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Biomedical subjects

A Pietrobelli

Publications and source records attributed to A Pietrobelli.

At least 37 records · Page 2Linked to original sources
PubMed2004

New bioimpedance analysis system: improved phenotyping with whole-body analysis.

OBJECTIVE: Bioimpedance analysis (BIA) is a potential field and clinical method for evaluating skeletal muscle mass (SM) and %fat. A new BIA system has 8-(two on each hand and foot) rather than 4-contact electrodes allowing for rapid 'whole-body' and regional body composition evaluation. DESIGN: This study evaluated the 50 kHz BC-418 8-contact electrode and TBF-310 4-contact electrode foot-foot BIA systems (Tanita Corp., Tokyo, Japan). SUBJECTS: There were 40 subject evaluations in males (n=20) and females (n=20) ranging in age from 6 to 64 y. BIA was evaluated in each subject and compared to reference lean soft-tissue (LST) and %fat estimates in the appendages and remainder (trunk+head) provided by dual-energy X-ray absorptiometry (DXA). Appendicular LST (ALST) estimates from both BIA and DXA were used to derive total body SM mass. RESULTS: The highest correlation between total body LST by DXA and impedance index (Ht(2)/Z) by BC-418 was for the foot-hand segments (r=0.986; left side only) compared to the arm (r=0.970-0.979) and leg segments (r=0.942-0.957)(all P<0.001). The within- and between-day coefficient of variation for %fat and ALST evaluated in five subjects was <1% and approximately 1-3.7%, respectively. The correlations between 8-electrode predicted and DXA appendicular (arms, legs, total) and trunk+head LST were strong and highly significant (all r> or =0.95, P<0.001) and group means did not differ across methods. Skeletal muscle mass calculated (Kim equation) from total ALST by DXA (X+/-s.d.)(23.7+/-9.7 kg) was not significantly different and highly correlated with BC-418 estimates (25.2+/-9.6 kg; r=0.96, P<0.001). There was a good correlation between total body %fat by 8-electrode BIA vs DXA (r=0.87, P<0.001) that exceeded the corresponding association with 4-electrode BIA (r=0.82, P<0.001). Group mean segmental %fat estimates from BC-418 did not differ significantly from corresponding DXA estimates. No between-method bias was detected in the whole body, ALST, and skeletal muscle analyses. CONCLUSIONS: The new 8-electrode BIA system offers an important new opportunity of evaluating SM in research and clinical settings. The additional electrodes of the new BIA system also improve the association with DXA %fat estimates over those provided by the conventional foot-foot BIA.

Absorptiometry, Photon↗
PubMed2004

New insights into the field of children and adolescents' obesity: the European perspective.

EDITOR'S NOTE: The problem of childhood obesity is accelerating throughout the world. The following is a position paper from The European Childhood Obesity Group (ECOG) that outlines the nature of the problem of childhood obesity along with treatment and prevention methods available today. The paucity of literature on prevention and treatment of obesity in children as documented in this paper points out the need for much additional research on obesity in children. OBJECTIVES: The awareness of childhood obesity as a major health problem and an uncontrolled worldwide epidemic has to be increased in the society. DESIGN: In order to improve the quality of the health care and to minimize the cost it is important to investigate and standardize pediatric obesity prevention and treatment and to adapt to social and cultural aspects. RESULTS: Obesity is the result of excess body fat. The different norms and definitions in Europe and the US is described and clarified. However, the available methods for the direct measurement of body fat are not easily used in daily practice. For this reason, obesity is often assessed by means of indirect estimates of body fat, that is, anthropometrics. There are essentially six relevant levels, which could be involved in prevention of child and adolescent obesity: family (child, parents, siblings, etc), schools, health professionals, government, industry and media. Evidence-based health promotion programs has to be given a high priority. Government should encourage media increase information about healthy nutrition and to avoid the marketing of unhealthy foods including sweet drinks, for example, in TV. Many different approaches of treatments of obesity have been investigated, including diet, exercise, behavioral therapy, surgery, and medication. None have been found to be effective enough as sole tools in children. This has led to focus on multidisciplinary programs especially involving families. Behavioral cognitive therapy is effective in treating childhood obesity as is family therapy. Surgery and drug treatment cannot be recommended without additional research. Clinicians should consider the various factors that can influence body composition. CONCLUSION: It is important to know and to follow nutritional factors, energy intake and composition of the diet, nutrition and hormonal status, food preferences and behavior, and the influence of non-nutritional factors. We recommend that obesity should be the major priority both in the health care system, on the scientific level and for future political actions.

Adolescent↗
PubMed2004

Outcome measurements in paediatric obesity prevention trials.

OBJECTIVE: Obesity in children impacts on their health in both the short and long term. Having an accurate and precise body composition assessment, it may be possible to control growth process and predict adult status in order to reduce the risk factors for various diseases. METHOD: To review methods for body composition assessment that may provide new insights into the clinical practicality of paediatric obesity prevention/treatment. To present which specific outcome measurements in paediatric obesity prevention trials could be used to detect subjects at risk as early as possible. RESULTS: We discussed body composition measurements that could be used in daily clinical practice and as outcome measurements in prevention trials. CONCLUSION: These measurement procedures could be associated with methods for preventing obesity onset or retarding the weight gain associated with ageing.

Absorptiometry, Photon↗
PubMed2004

"Cyst-like" structures within the ciliary shafts in children with bronchiectasis.

"Cyst-like" structures within the ciliary shafts were considered in four adults as a primary defect involved in the development of bronchiectasis. In this study, the presence and the primary or secondary nature of this abnormality were assessed in children with bronchiectasis. High resolution computed tomography (HRCT) and nasal biopsies for motion analysis and transmission electron microscopy (TEM) evaluation of cilia were obtained in 45 children with recurrent lower airway infections and abnormal chest radiography. HRCT disclosed bronchiectasis in 35 out of 45 (77.8%) children and cyst-like structures were demonstrated with TEM in 29 out of 45 (64.4%) patients. Cyst-like structures were constantly associated with other ultrastructural abnormalities commonly observed in chronic inflammation, and were found both in subjects with primary and with secondary ciliary dyskinesia. When considering only patients with bronchiectasis, a significant correlation between prevalence of cyst-like structures and the severity of bronchiectasis was demonstrated. Follow-up (2-22 months) of seven patients demonstrated that in the five children with secondary dyskinesia, the ultrastructural defect completely disappeared and there was a small reduction in the abnormality in the two patients with primary dyskinesia. In contrast to one previous report, the reversibility of the defect suggests its secondary origin, which is most likely related to chronic airway inflammation.

Adolescent↗
PubMed2003

Genetics of food intake and body composition: lessons from twin studies.

Twin studies are useful designs for decomposing genetic and environmental influences on traits, with the basic goal being to map variations in phenotypic similarity onto variances in genetic similarity. In this review, we provide an overview of twin studies that have been used to decompose the genetic and environmental influences behind body composition, eating style, and their covariation. Although many published reports have established that genes contribute anywhere from 50-90% of the variance in body mass index (BMI, kg/m(2)), fewer studies have used laboratory- based body composition measures. Moreover, comparable studies of human eating style are even more scarce. Advances in the laboratory measurement of human eating behavior may increase the yield of twin studies that solely focus on body composition.

Adolescent↗
PubMed2003

Predicting fat-free mass in children using bioimpedance analysis.

Body composition assessment is a useful procedure for the study of nutritional status and water distribution. In adults, it is a predictor of morbidity and mortality, since body fatness is associated with risk factors for cardiovascular disease. Bioelectric impedance analysis (BIA) is a simple, safe, and inexpensive method for assessment of body composition both in pediatric and adult subjects. The aim of our study was to validate the impedance index, ZI (H(2)/Z, height in cm(2)/impedance), as a predictor factor of fatfree mass (FFM) and fat mass (FM) in a sample ( n=75) of normal children. Dual-energy X-ray absorptiometry (DXA) was chosen as reference method. Despite some minor bias, DXAis considerably less expensive and easier to administer in pediatric subjects than other established gold standard reference methods for assessing body composition. ZI values were highly correlated with FFM measured with DXA. The following equations were obtained from the regression analysis: (a). male subjects, FFM(DXA)=0.6375 (ZI)+5.9913, r(2)=0.897, p<0.0001; (b). female subjects, FFM(DXA)=0.7597 (ZI)+ 3.5853, r(2)=0.903, p<0.0001. These data support the notion that BIA alone can be used as a surrogate to measure FFM in a pediatric sample.

Absorptiometry, Photon↗
PubMed2003

Pediatric body composition in clinical studies: which methods in which situations?

There is currently much interest in the subject of pediatric obesity. Accurate measures of body composition are required given the potential influence of variables such as growth, metabolic rate, physical activity, and physical fitness. Because boys and girls have a different growth pattern, gender is a fundamental consideration when measuring children and assessing body composition. The central aim of this paper is to review methods of pediatric body composition assessment that can provide new insights for clinical practice.

Absorptiometry, Photon↗
PubMed2003

Body mass index and skinfold thickness versus bioimpedance analysis: fat mass prediction in children.

Childhood obesity increases the risk of morbidity whether or not obesity persists into adulthood. Measurement of body fat content using bioimpedance analysis (BIA) is a useful tool in epidemiologic studies. Both tricep skinfold thickness (TST, mm) and body mass index (BMI, kg/m(2)) are indirect, simple methods and easy to perform for assessing body composition. These methods are generally accepted as good clinical measures for defining childhood obesity. The aim of our study was to evaluate fat mass (FM, kg and %) measurements using TST and BIA (50 kHz) in a cohort of 6-year-old Italian children. A total of 228 southern Italian children (121 boys, 107 girls), randomly selected in nine local primary schools, were included in the study. The correlation between methods for measuring FM was calculated. Linear regression analysis showed a significant positive correlation between FM measured with BIA and BMI ( r=0.92, p<0.001) and with TST ( r=0.79, p<0.001). We conclude that FM measurement using TST and BIA is comparable in different BMI ranges. However, BIA is a useful and alternative method for detecting body composition in children and may be a more precise tool than TST for measuring FM in epidemiological studies in pediatric populations.

Adipose Tissue↗
PubMed2003

Systemic activity of inhaled corticosteroid treatment in asthmatic children: corticotrophin releasing hormone test.

BACKGROUND: A study was undertaken to assess the function of the hypothalamic-pituitary-adrenal axis (HPA) in a group of asthmatic children before and after treatment with inhaled corticosteroids. METHODS: Thirty prepubertal patients of mean (SD) age 6.7 (1.8) years were treated with inhaled corticosteroids. All children underwent a corticotrophin releasing hormone (CRH) test with evaluation of serum cortisol and adrenocorticotrophin hormone (ACTH) levels before and after 3 months of treatment. Twenty four hour urine samples were also collected to measure free cortisol (UFC) excretion. RESULTS: Subjects showed no difference between basal serum cortisol levels (mean change -18; 95% CI -41 to 5; p=0.118) and delta (peak minus basal) levels (mean change -13; 95% CI -38 to 12; p=0.308) before and after treatment, whereas the peak cortisol level (mean change -31; 95% CI -55 to -7; p=0.013) and area under the curve (AUC) (mean change -175; 95% CI -288 to -63; p=0.003) after CRH were significantly lower following treatment. Basal, peak and AUC ACTH were significantly lower after treatment (p<0.05, p=0.004 and p=0.003, respectively), while delta ACTH was similar before and after treatment ((mean change -12; 95% CI - 31 to -7; p=0.199). No significant reduction in 24 hour UFC was observed after the treatment period (before 14.9 (7.1), after 15.0 (11.6); mean change 0.1, 95% CI -5.2 to 5.4; p=0.967). No correlation was found between UFC and any of the parameters of cortisol excretion following the CRH test, either before or after treatment. CONCLUSIONS: These data suggest that, at the dosage and for the treatment period used, inhaled steroids do not seem to suppress the HPA axis in the majority of patients. The CRH test may be more sensitive than 24 hour UFC and morning plasma cortisol levels in evaluating systemic activity of inhaled corticosteroid treatment.

Administration, Inhalation↗
PubMed2003

[Diagnosis and differential diagnosis of obesity in childhood].

About 2-3% of "essential" obesity in pediatric age is of endocrine or genetic origin (secondary obesity). The clinical picture of these forms is almost always characteristic; however, some patients affected by secondary obesity can present with an incomplete or atypical aspect. The aim of this review is to offer the pediatrician useful indications to correctly diagnose children presenting with obesity. It is advisable to make a careful anamnesis and an accurate medical examination in order to ascertain the causes that may have contributed to the onset and increase of weight gain. Obesity associated with mental retardation, short stature, cryptorchidism or hypogonadism, dysmorphism with facies sui generis, ocular or uditive defects, might suggest a genetic origin. Prader-Willi syndrome is the most frequent of these disorders and it is due to an alteration of chromosome 15 of paternal origin. These patients have to undergo the methilation test (easy and low cost genetic research) in order to confirm the clinical suspicion. Endocrine alterations, that play a pathogenic role in pediatric obesity (i.e., hypothyroidism, hypothalamic-pituitary diseases, pseudohypoparathyroidism), are rare. Early treatment of hormonal dysfunction generally allows to ameliorate or normalize the weight gain. In absence of specific clinical manifestations or lacking a significant clinical history, no endocrine test is required. The family pediatrician should require some routine hematochimic tests, in order to evaluate the possible presence of hyperlipidemia and/or glycometabolic complications. An oral glucose tolerance test is necessary only for patients presenting with serious weight gain, acanthosis nigricans, and for those with a family history of diabetes. In the most serious cases, a careful cardiovascular and respiratory evaluation should be performed. Children with a suspicion of secondary obesity have to be submitted to an endocrinologist, for a correct diagnosis and a specific treatment. However, the family pediatrician's assistance is essential during the follow-up period, in order to assure the patient and his/her family a proper assistance.

Adolescent↗
PubMed2002

Establishing body composition in obesity.

The field of human body composition research is reaching a mature stage in its development. Quantifying the main body components is integral to the study of growth, as the assessment of human physical characteristics is important both in anthropological and medical fields. This article will focus on body composition methodology. Specifically, our attention is aimed at estimates of body fatness. An overview is first provided of the five-level model of body composition as it relates to measures of fatness. We then provide general concepts related to techniques for estimating body composition. Finally, we briefly discuss the measurement of adipose tissue distribution.

Absorptiometry, Photon↗
PubMed2002

Benefits of immunotherapy with a standardized Dermatophagoides pteronyssinus extract in asthmatic children: a three-year prospective study.

BACKGROUND: Although widely practiced for over 80 years, the role of specific immunotherapy (SIT) in pediatric asthma treatment is still controversial. We assessed the effects of a 3-year period of subcutaneous administration of a standardized preparation of Dermatophagoides pteronyssinus (D pt) on the respiratory health in a group of asthmatic children monosensitized to house dust mite (HDM). METHODS: A randomized clinical trial was performed after 1-year run-in period. Fifteen children receiving SIT for HDM and 14 controls (four drop-outs), matched for age, allergen sensitization, asthma severity, lung function, and non-specific bronchial reactivity (BHR), were studied during the 3-year treatment period. During the whole trial, respiratory symptoms, pharmacological and respiratory function parameters were regularly evaluated. Skin prick tests and methacholine challenge were performed at the beginning and end of the study. RESULTS: In the SIT group significant improvement in asthmatic symptoms and marked reduction in drug intake was observed. The SIT group also showed a significant decrease in non-specific bronchial BHR. No new sensitivity occurred during the study period in the SIT group only. No major local or systemic side-effects were reported during the study. CONCLUSIONS: Our results confirm that SIT is effective in asthmatic children sensitive to mites. It is associated with a decrease in BHR and it may prevent the development of new sensitizations in monosensitized subjects.

Adolescent↗
PubMed2002

Assessment by bioimpedance of forearm cell mass: a new approach to calibration.

OBJECTIVE: Changes in skeletal muscle mass are involved in several important clinical disorders including sarcopenia and obesity. Unlike body fat, skeletal muscle is difficult to quantify in vivo, particularly without highly specialized equipment. The present study had a two-fold aim: to develop a regional (40)K counter for non-invasively estimating cell mass in the arm, mainly skeletal muscle cell mass, without radiation exposure; and to test the hypothesis that cell mass in the arm is highly correlated with electrical impedance after adjusting for the arm's length. METHODS: Forearm cell mass was estimated using a rectangular lead-shielded (40)K counter with 4-NaI crystals; impedance of the arm was measured at multiple frequencies using a segmental bioimpedance analysis (BIA) system. The system's within- and between-day coefficient of variation (CV) for (40)K-derived elemental potassium averaged 1.8+/-1.3 and 5.8+/-1.2%, respectively. The corresponding BIA system's CVs were 1.0+/-0.4 and 2.1+/-1.0%, respectively. SUBJECTS AND RESULTS: Participants in the study were 15 healthy adults (eight females, seven males; age 39+/-2.8 y, BMI 22.9+/-4.5 kg/m(2)). The right arm's K (5.2+/-1.7 g) was highly correlated with length-adjusted impedance (r(2)=0.81, 0.82, and 0.83 for 5, 50 and 300 kHz, respectively; all P<0.001); multiple regression analysis showed no additional improvement by adding age or sex to the prediction models. CONCLUSION: These results demonstrate the feasibility of calibrating BIA-measured electrical properties of the arm against estimates of arm cell mass, mainly of skeletal muscle, obtained by regional (40)K counting. This simple and practical approach should facilitate the development of BIA-based regional cell mass prediction formulas

Adult↗
PubMed2002

Sexual dimorphism in the energy content of weight change.

BACKGROUND: The energy content of weight change is assumed to be sex- and age-neutral at 3,500 kcal/pound or 32.2 MJ/kg. OBJECTIVES: As sexual dimorphism in body composition generally exists in mammals, the primary hypothesis advanced and tested was that the energy content of weight change differs between men and women. DESIGN: The energy content of 129 adult men and 287 women was measured by neutron activation analysis. Cross-sectional energy content prediction models were developed and then evaluated in two longitudinal samples: one that used the same methods in 26 obese women losing weight; and the other a compilation of 18 previously reported weight change-body composition studies. RESULTS: Multiple regression modeling identified weight, sex, age and height as total energy content predictor variables with significant sex x weight (P<0.001) and age x weight (P<0.001) interactions; total model r(2) and s.e.e. were 0.89 and 107.3 MJ, respectively. The model's predictive value was supported in both longitudinal evaluation samples. Model calculations using characteristics of representative adults gaining or losing weight suggested that the energy content of weight change in women (approximately 30.1-32.2 MJ/kg) is near to the classical value of 32.2 MJ/kg and that in men the value is substantially lower, approximately 21.8-23.8 MJ/kg. The predicted energy content of weight change increases by about 10% in older (age approximately 70 y) vs younger (approximately 35 y) men and women. CONCLUSIONS: Sexual dimorphism and age-dependency appears to exist in the estimated energy content of weight change and these observations have important clinical and research implications.

Adult↗
PubMed2002

Resistance to change of adulthood body mass index.

Numerous weight loss trials show that maintenance of weight loss is extremely difficult to sustain over time in adulthood. Using general population sample of adults whose weights were longitudinally tracked across several decades, we quantified resistance of weight to change by means of body mass index autocorrelation across a series of paired time points. Equations for age-adjusted sex-specific body mass index autocorrelation were developed. We found that body weight is quite resistant to change over years and decades. This finding partially de-mystifies the weight regain observed following intervention that last weeks or months.

Adult↗