Physical Activity Is Associated with Attention Capacity in Adolescents

OBJECTIVE

To assess the relationships among physical activity, measured objectively, and attention capacity in European adolescents.

STUDY DESIGN

The study included 273 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Participants wore a uniaxial accelerometer for 7 days to measure physical activity. The d2 Test of Attention was administered to assess attention capacity. Multivariate analyses were used to study the association of attention capacity with each measure of physical activity. Receiver operating characteristic analysis was performed to determine thresholds that best discriminate between low and good attention capacity.

RESULTS

After controlling for potential confounding variables (age, sex, body mass index, parental educational level, fat mass, aerobic fitness, and center), adolescents' attention capacity test performances were significantly and positively associated with longer time spent in moderate or moderate-to-vigorous physical activity (MVPA) in free-living conditions (P < .05). Receiver operating characteristic curve analyses revealed that the physical activity thresholds that best discriminated between low/good attention capacities were ≥41 min·day(-1) for moderate, ≥12 min·day(-1) for vigorous, and ≥58 min·day(-1) for MVPA.

CONCLUSION

These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.

Five year trends on total and abdominal adiposity in Spanish adolescents

OBJECTIVE

To assess five years trends in total and abdominal fat in Spanish adolescents.

DESIGN

Two cross-sectional studies: adolescents from the city of Zaragoza (Spain) assessed during 2001-2002 and 2006-2007.

SUBJECTS

399 adolescents in 2001-02 and 392 adolescents in 2006-07.

MAIN OUTCOME MEASUREMENTS

Socio-economic status was assessed using the education level of both parents. A complete anthropometric assessment was performed in both surveys using the same methodology: weight, height, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh and calf) and circumferences (waist and hip). The body mass index (BMI) and the sum of 6 skinfold thicknesses were calculated. Body fat percentage (BF%) was also calculated by the formulas described by Slaughter et al.

RESULTS

After adjusting for age and pubertal status, only females showed a significantly decrease in weight, BMI and waist circumference, and a significant increase in the sum of 6 skinfolds (all P < 0.05 and Cohen's d ≥ 0.25) in 2006-2007, when compared to values obtained in 2001-2002. Males did not show any significant change between the two surveys. Concerning centile values, a slight general reduction was observed in weight, BMI and waist circumference for both males and females. On the contrary, the sum of 6 skinfolds and the BF% were higher in 2006-2007 than in 2001-2002.

CONCLUSION

According to these results, there might be a levelling-off in the trends of BMI, BF% and waist circumference in male adolescents from Zaragoza. In females, despite a trend towards higher body fat mass, there was a trend towards lower BMI and waist circumference values.

Body fat distribution reference standards in Spanish adolescents: the AVENA Study

OBJECTIVE

To present body fat patterning reference standards to identify children with a predominant distribution of body fat in the abdominal or truncal region of the body.

DESIGN

Cross-sectional study in a representative sample of Spanish adolescents aged 13-18 years.

SUBJECTS

A total of 2160 adolescents with a complete set of anthropometric measurements (1109 males and 1051 females).

MEASUREMENTS

Weight, height, body mass index, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh, calf) and waist and hip circumferences.

RESULTS

In the majority of the age groups, subscapular/triceps skinfolds ratio, trunk-to-total skinfolds percent (TTS%)and waist circumference values were significantly higher in males than in females; hip circumference was higher in females than in males, except at 15.5 years. In males, age showed a significant effect for all the body fat distribution indices; however, in females, the effect was only significant for triceps skinfold, waist and hip circumferences and waist-to-hip ratio. Smoothed age- and sex-specific triceps skinfold, subscapular skinfold, subscapular/triceps skinfolds ratio, TTS%, waist circumference and hip circumference, waist-to-hip and waist-to-height ratio percentile values for male and female adolescents have been established.

CONCLUSION

These reference data for waist circumference and the other fat patterning indices, together with data from other countries, will help to establish international central obesity criteria for adolescents. The presented percentile values will give the possibility to estimate the proportion of adolescents with high or low regional adiposity amounts.

Screening Performances of the International Obesity Task Force Body Mass Index Cut-Off Values in Adolescents

OBJECTIVE

To try to improve the International Obesity Task Force (IOTF) BMI cut-off values, in terms of prediction of body fat percentage assessed by dual-energy X-ray absorptiometry (DXA), in adolescents.

METHODS

Cross-sectional survey of the adolescents from the city of Zaragoza (Spain). For this analysis we have included 286 adolescents (116 boys and 170 girls) aged 13.0-17.9 years. Body mass index (BMI) was calculated as body weight (kg), divided by height (m) squared. The percentage of body fat (BF%) was estimated by the use of DXA.

RESULTS

We have calculated, new BMI cut-off values (AVENA cut-offs) to predict BF%, for boys and girls in each age group. In male adolescents, sensitivity was higher with the IOTF cut-offs (0.71, 95th C.I.: 0.44, 0.90) than with the AVENA ones (0.53, 95th C.I.: 0.28, 0.77), and specificity was very similar with both cut-off values (0.86 and 0.88, respectively), the differences being not statistically significant. In girls, both sensitivities (0.75 and 0.79, respectively) and specificities (0.90 and 0.92, respectively) were very similar with both cut-off values, and the differences, not significant.

CONCLUSIONS

Optimization of the IOTF BMI cut-off values, in terms of BF%, seems not to be possible in adolescents. The IOTF criteria should be used only for overweight and obesity screening; however, in clinical settings, a more accurate measure of body fat should be recommended.

Anthropometric body fat composition reference values in Spanish adolescents. The AVENA Study

OBJECTIVE

To determine reference values for body mass index (BMI), sum of six skinfolds (sigma6 skinfolds) and body fat percentage (BF%) in Spanish adolescents aged 13-18 years, included in the AVENA Study (Alimentación y Valoración del Estado Nutricional en Adolescentes: Food and Assessment of the Nutritional Status of Adolescents).

DESIGN

Multicentre cross-sectional study.

SETTING

Representative sample of Spanish adolescents.

SUBJECTS

The population was selected by means of a multiplestep, simple random sampling. The final number of subjects included in the AVENA Study was 2859 adolescents; 2160 adolescents had a complete set of anthropometric measurements and were then included in this study (1109 males and 1051 females).

INTERVENTIONS

Weight, height and six skinfold thicknesses were measured. As indices of total adiposity, we calculated BMI, summation sigma6 skinfolds and BF% with the formulas described by Slaughter et al.

RESULTS

Sigma6 skinfolds and BF% in each age group were significantly higher in females than in males. In males, age showed a significant effect for BMI, sigma6 skinfolds and BF%; however, in females, the effect was only significant for BF%. The percentile distribution was more disperse towards higher sigma6 skinfolds and BF% values in males when compared with females.

CONCLUSIONS

The presented percentile values will help us to classify adolescents in comparison with a well-established reference population, and to estimate the proportion of adolescents with high or low adiposity amounts.

SPONSORSHIP

The AVENA-Study was supported by the Spanish Ministry of Health (FIS 00/0015), and grants from Panrico SA, Madaus SA and Procter and Gamble SA. This study was also supported by Instituto de Salud Carlos III (Spain), RCESP (C03/09) and Spanish Ministry of Education (AP2003-2128).

Secular trends in waist circumference in Spanish adolescents, 1995 to 2000-02

Two studies, in 1995 and 2000-02, were compared to assess changes in waist circumference in adolescents. Between the two time periods, waist circumference increased significantly in males at 13 years and in females at 14 years. Significant changes in waist circumference were observed during the study period; the rates of change were 0.53 and 0.86 cm/y in boys and 0.67 and 0.87 cm/y in girls. Future morbidity in adolescents may be affected due to accumulation of excess central fat.

Body fat measurement in adolescents: comparison of skinfold thickness equations with dual-energy X-ray absorptiometry

OBJECTIVE

To compare the most commonly used equations to predict body fatness from skinfold thickness, in male and female adolescents, with dual-energy X-ray absorptiometry (DXA) as a reference method of fatness measurement.

DESIGN

Cross-sectional nutrition survey.

SETTING

General adolescent population from Zaragoza (Spain).

SUBJECTS AND METHODS

A total of 238 Caucasian adolescents (167 females and 113 males), aged 13.0-17.9 y, were recruited from 15 school groups in 11 public and private schools. The percentage fat mass (%FM) was calculated by using skinfold-thickness equations. Predicted %FM was compared with the reference %FM values, measured by DXA. The lack of agreement between methods was assessed by calculating the bias and its 95% limits of agreement.

RESULTS

Most equations did not demonstrate good agreement compared with DXA. However, in male adolescents, Slaughter et al equations showed relative biases that were not dependent on body fatness and the limits of agreement were narrower than those obtained from the rest of equations. In females, Brook's equation showed nonsignificant differences against DXA and the narrowest 95% limits of agreement. Only biases from Brook and Slaughter et al equations were not dependent on body fatness in female adolescents.

CONCLUSIONS

Accuracy of most of the skinfold-thickness equations for assessment of %FM in adolescents was poor at the individual level. Nevertheless, to predict %FM when a relative index of fatness is required in field or clinical studies, Slaughter et al equations may be used in adolescents from both sexes and the Brook equation in female adolescents.

Cardiac findings in adolescents with anorexia nervosa at diagnosis and after weight restoration

The aim of this study was to compare heart abnormalities in a group of young women with anorexia nervosa at diagnosis and after weight restoration. A total of 40 young women with anorexia nervosa were evaluated, at baseline, (diagnosis) and follow-up (9 to 18 months later) and matched with 40 healthy women of the same age and of normal weight. QT interval was measured from surface electrocardiograms. QT dispersion was defined as the difference between maximum QT and minimum QT occurring in any of the 12 leads. Left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular mass, left ventricular mass index, cardiac output, fractional shortening and fractional ejection, were measured by echocardiography. In anorexia nervosa patients, corrected QT interval and QT dispersion, significantly decreased from baseline to follow-up. Left ventricular end-diastolic dimension, left ventricular mass index, and cardiac output, in anorexia nervosa were significantly lower at diagnosis than at follow-up after weight restoration.

CONCLUSION

Adolescents with anorexia nervosa have significant functional and structural cardiac abnormalities; weight gain was associated with improvement. Appropriate attention should be paid to cardiac involvement.

Electrocardiographic and echocardiographic findings in malnourished children

OBJECTIVE

To compare heart abnormalities in a group of malnourished children with a control group and to describe their predictive variables.

METHODS

Thirty children with malnutrition were matched with thirty healthy children. Anthropometry, plasma levels of albumin and electrolytes were determined. Among others, corrected QT interval (QTc) and QT dispersion (QTd: difference between the maximum and the minimum QT) were measured in 12-lead electrocardiogram; and left ventricular mass (LVm) and left ventricular mass index (LVmi) were measured by echocardiography. Regression analyses were performed with cardiac findings as dependent variables and anthropometric and biochemical data as independent variables.

RESULTS

Plasma levels of albumin, potassium and calcium were lower in malnourished children. QTc and QTd were significantly greater in patients with malnutrition than in controls (QTc: 445.9 +/- 31.4 vs. 400.9 +/- 17.7 ms, p = 0.000; QTd: 76.4 +/- 34.1 vs. 47.9 +/- 10.2 ms, p = 0.000). LVm and LVmi were significantly lower in malnourished children (LVm: 55.3 +/- 10.3 vs. 71.4 +/- 6.9 g, p = 0.000; LVmi: 46.5 +/- 6.6 vs. 60.5 +/- 4.9 g/m2, p = 0.000). The body mass index (kg/m2) was the most powerful predictor of the variability in QTc (39.1%), LVm (48.1%) and LVmi (51.2%).

CONCLUSIONS

Important electrocardiographic and echocardiographic abnormalities have been found in malnourished children associated with their nutritional status. Special precaution must be taken about the possibility of occurrence of arrhythmias and sudden death related with malnutrition.

Overweight, obesity and body fat composition in spanish adolescents. The AVENA Study

OBJECTIVE

To describe the prevalence of overweight and obesity in the Spanish adolescent population and its relationship with the socioeconomic status, and to assess their body fat composition and compare these results with previous data from our own country.

DESIGN

Cross-sectional multicenter study conducted in five Spanish cities (Granada, Madrid, Murcia, Santander and Zaragoza) in 2000-2002.

SUBJECTS

2,320 adolescents with complete set of anthropometric measurements, 1,192 boys and 1,128 girls.

MEASUREMENTS

Body mass index calculated from weight and height measurements, and body fat percentage calculated from skinfold thickness measurements.

RESULTS

Overweight + obesity prevalences were 25.69 and 19.13% in boys and girls, respectively. Overweight + obesity prevalence increased in boys from high to medium-low socioeconomic status categories (p = 0.015); meanwhile, there was not a significant effect of socioeconomic status in girls. In males, overweight + obesity prevalence changed from 1985 to 2000-2002 from 13 to 35% and in females from 16 to 32%. The rate of change in overweight + obesity prevalences seems to increase in the last years; from 0.88 (1985 to 1995) to 2.33%/year (1995 to 2000-2002) in males and from 0.5 (1985 to 1995) to 1.83%/year (1995 to 2000-2002) in females. The rate of body fat percentage increase was similar between 1980 and 1995 and between 1995 and 2000-2002: 0.26 and 0.23%/year, respectively, at 13 years of age, and 0.16 and 0.17%/year, respectively, at 14 years of age.

CONCLUSION

We observed elevated overweight and obesity prevalences in Spanish adolescents, similar to those observed in other European countries. There is a significant inverse relationship between socioeconomic status and overweight + obesity, but only in boys. The rate of change in overweight prevalence in Spanish adolescents seems to increase, and the rate of increase of body fat percentage seems to be similar as in previous years.

Psyllium fibre and the metabolic control of obese children and adolescents

In children and adolescents from developed countries, obesity prevalence has strongly increased in the last decades and insulin resistance and impaired glucose tolerance are frequently observed. Some dietary components such as low glycemic index foods and dietary fibre could be used in order to improve glucose homeostasis in these children. Psyllium or ispaghula husk (the husk of the seeds of Plantago ovata) is a mixture of neutral and acid polysaccharides containing galacturonic acid with a ratio of soluble/insoluble fibre of 70/30. Some foods could potentially be enriched with psyllium, like breads, breakfast cereals, pasta and snack foods. The aim of this review was to assess the usefulness of psyllium in the management of obese children and adolescents with abnormalities of carbohydrate and lipid metabolism. After psyllium supplementation, the percentage change in postprandial glucose in type 2 diabetes patients, ranged from -12.2 to -20.2%. In hypercholesterolemic children, the effect of psyllium in LDL-cholesterol serum concentrations ranged from 2.78 to -22.8%; the effect in HDL-cholesterol from -4.16 to 3.05%; and the effect on triglycerides from 8.49 to -19.54%. The reviewed evidence seems to show that psyllium improves glucose homeostasis and the lipid and lipoprotein profile; however, more well controlled trials and further studies are needed to clarify it's effects and the mechanisms involved.

[Cardiac disorders in young women with anorexia nervosa]

INTRODUCTION AND OBJECTIVES

The objective of this study was to compare heart abnormalities in young women with anorexia nervosa and in a control group of the same age and sex. Patients and method. We report a matched case-control study of 30 adolescents with anorexia nervosa and 30 healthy women of the same age with normal weight. An electrocardiogram and echocardiogram were done. Heart parameters were measured on the electrocardiographic tracings, and QT dispersion was defined as the difference between maximum QT and minimum QT in any of the 12 leads. Diameter, mass and left ventricular mass index were measured.

RESULTS

QT and corrected QT intervals were significantly greater in patients with anorexia nervosa than in the control group. QT dispersion and corrected QT dispersion were significantly greater in anorexia nervosa than in the control group (QTd, 59.3 23.0 vs 38.4 8.0 ms; p = 0.000; QTcd, 56.5 24.2 vs. 40.3 21.8 ms; p = 0.011). Left ventricular mass was significantly lower in young women with anorexia nervosa. We found a significant relationship between body mass index and left ventricular mass index, and between the former and corrected QT dispersion.

CONCLUSIONS

Adolescents with anorexia nervosa show significant cardiac disorders in comparison to healthy women of the same age. This finding may be a useful indicator of the risk of arrhythmia and sudden death in patients with anorexia nervosa.

Waist circumference for the screening of the metabolic syndrome in children

AIM

To identify the best anthropometric predictor of the metabolic syndrome in children.

METHODS

Screening performance was evaluated in a clinical setting. The study included 140 children: 72 non-obese and 68 with non-syndromal obesity. Body mass index (BMI), waist circumference and triceps/subscapular skinfolds ratio were used as predictor variables, and systolic blood pressure, diastolic blood pressure, glucose, uric acid, fasting insulin, triglycerides and HDL-C as metabolic syndrome variables.

RESULTS

The areas under the receiver operating characteristic (ROC) curves were 0.849 (95% CI: 0.780, 0.919) for BMI, 0.868 (95% CI: 0.801,0.934) for waist circumference and 0.834 (95% CI: 0.757,0.910) for the triceps/subscapular skinfolds ratio. No statistically significant differences were found for the three areas under the ROC curves. The point on the ROC curve closest to 1 corresponded to the 65th percentile for BMI, to the 70th percentile for waist, and to the 40th percentile for the triceps/subscapular skinfolds ratio.

CONCLUSION

Waist circumference seems to be the best predictor of children with the metabolic syndrome in paediatric clinical settings.

Serum mineral levels in children with intestinal parasitic infection

Parasitic infections are highly prevalent in the general population. A relation between a parasitic infection and absorption of minerals is not an easy task. Serum levels of copper, zinc and magnesium were prospectively measured in 64 children with intestinal parasitic infection. Thirty-nine children with Enterobius vermicularis were treated with pyrantel pamoate and 25 children with Giardia lamblia with tinidazole and metronidazole. Three months after treatment, significant differences in serum copper, zinc and magnesium were seen in patients with E. vermicularis infection, and in serum magnesium levels in patients with G. lamblia. Although the pathogenic mechanism is not clear, these findings could reflect a deficiency related to malabsorption due to mucous affection. Early detection and treatment of intestinal parasitosis could avoid these serum mineral deficiencies.

Leptin and metabolic syndrome in obese and non-obese children

Metabolic syndrome is characterized by a clustering of metabolic abnormalities: insulin resistance - hyperinsulinemia, dyslipidemia (high triglycerides and low HDL - cholesterol serum concentrations), impaired glucose tolerance and/or type 2 diabetes, and hypertension. The aim of this study was to analyse the role of different variables of metabolic syndrome, including leptin, in 74 non-obese children and 68 children with non-syndromal obesity. As metabolic syndrome variables, we have included body mass index, waist circumference, trunk-to-total skinfolds (%), systolic blood pressure, diastolic blood pressure, glucose, uric acid, fasting insulin, triglycerides and high-density lipoprotein-cholesterol (HDL-C). Factor analysis showed 4 factors in each group. In non-obese children, waist circumference, BMI, fasting insulin, triglycerides, trunk-to-total skinfolds (%), leptin and uric acid loaded positively on factor 1, and HDL-C loaded negatively on this factor; systolic and diastolic blood pressure had high positive loadings in factor 2; HDL-C and leptin showed positive loadings and triglycerides and uric acid, negative loadings in factor 3; and, finally, glucose and insulin showed positive loadings in factor 4. These four factors explained 72.16 % of the total variance in the non-obese group. In obese children, BMI, waist circumference, leptin, diastolic blood pressure and systolic blood pressure loaded positively on factor 1; diastolic blood pressure, trunk-to-total skinfolds (%), uric acid and systolic blood pressure showed high positive loadings in factor 2; fasting insulin, glucose and triglycerides showed positive loadings in factor 3; and, finally, triglycerides showed positive loadings and HDL-C negative loadings in factor 4. These four factors explained 74.18 % of the total variance in the obese group. Our results point to a different homeostatic control of metabolic syndrome characteristics in obese and non-obese children. Leptin seems to play a key underlying role in metabolic syndrome, especially in the obese group.

Resting energy expenditure in children and adolescents: agreement between calorimetry and prediction equations

BACKGROUND AND AIMS

To assess the degree of agreement between indirect calorimetry and five equations commonly used to predict resting energy expenditure (REE) in obese and non-obese children and adolescents.

METHODS

In 116 children and adolescents (57 obese and 59 non-obese) aged between 7.8 and 16.6 years, REE was measured (MREE) by open-circuit indirect calorimetry under standardized conditions. REE was predicted (PREE) in all subjects with equations from the Food and Agriculture/World Health Organization/United Nations University (FAO/WHO/UNU), Maffeis et al., Harris and Benedict, and two from Schofield: one using weight (W) and one using height and weight (H-W). Agreement between indirect calorimetry and equations was assessed following the Bland-Altman method.

RESULTS

In the entire cohort group, only data from FAO/WHO/UNU, Schofield-W and Schofield-HW equations showed non-statistic differences against calorimetry results. When agreement between equations and calorimetry was tested, Schofield-HW equation showed the lowest mean MREE-PREE difference: 3.7 kcal/d (limits of agreement -293 and 300 kcal/d; 95% confidence interval for the bias -24.0 to 31.5 kcal/d) and the best agreement. Group by group, equations which obtained the best agreement were: FAO/WHO/UNU in girls, Schofield-HW in boys, Schofield-HW in obese, and Schofield-W in non-obese.

CONCLUSIONS

Until more accurate prediction equations are developed, we recommend Schofield-HW equations for REE studies with a mixed population of obese and non-obese children and adolescents; however, FAO/WHO/UNU equation may also be useful in girls and Schofield-W equation in non-obese children.

Vitamin B12 and folic acid in children with intestinal parasitic infection

OBJECTIVE

To determine prospectively plasma levels of vitamin B12 and folic acid in children with intestinal parasitic infection before and three months after antiparasitic treatment.

METHODS

3036 stool samples were collected from 1959 children and 939 cello-tape anal swabs were taken from 688 children for intestinal parasite investigation. Of these, 155 children were identified as having a parasitic infection; however, only 86 were followed up during this study: 26 children with Giardia lamblia infection were treated with tinidazole and metronidazole, pyrantel pamoate was used in the treatment of 40 children with Enterobius vermicularis, and 20 patients infected with Cryptosporidium parvum received only symptomatic treatment. Vitamin B12 and folic acid levels were measured by radioimmunoassay, before and three months after the completion of treatment.

RESULTS

Vitamin B12 serum concentrations did not show any significant differences among the three groups. There was a significant increase in vitamin B12 serum concentrations after three months of anti-parasitic treatment (630.57+/-200.97 vs. 667.97+/-181.55 pg/dL, p = 0.002, n = 86). Paired analysis in each group showed only significant increases for vitamin B12 in the Giardia lamblia group and in the Enterobius vermicularis group. No statistically significant differences were found for folic acid serum concentrations before and three months after treatment.

CONCLUSIONS

Patients with symptomatic infection by Giardia lamblia and Enterobius vermicularis have lower vitamin B12 levels than asymptomatic patients. This could reflect a more affected intestinal mucous. These results could present the opportunity to treat these parasitic infections and to use vitamin B12 supplementation in symptomatic children with Giardia lamblia and Enterobius vermicularis infection.

Determinants of resting energy expenditure in obese and non-obese children and adolescents

Resting energy expenditure (REE) is the largest component of total daily energy expenditure. Objectives of this study were to examine whether differences in REE exist after obesity develops in a group of children and adolescents, and to determine the effects of body composition, gender, age, pubertal development and parental obesity on REE. In 116 Caucasian children and adolescents (57 obese and 59 non-obese), aged 7.8 to 16.6 years, REE was assessed by open-circuit indirect calorimetry and different anthropometric variables and bioelectrical impedance were obtained (weight, height, skinfold thicknesses, waist and hip circumferences). Anthropometric indices and body compartments were calculated: the body mass index, surface area (SA), fat-free mass (FFM), fat-mass (FM) and percentage of FM. Differences between obese and non-obese subjects were tested and stepwise multiple regression analysis was performed with REE as dependent variable. Results show that REE was significantly higher in obese than in non-obese children and adolescents but REE/FFM ratio was not significantly different between these groups. In the non-obese group, FFM explained 73.1% of the variability in REE and gender, age and SA added 3.8%, 2.6%, and 2.6% to it, respectively. In the obese group, FFM was also the most powerful predictor of REE with 72.3%, followed by waist circumference and age with 2.5% and 2.1%, respectively. These results show that REE differences between obese and lean children do not seem to justify the maintenance of obesity. The main determinant of REE is FFM in both groups. No significant contribution of FM, pubertal development or parental obesity in REE was found in children and adolescents.

Secular increases in body fat percentage in male children of Zaragoza, Spain, 1980-1995

BACKGROUND

Data on temporal changes on total body fat percentage (TBF%) are scarce, and no such data are known to exist in Spain. The aim of our study was to describe secular increases in TBF% in male children and adolescents of Zaragoza, Spain, from 1980 to 1995.

METHODS

The samples analyzed in the present study have been included in two cross-sectional surveys conducted in 1980 and 1995. The samples selected for the 1980 and 1995 surveys comprised 1553 and 701 male children with ages ranging from 6.0 to 14.9 years. Weight, height, and four skinfold thicknesses were measured. From these measurements we have calculated TBF%.

RESULTS

Concerning body mass index (BMI), we have observed significant increases from 8.5 to 11.5 years, ranging in this age group from 0.80 to 1.45 kg/m(2). TBF% showed significant increases at all age groups, with percentage increases of 2.46% at 13.5 years and 6.03% at 11.5 years.

CONCLUSIONS

We have shown a secular increase in TBF% in children aged 6.0 to 15.0 years that is greater than the increase in BMI. The similarity of our findings for both relative weight and skinfold thickness, even with less significant differences for BMI, suggests that, in children of Zaragoza, Spain, adiposity has increased during the 1980-1995 period.

Secular changes in body fat patterning in children and adolescents of Zaragoza (Spain), 1980-1995

OBJECTIVE

To examine whether children and adolescents of Zaragoza (Spain) are becoming centrally obese to a greater extent than would be predicted by their relative body weights.

DESIGN

Two cross-sectional surveys conducted in 1980 and 1995.

SUBJECTS

The samples selected for the 1980 and 1995 surveys comprised 1553 and 701 male children, and 1311 and 659 female children, respectively, with ages ranging from 6.0 to 14.9 y.

MEASUREMENTS

We measured four skinfold thicknesses (biceps, triceps, subscapular, suprailiac) and calculated some indices of fat patterning: triceps/subscapular skinfolds (T/SS), biceps+triceps/subscapular+suprailiac skinfolds (B+T/SS+SI), and (subscapular+suprailiac/biceps+triceps+subscapular+suprailiac skinfolds)x100 (trunk-to-total skinfolds %).

RESULTS

In males, B+T/SS+SI, and trunk-to-total skinfolds % showed a significant trend to a central pattern of fat distribution from 1980 to 1995, at the ages of 6.5-11.5 y. In females, B+T/SS+SI and trunk-to-total skinfolds % showed a significant trend to a central pattern of fat distribution from 1980 to 1995, at the ages of 6.5 and 7.5 y. Similar results were obtained when we adjusted for BMI values.

CONCLUSION

We have observed a trend to a central pattern of adipose tissue distribution, especially in males and at the youngest ages studied (6-11 y in males, and 6-7 y in females). These observations were independent of trends in BMI.

Sociodemographic factors and trends on overweight prevalence in children and adolescents in Aragón (Spain) from 1985 to 1995

From 1985 to 1995, the Aragón School Health Examination Surveys staff has surveyed the whole population of children (age 6-7 years) and adolescents (age 13-14 years). A total of 90,997 children (age 6-7 years) were examined in the nine cross-sectional surveys conducted between 1985 and 1995. A total of 106,284 adolescents (age 13-14 years) were also examined. We defined overweight when the body mass index was > or = 95th percentile. The measure of association between overweight and the other variables studied was the odds ratio, which was calculated by logistic regression. In the children and adolescents studied, the probability to be overweight was higher in the rural than in the urban areas. In the adolescents, the probability to be overweight was higher in the public than in the private schools. Our results also show a significant increase in the prevalence of overweight children in the region of Aragón (Spain) during the 1985-1995 decade, especially in males. Prevention of overweight in the populations at risk would help reduce social inequality in health, a major challenge for public health policy.

Body mass index, triceps skinfold and waist circumference in screening for adiposity in male children and adolescents

Simple anthropometric measurements and indices are the most commonly used tools for assessing body composition. Only a few papers have examined the sensitivity and specificity of the body mass index (BMI) against total body fat percentage (TBF%) from underwater weighing in children and adolescents. The objective of the study was to evaluate the screening performance of BMI, triceps skinfold thickness and waist circumference for excess TBF%. A total of 175 healthy volunteer males, aged 7.0-16.9 y, participated in the study. TBF% was measured using underwater weighing as the reference method. Receiver operating characteristic (ROC) curves were constructed to assess the value of the three anthropometric measurements as a screening measure for total adiposity. Sensitivity and specificity were calculated at several percentile cut-offs for BMI, triceps skinfold and waist circumference. The areas under the ROC curves were also calculated, and were 0.86 for BMI, 0.90 for triceps skinfold and 0.88 for waist circumference. The point on the ROC curve closest to 1 corresponded to the 70th percentile for BMI, to the 75th percentile for triceps skinfold, and to the 70th percentile for waist circumference.

CONCLUSION

BMI, triceps skinfold and waist circumference predicted total fat content well in male children and adolescents.

Postprandial triglyceridemia in obese and non-obese adolescents. Importance of body composition and fat distribution

BACKGROUND

It has recently been shown that obese adults have a disturbed metabolism of postprandial lipoproteins, resulting in postprandial hypertriglyceridemia. To the best of our knowledge, there are no data about postprandial triglyceridemia in obese and non-obese children and adolescents.

SUBJECTS

12 obese and 12 non-obese adolescents, aged 11.0 to 13.8 years.

METHODS

Body composition and fat distribution (waist-to-hip circumference ratio and triceps/ subscapular skinfold thickness ratio) were assessed by anthropometry. An oral fat tolerance test was carried out, and fasting and postprandial lipid-lipoprotein serum concentrations were measured.

RESULTS

We observed a significant increase in triglyceride serum concentrations 2 and 4 hours after the oral fat load, in both obese and non-obese adolescents. In obese and non-obese adolescents there were significant correlations between some variables of postprandial lipemia and the studied indices of body fat distribution. When we compare postprandial lipemia in adolescents having a central pattern of fat distribution with those having a peripheral pattern of fat distribution, we observed higher variables related to postprandial lipemia in those having a central pattern of fat distribution compared with those with a peripheral pattern (sum of serum triglyceride concentrations: 6.06 vs 4.41, p = 0.0243).

CONCLUSIONS

We present a protocol to study postprandial lipemia in children and adolescents that allowed us to observe significant changes after an oral fat load. Results obtained indicate that the pattern of distribution of adipose tissue may be more important for lipid metabolism disturbances than total adipose tissue per se.

Trends in body mass index and overweight prevalence among children and adolescents in the region of Aragón (Spain) from 1985 to 1995

OBJECTIVE

To analyse trends in body mass index (BMI) and overweight prevalence for children and adolescents in the region of Aragón (Spain), from 1985 to 1995.

DESIGN

Nine cross-sectional examinations of schoolchildren conducted yearly from 1985 to 1995.

SUBJECTS

A total of 90,997 children (45,970 males and 45,027 females) in the first school year (6-7 y of age); 106,284 scholars (52,772 males and 53,512 females) in the last school year (13-14 y of age).

MEASUREMENTS

Heights and weights were measured and BMI (kg/m2) was calculated.

RESULTS

We observed a trend to higher BMI values across the surveys, by sex and age. The secular trends in BMI showed the largest increases at the upper ends of the distribution, especially in males. In children in the first school year, prevalences of overweight were higher in females than in males (P<0. 001); however, in adolescents in the last school year, prevalences were higher in males than in females (P<0.001). We observed a significant trend in overweight prevalence from 1985 to 1995 in children from the first school year (P=0.0183, in males and P=0.0168, in females). In children in the last school year there was only a significant trend in males (P<0.0001).

CONCLUSION

Significant changes in BMI occurred in the population studied during the period 1985-1995, but these changes differ by age and sex. The increasing skewness of BMI in the upper percentiles of the population, especially in boys, suggests that, not only is the pediatric population getting fatter, but the fatter members are becoming more obese. Our results also show a striking increase in the prevalence of overweight children in the region of Aragón (Spain) during the 1985-1995 decade.

Assessment of nutritional status and body composition in children using physical anthropometry and bioelectrical impedance: influence of diurnal variations

BACKGROUND

To observe whether there are diurnal variations when assessing children's body composition, using physical anthropometric and bioelectrical impedance (BI) methods.

METHODS

In 32 children (18 females and 14 males) aged between 7.1 and 14.9 years, weight, height, arm circumference (AC), four skinfolds, and total body impedance (Z) were measured at 8 A.M., 12 noon, 4 P.M., and 8 P.M. on the same day. Body mass index (BMI), skinfolds sum (SS), total body water (TBW), fat-free mass (FFM), and fat mass (FM) were also calculated at these times.

RESULTS

Height at 8 P.M. was 1.156 +/- 0.54 cm less than at 8 A.M. (P < 0.001) and BMI increased 0.434 +/- 0.29 kg/m2 at 8 P.M. (P < 0.001). Weight, SS and AC underwent no significant changes in the course of the day. Z was 5.83% less at 8 P.M. than at 8 A.M. (P < 0.001), yielding a TBW and FFM increase at 8 P.M. of 0.855 +/- 1.061 and 1.173 +/- 1.47 kg, respectively (P < 0.001).

CONCLUSIONS

In children there is a diurnal decrease in height, impedance and FM, and an increase in BMI, TBW, and FFM. These factors must be taken into account when using such methods for assessing nutritional status in childhood.

Waist circumference values in Spanish children--gender related differences

OBJECTIVE

To obtain reference values of the waist circumference in Spanish children, and to investigate their dependence on age and gender.

DESIGN

Cross-sectional study.

SETTING

General school-age population.

SUBJECTS

A representative sample of the schools in Zaragoza, Spain, was drawn from seven schools. The population selected comprised 1728 children with ages ranging from 6.0-14.9y. Of the original sample, 368 children (21.29%) were excluded because of chronic diseases or refusal. Finally, 1360 children and adolescents: 701 boys and 659 girls, were studied.

INTERVENTIONS

Waist and hip circumferences were measured with an unelastic tape.

RESULTS

Waist circumference tended to be higher in males than in females and this difference was significant after 11.5y. In general, hip circumference was higher in females than in males (statistically significant differences at 7.5, 10.5, 12.5 and 13.5 y). In general, percentile values of waist circumference were higher in males than in females, especially after 12.5 y. Difference between males and females on percentile 95 at 14.5 y was 7.6 cm. Hip was greater than waist in both sexes, and the two curves run nearly parallel in males. In females, while hip enlarges continuously, waist shows the reverse tendency between 11.5 and 14.5 y.

CONCLUSIONS

Waist circumference showed higher values in boys than in girls, especially after 11.5 y, and waist values increase with age both in males and females. These findings justify the use of age and gender specific reference standards.

Skinfold thickness measurements are better predictors of body fat percentage than body mass index in male Spanish children and adolescents

OBJECTIVE

To develop equations, from some simple anthropometric measurements, for the prediction of body density from underwater weighing in male spanish children and adolescents.

SUBJECTS

One hundred and seventy-five males, aged 7.0-16.9 y, participated in this study, they were recruited from primary and secondary schools.

MEASUREMENTS

Body weight and height and skinfold thicknesses by anthropometry, body density by underwater weighing.

RESULTS

Correlations between body density and body mass index (BMI) were high until 14.0-16.9y. Correlations between body density and log sigma 4 skinfolds were higher than those with BMI at all ages. Log sigma 4 skinfolds explained between 61% (14.0-16.9 y) and 68% (11.0-13.9 y) of the body density variance. Regression equations for body density from BMI and triceps skinfold thickness explained between 51% (14.0-16.9y) and 68% (7.0-10.9 y) of the body density variance.

CONCLUSIONS

The best estimators of body density in the children and adolescents studied were log sigma 4 skinfolds and a combination of BMI and triceps skinfold.

Fat distribution in obese and nonobese children and adolescents

BACKGROUND

It is not known whether fat deposition in obese children and adolescents occurs in the body's central or peripheral regions.

METHODS

A representative sample of children was drawn from the schools of Zaragoza, Spain. The population selected comprised 1728 children ranging in ages from 6 to 14.9 years. Of the original sample, 368 children (21.29%) were excluded because of chronic diseases or refusal to participate. The waist-to-hip circumference ratio and the triceps-to-subscapular skin-fold thickness ratio were calculated and served as indexes of body fat distribution. The children were divided into tertiles according to standard deviation score of body mass index.

RESULTS

Both in boys and in girls, waist-to-hip circumference ratio was higher in tertile 3 than in the other two tertiles, and triceps-to-subscapular skinfold thickness ratio was lower in tertile 3 than in the other two tertiles. Waist-to-hip circumference ratio was higher and triceps-to-subscapular skinfold thickness ratio was lower in obese than in nonobese children and adolescents of both sexes.

CONCLUSIONS

Increased adiposity may be accompanied by an increase of fat depot in the abdominal region. In obese children and adolescents, fat deposition seems to occur in the body's central regions.

Indices of body fat distribution in Spanish children aged 4.0 to 14.9 years

BACKGROUND

Reference values for the main indices of body fat distribution in children are not available.

METHODS

The study population comprised 1638 Caucasian children and adolescents: 848 boys and 790 girls, with ages ranging from 4.0 to 14.9 years, and living in the central part of Spain (Provincia de Zaragoza). The waist-to-hip circumference ratio and the triceps-to-subscapular skinfold thickness ratio were measured.

RESULTS

In boys, mean waist-to-hip circumference ratio ranges from 0.834, at 13.5 years, to 0.896 at 4.5 years. In girls, waist-to-hip circumference ratio ranges from 0.756, at 14.5 years, to 0.877, at 4.5 years. We observed a decrease of waist-to-hip circumference ratio with age, especially in girls. In boys, triceps-to-subscapular skinfold thickness ratio ranges from 1.360, at age 14.5, to 1.704, at age 5.5. In girls, triceps-to-subscapular skinfold thickness ratio ranges from 1.468, at age 13.5, to 1.727, at age 9.5. We observed a decrease with age only in boys.

CONCLUSIONS

We present reference values for the main indices of body fat distribution, which could be useful in clinical practice. However, research is needed that will compare these indices with data on body fat distribution obtained by a gold standard method, such as computed tomography or magnetic resonance imaging.

Seasonality of cryptosporidiosis in children

The seasonal distribution of cryptosporidiosis in children in Aragón, a region in northeastern Spain, was determined. Over a period of six years (October 1988 to September 1994), 10,034 stool samples from 4,508 children with gastrointestinal symptoms were analyzed for this purpose. The age of the patients ranged from 1 month to 14 years. Cryptosporidium oocysts were identified in 87 (1.93%) patients. Prevalence was highest (6.20%) in children aged 1 to 3 years old. The prevalence was significantly higher in the autumn-winter period (October to March) than in the spring-summer period (April to September) in the whole population (2.41% vs. 1.35%, p = 0.010) and in the 1- to 3-year-old age group (8.44% vs. 3.20%, p = 0.002), but not in the other age groups. A possible relationship of this pattern to attendance at child care centres is suggested.

Detection of Cryptosporidium oocysts in extra-intestinal tissues of sheep and pigs

Extra-intestinal infections by Cryptosporidium parvum have been detected in pigs and sheep. Detection was carried out by imprints of the mucosa of different organs and viscera in 55 sheep and 57 pigs slaughtered at three abattoirs in Zaragoza (northeast Spain). Imprints were stained by using a modified Ziehl-Neelsen technique. In addition to intestinal infections, cryptosporidial oocysts were found in the gall-bladders of two pigs which were 2 months old, and in some organs of sheep aged 5 days or more, including the gall-bladder (5), mesenteric lymph nodes (2), trachea (7), lung (3) and the uterus of one lamb.

[Magnetic resonance in Hallevorden-Spatz disease]

The Hallevorden-Spatz disease should be suspected in children or young people with motor, pyramidal or extrapyramidal symptomatology and deterioration of superior functions specially upon the existence of family history. Pathognomonic diagnosis may only be obtained by necropsy but magnetic resonance images, although not pathognomic, are sufficiently characteristics to strongly support the diagnosis. Four cases of Hallevorden-Spatz disease are presented with special emphasis on the MR images characteristic of this disease.

Relationship of body fat distribution to metabolic complications in obese prepubertal boys: gender related differences

Our purpose was to assess the relationship of obesity and body fat distribution to serum glucose values, insulin concentration and insulin resistance in obese prepubertal boys. Thirteen obese and 15 control prepubertal boys were studied. Biceps, triceps, subscapular and suprailiac skin fold thicknesses were measured. Percentage of body fat and total body fat were calculated. Body fat distribution was assessed by analyzing the central (supra-iliac, subscapular)/peripheral (biceps, triceps) ratios. During an oral glucose tolerance test, serum glucose and insulin were measured and insulin/glucose was calculated. Body fat data and body fat distribution indices were significantly higher in the obese group. The obese population presented significantly elevated values of insulin and insulin/glucose. In the obese group insulin showed significant correlations with percentage of body fat, total body fat and subscapular skin fold thickness, whereas insulin/glucose had significant positive correlations with percentage of body fat, total body fat and supra-iliac skin fold thickness. In obese boys significant positive correlations were also shown by subscapular/supra-iliac with insulin and insulin/glucose, and by subscapular/triceps with insulin. In prepubertal boys obesity is centripetal and an upper central body fat distribution seems to be first associated with an abnormal glucose-insulin homeostasis.