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Biomedical subjects

K Widhalm

Publications and source records attributed to K Widhalm.

At least 19 recordsLinked to original sources
PubMed2001

Underestimation of percentage fat mass measured by bioelectrical impedance analysis compared to dual energy X-ray absorptiometry method in obese children.

OBJECTIVE: The aim of the study was to investigate whether there is a difference between body fat mass percentage measured by BIA and DXA method. DESIGN: Transversal study, randomized. SETTING: Lipid and Obesity Outpatient Clinic, Department of Pediatrics, University of Vienna, Austria. SUBJECTS: Twenty-seven children and adolescents from the Lipid and Obesity Outpatient Clinic, Department of Pediatrics, University of Vienna, were included in the study (14 boys and 13 girls between 6 and 18 y; mean age 12.6 and 13.1 y). METHODS: The body fat percentage was measured with BIA (bioelectrical impedance analyzer BIA 2000-M) and DXA (dual energy X-ray absorptiometry) methods on the same day. RESULTS: The mean difference between the body fat mass percentage measured by BIA and DXA was 4.48 with a standard deviation of 2.93. The results measured by BIA were almost always lower than that by DXA by about 12%. The lower and upper limit of the difference in 95% confidence interval was -5.64 and -3.32. By paired t-test, these results were significantly different (P<0.001). The correlation between the two measurements was 0.826. The mean percentage of body fat mass measured by BIA was 34.86+/-7.08% and by DXA 39.75+/-5.63%. The differences were not changed by age and body fat percentage but they were by sex. CONCLUSIONS: The results of the study show that the body fat percentages measured by BIA and DXA method were significantly different. This is very important because BIA technique is a routine technique for clinical purposes. Adjustments to the formula used for calculating the total fat mass in obese children and adolescence are necessary. Underestimation of body fat percentage measured by bioelectrical impedance analysis compared to dual X-ray absorptiometry method in obese children is three times higher with boys than with girls.

Absorptiometry, Photon↗
PubMed2001

Does the BMI reflect body fat in obese children and adolescents? A study using the TOBEC method.

OBJECTIVE: Due to the fact that obesity is defined as excess of body fat mass, we tested the hypothesis whether the body mass index (BMI) can be used as a valid measure for the detection of the degree of obesity in individual obese children and adolescents. METHODS: A total of 204 obese children and adolescents (105 boys, 99 girls) aged 6-17 y, using total body electrical conductivity (TOBEC) for fat measurement, were included into this study. A multiple regression analysis was performed with percentage body fat (PBF) as dependent variable and BMI, age and sex as independent variables. First- and second-order interaction terms were also included. Since all interaction terms showed a significant influence on PBF, regression analysis was performed separately for boys and girls, dividing each group into two age subgroups (subjects younger than 10 y, and subjects 10 y or older). RESULTS: BMI and PBF were observed to be positively correlated (overall: r=0,65; P=0.0001; boys r=0.63 and girls: r=0.68). Through a multiple regression analysis 57% of the variance of PBF could be explained by the independent variables. In boys younger than 10 y 73% and in girls younger than 10 y 63% of the variance of PBF was explained by the BMI. In subjects 10 y or older the association was poor (boys: 27%; girls: 38%). It should be emphasized that there is a wide range in the relationship between PBF and BMI in the obese subjects. CONCLUSION: From these results we conclude that BMI might be a useful parameter for epidemiological studies: however in the individual pediatric patient, especially from 10 y onwards, it gives only a limited insight to the degree of obesity based on the definition.

Adipose Tissue↗
PubMed1999

Perceived benefits and barriers to physical activity in a nationally representative sample in the European Union.

OBJECTIVE: To examine the attitudes of consumers, in particular their perceived benefits and barriers to physical activity from all EU member states, and having a measure of prevailing levels of activity, inactivity and self-reported body weight and body shape. DESIGN: Cross-sectional survey using an interview-assisted face-to-face questionnaire. SETTING: The survey was conducted between March and April 1997 in the 15 member states of the EU. SUBJECTS: Overall, 15,239 EU subjects, classified according to sex, age (six levels) and highest level of education attained (primary, secondary or tertiary), completed the survey. Sample selection of subjects in each EU member state was quota-controlled to ensure they were nationally representative. RESULTS: The most important motivation for people to participate in physical activity is to maintain good health (42%), to release tension (30%) and to get fit (30%). The importance of the health argument is highest in older persons and in subjects with a primary education level. Only 13% of the EU population (16% of women, 10% of men) perceived losing weight as a benefit of physical exercise. The most important barriers to increase physical activity are work or study commitments (28%) and the subjects' belief that they are not 'the sporty type' (25%). There is considerable between-country variation in the answering pattern within the EU.

Adolescent↗
PubMed1999

Elevation of plasma leptin concentrations in obese hyperinsulinaemic hypothyroidism before and after treatment.

BACKGROUND: Plasma leptin is considered to play a role in maintenance of energy balance and body weight by neuroendocrine mechanisms. Thyroid hormones are permissive for adrenergic activation, which in turn has been shown to decrease leptin expression. This study was therefore designed to test the hypothesis that hyperthyroidism results in lower leptin concentrations, whereas hypothyroidism leads to higher plasma leptin concentrations. In addition, the effects of normalization of thyroid function on plasma leptin were investigated. MATERIALS AND METHODS: Fasting plasma leptin concentrations and body fat mass (total body electrical conductivity) were measured in patients with overt hypothyroidism and hyperthyroidism before and after successful treatment. Plasma leptin, glucose, insulin and free fatty acid concentrations were monitored during an oral glucose tolerance test (OGTT 75 g). RESULTS: Fasting plasma leptin concentrations were similar in lean patients, independently of their thyroid function (hyperthyroid 12.5 +/- 2 ng mL-1, hypothyroid 10.2 +/- ng mL-1, euthyroid 12.7 +/- 3 ng mL-1). In obese hypothyroid patients, plasma leptin was threefold higher (P < 0.0005) than in lean hypothyroid patients, twofold higher (P < 0.005) than in obese hyperthyroid patients matched for fat mass and 30% increased (P < 0.01) compared with obese euthyroid subjects. There were no differences between fasting and post-prandial (OGTT) leptin concentrations in any group. Normalization of thyroid function did not affect plasma leptin, which remained elevated (P < 0.005) in formerly obese hypothyroid patients. Plasma leptin was not associated with serum thyroid hormones but highly correlated with body mass index and body fat mass in all patients (r = 0.85, P < 0.001). Plasma leptin correlated with plasma insulin concentration only in hyperthyroid patients (P < 0.01, r = 0.64), who presented with blunted stimulation of insulin release and higher plasma glucose (P < 0.05) than hypothyroid subjects. CONCLUSION: The results indicate that (a) the correlation of leptin with body fat mass is preserved in thyroid dysfunction, (b) plasma leptin is markedly increased in obese hypothyroid hyperinsulinaemic patients and (c) plasma leptin is not affected by oral glucose loading.

Adult↗
PubMed1997

Diet does not ensure normal development in galactosemia.

This review deals with the treatment of inherited classical galactosemia by a lactose-free diet. Although, with dietary treatment, there is a remarkable improvement in the acute phase of the disease, the long-term outcome has been disappointing for most patients, especially regarding the central nervous system and ovarian dysfunction in females. There is a need for new approaches to treatment, in combination with diet therapy, that could improve the outcome of patients with galactosemia.

Galactosemias↗
PubMed1997

Perceived need to alter eating habits among representative samples of adults from all member states of the European Union.

OBJECTIVE: To examine the perceived need to alter eating habits among nationally-representative samples from each member state of the European Union (EU). DESIGN: A cross-sectional study in which quota-controlled, nationally-representative samples of approximately 1000 adults from each country completed a face-to-face interview-assisted questionnaire. SETTING: The survey was conducted between October 1995 and February 1996 in the 15 member states of the European Union. SUBJECTS: 14,331 subjects (aged 15 y upwards) completed the questionnaire. Data were weighted by population size for each country and by sex, age and regional distribution within each member state. RESULTS: 71% of EU subjects agreed with the statement 'I do not need to make changes to the food I eat, as it is already healthy enough'. There was wide variation between the member states ranging from 47% in Finland to 87% in Italy indicating agreement. Overall there was little difference between the sexes except in Austria, Belgium, Germany, Greece and Ireland, but the proportions of subjects agreeing with the statement generally increased with advancing age and decreased with higher levels of education. The effects of demographics were not consistent across member states. A total of 49% of EU subjects agreed with the statement 'I usually do not think of the nutritional aspects of the food I eat'. Significantly more females than males disagreed with the statement in all countries except Portugal. In all member states there were widespread beliefs that people in general should decrease their consumption of savoury snacks and increase their consumption of fruit and vegetables. CONCLUSIONS: The results of this study demonstrate that dietary advice may not be perceived as personally relevant among EU subjects. In addition important target groups for the promotion of healthy eating have been identified for example, males or subjects with low levels of education. Because of the variation in attitudes a single pan-EU healthy eating programme is unlikely to be effective for all countries or for different demographic groups.

Adolescent↗
PubMed1996

The clinical application of two newly developed lipid emulsions (Solipid 20% S&E) in critically ill patients.

OBJECTIVE: The clinical compatibility of two newly developed lipid emulsions based on soy oil (20%) emulsified with egg lecithin (12 g/l) or soy lecithin (15 g/l) (Solipid 20% E&S) has been compared. DESIGN: Double-blind prospective randomized study. SETTING: Intensive care unit of a university hospital. PATIENTS: 20 patients (16 men, 4 women, age 20-59 years) were entered into the study. INTERVENTIONS: One g of lipids/kg body weight per day was administered on day 1 and subsequently 2 g/kg/day on days 2-5. Blood was drawn once a day, lipids, lipoproteins, apoproteins and other routine clinical chemistry parameters were determined. RESULTS: No significant increase of total triglycerides could be observed. Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoproteins A I and B usually remained below the reference ranges. Electrolytes, uric acid and glucose, blood cells, parameters of liver and kidney function, coagulation and protein metabolism did not show relevant changes; only the activity of gamma-GT in both groups--independent of the sort of lecithin--increased significantly. CONCLUSION: The results indicate adequate elimination of both tested lipid emulsions from the plasma at usual clinical conditions. Therefore Solipid 20% S&E can be used in critically ill patients.

Adult↗
PubMed1995

Oxyradical damage and mitochondrial enzyme activities in the mdx mouse.

A number of studies have already been undertaken to investigate involvement of oxyradicals in muscle diseases by means of measurements of oxyradical protective enzymes. We investigated o-tyrosine, which is a biomarker for OH radical damage in vivo, in 10 mdx and 10 control mice. We also measured mitochondrial enzymes in muscle homogenates of 10 mdx and 10 control mice. Mdx mice had significantly elevated values for o-tyrosine, succinat-phenacinmetosulfat oxidoreductase. NADH O2 oxidoreductase and cytochrome C oxidoreductase. Our findings confirm the suggestion that elevated oxyradical production occurs in muscular dystrophies with lack of dystrophin. Furthermore, our results demonstrate that OH radical damage does not impair mitochondrial enzyme activities in the mdx mouse.

Animals↗
PubMed1994

Long-term follow-up of children with classical phenylketonuria after diet discontinuation: a review.

The age at which children suffering from classical phenylketonuria can safely discontinue their dietary therapy has been constantly disputed over the past decades. Recently, most phenylketonuria centers have begun to recommend a life-long diet, especially for female patients. Male patients are also advised to continue their diet until at least well into adult age. As a result of this new outlook in therapy management, we reviewed the existing literature and summarized all relevant long-term follow-up data of children who discontinued their debts at an early age, focusing on intellectual and neurological performance. The abilities of these children are compared during dietary treatment and again several years after diet discontinuation. Results show clearly that children maintaining their diets into their teens have fewer deficits than do those terminating their diets before 10 years of age. It seems essential to initiate diet early, and to keep blood phenylalanine levels < 600 mumol/L and well controlled to at least age 10 to ensure satisfactory long-term development of the patient. Furthermore, it seems highly justified to maintain a life-long diet which can be liberalized, but not completely discontinued in adulthood.

Adolescent↗
PubMed1994

Evaluation of clinical and biochemical parameters in children after consumption of microparticulated protein fat substitute (Simplesse).

OBJECTIVE: The objective of this randomized, double-blind, two-way crossover study in healthy children was to evaluate whether microparticulated protein (MPP, Simplesse) fat substitute had any effects on various clinical and biochemical parameters when compared to super premium ice cream (approximately 16% butterfat). METHODS: Twenty-four children (12 males, 12 females), 7-10 years of age, received their normal diet plus two consecutive 7-day treatment regimens consisting of one serving (approximately 196 mL) per day of either ice cream or a frozen dessert made with MPP. Three-day food diaries, routine hematologies, clinical chemistries, urinalyses, fasting plasma lipids and amino acids, vital signs and adverse experiences were compared between treatments. RESULTS: There were no clinically significant effects on any of the parameters following either treatment, although there were statistically significant increases in fasting plasma cholesterol and high-density lipoprotein cholesterol following ice cream when compared to MPP. There were no statistically significant differences between the two treatments in regard to macronutrient consumption. The only adverse experience related to treatment was one episode of vomiting following the ice cream. The children ingested more than five times the amount of MPP than that found in the 90th percentile of frozen dessert consumption by this age group. The protein intake (5.5 g/day) from MPP at this level of consumption would only modestly increase the total daily protein intake. CONCLUSION: Children ingesting approximately 196 mL/day of frozen dessert made with MPP did not show any clinically significant changes in various clinical and biochemical parameters.

Amino Acids↗