Cell integrity indicators assessed by bioelectrical impedance: A systematic review of studies involving athletes.

INTRODUCTION: Bioelectrical impedance analysis (BIA) has been used to evaluate cellular health and integrity through bioelectrical indicators. In the sporting context, monitoring these indicators can be useful to assess the quality and vitality of cells and body tissues. OBJECTIVE: The aim of this systematic review was to investigate indicators of cellular health and integrity evaluated by BIA in athletes. METHODS: Searches were performed in December 2017 in the Lilacs, Medline, PubMed, Science Direct, Scielo, Scopus, SPORTDiscus, and Web of Science databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: The searches retrieved 31 articles (30 involving professional athletes and one involving university athletes). In longitudinal studies (n = 15), the bioelectrical parameters directly associated with cellular health and integrity were extracellular water (ECW), phase angle (PA), BIA vector analysis (BIVA), crude reactance data (Xc), resistance (R), and ECW/BCM ratio. Regarding the findings of cross-sectional studies (n = 16), the investigated parameters (ECW, PA, BIVA, Z, BCM, and ECW/BCM) were directly associated with gender, age, sports performance level, modality, and game position. CONCLUSIONS: In the included studies, the cellular health and integrity indicators were: Z, Xc, R, total water, intracellular water, ECW, PA, BIVA, BCM, and ECW/BCM.

Usefulness of raw bioelectrical impedance parameters in tracking fluid shifts in judo athletes.

Bioelectrical impedance (BI) has been widely used but clarification about the behaviour of raw BI measurements under specific athletic conditions is required. Thus, we determined the usefulness of raw BI measures in tracking body fluids changes during the preparation period prior to competition in elite Judo athletes. At baseline (weight stability), 27 male athletes were evaluated (23.2 ± 2.8y) and again 1-3 days before competition (∼1-2 months apart). Athletes were free to gain/lost weight based upon specific competition needs. Using dilution techniques (deuterium and bromide), total-body water (TBW) and extracellular water were estimated, and intracellular water calculated as TBW minus extracellular water. Body fluid distribution was determined as Extra-to-/Intracellular water (E/I). Fat and fat-free mass (FFM) was assessed by dual-energy x-ray absorptiometry. Resistance, reactance, and phase angle (PhA) were obtained from bioelectrical impedance spectroscopy (50-kHz frequency). No differences in raw BI measures were observed between athletes that lost (N = 17) or gain weight (N = 10), except for fat, FFM, extracellular water, and EI (p < 0.05). After adjusting for FFM and height, resistance explained TBW (ß = -0.047, p = 0.002) and extracelular water (ß = -0.025, p = 0.001). Reactance explained ECW (ß = -0.098, p = 0.004) and EI (ß = -0.004, p = 0.006), while PhA predicted TBW (ß = 1.609, p = 0.047), ICW (ß = 1.899, p = 0.001) and EI (ß = -0.056, p = 0.001). Regardless of body composition changes, athletes who increase reactance and resistance reduced extracellular water and body fluids while those who raised PhA increased intracellular water. Judo athletes who reduced weight, decreased FFM but cellular health was not compromised, as PhA remained stable and, consequently, cell hydration.

Acute-Weight-Loss Strategies for Combat Sports and Applications to Olympic Success.

It is common for athletes in weight-category sports to try to gain a theoretical advantage by competing in weight divisions that are lower than their day-to-day body mass (BM). Weight loss is achieved not only through chronic strategies (body-fat losses) but also through acute manipulations before weigh-in ("making weight"). Both have performance implications. This review focuses on Olympic combat sports, noting that the varied nature of regulations surrounding the weigh-in procedures, weight requirements, and recovery opportunities in these sports provide opportunity for a wider discussion of factors that can be applied to other weight-category sports. The authors summarize previous literature that has examined the performance effects of weightmaking practices before investigating the physiological nature of these BM losses. Practical recommendations in the form of a decision tree are provided to guide the achievement of acute BM loss while minimizing performance decrements.

A Temperature-Based Bioimpedance Correction for Water Loss Estimation During Sports.

The amount of total body water (TBW) can be estimated based on bioimpedance measurements of the human body. In sports, TBW estimations are of importance because mild water losses can impair muscular strength and aerobic endurance. Severe water losses can even be life threatening. TBW estimations based on bioimpedance, however, fail during sports because the increased body temperature corrupts bioimpedance measurements. Therefore, this paper proposes a machine learning method that eliminates the effects of increased temperature on bioimpedance and, consequently, reveals the changes in bioimpedance that are due to TBW loss. This is facilitated by utilizing changes in skin and core temperature. The method was evaluated in a study in which bioimpedance, temperature, and TBW loss were recorded every 15 min during a 2-h running workout. The evaluation demonstrated that the proposed method is able to reduce the error of TBW loss estimation by up to 71%, compared to the state of art. In the future, the proposed method in combination with portable bioimpedance devices might facilitate the development of wearable systems for continuous and noninvasive TBW loss monitoring during sports.

Quantification of chromatographic effects of vitamin B supplementation in urine and implications for hydration assessment.

Changes in body water elicit reflex adjustments at the kidney, thus maintaining fluid volume homeostasis. These renal adjustments change the concentration and color of urine, variables that can, in turn, be used as biomarkers of hydration status. It has been suggested that vitamin supplementation alters urine color; it is unclear whether any such alteration would confound hydration assessment via colorimetric evaluation. We tested the hypothesis that overnight vitamin B2 and/or B12 supplementation alters urine color as a marker of hydration status. Thirty healthy volunteers were monitored during a 3-day euhydrated baseline, confirmed via first morning nude body mass, urine specific gravity, and urine osmolality. Volunteers then randomly received B2 (n = 10), B12 (n = 10), or B2 + B12 (n = 10) at ∼200 × recommended dietary allowance. Euhydration was verified on trial days (two of the following: body mass ± 1.0% of the mean of visits 1-3, urine specific gravity < 1.02, urine osmolality < 700 mmol/kg). Vitamin purity and urinary B2 concentration ([B2]) and [B12] were quantified via ultraperformance liquid chromatography. Two independent observers assessed urine color using an eight-point standardized color chart. Following supplementation, urinary [B2] was elevated; however, urine color was not different between nonsupplemented and supplemented trials. For example, in the B2 trial, urinary [B2] increased from 8.6 × 10(4) ± 7.7 × 10(4) to 5.7 × 10(6) ± 5.3 × 10(6) nmol/l (P < 0.05), and urine color went from 4 ± 1 to 5 ± 1 (P > 0.05). Both conditions met the euhydrated color classification. We conclude that a large overnight dose of vitamins B2 and B12 does not confound assessment of euhydrated status via urine color.

Water, sodium, potassium and chloride.

The sudden disruption of excessive placental supply with fluids and electrolytes is challenging for neonatal physiology during the period of postnatal adaptation. Different from many other nutrients, the body experiences large changes in daily requirements during the first 7-14 postnatal days, and on the other hand does not tolerate conditions of excess and deficiency very well. Imbalances of fluid and electrolytes are common in neonates, which--in addition--might be further aggravated by NICU treatment procedures. Therefore, fluid and electrolyte management can be one of the most challenging aspects of neonatal care of the premature infant. An understanding of the physiological adaptation process to extrauterine life--and how immaturity effects that transition--is the basis which is needed to understand and manage fluid and electrolyte balance in premature infants. This chapter addresses the physiology of postnatal adaptation and other aspects of fluid and electrolyte management (concerning potassium, sodium and chloride) of the preterm infant.

Association between lifestyle and physical activity level in the elderly: a study using doubly labeled water and simplified physical activity record.

PURPOSE: Physical activity level (PAL) is associated with all-cause mortality in the elderly. However, few studies have attempted to clarify the relationship between lifestyle and PAL in the elderly. This study aimed to examine the determinants of PAL in the elderly in terms of behavioral patterns and exercise intensity, and to validate the simplified physical activity record (sPAR). METHODS: Thirty healthy, elderly individuals, aged 64-87 years, participated in the study. Total energy expenditure (TEEDLW), physical activity energy expenditure (PAEEDLW), and PAL (PALDLW) were calculated based on doubly labeled water (DLW) and measured basal metabolic rate. Physical activity was recorded using the sPAR. RESULTS: PALDLW was significantly correlated with PAL estimated by sPAR (r = 0.588, P < 0.001). Good agreement was observed between TEEDLW (1,860 ± 373 kcal/day) and TEE estimated by sPAR (1,854 ± 377 kcal/day) (r = 0.825, P < 0.001). Good agreement was also observed between PAEEDLW (552 ± 242 kcal/day) and PAEE estimated by sPAR (562 ± 240 kcal/day) (r = 0.666, P < 0.001). The high PALDLW group had significantly shorter durations of 'sleeping time and rest periods' and 'daily life sedentary activities', and significantly longer durations of 'bicycling with moderate speed', 'housekeeping with standing', 'gymnastics, tai chi, stretching' and "swimming, hill climbing, fast jogging" than the low PAL group (P < 0.05). CONCLUSIONS: The sPAR provides valid estimates of TEE and PAEE in the healthy elderly. The results suggest that engaging in housekeeping or sports activities for longer and being less sedentary may increase PALDLW in healthy elderly individuals.

Proanthocyanidin-rich grape seed extract reduces leg swelling in healthy women during prolonged sitting.

BACKGROUND: Leg swelling is a modern-day affliction of sedentary working women. The aim of this study was to evaluate the effectiveness of the intake of grape seed extract (GSE) on leg swelling in healthy Japanese women while sitting. RESULTS: Single intake trials and 14 day intake trials were held in a double-blind, placebo-controlled, crossover clinical study. A prolonged sedentary position was maintained for 6 h after GSE or placebo administration. Leg volume distension, increase in body extracellular fluid, and leg water were significantly suppressed in the GSE groups. CONCLUSION: The intake of GSE is a contributing factor in the inhibition of leg swelling in healthy women during prolonged sitting.

Change in total body water as a predictive tool for growth hormone treatment response.

BACKGROUND/AIMS: To investigate whether short-term changes in body composition as a result of growth hormone therapy could be used to predict its growth effect after 1 year in children with growth hormone deficiency (GHD) and children born small for gestational age (SGA). METHODS: 88 GHD children and 99 SGA children who started treatment with recombinant human growth hormone were included. Total body water (TBW) and height were measured. After 1 year, patients were divided into adequate and inadequate responders. RESULTS: In GHD and SGA children a sensitivity of 87 and 53%, respectively, and a specificity of 58 and 83%, respectively, were found. The positive predictive values for GHD and SGA children were 73 and 90%, respectively. The negative predictive values were 75 and 32%, respectively. CONCLUSION: Changes in body composition data measured by TBW are a valuable tool to correctly predict 75% of the GHD children and are only useful in SGA children when the change in TBW is above the cut-off value of 0.7 l/m(2).

Hyaluronic acid plus mannitol treatment for improved skin hydration and elasticity.

BACKGROUND: Mesotherapy treatment of aging skin aims to replace depleting levels of minerals, vitamins, amino acids, and hyaluronic acid (HA). AIM: To investigate the efficacy of 13.5 mg/g uncross-linked HA+0.9% mannitol (HA+mannitol) on skin hydration and elasticity. PATIENTS/METHODS: Four centers enrolled 34 women: Subgroup 1 comprised 27 subjects injected using a "depot" technique; Subgroup 2 comprised seven subjects injected using a "picotage" technique. RESULTS: A notable difference was seen between the two subgroups in outcome and subject satisfaction. In Subgroup 1, a significant improvement was seen in hydration, anisotropy, and skin roughness, but Subgroup 2 showed no significant improvements. Most physicians assessed HA+mannitol as "easy/very easy" to inject. Physician esthetic assessment in Subgroup 1 was "improved/very improved" for >90% of subjects at Day 60, and >80% according to subject assessment. 95% of subjects were delighted with treatment, and 85% would undergo repeat treatment and would recommend treatment to a friend. However, results for Subgroup 2 indicated 86% of subjects were unhappy with treatment and 83% would refuse to undergo repeat treatment. CONCLUSIONS: HA+mannitol is effective for skin hydration, anisotropy, and roughness when treated using a depot technique.

Maternal nutritional status in early pregnancy is associated with body water and plasma volume changes in a pregnancy cohort in rural Bangladesh.

Plasma volume expansion has been associated with fetal growth. Our objective was to examine the associations between maternal nutritional status in early pregnancy and extracellular water (ECW), total body water (TBW), and percentage plasma volume change across pregnancy. In a subsample of 377 pregnant women participating in a cluster-randomized trial of micronutrient supplementation, hemoglobin, hematocrit, and multi-frequency bioelectrical impedance were measured at ~10, 20, and 32 wk of gestation. In early pregnancy, women were short (mean ± SD, 148.9 ± 5.3 cm) and thin (19.5 ± 2.5 kg/m(2)). In mixed-effects multiple regression models, a 1-unit higher BMI at ~10 wk was associated with higher ECW and TBW (0.27 and 0.66 kg per kg/m(2), respectively; P < 0.01) at ~10, ~20, and ~32 wk. Height was also positively associated with ECW and TBW at each time point. Early pregnancy BMI was negatively associated with gains in ECW and TBW (-0.06 and -0.14 kg per kg/m(2), respectively; P < 0.01) from 10 to 20 wk, but not with 20- to 32-wk gains after accounting for weight gain. BMI was positively associated with percentage changes in plasma volume from 20 to 32 wk (0.57% per kg/m(2); P < 0.05). Height was not associated with changes in body water or plasma volume. Women with low BMI and height in early pregnancy have lower ECW and TBW in early, mid, and late pregnancy and lower late pregnancy plasma volume expansion, potentially increasing risk of fetal growth restriction.

Effects of supplemental recombinant bovine somatotropin and mist-fan cooling on the renal tubular handling of sodium in different stages of lactation in crossbred Holstein cattle.

The effect of supplementary administration of recombinant bovine somatotrophin (rbST) on the renal tubular handling of sodium in crossbred 87.5% Holstein cattle housed in normal shade (NS) or mist-fan cooled (MF) barns was evaluated. The cows were injected with 500 mg rbST at three different stages of lactation. The MF barn housed cows showed a slightly decreased ambient temperature and temperature humidity index, but an increased relative humidity. Rectal temperature and respiration rates were significantly lower in cooled cows. The rbST treated cows, housed in NS or MF barns, showed markedly increased milk yields, total body water, extracellular fluid and plasma volume levels, along with a reduced rate of urine flow and urinary excretion of sodium, potassium and chloride ions and osmolar clearance, in all three stages of lactation. Renal tubular sodium and water reabsorption were increased after rbST administration without any alteration in the renal hemodynamics. Lithium clearance data suggested that the site of response is in the proximal nephron segment, which may be mediated via increases in the plasma levels of aldosterone and IGF-1, but not vasopressin, during rbST administration.

Relationship between changes in total-body water and fluid distribution with maximal forearm strength in elite judo athletes.

Among judo athletes, strong grip strength is crucial for performing offensive and defensive maneuvers that rely predominantly on forearm maximal strength (FMS). The study aims were to evaluate changes in total-body water (TBW) and its compartments (extracellular water [ECW] and intracellular water [ICW]) and their relationship with loss of FMS in elite judo athletes. At baseline (weight stability), 27 male elite athletes were evaluated (age: 23.2 ± 2.8 years) and again evaluated 1-3 days before competition. Athletes were free to gain or lose weight based upon their specific competition needs. Using dilution techniques (deuterium and bromide), TBW and ECW were estimated, and ICW was calculated (ICW = TBW - ECW). Fat, fat-free mass, and appendicular lean soft tissue (LST) were assessed by dual-energy x-ray absorptiometry. Handgrip was used to assess FMS. Using a reduction of 2% as a representative outcome for decreased FMS, 10 athletes were identified as having lost FMS, whereas 17 changed <2% or gained. Comparison of means and logistic regression analysis were performed. Results from baseline to before competition indicated that those who lost ≥2% of FMS significantly decreased TBW and ICW by -2.7 ± 3.0 and -4.4 ± 4.2%, respectively. The groups differed in ICW changes (-4.4 ± 4.2 vs. 1.9 ± 6.1%), respectively, for those who lost FMS by ≥2%. The ICW changes, but not in TBW or ECW, significantly predicted the risk of losing FMS (ß = 0.206; p = 0.027), even adjusting for weight and arm LST changes. These findings indicated that reductions in ICW increased the risk of losing grip strength in elite judo athletes.

Sphenopalatine ganglion stimulation for vasospasm after experimental subarachnoid hemorrhage.

OBJECT: Sphenopalatine ganglion stimulation activates perivascular vasodilatory nerves in the ipsilateral anterior circle of Willis. This experiment tested whether stimulation of the ganglion could reverse vasospasm and improve cerebral perfusion after subarachnoid hemorrhage (SAH) in monkeys. METHODS: Thirteen cynomolgus monkeys underwent baseline angiography followed by creation of SAH by placement of autologous blood against the right intradural internal carotid artery, the middle cerebral artery (MCA), and the anterior cerebral artery. Seven days later, angiography was repeated, and the right sphenopalatine ganglion was exposed microsurgically. Angiography was repeated 15 minutes after exposure of the ganglion. The ganglion was stimulated electrically 3 times, and angiography was repeated during and 15 and 30 minutes after stimulation. Cerebral blood flow (CBF) was monitored using laser Doppler flowmetry, and intracranial pressure (ICP) was measured throughout. The protocol was repeated again. Evans blue was injected and the animals were killed. The brains were removed for analysis of water and Evans blue content and histology. RESULTS: Subarachnoid hemorrhage was associated with significant vasospasm of the ipsilateral major cerebral arteries (23% ± 10% to 39% ± 4%; p < 0.05, paired t-tests). Exposure of the ganglion and sham stimulation had no significant effects on arterial diameters, ICP, or CBF (4 monkeys, ANOVA and paired t-tests). Sphenopalatine ganglion stimulation dilated the ipsilateral extracranial and intracranial internal carotid artery, MCA, and anterior cerebral artery compared with the contralateral arteries (9 monkeys, 7% ± 9% to 15% ± 19%; p < 0.05, ANOVA). There was a significant increase in ipsilateral CBF. Stimulation had no effect on ICP or brain histology. Brain water content did not increase but Evans blue content was significantly elevated in the MCA territory of the stimulated hemisphere. CONCLUSIONS: Sphenopalatine ganglion stimulation decreased vasospasm and increased CBF after SAH in monkeys. This was associated with opening of the blood-brain barrier.

Influence of performance level on anaerobic power and body composition in elite male judoists.

This study examined the relationship between 30-second anaerobic power and body composition by performance level in elite Judoists. During a 3-month period, 10 male Korean Judo national team athletes (NT), 26 male university varsity team athletes (VT), and 28 male junior varsity team athletes (JT) were assessed for 30-second anaerobic power and body composition at the Youngin University. Anaerobic power was measured using a 30-second Wingate test. Body composition was assessed via bioelectric impedance analysis in standardized conditions using BioSpace (Korean)-specific prediction formulas. All testing occurred at the beginning of the winter nonseason period but excluded a brief weight-loss period before the competition phase. Anaerobic power measures were significantly greater (p < 0.05) in NT and VT than in JT. Fat-free mass (FFM), muscle mass (MM), and total body water in JT were also greater than in VT and JT (p < 0.05). Muscle mass in VT was significantly lower than in NT (p < 0.05). Fat-free mass in NT was strongly correlated to mean and peak anaerobic power (r = 0.77, p = 0.009; r = 0.87, p < 0.001, respectively). Varsity team athletes also indicated a moderate association between FFM and peak and mean anaerobic power (r = 0.63, p < 0.001; r = 0.48, p = 0.013, respectively). However, relationship between FFM and anaerobic power was not statistically significantly correlated in JT (r = 0.14, p = 0.470; r = 0.23, p = 0.232, separately). In conclusion, our data indicated that anaerobic power is closely correlated with increase in FFM and MM and was different dependent among performance levels. Further research in the field is warranted to elucidate the Judo-specific relationship between FFM and performance.

Magnesium and strength in elite judo athletes according to intracellular water changes.

Magnesium (Mg) deficiency strongly affects muscle performance. In judo, many athletes often undergo impressive weight changes associated with severe dehydration. Common practices used by athletes to achieve a target weight can lead to Mg deficit. This study aimed to understand the impact of Mg changes on strength from periods of weight stability to prior to competition in a sample of elite judo athletes who differentially changed their intracellular water (ICW). The sample consisted of 20 elite male judo athletes. Subjects were divided according to ICW changes: losses below 2% and losses equal to or above 2%. Mg was measured in serum, red blood cells and urine by atomic absorption spectrophotometry. ICW was calculated as the difference between total-body water and extracellular water using dilution techniques. Maximal handgrip strength was evaluated using Jamar Hydraulic Hand Dynamometer. Upper-body power was determined in a bench press. Higher ICW decreases were associated with higher strength reductions, though our results suggest that an increase in red blood cell Mg might attenuate those strength reductions in athletes who decrease the ICW compartment. As Mg losses can be considerable and intake is frequently insufficient, athletes should consider supplementation, especially during periods of weight reduction.

Neuro magnetic resonance spectroscopy using wavelet decomposition and statistical testing identifies biochemical changes in people with spinal cord injury and pain.

Spinal cord injury (SCI) can be accompanied by chronic pain, the mechanisms for which are poorly understood. Here we report that magnetic resonance spectroscopy measurements from the brain, collected at 3T, and processed using wavelet-based feature extraction and classification algorithms, can identify biochemical changes that distinguish control subjects from subjects with SCI as well as subdividing the SCI group into those with and without chronic pain. The results from control subjects (n=10) were compared to those with SCI (n=10). The SCI cohort was made up of subjects with chronic neuropathic pain (n=5) and those without chronic pain (n=5). The wavelet-based decomposition of frequency domain MRS signals employs statistical significance testing to identify features best suited to discriminate different classes. Moreover, the features benefit from careful attention to the post-processing of the spectroscopy data prior to the comparison of the three cohorts. The spectroscopy data, from the thalamus, best distinguished control subjects without SCI from those with SCI with a sensitivity and specificity of 0.9 (Percentage of Correct Classification). The spectroscopy data obtained from the prefrontal cortex and anterior cingulate cortex both distinguished between SCI subjects with chronic neuropathic pain and those without pain with a sensitivity and specificity of 1.0. In this study, where two underlying mechanisms co-exist (i.e. SCI and pain), the thalamic changes appear to be linked more strongly to SCI, while the anterior cingulate cortex and prefrontal cortex changes appear to be specifically linked to the presence of pain.

Body composition and power changes in elite judo athletes.

The purpose of this study was to analyse the association between body composition changes, from a weight stable period to prior competition, on upper-body power in judo athletes. 27 top-level male athletes were evaluated at baseline (weight stable period) and 1-3 days before competition, with a time difference of approximately 1 month. Total body and extracellular water were estimated by dilution techniques (deuterium and bromide, respectively) and intracellular water was calculated as the difference. Body composition was assessed by DXA. A power-load spectrum was used to assess upper-body power output in a bench-press position. Comparison of means, bivariate, and partial correlations were used. Results indicate that though no significant mean changes were found in body composition and upper-body power, individual variability was large. Among all body composition changes, only total-body water (r=0.672; p<0.001) and intracellular water (r=0.596; p=0.001) were related to upper-body power variation. These associations remained significant after controlling for weight and arm lean-soft tissue changes (r=0.594, p=0.002 for total-body water; r=0.524, p=0.007 for intracellular water). These findings highlight the need for tracking total-body water, specifically the intracellular compartment in elite judo athletes in order to avoid reductions in upper-body power when a target body weight is desired prior to competition.

The influence of nutritional ergogenic aids on exercise heat tolerance and hydration status.

Exercise in the heat may predispose an athlete to an exertional heat illness. It is imperative to be knowledgeable on the influence of various nutritional supplements on exercise tolerance and hydration status. Because of the variety of nutritional ergogenic aids that are easily accessible to athletes, medical and health professionals must rely on empirical evidence when making conclusions about the efficacy of a supplement while not ignoring significant anecdotal reports that may resemble real-life situations more closely.