he association of total and abdominal obesity with Health-Related Quality of Life in a sample of Greek healthy adults

Background: in the Greek population, the association between obesity and Health-Related Quality of Life (HRQoL) has not been examined so far. Thus, the purpose of the present study is to explore obesity-related predictors of HRQoL in a sample of Greek healthy adults. Methods: a cross-sectional design was used. The sample consisted of three hundred twenty seven healthy men (N=105) and women (N=222), between the ages of 30 and 50 years (mean age=39.57 ± 6.68) who lived in Athens. Body mass index (BMI), waist to hip ratio (WHR), and body fat (BF) were assessed. HRQoL was evaluated using the short-form 36 (SF-36) health survey, which consists of eight subscales and two health factors (physical and psychological health). Socio-demographic variables and health-related behaviours were assessed by questionnaires. Separate hierarchical regression analyses were conducted to examine the associations between BMI, WHR, BF and SF-36 health survey subscales and factors. Results: socio-demographic and health-related variables were moderately associated with the HRQoL subscales and factors. Furthermore, after controlling the socio-demographic variables and health-related behaviours, (a) BMI negatively predicted the physical functioning, physical role, bodily pain, and social functioning subscales, as well as the physical health factor and (b) WHR and BF negatively predicted the physical functioning subscale. However, the obesity indexes did not predict other psychological health subscales. Conclusions: the results indicated negative associations of BMI, WHR, BF with physical functioning and health in a sample of Greek healthy adults. Such data relating total and abdominal obesity to HRQoL, as assessed by BMI, WHR, and BF, have not been reported until now in the literature. One limitation of this study was that the sample size was relatively small and the results could not be generalized to the entire Greek population

Neuromuscular Blockade with Rocuronium Bromide Increases the Tolerance of Acute Normovolemic Anemia in Anesthetized Pigs

Background: The patient's individual anemia tolerance is pivotal when blood transfusions become necessary, but are not feasible for some reason. To date, the effects of neuromuscular blockade (NMB) on anemia tolerance have not been investigated. Methods: 14 anesthetized and mechanically ventilated pigs were randomly assigned to the Roc group (3.78 mg/kg rocuronium bromide followed by continuous infusion of 1 mg/kg/min, n = 7) or to the Sal group (administration of the corresponding volume of normal saline, n = 7). Subsequently, acute normovolemic anemia was induced by simultaneous exchange of whole blood for a 6% hydroxyethyl starch solution (130/0.4) until a sudden decrease of total body O-2 consumption (VO2) indicated a critical limitation of O-2 transport capacity. The Hb concentration quantified at this time point (Hb(crit)) was the primary end-point of the protocol. Secondary endpoints were parameters of hemodynamics, O-2 transport and tissue oxygenation. Results: Hb(crit) was significantly lower in the Roc group (2.4 +/- 0.5 vs. 3.2 +/- 0.7 g/dl) reflecting increased anemia tolerance. NMB with rocuronium bromide reduced skeletal muscular VO2 and total body O-2 extraction rate. As the cardiac index increased simultaneously, total body VO2 only decreased marginally in the Roc group (change of VO2 relative to baseline -1.7 +/- 0.8 vs. 3.2 +/- 1.9% in the Sal group, p < 0.05). Conclusion: Deep NMB with rocuronium bromide increases the tolerance of acute normovolemic anemia. The underlying mechanism most likely involves a reduction of skeletal muscular VO2. During acellular treatment of an acute blood loss, NMB might play an adjuvant role in situations where profound stages of normovolemic anemia have to be tolerated (e.g. bridging an unexpected blood loss until blood products become available for transfusion). Copyright (C) 2011 S. Karger AG, Base

Arterial hypoxemia and performance during intense exercise

A substantial decrease in percent arterial hemoglobin saturation (%SaC₂) has been observed in some highly aerobically trained athletes during intense exercise [≥ 90% of maximal oxygen uptake (V0₂[formula omitted]) or oxygen uptake (VO₂) ≥ 3.5 1‧minˉ¹] at sea level, and a reduction in %Sa0₂ has been associated with impaired performance. In order to explore the level of hypoxemia which is sufficient to impair maximal performance, 7 well-trained male cyclists (V0₂[formula omitted] ≥ 60 ml‧kgˉ¹‧minˉ¹ or V0₂[formula omitted] ≥ 5 1‧minˉ¹) who did not develop exercise-induced hypoxemia performed a 5-min performance cycle test to exhaustion at maximal intensity as controlled by the subject, under three experimental conditions: normoxemia (%SaO₂ > 94%), and artificially induced mild (%SaO₂ = 87±1%) and moderate (%SaO₂ = 90±1%) hypoxemia. %SaO₂ was continuously measured using an ear oximeter. In the two hypoxemic conditions, pure N₂ was added to the inspired air throughout the performance test according to the oximeter readings so as to achieve the desired hypoxemic level averaged over the 5-min period. Performance was evaluated as the total work output (Worktot) performed in the 5-min cycle test. Heart rate and ventilatory parameters were measured continuously during the test. ANOVA for repeated measures was used to compare differences in the results among the three experimental conditions. Performance progressively decreased with decreasing %SaO₂ (mean Worktot = 107.40 kJ, 104.07 kJ, and 102.52 kJ, under normoxemia, mild, and moderate hypoxemia, respectively), but only performance in the moderate hypoxemia condition was significantly different than normoxemia (p = 0.0216). Mean heart rate (HR) was similar in the three experimental conditions (p = 0.9536). Similarly, mean VO₂ was not significantly different among conditions (p = 0.1751). However, end-tidal partial pressure of CO₂ (PETCO₂) was significantly lower (p = 0.0053) during moderate hypoxemia compared with normoxemia, and VE/VCO₂ was significantly higher (p = 0.0052) in both hypoxemic conditions when compared with normoxemia, indicating hyperventilation possibly compensating for increasing metabolic acidosis during hypoxemia. It is concluded that maximal performance capacity is significantly impaired in highly trained cyclists working under an arterial oxyhemoglobin saturation level of 87% but not under a milder desaturation level of 90%. Since VO₂ was not different among the experimental conditions, the reduction in maximal performance capacity is possibly related to a worsening of the metabolic acidosis elicited by hypoxemia.Education, Faculty ofCurriculum and Pedagogy (EDCP), Department ofGraduat

Oxygen saturation in the triceps brachii muscle during an arm wingate test: The role of training and power output

The purpose of this study was to investigate the role of training and power output on muscle oxygen desaturation during and resaturation after an arm Wingate test (WAnT). Two groups of subjects were studied; the first group consisted of nine athletes participating in upper arm anaerobic sports and the second group of 11 university students. As a consequence, the group of athletes (HP) produced higher peak and mean power output (p &lt; 0.01) than the group of university students (LP). Muscle oxygenation status was evaluated by using near infrared spectroscopy at the triceps brachii. The HP group exhibited 17.6 ± 8.0% less muscle oxygen desaturation than the LP group (p &lt; 0.05) but similar muscle total hemoglobin during exercise and faster (p &lt; 0.05) muscle oxygen resaturation during recovery ( τ= 12.4 ± 5.2 sec in HP vs. τ= 24.2 ± 11.0 sec in LP). These results indicate that the HP group exhibits less muscle desaturation during an arm WAnT and has a faster resaturation rate, probably attributed to differences in muscle mass, muscle fiber recruitment capability, and ATP production through anaerobic pathways

Arterial O2 content and tension in regulation of cardiac output and leg blood flow during exercise in humans

A universal O2 sensor presumes that compensation for impaired O2 delivery is triggered by low O2 tension, but in humans, comparisons of compensatory responses to altered arterial O2 content (Ca(O2)) or tension (Pa(O2)) have not been reported. To directly compare cardiac output (Q(TOT)) and leg blood flow (LBF) responses to a range of Ca(O2) and Pa(O2), seven healthy young men were studied during two-legged knee extension exercise with control hemoglobin concentration ([Hb] = 144.4 ± 4 g/l) and at least 1 wk later after isovolemic hemodilution ([Hb] = 115 ± 2 g/l). On each study day, subjects exercised twice at 30 W and on to voluntary exhaustion with an FI(O2) of 0.21 or 0.11. The interventions resulted in two conditions with matched Ca(O2) but markedly different Pa(O2) (hypoxia and anemia) and two conditions with matched Pa(O2) and different Ca(O2) (hypoxia and anemia + hypoxia). Pa(O2) varied from 46 ± 3 Torr in hypoxia to 95 ± 3 Torr (range 37 to &amp;gt;100) in anemia (P &amp;lt; 0.001), yet LBF at exercise was nearly identical. However, as Ca(O2) dropped from 190 ± 5 ml/l in control to 132 ± 2 ml/l in anemia + hypoxia (P &amp;lt; 0.001), Q(TOT) and LBF at 30 W rose to 12.8 ± 0.8 and 7.2 ± 0.3 1/min, respectively, values 23 and 47% above control (P &amp;lt; 0.01). Thus regulation of Q(TOT), LBF, and arterial O2 delivery to contracting intact human skeletal muscle is dependent for signaling primarily on Ca(O2), not Pa(O2). This finding suggests that factors related to Ca(O2) or [Hb] may play an important role in the regulation of blood flow during exercise in humans

Importance of hemoglobin concentration to exercise: Acute manipulations

An acute reduction of blood hemoglobin concentration ([Hb]), even when the circulating blood volume is maintained, results in lower over (V̇O2max and endurance performance, due to the reduction of the oxygen carrying capacity of blood. Conversely, an increase of [Hb] is associated with enhanced over(V, ̇)O2max and endurance capacity, that is also proportional to the increase in the oxygen carrying capacity of blood. The effects on endurance capacity appear more pronounced and prolonged than on over(V̇O2max. During submaximal exercise, there is a tight coupling between O2 demand and O2 delivery, such that if [Hb] is acutely decreased muscle blood flow is increased proportionally and vice versa. During maximal exercise with either a small or a large muscle mass, neither peak cardiac output nor peak leg blood flow are affected by reduced [Hb]. An acute increase of [Hb] has no effect on maximal exercise capacity or over(V̇O2max during exercise in acute hypoxia. Likewise, reducing [Hb] in altitude-acclimatized humans to pre-acclimatization values has no effect on over(V̇O2max peak during exercise in hypoxia. © 2006 Elsevier B.V. All rights reserved

The association of total and abdominal obesity with health-related quality of life in a sample of Greek healthy adults

Background: in the Greek population, the association between obesity and Health-Related Quality of Life (HRQoL) has not been examined so far. Thus, the purpose of the present study is to explore obesity-related predictors of HRQoL in a sample of Greek healthy adults. Methods: a cross-sectional design was used. The sample consisted of three hundred twenty seven healthy men (N=105) and women (N=222), between the ages of 30 and 50 years (mean age=39.57 ± 6.68) who lived in Athens. Body mass index (BMI), waist to hip ratio (WHR), and body fat (BF) were assessed. HRQoL was evaluated using the short-form 36 (SF-36) health survey, which consists of eight subscales and two health factors (physical and psychological health). Socio-demographic variables and health-related behaviours were assessed by questionnaires. Separate hierarchical regression analyses were conducted to examine the associations between BMI, WHR, BF and SF-36 health survey subscales and factors. Results: socio-demographic and health-related variables were moderately associated with the HRQoL subscales and factors. Furthermore, after controlling the socio-demographic variables and health-related behaviours, (a) BMI negatively predicted the physical functioning, physical role, bodily pain, and social functioning subscales, as well as the physical health factor and (b) WHR and BF negatively predicted the physical functioning subscale. However, the obesity indexes did not predict other psychological health subscales. ConclusionS: the results indicated negative associations of BMI, WHR, BF with physical functioning and health in a sample of Greek healthy adults. Such data relating total and abdominal obesity to HRQoL, as assessed by BMI, WHR, and BF, have not been reported until now in the literature. One limitation of this study was that the sample size was relatively small and the results could not be generalized to the entire Greek population

Effect of gender on maximal breath-hold time

This study examined the effect of gender on breath-hold time (BHT). Sixteen healthy subjects, eight males (M) and eight females (F), aged 18-30 years, without breath-hold (BH) experience, performed: (a) a pulmonary function test, (b) an incremental cycle ergometer test to exhaustion and (c) a BH protocol, which included eight repeated maximal efforts separated by 2-min intervals on two occasions: without (BHFOI) and with face immersion (BH FI) in cool water (14.8 ± 0.07 C). Cardiovascular, ventilatory and hematological responses were studied before, during and after BH efforts. Maximal BHT was similar between genders (M: 103.90 ± 25.68 s; F: 104.97 ± 32.71 s, p &amp;gt; 0.05) and unaffected by face immersion (BH FOI: 105.13 ± 28.68 s; BHFI: 103.74 ± 31.19 s, p &amp;gt; 0.05). The aerobic capacity, lung volumes and hematological indexes were higher in males compared to females. BHT was predicted (r 2 = 0.98, p = 0.005) by aerobic capacity, total lung volume, hematocrit and hemoglobin concentration only in males. It was concluded that despite gender differences in physiological and anthropometrical traits, BH ability was not different between males and females, both not experienced in apneas. © 2012 Springer-Verlag Berlin Heidelberg

Anaerobic capacity of the upper arms in top-level team handball players

Purpose: Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate test (WT) performed with the legs, but there are no data available concerning power production during a WT performed with the arms in handball players (HndP). Therefore, the purpose of this study was to explore the arm anaerobic profile of HndP during a WT. Methods: Twenty-one elite HndP and 9 physical education students (CON), performed a 30-s arm. WT. Power production and muscle oxygenation were recorded. Results: Peak power (PP) as well as mean power (MP) was higher (P = .0.17 and 0.03, and ES = 1.00 and 0.86, respectively) for HndP (HndP PP: 7.6 ± 0.8 W·k·kg -1, CON PP: 6.7 ± 1.1 W·kg-1; HndP MP 5.3 ± 0.6 W·kg-1. CON MP 4.7 ± 0.9 W·kg -1) with no significant difference in fatigue index between the two groups. Muscle oxygen saturation (StO2) declined ∼30% with exercise with no differences between groups. During recovery the HndP group had higher StO2 (P = .01, ES= 3.04), total, hemoglobin and oxygenated, hemoglobin compared, with the CON group (P &amp;lt; .0.1 ES = 3.29 and 0.99, respectively). StO2 returned to resting values in 29.5 ± 2.3 s in HndP, whereas this variable did not recover after 2 min in CON. Conclusions: The arm anaerobic capacity of the HndP was &quot;excellent,&quot; significantly higher than, that by the control group. Moreover, HndP exhibited faster recovery of StO2 compared with the control group. The greater power output and the fester muscle reoxygenation of arms in HndP can be attributed to specific training adaptations related to high, performance in handball. © 2008 Human Kinetics, Inc