Body composition measurement in highly trained male athletes. A comparison of three methods

The purpose of the present study was to evaluate the differences in the body composition estimate of highly trained male athletes by three different methods: dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and skinfold thickness measurement (SFT)

Body composition measurement in highly trained male athletes: A comparison of three methods

Background. The purpose of the present study was to evaluate the differences in the body composition estimate of highly trained male athletes by three different methods: dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BW) and skinfold thickness measurement (SFT). Methods. The study occurred during a non-intensive training period. The measurements were performed at the Human Physiology laboratory, Participants: forty-three male athletes (19 waterpolo, 9 judo, 15 karate) who exercised regularly at least three hours per day, six days per week. Measurements: DXA, BLS. and SFT measurements of percentage fat mass (%FM) and the amount of fat-free mass (FFM) were performed. Statistical analyses: the different %FM estimates by the three methods were compared using a one-may ANOVA, with posthoc Bonferroni test when values mere significantly different. The same test was used to compare FFM values, The coefficient of variation (CV%=100xSD/mean) was calculated for each methods, Methodological differences among the various methods were analysed with the method of Bland-Altman. Results. ANOVA test showed significant differences among the three methods, Ln particular, DXA significantly (p<0.001) over-estimated %FM(12.4+/-4.1%) and underestimate FFM (67.0+/-6.9 kg) respect to SFT (7.8+/-0.9% and 71.0+/-8.2 kg) and BW (9.9+/-1.4% and 69.4+/-7.9 kg), Also Bland-Altman comparison among the estimates indicated nide differences between methods. Conclusions. DSA provides different body composition estimates than those derived from skinfold thickness measurement and BIA, so that the methods should not be used interchangeably

Validation of food frequency questionnaire for assessing dietary macronutrients and calcium intake in Italian children and adolescents

Objectives: To validate a food frequency questionnaire to determine calcium and macronutrient intake in healthy children and adolescents. Materials and Methods: The questionnaire consisted of 16 main food groups containing the main foods composing the diet of Italian children, a total of 136 items and 23 questions about food habits, supplements and servings. Color photographs to identify serving size were included. The questionnaire was validated by comparing it with the 7-day weighed record method in 37 healthy volunteers in two different age groups: children aged 6-10 years (n = 18) and adolescents aged 16-20 years (n = 19). Results: The food frequency questionnaire seemed to over-estimate the nutrient intake when compared with 7-day weighed records; however the two methods were highly correlated for all the nutrients considered. The range of Pearson's correlations between energy and nutrient intake (protein, fat, carbohydrates and calcium) determined from food frequency questionnaire and 7-day weighed record were 0.5-0.6 in children and 0.5-0.8 in young adults. Agreement between the two methods in classifying relative intakes was examined by determining the frequency of similar classification into terciles. Two thirds of the subjects were correctly classified for most nutrients, with a very low (2% to 5%) percentage of grossly misclassifications. Discussion: The food frequency questionnaire has proved adequate to rank a pediatric population in terms of calcium and macronutrient intakes. The ranking of subjects is extremely useful for epidemiologic studies evaluating the relation between nutrient intake and disease. (copyright) 2005 Lippincott Williams & Wilkins

Nanostructured Ti02 triggers protein nitration during PC12 cell differentiation

Cells in their natural environment interact with extracellular matrix components in the nanometer scale and respond to nanoscale features when grown on synthetic substrates. Therefore, in studying neuronal proliferation and differentiation processes, nanoscale topography of synthetic materials has been receiving increasing attention because of its resemblance to in vivo surroundings. It has been recently proposed that the physical properties of the substrates can be considered as a new kind of stimulus based on the finding that surface energy distribution, through cell-substrate interactions, triggers neuritogenesis of PC12 cells in the absence of nerve growth factor (NGF) or other inducers. However the molecular mechanisms of the triggered signalling cascade has not been identified, yet. To address this issue, with a particular emphasis on the potential role exerted by protein nitration, we studied the behaviour of PC12 cells on nanostructured TiO2 films of different thickness in the presence and in the absence of NGF while cells grown on PLL (poly-L-Lysine) coated glass were taken as the control. Since it has been demonstrated that NGF induces NO production by nitric oxide synthases (NOS) and that differentiation in PC12 cells grown on PLL-glass in the presence of NGF is associated to an increase in protein nitration, our investigation was aimed at detecting whether increased protein nitration is also observed during PC12 differentiation triggered by nanostructed TiO2 films in the absence of NGF. In order to detect nitrated proteins, cellular extracts were submitted to SDS-PAGE; gels were sliced and proteins reduced, carbamidated, digested with trypsin and analysed by nano-LC-MS/MS with an LTQ Orbitrap Velos (Thermo Scientific) mass spectrometer. Altogether the data suggest that protein nitration is involved in the differentiation process induced by nanotopography similarly to what is described in PC12 cells differentiated upon NGF

Intramyocellular lipid accumulation and reduced whole body lipid oxidation in HIV lipodystrophy

Antiretroviral therapy in human immunodeficiency virus (HIV)-positive patients can induce a lipodystrophy syndrome of peripheral fat wasting and central adiposity, dyslipidemia, and insulin resistance. To test whether in this syndrome insulin resistance is associated with abnormal muscle handling of fatty acids, 12 HIV-1 patients (8 females/4 males, age = 26 ± 2 yr, HIV duration = 8 ± 1 yr, body mass index = 22.0 ± 1.0 kg/m2, on protease inhibitors and nucleoside analog RT inhibitors) and 12 healthy subjects were studied. HIV-1 patients had a total body fat content (assessed by dual-energy X-ray absorptiometry) similar to that of controls (22 ± 1 vs. 23 ± 2%; P = 0.56), with a topographic fat redistribution characterized by reduced fat content in the legs (18 ± 2 vs. 32 ± 3%; P < 0.01) and increased fat content in the trunk (25 ± 2 vs. 19 ± 2%; P = 0.03). In HIV-positive patients, insulin sensitivity (assessed by QUICKI) was markedly impaired (0.341 ± 0.011 vs. 0.376 ± 0.007; P = 0.012). HIV-positive patients also had increased total plasma cholesterol (216 ± 20 vs. 174 ± 9 mg/dl; P = 0.05) and triglyceride (298 ± 96 vs. 87 ± 11 mg/dl; P = 0.03) concentrations. Muscular triglyceride content assessed by means of 1H NMR spectroscopy was higher in HIV patients in soleus [92 ± 12 vs. 42 ± 5 arbitrary units (AU); P < 0.011 and tibialis anterior (26 ± 6 vs. 11 ± 3 AU; P = 0.04) muscles; in a stepwise regression analysis, it was strongly associated with QUICKI (R2 = 0.27; P < 0.0093). Even if the basal metabolic rate (assessed by indirect calorimetry) was comparable to that of normal subjects, postabsorptive lipid oxidation was significantly impaired (0.30 ± 0.07 vs. 0.88 ± 0.09 mg·kg-1·min-1; P ± 0.01). In conclusion, lipodystrophy in HIV-1 patients in antiretroviral treatment is associated with intramuscular fat accumulation, which may mediate the development of the insulin resistance syndrome

A new protein-based bioadhesive material from fish parasites

Monogenoids are fish parasites which are able to quickly and reversibly attach to their host in the presence of strong water currents through the secretion of a proteic glue. The adhesive secretion is produced by glands located in the antero-lateral region of the animal. Unlike most adhesive secretions found in the animal world which stick to abiotic substrates, monogenoidean adhesive secretion works on living tissues. All these features make it a very promising material for exploitation in the surgical field. The aim of this work is the characterization of the bio-adhesive material by means of a proteomic approach. Since no genomic data for monogenoids are available, an MS/MS based de novo sequencing strategy was applied. The secreted material was obtained by electrostimulation of the parasites in a 50% PBS solution using 40 volts electric field and 2 Hz frequency. The secretion of 30 parasites was collected in a test tube and the SDS soluble and unsoluble components were analysed separately. Following to 2D-electrophoresis, each spot was trypsin digested and analysed by nano-LC-MS/MS using an LTQ Orbitrap Velos (Thermo Scientific, Germany). De novo sequence analysis and protein identification were obtained using Peaks Studio 5.3 (Bionformatics Solutions, Canada). Separate analysis of SDS soluble and unsoluble components of the glue suggests that more than 90% of the proteinaceous adhesive material is SDS unsoluble. Identification of proteins following de novo sequencing and database similarity searches using Peaks Studio allowed concluding that the glue is composed by a relatively small number of proteins, as expected for this type of material. De novo sequencing by high resolution MS/MS allowed the characterization of the proteic components of a new bioadhesive material with potential medical applications. Acknowledgments: this research was founded by grants from Fondazione CARIPLO, Milano, Ital