Association of physical activity and the metabolic syndrome in children and adolescents: CASPIAN Study

BACKGROUND/AIM: To determine the association of physical activity and the metabolic syndrome in a large national-representative sample of children. METHODS: This study was performed in 2003-2004 on 4,811 school students aged 6-18 years, selected by multi-stage random cluster sampling from six provinces in Iran. We assessed the level of physical activity using a standardized questionnaire, and categorized it to the tertiles. The metabolic syndrome was defined based on criteria analogous to those of the Adult Treatment Panel III. RESULTS: The participants comprised 2,248 boys and 2,563 girls with a mean age of 12.07 +/- 3.2 years. In all age groups, boys were more physically active than girls. The metabolic syndrome was detected in 14.1% of participants, and its prevalence was higher in those subjects in the 1st, 2nd and 3rd tertiles of physical activity, respectively (15.1 vs.14.2 and 13.1%, respectively, p <0.05). This difference was seen in boys, while no difference was found between girls in the 2nd and 3rd tertiles of physical activity. Physical activity was linked to a cluster of factors consisting of high-density lipoprotein-cholesterol and waist circumference, followed by triglycerides in boys, and of triglycerides, waist circumference and blood pressure in girls. In both genders, before and after adjustment for age and body mass index, low levels of physical activity significantly increased the risk of having the metabolic syndrome [in boys: OR: 1.8, 95% CI: 1.1, 2.1; and in girls, OR: 1.6 (1.1, 1.9)]. CONCLUSION: We found an association between physical activity and the metabolic syndrome, which was independent of body mass index and age. Children should be encouraged to have greater physical activity.     

Somatotyping of children and adolescents

Longitudinal observations on growth and development in children and adolescents with a usual (school) and increased (sporting) motor activity regimens have been performed for 13 years and certain metrical characteristics have been obtained. After their treatment by means of the factor and correlative analyses, they are divided into basic and auxiliary. The basic characteristics have a high correlative connection with progress in certain kinds of physical activity (sporting achievements), the auxiliary ones determine the technique of carrying out the movement. Basing on theoretical generalization of the literature data and analyzing the metrical values obtained at anthropometry, an objective scheme of somatotyping is worked out. It considers an independent variation of the signs according to spatial (clearance limit, componental and proportional) and time (variants of development) scales. Nontraditional estimation on manifestation of fatty, muscular and osseous components is elaborated, algorhythm of their estimation is suggested. Three main (micro-, meso-, macrosomatic) and two additional (micromesosomatic and mesomacrosomatic) somatic types are defined. They include manifestation of fatty, muscular and osseous masses, as well as the proportion of the body-build. The mark scale estimation of individual metrical values according to the elaborated age nomograms and scales makes the base of the typing. As demonstrates the retrospective analysis of the material, in 86% of cases the somatic type does not change in the course of ontogenesis. Estimation of the somatic type during the pubertal period should be carried out with a strict consideration of the variant of the child's development.(ABSTRACT TRUNCATED AT 250 WORDS)     

Psychosocial stress and abdominal pain in adolescents

Children and adolescents may express psychiatric symptoms via somatic complaints. Likewise, children with chronic somatic illnesses are likely to experience psychiatric sequelae. We report three cases of adolescents who were admitted to general paediatrics services for abdominal pain and/or nausea and vomiting with a negative medical workup. In each case, a clear psychosocial stressor was evident. It is possible that somatic symptoms without clear medical causes may reflect psychosocial stress, but it is difficult to discern whether the psychosocial issues preceded the somatic complaints or were a result of them. Making an accurate diagnosis is difficult, and broaching such a subject with patients and their families is a delicate matter. More research is needed to determine appropriate screening tools for identifying cases where psychosocial stress may play a relevant role in symptom presentation, as well as potential treatment modalities for such cases.     

Evaluation of a urinary multi-parameter biomarker set for oxidative stress in children, adolescents and young adults

The involvement of reactive oxygen species (ROS) and oxidative stress in pediatric diseases is an important concern, but oxidative stress status in healthy young subjects and appropriate methods for its measurement remain unclear. This study evaluated a comprehensive set of urinary biomarkers for oxidative stress in healthy children, adolescents and young adults. Results show that urinary excretion of acrolein-lysine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), nitrite/nitrate and pentosidine were highest in the youngest subjects and decreased to constant levels by early adolescence. Urinary acrolein-lysine, 8-OHdG, nitrite/nitrate and pentosidine showed significant inverse correlations with age, but pyrraline did not change significantly with age. No significant differences in biomarkers were apparent between males and females. Younger subjects grow rapidly and sustain immune activation, and are probably exposed to high concentrations of ROS and nitric oxide. Consequently, they are more vulnerable to oxidation of lipids, proteins, DNA and carbohydrates. Normal reported values in this study are a basis for future studies of disease mechanisms involving oxidative stress and for future trials using antioxidant therapies for oxidative stress-related diseases in the pediatric field.     

Evaluation of a urinary multi-parameter biomarker set for oxidative stress in children,adolescents and young adults

The involvement of reactive oxygen species (ROS) and oxidative stress in pediatric diseases is an important concern, but oxidative stress status in healthy young subjects and appropriate methods for its measurement remain unclear. This study evaluated a comprehensive set of urinary biomarkers for oxidative stress in healthy children, adolescents and young adults. Results show that urinary excretion of acrolein–lysine, 8-hydroxy-2′-deoxyguanosine (8-OHdG), nitrite/nitrate and pentosidine were highest in the youngest subjects and decreased to constant levels by early adolescence. Urinary acrolein–lysine, 8-OHdG, nitrite/nitrate and pentosidine showed significant inverse correlations with age, but pyrraline did not change significantly with age. No significant differences in biomarkers were apparent between males and females. Younger subjects grow rapidly and sustain immune activation, and are probably exposed to high concentrations of ROS and nitric oxide. Consequently, they are more vulnerable to oxidation of lipids, proteins, DNA and carbohydrates. Normal reported values in this study are a basis for future studies of disease mechanisms involving oxidative stress and for future trials using antioxidant therapies for oxidative stress-related diseases in the pediatric field.     

Cheek dimples in Greek children and adolescents

In 14141 male and 14141 female Greek children and adolescents ranging in age between seven and fifteen years the presence of cheek dimples was investigated. Neither sex (12.6% in both female and males) nor side differences when expressed unilaterally were observed. There was however a significant increase of dimples with age as well as significantly higher numbers of asymmetric than symmetric expressions in all age groups. With respect to these observations hypotheses of origin of cheek dimples and related effects of age are discussed.     

Epidemiology of ADHD in Chilean children and adolescents

ADHD prevalence, associated factors, comorbidity and service use are reported for a sample of 1,558 children and adolescents, belonging to four provinces in Chile. The sample is weighted in each step for selection bias. Psychiatric disorders and impairment are assessed with computerized in-home DISC-IV interviews, and a questionnaire regarding socioeconomic and family variables and service use. Estimates of prevalence rates are obtained by means of STATA 11.0 software, with complex sample design. Multivariate logistic regression is used to determine which factors were the best predictors for mental disorders. Participation rate is 82.4 %. The prevalence of ADHD is 10 %, and the most prevalent subtype is the hyperactive/impulsive, with no gender differences. Both hyperactive/impulsive and combined subtypes are more prevalent in children 4–11 than in adolescents. The most prevalent comorbidities are anxiety disorders and oppositional disorder. Anxiety is the more prevalent comorbid disorder in girls and correlated with a combined subtype. Perception of good family functioning, adolescent age and school dropout have a negative association with ADHD diagnosis, while maltreatment shows a positive correlation. Over 50 % of children and adolescents diagnosed with ADHD have used services in the last year. This is the first comprehensive community study of psychiatric disorders in children and adolescents in a South American country. It yields information for child and adolescent mental health programmes in Chile and contributes to cross-cultural epidemiological research.     

Thyroid function and obesity in children and adolescents

The aim of this retrospective study was to investigate the frequency of thyroid dysfunction as assessed by TSH, T3 and T4 in a large cohort of 290 obese and 280 healthy children. In addition, thyroid autoantibodies were measured in random subgroups of 123 obese and 80 control children, iodine excretion in 50 and thyroid volume in 23 of the obese children. Elevated TSH levels (>4 U/l) were found in 22 obese children (7.5%), but only in one control (0.3%). The medians of TSH and T3 concentrations were normal, but significantly higher in the obese group than in the controls, while T4 levels did not differ. The prevalence of positive thyroid autoantibodies was increased in the obese children, for the most part in those with elevated TSH. There was no evidence for iodine deficiency as a cause of the average increase of TSH. We conclude that in childhood obesity TSH and T3 levels are significantly increased; in most cases, however, these increases are not accounted for by thyroid autoimmunity or iodine deficiency. As a consequence, TSH elevations with normal thyroid hormone levels in obese children don't need any thyroxine treatment, if thyroid disorders were definitely excluded beforehand.     

Zinc nutritional status in obese children and adolescents

Studies in animals and humans have corroborated that zinc (Zn) metabolism is altered in obesity. The present work intends to evaluate the Zn nutritional status in obese children and adolescents by the determination of some biochemical parameters and analyses of the diets. The investigation was carried out in a group of obese children and adolescents (n=23) and compared to a control group (n=21), both between 7 and 14 yr of age. A software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index, bioelectrical impedance, and skinfold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (γ=213.9 nm). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion was significantly higher in the same group. The results allowed one to conclude that zinc nutritional status in obese individuals is altered.