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Biomedical subjects

A Pietrobelli

Publications and source records attributed to A Pietrobelli.

At least 19 recordsLinked to original sources
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↗
PubMed2002

Mite avoidance can reduce air trapping and airway inflammation in allergic asthmatic children.

BACKGROUND: We investigated the effects of prolonged allergen avoidance in 18 house dust mite-sensitized asthmatic children during a prolonged residential period at a high altitude, allergen-free environment. METHODS: Evaluations of residual volume (RV) and exhaled nitric oxide (eNO) were performed (i) at admission to the residential house in September, (ii) in December after 3 months of stay, (iii) in January after 15 days at home, exposed to allergens, and (iv) in June after 9 months of stay. RESULTS: During the study period RV showed a significant decrease in December (from 117.5 +/- 7.7% to 96.5 +/- 3.2%) (P < 0.02) and a following increase in January (126.2 +/- 17.2%), after allergen re-exposure (P < 0.03). RV decreased again in June at the end of the study period (91.1 +/- 6.0%) (P = 0.001). FEV(1), FEF(25-75) and VC values did not present significant variations. ENO showed a significant decrease in December after 3 months at high altitude (from 21.3 +/- 3.9 p.p.b. to 11.9 +/- 1.7 p.p.b.) (P = 0.03), but no further significant change. No correlation was found between lung volumes and eNO, probably reflecting different aspects of asthma. CONCLUSIONS: Results suggest that RV may be more sensitive than other respiratory function parameters in identifying children with air trapping, being influenced significantly as the inflammatory indices by effective allergen avoidance/exposure regimen.

Adolescent↗
PubMed2002

New bioimpedance model accurately predicts lower limb muscle volume: validation by magnetic resonance imaging.

Conventional bioimpedance analysis (BIA) methods now simplify the representation of lower limb geometry and electrical properties for body composition estimation. In the present study, a three-dimensional model of the lower limb was assembled by segmentation of magnetic resonance cross-sectional images (MRI) for adipose tissue, skeletal muscle, and bone. An electrical network was then associated with this model. BIA and MRI measurements were made in six lean subjects (3 men and 3 women, age 32.2 +/- 6.9 yr). Assuming 0.85 S/m for the longitudinal conductivity of the muscle, the model predicted in the examined subjects an impedance profile that conformed well to the BIA impedance profile; predicted and measured resistances were similar (261.3 +/- 7.7 vs. 249 +/- 9 Omega; P = not significant). The resistance profile provided, through a simpler model, muscle area estimates along the lower limb and total leg muscle volume (mean 4,534 cm(3) for men and 4,071 cm(3) for women) with a mean of the absolute value of relative error with respect to MRI of 6.2 +/- 3.9. The new approach suggests that BIA can reasonably estimate the distribution and volume of muscles in the lower extremities of lean subjects.

Adipose Tissue↗
PubMed2002

The combination of single-dose montelukast and loratadine on exercise-induced bronchospasm in children.

The aim of the study was to evaluate the protective effect of single-dose, combination treatment comprising montelukast (5 mg) and loratadine (10 mg), on exercise-induced bronchoconstriction in asthmatic children. The combination was compared to placebo, loratadine and montelukast alone. Nineteen children were enrolled in a double-blind randomised, single-dose, crossover study. For each treatment patients undertook two treadmill exercise tests, 2 and 12 h respectively after single-dose administration. No significant differences were seen in the maximum fall in forced expiratory volume in one second (FEV1) 2 h after treatment and placebo. Whereas significant differences in maximum fall in FEV1 were observed between treatment groups 12 h after administration. Loratadine alone did not show any significant protection or any additional effect in comparison with montelukast alone. Single doses of montelukast and montelukast plus loratadine were significantly more effective than loratadine at 12 h. The present study, performed using single-dose treatments, demonstrated that maximal protective effect by montelukast was obtained 12 h after dosing and that montelukast plus loratadine did not result in significant additive bronchoprotective effects on exercise-induced bronchoconstriction.

Acetates↗
PubMed2001

Waist circumference and cardiovascular risk factors in prepubertal children.

OBJECTIVE: Intra-abdominal fat has been identified as being the most clinically relevant type of fat in humans. Therefore, an assessment of body-fat distribution could possibly identify subjects with the highest risk of adverse lipid profile and hypertension. Few data on the relationship between body-fat distribution and cardiovascular risk factors are available in children, especially before puberty. RESEARCH METHODS AND PROCEDURES: This cross-sectional study was undertaken to explore the relationship between anthropometric variables, lipid concentrations, and blood pressure (BP) in a sample of 818 prepubertal children (ages 3 to 11 years) and to assess the clinical relevance of waist circumference in identifying prepubertal children with higher cardiovascular risk. Height, weight, triceps and subscapular skinfolds, waist circumference, and BP were measured. Plasma levels for triacylglycerol, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were determined. RESULTS: Females were fatter than males (5.8 [3.5] vs. 4.8 [3.3] kg of fat mass; p < 0.01). Males had higher HDL cholesterol and ApoA1/ApoB plasma concentrations than females (p < 0.001 and p < 0.01, respectively). Waist circumference had a higher correlation with systolic and diastolic BP (r = 0.40 and 0.29, respectively; p < 0.001) than triceps (r = 0.35 and 0.21, respectively; p < 0.001) and subscapular (r = 0.28 and 0.16, respectively; p < 0.001) skinfolds and relative body weight (0.33 and 0.23, respectively; p < 0.001). Multivariate linear model analysis showed that ApoA1/ApoB, HDL cholesterol, total cholesterol/HDL cholesterol, and systolic as well as diastolic BP were significantly associated with waist circumference and triceps and subscapular skinfolds, independently of age, gender, and body mass index. DISCUSSION: Waist circumference as well as subscapular and triceps skinfolds may be helpful parameters in identifying prepubertal children with an adverse blood-lipids profile and hypertension. However, waist circumference, which is easy to measure and more easily reproducible than skinfolds, may be considered in clinical practice. Children with a waist circumference greater than the 90th percentile are more likely to have multiple risk factors than children with a waist circumference that is less than or equal to the 90th percentile.

Abdomen↗
PubMed2001

Is body mass index a measure of adiposity in elderly women?

OBJECTIVE: To evaluate the accuracy of body mass index (BMI) as a predictor of body fat in elderly women. RESEARCH METHODS AND PROCEDURES: A total of 1423 women aged 67 +/- 5 (mean +/- SD, range: 60 to 88) years were consecutively enrolled into the study. Fat mass (FM) was measured using DXA. RESULTS: BMI explained 72.9% of FM variance (p < 0.0001), with a root mean square error of estimate (RMSE) of 3.5 kg. After standardization of RMSE on the dependent variable as RMSE%, the prediction error equaled 15%. BMI explained 54.8% of FM% variance (p < 0.0001), with an RMSE of 4.1%, corresponding to an RMSE% of 11%. DISCUSSION: The relatively high RMSE% of the FM and FM%-BMI associations caution against the use of BMI as an adiposity index in individual elderly women. However, an error corresponding to 11% of FM% may be accepted for population studies of body fat in elderly women.

Absorptiometry, Photon↗
PubMed2001

Multi-component body composition models: recent advances and future directions.

OBJECTIVE: This overview examines concepts related to a category of body composition methods generally referred to as multi-component models, that is, those models that include three or more components. We summarize the rationale for, applications, and types of multi-component models along with sources of error. Our review presents the strengths and limitations of available models and identifies important future research directions.

Body Composition↗
PubMed2001

Does waist circumference predict fat gain in children?

OBJECTIVE: The aim of this study was to identify in a group of 8-y-old prepubertal children the anthropometric parameter with the highest prediction power of overweight, measured 4 y later. SUBJECTS: One-hundred and twelve Caucasian children (54 males, 58 females), aged 8.7+/-0.9 y, were studied. RESULTS: An analysis of the association between relative body mass index (BMI) at follow-up (%) and some indexes of adiposity like relative BMI (%), waist circumference, subscapular and triceps skinfolds, the sum of four skinfolds and percentage fat mass measured at baseline, showed that relative BMI (relBMI) at baseline had the highest association with relBMI at follow-up (r=0.77; P<0.001); waist circumference had a slightly lower significant association with relBMI at follow-up (r=0.74; P<0.001). In a multiple regression analysis, waist circumference (adjusted for age) accounted for approximately 64% of the variation of relBMI at follow-up (P<0.001). RelBMI measured at baseline accounted for approximately 59% of the variation of relBMI at follow-up (P<0.001). Multiple logistic regression analysis included waist circumference, adjusted for age, mother's BMI and relBMI measured at baseline as independent variables in the final equation. In particular, each centimeter increase of waist circumference at the age of 8 y doubled the risk of having a relBMI greater than 120% at the age of 12 y. CONCLUSION: The results of this study, the first which has approached this investigation in children, showed that waist circumference measured at the age of 8 y, which is simple to perform and easy to reproduce, may be a promising index to assess adiposity as well as to predict overweight at puberty.

Adipose Tissue↗
PubMed2001

Sexual dimorphism in circulating leptin concentrations is not accounted for by differences in adipose tissue distribution.

BACKGROUND: Circulating concentrations of leptin normalized to total adipose tissue mass are significantly greater in females than in males. Rates of leptin expression (per gram of adipose tissue) are significantly greater in subcutaneous (SAT) than visceral (VAT) adipose tissue and the relative amount of fat stored as SAT vs VAT is significantly greater in pre-menopausal females than in males. Gender-related differences in the relative amounts of SAT and VAT may account for the greater circulating leptin concentration relative to fat-mass in females than males. METHODS: We examined body composition and anatomic fat distribution by dual energy X-ray-absorptiometry (DEXA) and magnetic resonance imaging (MRI), and post-absorptive circulating concentrations of leptin and insulin in 58 subjects (26 females, 32 males). Stepwise multiple linear regression analyses, treating gender as a dichotomous variable, were performed to determine inter-relationships among leptin concentrations and insulin concentrations, VAT and SAT. RESULTS: Body composition by DEXA and MRI were highly correlated (r(2)=0.97, P<0.0001). There were significant gender effects on leptin/total fat mass (males, 0.17+/-0.01 ng/ml/kg; females, 0.49+/-0.05 ng/ml/kg; P<0.0001) and relative amounts of fat in SAT and VAT depots (ratio of SAT/VAT; males, 12.3+/-1.5; females, 32.9+/-3.2; P<0.0001). Circulating leptin concentration was significantly correlated with insulin concentration (P=0.001), SAT (P<0.0001) and gender (P=0.033). Circulating concentrations of insulin were significantly correlated with VAT, but not SAT, in males and with SAT, but not VAT, in females. CONCLUSIONS: The sexual dimorphism in the relationship between leptin and adipose tissue mass cannot be explained by differences in the relative amounts of VAT and SAT. Thus, the sexual dimorphism in plasma leptin concentration appears to reflect, at least in part, effects of circulating concentrations of gonadal steroids (especially androgens) and/or primary genetic differences that are independent of amounts of VAT or SAT.

Absorptiometry, Photon↗
PubMed2001

Unreliable use of standard muscle hydration value in obesity.

Intramuscular water content is assumed to be constant in humans independent of their anthropometric characteristics. To verify whether this assumption is correct, intramuscular water, proteins, glycogen, and both total and intramyocytic triglycerides were measured in 51 samples of rectus abdominis muscle obtained from 16 lean and 35 overweight and obese subjects (body mass index cutoff 24.9 kg/m2). Data (referred to as wet tissue) were analyzed by means of a composition model at the cellular level of the skeletal muscle (SM). The average SM water content was 76.3 +/- 3.3% in normal-weight individuals and 65.7 +/- 5.8% in obese subjects (P < 0.0001). Total triglycerides were 5.5 +/- 2.3% in controls and 19.0 +/- 7.0% in obese subjects (P < 0.0001). The intramyocytic triglyceride fraction was also increased in obese subjects. The composition model provides an explanation for the negative correlation between total triglycerides and intramuscular water, and some of the model parameters were determined from the experimental data. In conclusion, although the hydration of fat-free SM mass may be unchanged in obese subjects, the hydration of in toto muscle mass decreases as its lipid content increases.

Adult↗
PubMed2001

Effects of contingent television on physical activity and television viewing in obese children.

OBJECTIVE: Elevated television (TV) viewing and physical inactivity promote obesity in children. Thus, changes in physical activity and sedentary behavior seem critical to treating childhood obesity. PRESENT STUDY: Using a randomized, 2-arm design, this pilot study tested the effects of contingent TV on physical activity and TV viewing in 10 obese children. TV viewing was contingent on pedaling a stationary cycle ergometer for experimental participants but was not contingent on pedaling for control participants. The study was conducted over 12 weeks, including a 2-week baseline period. RESULTS: Multivariate analyses indicated that the intervention significantly increased pedaling and reduced TV-viewing time. During the treatment phase, the experimental group pedaled 64.4 minutes per week on average, compared with 8.3 minutes by controls. The experimental group watched 1.6 hours of TV per week on average, compared with 21.0 hours per week on average by controls during this phase. Secondary analyses indicated that the experimental group showed significantly greater reductions in total body fat and percent leg fat. Total pedaling time during intervention correlated with greater reductions in percent body fat (r = -0.68). CONCLUSIONS: Contingencies in the home environment can be arranged to modify physical activity and TV viewing and may have a role in treating childhood obesity. Contingent TV may be one method to help achieve this goal.

Behavior Therapy↗
PubMed2000

Cat sensitivity: 7-yr audit in children attending a paediatric allergy clinic in North Italy.

Sensitivity to cats and exposure to cat allergen is a common cause of asthma exacerbation in children. To date, there is no data on the prevalence of cat sensitivity in children living in North Italy. Therefore, a 7-yr survey was performed in patients attending an allergy clinic for the first time. Skin prick tests (SPT) for perennial allergens and for pollens relevant to the region were performed in 4,957 children attending the outpatient clinic 1992-1998. A questionnaire on present or past cat ownership was presented to all cat-skin prick test positive children. An evaluation of cat ownership on the general population was made by telephone interview on a random sample of 1,268 families living in the same area. With a 3-mm wheal as a positive cut-off 439 (8.85%) children had a positive SPT to cats. Of these 103 (23.4%) had a cat at home and 336 (76.6%) never had a cat in the house. With a greater positive cut-off(a wheal diameter > or =4 mm) 140 (2.8%) showed a positive SPT to cats of these 35 (25%) had a cat at home and 105 (75%) had only an indirect exposure to the pet. Of the telephone interviewed families; 16% stated they had a cat at home. Cat sensitivity is less prevalent in Italy, in this hospital based population, compared with other European countries and this is in agreement with a lower rate of cat ownership. Cat sensitivity was three times more frequent in children who never had a cat at home, than in children living with cats, when the selected positive cut-off was either a wheal diameter of 3 mm or > or =4 mm. Thus in a population with a low prevalence of cat ownership public exposure seems to be more important than domestic exposure for the development of sensitivity.

Animals↗