.

The reliability and accuracy of five portable blood lactate (BLa) analysers (Lactate Pro, Lactate Pro2, Lactate Scout+, Xpress™, and Edge) and one handheld point-of-care analyser (i-STAT) were compared to a criterion (Radiometer ABL90). Two devices of each brand of analyser were assessed using 22 x 6 mL blood samples taken from five subjects at rest and during exercise who generated lactate ranging ~1-23 mM. Each sample was measured simultaneously ~6 times on each device. Reliability was assessed as the within-sample standard deviation (wsSD) of the six replicates; accuracy as the bias compared with the ABL90; and overall error (the root mean squared error (√MSE)) was calculated as the square root of (wsSD(2) and bias(2)). The √MSE indicated that both the Edge and Xpress had low total error (~0-2 mM) for lactate concentrations <15 mM, whereas the Edge and Lactate Pro2 were the better of the portable analysers for concentrations >15 mM. In all cases, bias (negative) was the major contribution to the √MSE. In conclusion, in a clinical setting where BLa is generally <15 mM the Edge and Xpress devices are relevant, but for athlete testing where peak BLa is important for training prescription the Edge and Lactate Pro2 are preferred. Key pointsThe reliability of five common portable blood lactate analysers were generally <0.5 mM for concentrations in the range of ~1.0-10 mM.For all five portable analysers, the analytical error within a brand was much smaller than the biological variation in blood lactate (BLa).Compared with a criterion blood lactate analyser, there was a tendency for all portable analysers to under-read (i.e. a negative bias), which was particularly evident at the highest concentrations (BLa ~15-23 mM).The practical application of these negative biases would overestimate the ability of the athlete and prescribe a training intensity that would be too high.

Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis.

OBJECTIVE: To characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure. METHODS: This meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The 'true' between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD. RESULTS: During-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the 'true' response of an athlete exposed to 300 h of altitude was estimated to be 1.1-6%. CONCLUSIONS: Camps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.

Pilot study of remote telemonitoring in COPD.

BACKGROUND: Remote in-home monitoring (RM) of symptoms and physiological variables may allow early detection and treatment of exacerbations of chronic obstructive pulmonary disease (COPD). It is unclear whether RM improves patient outcomes or healthcare resource utilization. This study determined whether RM is feasible in patients with COPD and if RM reduces hospital admissions or length of stay (LOS) or improves health-related quality of life (HRQOL). SUBJECTS AND METHODS: Forty-four patients were randomized to standard best practice care (SBP) (n=22) or SBP+RM (n=22). RM involved daily recording of physiological variables, symptoms, and medication usage. RESULTS: There were no differences (mean±SD, SBP versus SBP+RM) in age (68±8 versus 70±9 years), gender (male:female 10:12 in both groups), or previous computer familiarity (59% versus 50%) between groups. The SBP group had a lower forced expiratory volume in 1 s (0.66±0.24 versus 0.91±0.34 L, p<0.01) and more current smokers (six versus none, p<0.05). There were no differences in number of COPD-related admissions/year (1.5±1.8 versus 1.3±1.7, p=0.76), COPD-related LOS days/year (15.6±19.4 versus 11.4±19.6, p=0.66), total admissions/year (2.2±2.1 versus 2.0±2.3, p=0.86), total LOS days/year (22.1±29.9 versus 21.6±30.4, p=0.88), or HRQOL between the two groups. CONCLUSIONS: The addition of RM to SBP was feasible but did not reduce healthcare utilization or improve quality of life in this group of patients already receiving comprehensive respiratory care.

A randomised trial of domiciliary, ambulatory oxygen in patients with COPD and dyspnoea but without resting hypoxaemia.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) who are not severely hypoxaemic at rest may experience significant breathlessness on exertion, and ambulatory oxygen is often prescribed in this circumstance despite a lack of conclusive evidence for benefit. This study aimed to determine whether such patients benefit from domiciliary ambulatory oxygen and, if so, which factors may be associated with benefit. METHODS: This was a 12 week, parallel, double-blinded, randomised, placebo-controlled trial of cylinder air versus cylinder oxygen, provided at 6 l/min intranasally, for use during any activity provoking breathlessness. Patients underwent baseline measurements of arterial blood gases and lung function. Outcome measures assessed dyspnoea, health-related quality of life, mood disturbance, functional status and cylinder utilisation. Data were analysed on an intention-to-treat basis, p≤0.05. RESULTS: 143 subjects (44 female), mean±SD age 71.8±9.8 years, forced expiratory volume in 1 s (FEV(1))1.16±0.51 litres, Pao(2) 9.5±1.1 kPa (71.4±8.5 mm Hg) were randomised, including 50 patients with exertional desaturation to ≤88%. No significant differences in any outcome were found between groups receiving air or oxygen. Statistically significant but clinically small improvements in dyspnoea and depression were observed in the whole study group over the 12 weeks of the study. CONCLUSION: In breathless patients with COPD who do not have severe resting hypoxaemia, domiciliary ambulatory oxygen confers no benefits in terms of dyspnoea, quality of life or function. Exertional desaturation is not predictive of outcome. Intranasal gas (either air or oxygen) may provide a placebo benefit. CLINICAL TRIAL NUMBER: ACTRN12605000457640.

Current markers of the Athlete Blood Passport do not flag microdose EPO doping.

The Athlete Blood Passport is the most recent tool adopted by anti-doping authorities to detect athletes using performance-enhancing drugs such as recombinant human erythropoietin (rhEPO). This strategy relies on detecting abnormal variations in haematological variables caused by doping, against a background of biological and analytical variability. Ten subjects were given twice weekly intravenous injections of rhEPO for up to 12 weeks. Full blood counts were measured using a Sysmex XE-2100 automated haematology analyser, and total haemoglobin mass via a carbon monoxide rebreathing test. The sensitivity of the passport to flag abnormal deviations in blood values was evaluated using dedicated Athlete Blood Passport software. Our treatment regimen elicited a 10% increase in total haemoglobin mass equivalent to approximately two bags of reinfused blood. The passport software did not flag any subjects as being suspicious of doping whilst they were receiving rhEPO. We conclude that it is possible for athletes to use rhEPO without eliciting abnormal changes in the blood variables currently monitored by the Athlete Blood Passport.

Evaluation of blood parameters by linear discriminant models for the detection of testosterone administration.

The steroidal module of the Athlete Biological Passport (ABP) has been used since 2014 for the longitudinal monitoring of urinary testosterone and its metabolites to identify samples suspicious for the use of synthetic forms of Endogenous Anabolic Androgenic Steroids (EAAS). Multiple recent studies have suggested that monitoring of blood parameters may provide enhanced detectability of exogenous testosterone administration. Transdermal and intramuscular testosterone administration studies were carried out in 15 subjects, and the effect on blood steroidal levels, hematological parameters, and gonadotropins was evaluated. Serum testosterone and dihydrotestosterone levels increased while gonadotropin levels were suppressed after administration. A modest increase in reticulocytes was also observed. The blood parameters that were responsive to the administrations were combined into several linear discriminant models targeting both administration (on) and washout (off) phases. The models were effective in detecting the large dose intramuscular administration but were less successful in the detection of the lower dose transdermal application. The blood profiling models may provide complementary value but do not appear to be substantially more advantageous than longitudinal urinary profiling.

Low testosterone and anaemia in men with type 2 diabetes.

OBJECTIVE: Anaemia is frequently found in patients with diabetes, in whom it is associated with increased morbidity and mortality. Low testosterone levels are also common in men with type 2 diabetes. We hypothesized that low testosterone levels are also associated with anaemia in men with type 2 diabetes, over the effects of chronic kidney disease. DESIGN: Cross-sectional cohort study, performed in 2005 in a tertiary diabetes clinic. Patients 464 men with type 2 diabetes. MAIN OUTCOME MEASURE: Anaemia (haemoglobin (Hb) < 13.7 g/dl in men aged < 60, or < 13.2 g/dl in men aged 60 and older). RESULTS: About 24% of study participants had anaemia, which was associated with the presence and severity of chronic kidney disease, systemic inflammation, increased age, and reduced iron availability. In addition, testosterone levels were independently associated with reduced Hb levels, determining between 6 and 8% of the total variability in raw Hb levels in this population after adjusting for these other factors. Individuals with total testosterone level < 10 nmol/l (43% of the cohort) were more likely to have anaemia (adjusted odds ratio 1.7; 95% CI 1.1-2.8). Similarly, anaemia was twice as common in individuals with a calculated free testosterone of < 0.23 nmol/l (adjusted odds ratio 2.0, 95% CI 1.2-3.1). CONCLUSIONS: These findings suggest that testosterone deficiency may contribute to the increased frequency of anaemia in men with type 2 diabetes. However, the appropriate clinical response to testosterone deficiency in anaemic patients remains to be established by prospective clinical trials.

Low testosterone levels are common and associated with insulin resistance in men with diabetes.

CONTEXT: Low testosterone levels are common in men with type 2 diabetes and may be associated with insulin resistance. OBJECTIVE: We investigated prevalence of testosterone deficiency and the relationship between testosterone and insulin resistance in a large cohort of men with type 2 and type 1 diabetes. DESIGN: The study was a cross-sectional survey of 580 men with type 2 diabetes and 69 men with type 1 diabetes. A subgroup of 262 men with type 2 diabetes was then reassessed after a median of 6 months. RESULTS: Forty-three percent of men with type 2 diabetes had a reduced total testosterone, and 57% had a reduced calculated free testosterone. Only 7% of men with type 1 diabetes had low total testosterone. By contrast, 20.3% of men with type 1 diabetes had low calculated free testosterone, similar to that observed in type 2 diabetes (age-body mass index adjusted odds ratio = 1.4; 95% confidence interval = 0.7-2.9). Low testosterone levels were independently associated with insulin resistance in men with type 1 diabetes as well as type 2 diabetes. Serial measurements also revealed an inverse relationship between changes in testosterone levels and insulin resistance. CONCLUSIONS: Testosterone deficiency is common in men with diabetes, regardless of the type. Testosterone levels are partly influenced by insulin resistance, which may represent an important avenue for intervention, whereas the utility of testosterone replacement remains to be established in prospective trials.

Core Temperature Responses to Cold-Water Immersion Recovery: A Pooled-Data Analysis.

PURPOSE: To examine the effect of postexercise cold-water immersion (CWI) protocols, compared with control (CON), on the magnitude and time course of core temperature (Tc) responses. METHODS: Pooled-data analyses were used to examine the Tc responses of 157 subjects from previous postexercise CWI trials in the authors' laboratories. CWI protocols varied with different combinations of temperature, duration, immersion depth, and mode (continuous vs intermittent). Tc was examined as a double difference (ΔΔTc), calculated as the change in Tc in CWI condition minus the corresponding change in CON. The effect of CWI on ΔΔTc was assessed using separate linear mixed models across 2 time components (component 1, immersion; component 2, postintervention). RESULTS: Intermittent CWI resulted in a mean decrease in ΔΔTc that was 0.25°C (0.10°C) (estimate [SE]) greater than continuous CWI during the immersion component (P = .02). There was a significant effect of CWI temperature during the immersion component (P = .05), where reductions in water temperature of 1°C resulted in decreases in ΔΔTc of 0.03°C (0.01°C). Similarly, the effect of CWI duration was significant during the immersion component (P = .01), where every 1 min of immersion resulted in a decrease in ΔΔTc of 0.02°C (0.01°C). The peak difference in Tc between the CWI and CON interventions during the postimmersion component occurred at 60 min postintervention. CONCLUSIONS: Variations in CWI mode, duration, and temperature may have a significant effect on the extent of change in Tc. Careful consideration should be given to determine the optimal amount of core cooling before deciding which combination of protocol factors to prescribe.

Influence of nutrient intake after weigh-in on lightweight rowing performance.

PURPOSE: The aim of the present study was to compare the effectiveness of different nutritional recovery strategies between weigh-in and racing on 2000-m rowing ergometer performance among oarsmen undertaking short-term weight loss before competition. METHODS: Competitive rowers (N = 12) completed four ergometer trials, each separated by 48 h. No weight restrictions were imposed for the first trial (TR1). Thereafter, athletes were required to reduce their body mass by 5.2% in the 24 h before trial 2 (TR2), again reaching this body mass before the final two trials (TR3 and TR4). Athletes were provided with one of three nutritional recovery strategies in the 2 h between weigh-in and racing in a counterbalanced fashion according to a Latin square design: fluid (2.8 kJ.kg(-1), 0.0 g.kg(-1) carbohydrate, 0.6 mg.kg(-1) sodium, 28.5 mL.kg(-1) fluid; FLU), carbohydrate/sodium (45.3 kJ.kg(-1), 2.2 g.kg(-1) carbohydrate, 32.9 mg.kg(-1) sodium, 7.2 mL.kg(-1) fluid; CHO), and a combination of water and carbohydrate/sodium (44.8 kJ.kg(-1), 2.3 g.kg(-1) carbohydrate, 33 mg.kg(-1) sodium, 28.5 mL.kg(-1) fluid; COM). RESULTS: Performance was slower for CHO compared with both COM (mean difference, 4.13; 95% CI, 1.37-6.88 s; P = 0.003) and FLU (2.88; 95% CI, 0.13-5.63 s; P = 0.039). However, FLU was not significantly slower than COM (1.24; 95% CI, -1.41 to 3.90 s; P = 0.474). CONCLUSIONS: The present investigation has shown that although carbohydrate and sodium intake may be important in the recovery period between weigh-in and 2000-m rowing ergometer performance, fluid intake has a greater influence on performance among lightweight male rowers who undertake short-term weight loss to achieve specified body-mass limits.

Temporal changes in physiology and haematology in response to high- and micro-doses of recombinant human erythropoietin.

There is evidence to suggest athletes have adopted recombinant human erythropoietin (rHuEPO) dosing regimens that diminish the likelihood of being caught by direct detection techniques. However, the temporal response in physiology, performance, and Athlete Biological Passport (ABP) parameters to such regimens is not clearly understood. Participants were assigned to a high-dose only group (HIGH, n = 8, six rHuEPO doses of 250 IU/kg over two weeks), a combined high micro-dose group (COMB, n = 8, high-dose plus nine rHuEPO micro-doses over a further three weeks), or one of two placebo control groups who received saline in the same pattern as the HIGH (HIGH-PLACEBO, n = 4) or COMB (COMB-PLACEBO, n = 4) groups. Temporal changes in physiology and performance were tracked by graded exercise test (GXT) and haemoglobin mass assessment at baseline, after high dose, after micro-dose (COMB and COMB-PLACEBO only) and after a four-week washout. Venous blood samples were collected throughout the baseline, rHuEPO administration, and washout periods to determine the haematological and ABP response to each dosing regimen. Physiological adaptations induced by a two-week rHuEPO high-dose were maintained by rHuEPO micro-dosing for at least three weeks. However, all participants administered rHuEPO registered at least one suspicious ABP value during the administration or washout periods. These results indicate there is sufficient sensitivity in the ABP to detect use of high rHuEPO doping regimens in athletic populations and they provide important empirical examples for use by anti-doping experts. Copyright © 2017 John Wiley & Sons, Ltd.

A third generation approach to detect erythropoietin abuse in athletes.

BACKGROUND AND OBJECTIVES: Information derived from blood analyses can assist in the detection and/or deterrence of blood doping in sport. We investigated whether comparing an athlete's hematologic values against his or her own historical baseline rather than population-derived thresholds enhanced the ability to detect blood doping. DESIGN AND METHODS: We developed an approach whereby an athlete's true baseline value could be estimated with just one prior blood test. We also estimated a universal value for within-subject variability for key hematologic parameters using the highest value obtained among four separate cohorts of male athletes including 80 elite rowers, 124 endurance-trained or team-sport subjects, 288 professional football players and 630 athletes competing at national or international level. The (individual) baseline and (universal) variability were then incorporated so as to define expected thresholds for subsequent blood tests. The sensitivity of our approach was obtained by analyzing data from 49 recreational athletes administered either recombinant human erythropoietin (n=37) or placebo (n=12). RESULTS: We found that removing within-subject variability by comparing new results against an historical baseline heightened the capacity to detect blood doping. It was possible to delineate the longitudinal changes in either hemoglobin (Hb) or the OFF-hr model score (an algorithm using both Hb and percent reticulocytes) caused by recombinant human erythropoietin treatment from the natural biological fluctuations found in subjects treated with placebo. INTERPRETATION AND CONCLUSIONS: Our objective data supported the intuitive belief that longitudinal monitoring of athletes' blood profiles will help detect blood doping. This information could be used to instigate target-testing of suspicious athletes, or even warrant the exclusion from competition of athletes with aberrant variations in key hematologic values.

Impact of two different body mass management strategies on repeat rowing performance.

PURPOSE: The present study was conducted to examine the impact of acute weight loss on repeat 2000-m rowing ergometer performance during a simulated multiday regatta, and to compare two different body mass management strategies between races. METHODS: Competitive rowers (N = 16) were assigned to either a control (CON), partial recovery (REC(partial)), or complete recovery (REC(complete)) group. Volunteers completed four trials, each separated by 48 h. No weight restrictions were imposed for the first trial. Thereafter, athletes in REC(partial) and REC(complete) were required to reduce their body mass by 4% in the 24 h before trial 2, again reaching this body mass before the final two trials. No weight restrictions were imposed on CON. Aggressive nutritional recovery strategies were used in the 2 h following weigh-in for all athletes. These strategies were maintained for the 12-16 h following racing for REC(complete) with the aim of restoring at least three quarters of the original 4% body mass loss. Postrace recovery strategies were less aggressive in REC(partial); volunteers were encouraged to restore no more than half of their initial 4% body mass loss. RESULTS: Acute weight loss increased time to complete the first "at-weight" performance trial by a small margin (mean 3.0, 95% CI -0.3 to 6.3 s, P = 0.07) when compared with the CON response. This effect decreased when sustained for several days. Aggressive postrace recovery strategies tended to eliminate the effect of acute weight loss on subsequent performance. CONCLUSION: Acute weight loss resulted in a small performance compromise that was reduced or eliminated when repeated over several days. Athletes should be encouraged to maximize recovery in the 12-16 h following racing when attempting to optimize subsequent performance.

Body-mass management of Australian lightweight rowers prior to and during competition.

PURPOSE: Although the body-mass management strategies of athletes in high-participation weight-category sports such as wrestling have been thoroughly investigated, little is known about such practices among lightweight rowers. This study examined the body-mass management practices of lightweight rowers before competition and compared these with current guidelines of the International Federation of Rowing Association (FISA). Quantification of nutrient intake in the 1-2 h between weigh-in and racing was also sought. METHODS: Lightweight rowers (N = 100) competing in a national regatta completed a questionnaire that assessed body-mass management practices during the 4 wk before and throughout a regatta plus recovery strategies after weigh-in. Biochemical data were collected immediately after weigh-in to validate questionnaire responses. Responses were categorized according to gender and age category (Senior B or younger than 23 yr old, i.e., U23, Senior A or OPEN, i.e., open age limit) for competition. RESULTS: Most athletes (male U23 76.5%, OPEN 92.3%; female U23 84.0%, OPEN 94.1%) decreased their body mass in the weeks before the regatta at rates compliant with FISA guidelines. Gradual dieting, fluid restriction, and increased training load were the most popular methods of body-mass management. Although the importance of recovery after weigh-in was recognized by athletes, nutrient intake and especially sodium (male U23 5.3 +/- 4.9, OPEN 7.7 +/- 5.9; female U23 5.7 +/- 6.8, OPEN 10.2 +/- 5.4 mg x kg(-1)) and fluid intake (male U23 12.1 +/- 7.1, OPEN 13.5 +/- 8.1; female U23 9.4 +/- 7.4, OPEN 14.8 +/- 6.9 mL x kg(-1)) were below current sports nutrition recommendations. CONCLUSION: Few rowers were natural lightweights; the majority reduced their body mass in the weeks before a regatta. Nutritional recovery strategies implemented by lightweight rowers after weigh-in were not consistent with current guidelines.

Impact of acute weight loss and/or thermal stress on rowing ergometer performance.

PURPOSE: The impact of acute weight loss on rowing performance was assessed when generous nutrient intake was provided in 2 h of recovery after making weight. METHODS: Competitive rowers (N = 17) completed four ergometer trials, each separated by 48 h. Two trials were performed after a 4% body mass loss in the previous 24 h (WT) and two were performed after no weight restrictions, that is, unrestricted (UNR). In addition, two trials (1 x WT, 1 x UNR) were in a thermoneutral environment (NEUTRAL, mean 21.1 +/- SD 0.7 degrees C, 29.0 +/- 4.5% RH) and two were in the heat (HOT 32.4, +/- 0.4 degrees C, 60.4 +/- 2.7% RH). Trials were performed in a counterbalanced fashion according to a Latin square design. Aggressive nutritional recovery strategies (WT 2.3 g x kg(-1) carbohydrate, 34 mg x kg(-1) Na, 28.4 mL x kg(-1) fluid; UNR ad libitum) were employed in the 2 h after weigh-in. RESULTS: Both WT (mean 2.1, 95% CI 0.7-3.4 s; P = 0.003) and HOT (4.1, 2.7 - 5.4 s; P < 0.001) compromised 2000-m time-trial performance. Whereas WT resulted in hypohydration, the associated reduction in plasma volume explained only part of the performance compromise observed (0.2 s for every 1% decrement) Moreover, WT did not influence core temperature or indices of cardiovascular function. CONCLUSIONS: Acute weight loss compromised performance, despite generous nutrient intake in recovery, although the effect was small. Performance decrements were further exacerbated when exercise was performed in the heat.

Combining wheat bran with resistant starch has more beneficial effects on fecal indexes than does wheat bran alone.

BACKGROUND: Wheat bran (WB) increases fecal bulk and hastens colonic transit, whereas resistant starch (RS) has effects on colonic fermentation, including increasing concentrations of butyrate. OBJECTIVE: We hypothesized that a diet combining WB with RS would produce more favorable changes in fecal variables (eg, fecal bulk, rapid transit time, lower pH, and higher butyrate) than would WB alone. DESIGN: This was a randomized crossover block-design study for which 20 volunteers with a family history of colorectal cancer were recruited. The study included 3 diets: control, WB (12 g fiber/d), and WBRS (12 g WB fiber/d plus 22 g RS/d), each continued for 3 wk. In each diet, the major source of protein was lean red meat. During 5 consecutive days (days 15-19) of each dietary period, the subjects collected their total fecal output for analysis. RESULTS: The WB diet resulted in greater fecal output (by 23% and 21% for wet and dry weights, respectively) and a lesser transit time (-11 h) than did the control diet but did not have major effects on fermentation variables. Compared with the control diet, the WBRS diet resulted in greater fecal output (by 56%) and a shorter transit time (-10 h), lower fecal pH (-0.15 units), higher fecal concentration (by 14%) and daily excretion (by 101%) of acetate, higher fecal concentration (by 79%) and daily excretion (by 162%) of butyrate, a higher fecal ratio of butyrate to total short-chain fatty acids (by 45%), and lower concentrations of total phenols (-34%) and ammonia (-27%). CONCLUSIONS: Combining WB with RS had more benefits than did WB alone. This finding may have important implications for the dietary modulation of luminal contents, especially in the distal colon (the most common site of tumor formation).

Proof of homologous blood transfusion through quantification of blood group antigens.

BACKGROUND AND OBJECTIVES: Athletes may illegally enhance endurance performance by transfusing homologous red blood cells (RBCs) and thereby increasing the oxygen carrying capacity of their blood. Detecting this dangerous practice is difficult by currently used methods. The aim of this work was to develop tests capable of detecting a mixed red cell population by flow cytometry, utilizing the likelihood of differences in minor blood group antigens. DESIGN AND METHODS: Twelve antisera directed against blood group antigens, derived from donor plasma, were used in conjunction with a secondary antibody directly conjugated with fluorescein to label IgG-coated RBCs. Optimal concentrations of RBCs and antibodies were determined on panel cells used in blood banking for the identification of specific antibodies. Blood samples from 25 patients purportedly transfused with 1-3 units of RBCs were screened for evidence of transfusion, and the percentages of antigen-positive and antigen-negative red cells were automatically calculated by the software installed in the flow cytometer after setting gates around these populations on histograms of fluorescence. RESULTS: Mixed RBC populations were identified in 22 of 25 patients tested. The three patients with antigenically homogeneous populations of RBCs were subsequently found not to have received their scheduled transfusions. INTERPRETATION AND CONCLUSIONS: This technique can detect small (<5%) populations of cells that are antigenically distinct from an individual's own RBCs. These results show the potential for flow cytometry to identify illicit homologous blood transfusion in athletes, and suggest the risk of false positives may be low.

Longitudinal variation of hemoglobin and reticulocytes in elite rowers.

Longitudinal monitoring of athlete's hematologic parameters holds considerable promise as a strategy to detect and thereby deter illicit blood doping. This study documents temporal changes of hemoglobin concentration (Hb) and reticulocyte counts in elite rowers. The 'within subject' variation in rowers was comparable to that of athletes from other sports. Reticulocyte results were dependent on the type of instrument used.

Effect of pre-competition and altitude training on blood models used to detect erythropoietin abuse by athletes.

This study reports blood model scores used for detection of recombinant human erythropoietin (rHuEPO) abuse by athletes. Elite female rowers were monitored prior to their World Championships, including a period spent training at moderate altitude. In contrast to previous results, no substantial increase in model scores was found following altitude exposure.