Assessment of total body potassium in healthy Italian men.

BACKGROUND: Whole-body (40)K counting is a valuable tool for assessing cellular changes in body composition with ageing. AIM: The objectives of this study were to assess total body potassium (TBK) and body cell mass (BCM) differences with age, and to compare TBK and BCM between individuals with a body mass index (BMI) < 25 kg m(-2) versus > 25 kg m(-2). SUBJECTS AND METHODS: Body composition of 840 healthy Italian men, 18-70 years of age, was measured by whole-body counting of (40)K. BCM (kg) was calculated as 0.00833 x TBK (mmol). RESULTS: Body weight did not differ among groups. TBK, TBK/height, TBK/body weight, and BCM were significantly lower for the 51-70-year-old group compared with all other groups. The 51-70-year-old group with a BMI < 25 kg m(-2) had significantly lower TBK, TBK/height, and BCM than all other decades with a BMI < 25 kg m(-2); whereas TBK/body weight was significantly lower than the 18-30 and 31-40-year-old groups. The 51-70-year-old group with a BMI > 25 kg m(-2) had significantly lower TBK, TBK/height, TBK/body weight, and BCM than all other decades with a BMI > 25 kg m(-2). CONCLUSION: TBK and BCM decrease significantly with ageing, which could result in decreased functional capacity in older adults.

[Changes in body composition caused by intense physical training]. / Variazione della composizione corporea dovuta ad un intenso periodo di allenamento.

PURPOSE: To show the importance of the study of body composition in functional capacity evaluation of athletes who play professional football, during periods of very hard training (before the beginning of the championship), in order to appreciate every kind of adaptation to the training itself more precisely. MATERIALS AND METHODS: 18 semiprofessional football players, ages 18-32 yr., weight 75.2 +/- 8.1 kg, height 180.8 +/- 5.5 cm have been subjected to body composition evaluation, using Biolectrical Impedance Analysis (B.I.A) and antropometrics measurements, the day before the beginning of the trainings and at the end of them (just before the beginning of the championship). RESULTS: The athletes at end the training period (15 day) showed significant loss of weight (1.6 kg; p < 0.001). This reduction was attributed to a loss of the fat mass (2.8 kg; p < 0.001). Fat free mass increased 1.2 kg (p < 0.05); at the same time total body water increased too (1.0 l; p < 0.05) proving that, in spite of hard training, the athletes mateined a good hydratation. CONCLUSIONS: The results suggest that is very important to analyse body composition in the football players, since otherwise we couldn't attained the variation of weight in a quantitative and qualitative way.

A new predictive equation to calculate resting metabolic rate in athletes.

BACKGROUND: The purposes of the present study were: 1) to examine the accuracy and precision of seven published equations for predicting resting metabolic rate (RMR) in male athletes and 2) to develop a population-specific equation. SETTING: The study occurred during a non-intensive training period. The measurements were performed at the Human Physiology laboratory. PARTICIPANTS: Fifty-one male athletes (22 waterpolo, 12 judo, 17 karate) who exercised regularly at least three hours per day. MEASURES: RMR was measured (mRMR) using indirect calorimetry (ventilated hood system). Besides, mRMR was compared with values predicted (pRMR) using equations of FAO/WHO/UNU, Harris and Benedict, Mifflin et al., Owen et al., Cunningham, Robertson and Reid, Fleisch. Statistical analyses. mRMR was compared with pRMR by means of Student's paired "t" tests, linear regression analysis and the Bland-Altman test. Relationships between mRMR and the different predictive variables were evaluated by Pearson correlation coefficients. The best subset was used to develop the predictive equation for RMR. RESULTS: mRMR was significantly underestimated by six of the seven equations in this sample of athletes. Only the Cunningham equation overestimated (+59 kcal/d) the actual RMR. Bland-Altman 95% limits of agreement were wide (+/- 200-300 kcal/d) for all equations. RMR correlated best with body surface area (r = 0.88), body weight (r = 0.84) and height (r = 0.81). The best-fit equation for the entire data included both weight and height and it was given by: RMR (kcal/d) = -857 + 9.0 (Wt in kg) + 11.7 (Ht in cm) (R2 = 0.78; SEE = 91 kcal/d; 95% IC: -226, 228). CONCLUSIONS: For an individual resting metabolic rate evaluation, the use of indirect calorimetry is recommended. In conditions where this technique cannot be used, our developed equation can predict the RMR of athletes better than any of the currently available prediction equations.

New insights into body composition assessment in obese women.

During treatment of patients with non-insulin-dependent diabetes mellitus, there may be marked body weight loss. Therefore, body composition should be monitored to check for a decrease in fat mass alone, without an excessive decrease of both fat-free mass and total body water. Accordingly, it is useful to monitor the hydration of these patients. One method that allows us to check the status of body hydration is the multifrequency bioelectric impedance analysis (MFBIA). It makes use of formulas that estimate total body water on the basis of the concept that the human body may be approximated to a cylinder of length equal to body height. In normal subjects body water estimates are sufficiently accurate, but in obese subjects the true hydration status may be overestimated. In this report, we describe the accuracy of mathematical models previously described in the literature, and correct for the overestimation of total body water in obese subjects by means of a new equation based on a new model. The coefficients for each model have been recalculated by the weighing of our sample in order to test the accuracy of estimates obtained with the equations. This new model includes both body volume and two impedances at appropriate frequencies useful for identifying two terms strictly related to extra- and intra-cellular water. The new formulas do not include body weight, but they include the body volume, a parameter more closely related to the biophysical reference model. Fifty-five overweight females, body mass index ranging from 26.8 to 50.2 kg/m2, were enrolled in the study. The proposed equations, taking advantage of two impedance values at appropriate frequencies, better predict total body water in obese women. This was particularly evident when the results obtained with the multifrequency bioelectric impedance analysis and deuterium isotopic oxide dilution method were compared. Although this last method is considered the "gold standard," it is not suitable for use in routine clinical practice. In conclusion, evaluation of total body composition by means of bioelectric impedance analysis might be included in programs for the prevention of non-insulin-dependent diabetes and for monitoring weight loss during overt pathology.

Comparison of different techniques to measure body composition in moderately active adolescents.

OBJECTIVE: To evaluate the differences in the estimate of body fat percentage (%FM) and the amount (kg) of fat free mass (FFM) by different methods in 26 moderately active adolescents very similar in age, body fatness, and training status. METHODS: Mean (SD) age was 16.7 (0.9) years, height was 177.0 (5.1) cm, and weight 68.0 (5.2) kg. %FM was assessed using dual-energy x ray absorptiometry (DXA) and two skinfold prediction equations: that of Slaughter et al (%FM Sla) and that of Deurenberg et al (%FM Deu). In the same way, FFM was measured using DXA and different impedance equations: those of Suprasongsin et al (FFM Sup), Schaefer et al (FFM Sch), Houtkooper et al (FFM Hou), and Deurenberg et al (FFM Deu). To determine the interchangeability of the different methods of measuring %FM and FFM, one way analysis of variance, standard error (SE), and coefficient of variation (CV%) ((SD/mean) x 100) were used. RESULTS: On average, no significant statistical differences were observed between the values determined for %FM: DXA value, 11.7 (5.4%); %FM Sla, 10.9 (4.0)%; %FM Deu, 11.5 (2.3)%. On the other hand, SE and CV% between each pair of the three methods used showed very large variability. With regard to the measurement or prediction of FFM, the mean value measured by DXA was significantly higher than that predicted by the equation of Sch (+7.2 kg, p < 0.001), Deu (+3.2 kg, p < 0.001), and Hou (+2.6 kg, p < 0.001), whereas it was lower than that predicted by the equation of Sup (-1.6 kg, p < 0.05). The Hou and Deu values were the only two that, on average, did not differ in a statistically significant way, although they showed the highest CV%. CONCLUSIONS: In our sample of moderately active adolescents the estimated values for %FM and FFM appear to be highly dependent on method.

Total body capacity correlated with basal metabolic rate.

This study was conducted to establish the relationship between a new bioelectrical parameter, total body capacitance (TBpF), as an expression of body cell mass, measured using an impedance analyser and basal metabolic rate (BMR), by indirect calorimetry in 75 healthy subjects (38 females and 37 males, aged between 13 y and 43 y). A significant high correlation was found between TBpF and BMR (r = 0.992, SEE = 238 kcal) with the equation: BMR (kcal day-1) = Capacity (pF) x 2.29.

[Mirizzi's syndrome as the cause of intrahepatic lithiasis. A clinical case]. / Sindrome di Mirizzi come causa di litiasi intraepatica, Caso clinico.

The authors report a case of Mirizzi's syndrome that was the cause of intrahepatic lithiasis. The recurrence of acute episodes of cholecystitis may lead to a partial obstruction of hepato-choledochal duct through compression and phlogosis (Type 1 Mirizzi's syndrome); moreover, the compression of calculous material wedged in the cystic duct may also result in ischemic necrosis of the wall, thus causing a cholecystic-choledochal internal biliary fistula (Type 2 Mirizzi's syndrome). The authors analyse problems relating to the complications of gallbladder calculosis with indications for surgery at the first symptomatic manifestation, given that the recurrence of cholecystic inflammatory episodes provokes pathological conditions in the biliary tract that require major surgery with a consequent increase in mortality and morbidity, above all in elderly patients. The authors recommended performing a through intraoperative study to ensure the correct identification of intrahepatic lithiasis, given the difficulty of preoperative diagnosis. The objective of treatment is to suppress the lithogenic focus and ensure good biliary drainage.

Within-subject variability in body composition using dual-energy X-ray absorptiometry.

The reproducibility of dual-energy X-ray absorptiometry (DXA) measurements for total body composition and for segmental body composition was investigated in 22 healthy male subjects who underwent six consecutive measurements in 90 min. Body weight (mean +/- SD) and body height were 72.3 +/- 8.8 kg and 1.75 +/- 0.04 m respectively, and body mass index was 23.5 +/- 2.5 kg m(-2). Bone mineral content (BMC) was 3.30 +/- 0.36 kg, lean mass and fat mass as measured by DXA were 57.1 +/- 6.1 kg and 11.8 +/- 6.5 kg respectively. For BMC, the reproducibility, expressed as the coefficient of variation, was 12%, 1.5%, 2.5%, 4.1% and 3.1% for total body, legs, arms, trunk and abdominal respectively. For lean tissue and for fat tissue, these values were 1.5% and 50%; 1.8% and 2.1%, 8.3% and 11.7%, 26% and 10.0%, 3.9% and 10.7% respectively. It is concluded that the reproducibility for BMC is excellent, but that for lean tissue and for fat tissue the variability is relatively high, especially in body segments.

Comparison of the body composition of age-matched Italian, Ukrainian, and Dutch children.

In the present study, the body composition was measured in 35 Ukrainian children, 14 boys and 21 girls, aged 8-12 years, by dual-energy X-ray absorptiometry (DEXA), anthropometry, and bioelectrical impedance. The results were compared with those obtained from a sample of the same number of Italian and Dutch children of the same sex and range of age. The Ukrainian children were slightly smaller, had a lower body weight, and had a lower body fat percentage, as measured by skinfolds, as compared with the Italian and Dutch children, as well as a lower calculated fat-free mass (FFM) by impedance. Comparison between FFM as determined by different methods in the Ukrainian children showed that all assessed values differed significantly. In particular, all methods overestimated the FFM as compared with DEXA, but the differences between DEXA and the other methods were not dependent on the level of FFM as determined by DEXA. Furthermore, the difference between predicted FFM and FFM values obtained by DEXA was correlated for skinfolds and body mass index (r = 0.77, p < 0.01), but not for body mass index and impedance, or skinfolds and impedance. The mean differences were 1.8 +/- 1.5 for body mass index, 1.0 +/- 1.4 for impedance, and 3.6 +/- 1.6 for skinfolds. Some differences in the body composition have also been found between boys and girls. The boys had higher values of lean tissue (23.3 +/- 3.1 vs. 20.7 +/- 3.3; p < 0.01) and FFM (24.5 +/- 3.3 vs. 21.8 +/- 3.5; p < 0.01) as compared with the girls and slightly higher values of bone mineral content. It should be noted, however, that the differences between different groups and different methods are always small, even when they are statistically significant.

[Effects of prolonged administration of branched-chain amino acids on body composition and physical fitness]. / Effetti di una somministrazione prolungata di aminoacidi ramificati sulla composizione corporea e sulla capacità fisica.

No conclusive data are reported about the effects of long-term branched-chain amino-acids (BCAA) administration on metabolic and respiratory parameters during the sustained hand-grip test (SHGT). Bedside, few data are reported about the relationship between BCAA administration and body composition. Thus, BCAA (14 g/die; 50% L-Leucine, 25% L-Isoleucine, 25% L-Valine) were administered orally to 10 untrained male healthy subjects for 30 days. Before (T0) and after (T1) BCAA administration, oxygen uptake (VO2) and pulmonary ventilation (VE) were evaluated at rest ("baseline", B) and during SHGT. Body height and body weight, body mass index (BMI), fat mass (FM), fat-free mass (FFM), arm muscle area (AMA) and maximal voluntary contraction of forearm muscler (GS, grip strength) were also evaluated at T0 and T1. At T1 FFM increased significantly (T0: 62.3 +/- 7.6 kg; T1: 63.1 +/- 7.5 kg; mean +/- SD; p < 0.05), as well as GS (T0: 46.8 +/- 7.9; T1: 50.6 +/- 7.8; p < 0.01). At T0, VO2 increased significantly during the test (B: 271 +/- 36 ml/min; SHGT: 332 +/- 71 ml/min; p < 0.01), whereas at T1 no significant increase was observed (B: 271 +/- 50 ml/min; SHGT: 286 +/- 60 ml/min). We conclude that the physical fitness of BCAA treated subjects was improved, because of the decrease of O2 uptake during SHGT. Moreover, in our subjects, BCAA seemed to promote FFM-protein synthesis mostly.

Improved prediction formula for total body water assessment in obese women.

OBJECTIVE: To validate an improved formula for the calculation of total body water (TBW) from impedance values in obese women. SUBJECTS: A sample of 37 overweight females BMI ranging from 29.5 to 44.1 kg/m2. MEASUREMENTS: The reference measurements for TBW were obtained by deuterium oxide dilution. Body height (h), hip circumference (C) as well as body impedance at 100 kHz (Z100) were also measured. RESULTS: The values obtained for h, C and Z100 were introduced in the calculations and the following developed formula for total body water was determined: TBW = 0.069 [hC2/(4 pi .Z100)]+19.671. The validity of this formula was assessed through the statistical test of Bland and Altman which we also performed for other formulas containing the weight and/or the height. CONCLUSION: We found that the accuracy of the prediction of TBW by our formula, although lower than those formulas using body weight, is higher than that which takes into account only body height. We conclude that body volume, expressed through body height and hip circumference, is a good choice of parameter in bioelectrical impedance measurements. The new approach can be useful in clinical settings for repeated monitoring of obese women, during diet-restricted treatment.

Determination of intracellular water by multifrequency bioelectrical impedance.

Body composition was measured in 57 healthy males by 40K measurements and by multifrequency bioelectrical impedance. Intracellular resistance (Ricf) was calculated from the impedance values using the Cole-Cole model. From total body potassium, intracellular water (ICW) was calculated. In addition, in 14 subjects, total body water (TBW) and extracellular water (ECW) was measured using deuterium oxide dilution and bromide dilution, respectively. Prediction formulas from the literature from impedance at different frequencies were used to predict TBW and ECW, and ICW was calculated as the difference of predicted TBW and ECW. Predicted and measured values of TBW, ECW and ICW did not always show the same values as measured. Generally the ICW from potassium was well correlated with calculated ICW from impedance values, correlation coefficients varying from 0.68 to 0.79, depending on the used prediction formula. From the impedance index H2/Ricf, body weight and age, ICW from potassium was predicted with stepwise multiple regression. The prediction formula was ICW = 0.37065.H2/Ricf - 0.132.age + 0.105.weight + 12.2. The prediction error was 1.9 kg and the explained variance 0.69. The residuals of this prediction formula were dependent on the level of ICW as measured by potassium. The same phenomenon was observed when ICW was calculated as the difference of predicted TBW and ECW. The results show that multifrequency impedance is able to predict ICW, however, the prediction is influenced by body water distribution.

The influence of extra load on the mechanical behavior of skeletal muscle.

Eleven international jumpers and throwers engaged in year round training were divided into experimental (n = 6) and control (n = 5) groups. The experimental group was tested before and after a 3 weeks simulated hypergravity period, and again 4 weeks after the hypergravity period. The high gravity condition was created by wearing a vest weighing about 13% of the subjects body weight. The vest was worn from morning to evening including the training sessions, and only removed during sleep. The daily training of all subjects consisted of classical weight training and jumping drills. No changes in the ordinary training program were allowed in the experimental group, except for the use of the vest. Vertical jumps, drop jumps and a 15 s continuous jumping test were used to measure the explosive power characteristics of the subjects. After the hypergravity period the experimental subjects demonstrated significant (5-10%, P less than 0.05-0.01) improvements in most of the variables studied: however, 4 weeks after cessation of the high gravity period they tended to return towards the starting values. No changes were observed in the results of the control group. The improvement observed in the experimental subjects was explained as fast adaptation to the simulated high gravity field. It is suggested that adaptation had occurred both in neuromuscular functions and in metabolic processes.