Predicting VO2max in Children and Adolescents Aged between 6 and 17 Using Physiological Characteristics and Participation in Sport Activities: A Cross-Sectional Study Comparing Different Regression Models Stratified by Gender.

Background: The aim of this study is to use different regression models to capture the association between cardiorespiratory fitness VO2max (measured in mL/kg/min) and somatometric characteristics and sports activities and making better predictions. Methods: multiple linear regression (MLR), quantile regression (QR), ridge regression (RR), support vector regression (SVR) with three different kernels, artificial neural networks (ANNs), and boosted regression trees (RTs) were compared to explain and predict VO2max and to choose the best performance model. The sample consisted of 4908 children (2314 males and 2594 females) aged between 6 and 17. Cardiorespiratory fitness was assessed by the 20 m maximal multistage shuttle run test and maximal oxygen uptake (VO2max) was calculated. Welch t-tests, Mann−Whitney-U tests, X2 tests, and ANOVA tests were performed. The performance measures were root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2). All analyses were stratified by gender. Results: A comparison of the statistical indices for both the predicted and actual data indicated that in boys, the MLR model outperformed all other models in all indices, followed by the linear SVR model. In girls, the MLR model performed better than the other models in R2 but was outperformed by SVR-RBF in terms of RMSE and MAE. The overweight and obesity categories in both sexes (p < 0.001) and maternal prepregnancy obesity in girls had a significant negative effect on VO2max. Age, weekly football training, track and field, basketball, and swimming had different positive effects based on gender. Conclusion: The MLR model showed remarkable performance against all other models and was competitive with the SVR models. In addition, this study's data showed that changes in cardiorespiratory fitness were dependent, to a different extent based on gender, on BMI category, weight, height, age, and participation in some organized sports activities. Predictors that are not considered modifiable, such as gender, can be used to guide targeted interventions and policies.

Effects of Nutrition, and Physical Activity Habits and Perceptions on Body Mass Index (BMI) in Children Aged 12-15 Years: A Cross-Sectional Study Comparing Boys and Girls.

Background: The aim of the present study was to examine the effects of socioeconomic status, nutrition and physical activity lifestyle habits and perceptions on Body Mass Index (BMI) in children aged 12-15 years in Greece. Furthermore, to compare the difference between the two sexes. Methods: This is a cross-sectional study conducted on a representative secondary school cohort that included 5144 subjects, aged 12 to 15 years. Students and their parents filled in validated questionnaires evaluating socioeconomic status, nutrition and physical activity. International Obesity Task Force cut offs were used to classify the children. Factor analysis of mixed data and partial proportional ordered logistic models were used to analyze ΒMΙ distributions. All analyses were stratified by gender. Results: Boys were 2.9 (95%CI: 2.592-3.328) times more likely to be overweight/obese than girls. Partial proportional ordinal models indicate significant associations between nutritional and physical habits and perceptions variables but also significant gender differences in socio-demographic, nutritional risk factors as well as physical activity habits and perceptions. Conclusions: A clear understanding of the factors that contribute to the sex differences in nutrition and physical activity habits and perceptions may guide intervention efforts.

Evolution of Hashimoto thyroiditis in children with type 1 diabetes mellitus (TIDM).

OBJECTIVES: Treatment of children with Hashimoto thyroiditis (HT) and particularly of those with coexistent diabetes mellitus type 1 (TIDM) and normal/mildly elevated serum TSH is controversial. The aim of the study was to evaluate the natural course of HT in children with TIDM compared with children with no other coexistent autoimmunity and investigate for possible predictive factors of thyroid function deterioration. METHODS: Data from 96 children with HT, 32 with T1DM (23 girls, nine boys) mean (sd) age: 10.6 (2.3) years, and 64 age and sex-matched without T1DΜ (46 girls, 18 boys), mean (sd) age: 10.2 (2.9) years were evaluated retrospectively. They all had fT4 and TSH values within normal ranges and available data for at least three years' follow-up. RESULTS: During the follow-up period, 11 children (34.4%) with TIDM exhibited subclinical hypothyroidism and two children (6.2%) progressed to overt hypothyroidism compared to 12 (18.8%) and two (3.1%) among children without TIDM, respectively. Among children with HT, a higher percentage (40.6%) of children with T1DM progressed to subclinical or overt hypothyroidism, compared with children (21.9%) with similar characteristics but without TIDM or other coexistent autoimmunity. CONCLUSIONS: The annual conversion rate from euthyroidism to hypothyroidism in children with T1DM was significantly higher compared to sex and age-matched children without TIDM. Prospective randomized trials are needed to support the view of an earlier intervention therapy even in milder degrees of thyroid failure in these children.

Effects of Body Mass Index (BMI), demographic and socioeconomic factors on organized physical activity (OPA) participation in children aged 6-15 years: a cross-sectional study comparing primary and secondary school children in Greece.

BACKGROUND: The aim of the present study was to examine the influence of body mass index category, as well as of demographic and socioeconomic factors on the participation in organized physical activity (OPA) of schoolchildren attending primary and secondary school in Greece. Furthermore, to compare the difference between the two levels. METHODS: This is a cross-sectional study conducted on a representative elementary and secondary school cohort, derived using stratification and probability proportional to size (PPS) methodology. The final sample included 18,264 subjects, aged 6 to 15 years. Parents of all students and students of secondary schools fulfilled validated questionnaires evaluating socioeconomic status, and participation to OPA. International Obesity Task Force (IOTF) cut offs were used to classify the children. Univariate and multivariate logistic models examined factors associated with OPA. All analyses were stratified by school level. RESULTS: Sport participation was not reported in 37.7 and 54.4% of primary and secondary schoolchildren respectively. Having BMI within normal range, being male, having parents participating in an organized activity and a high socio-economic status seem to encourage participation in OPA in both school levels. CONCLUSIONS: Children with normal BMI are more likely to participate in OPA. Parents as role model as well as higher socioeconomic status of the family emerge as important influencers. Participation in OPA declines as students enter secondary school. Interventions focusing on increasing physical education and activity into school daily program should be tailored to the specific needs of different weight categories and can possibly eliminate the impact of SES inequalities.

The Challenges in the Development of Diabetes Prevention and Care Models in Low-Income Settings.

In low- and middle-income countries (LMICs), the burden of non-communicable diseases such as diabetes is rapidly rising, overpassing the existing burden of communicable diseases. Patients with diabetes living in low-income communities face unique challenges related to lack of awareness, difficulty in accessing health care systems and medications, and consequently failure in achieving optimal diabetes management and preventing complications. Effective diabetes prevention and care models could help reduce the rising burden by standardizing guidelines for prevention and management, improving access to care, engaging community and peers, improving the training of professionals and patients and using the newest technology in the management of the disease. In this article, we review the latest research and evidence on effective models of diabetes prevention and diabetes care delivery in low- income settings. We also provide existing evidence relating to the effectiveness of these models in low-resource contexts, with the aim to highlight characteristics and strengths that make their implementation successful and long-lasting.

Prevalence of asthma symptoms and association with obesity, sedentary lifestyle and sociodemographic factors: data from the Hellenic National Action Plan for the assessment, prevention and treatment of childhood obesity (MIS301205).

Objectives: To evaluate the prevalence of asthma symptoms in a representative sample of Greek schoolchildren and to evaluate its association with overweight/obesity as well as other socioeconomic, demographic, and lifestyle factors. Methods: This is a cross-sectional study conducted from 10/2012 to 12/2013 on a pre-selected, representative elementary school cohort. Parents completed standardized questionnaires evaluating among others socioeconomic and sedentary activity habits. Students were measured with high sensitivity methods. Socioeconomic status (SES) index (range: 0-13) was calculated on years of parental education, rented versus owned residence, size of residence evaluated as meters squared per person (m2/person), and number of vehicles. Asthma was defined according to the approved Greek version of the International Study on Allergies and Asthma in Childhood (ISAAC) criteria. Results: The prevalence of any asthma symptoms was documented in 31% of population. The odds of presenting any asthma symptoms decreased with increase in age (odds ratio: 0.96, 95% CI: 0.94-0.98) and increased with overweight (odds ratio: 1.13, 95% CI: 1.03-1.25), obesity (odds ratio: 1.27, 95% CI: 1.11-1.46) and sedentary lifestyle. Conclusion: This is the first representative survey of prevalence of asthma symptoms in children and adolescents in Greece indicating its continuous increase. A strong association between presence of asthma symptoms and obesity and sedentary activities was documented irrespectively of socioeconomic and regional factors. The findings stress the importance of public health policies toward obesity prevention and enhancement of physical activities in pediatric populations.

A cohort of children with type 1 diabetes in Greece: predictors of direct costs of care.

AIM: To examine the predictors of direct costs of pediatric type 1 diabetes (T1D) in a hospital-based outpatient clinic in Greece. METHODS: The outpatient records of 89 children and adolescents (mean age: 12.05 ± 5.15 y) with T1D followed in the Second Department of Pediatrics, University of Athens Medical School, were analyzed. RESULTS: The mean ± SD diabetes duration was 4.9 ± 3.88 y (range: 0.25-17) and glycated hemoglobin (HbA1c) was 8.2 ± 1.09% (66 ± 11.9 mmol/mol). A total of 80% of patients were on multiple daily injections regimen, 10% on pump therapy, and 10% on conventional regimen. Total direct costs per patient-year (ppy) were estimated at €2.712 [95% confidence interval (CI): 2.468-2.956]. Supply costs accounted for 73.7% of total costs and were the highest for pump therapy (P < .001). Multivariate linear regression analysis showed that costs were significantly higher for children (1) on multiple daily injections or pump therapy (r = 0.364, P < .001), (2) of older age (r = 0.25, P < .001) and (3) higher daily insulin dose (r = 0.46, P < .001). Patients on pump therapy had significantly higher costs €5.538 (95%CI 4480-6597) compared with patients on multiple daily injections €2.447 (95% CI 2320-2574) and conventional regimen €1.978.5 (95%CI 1682-2275) (P = .0001). Patients on pump therapy had better glycemic control compared with all other patients [HbA1c (mean ± SD): 7.2% ± 1.0 vs 8.3% ±1.5, P = .039]. CONCLUSION: The total T1D cost in this cohort of Greek children was €2712 ppy. The main factor that predicted direct cost was the use of pump. However, pump therapy was associated with better glycaemic control, which may decrease the risk of total long-term diabetes care cost.

Utility and applicability of the "Childhood Obesity Risk Evaluation" (CORE)-index in predicting obesity in childhood and adolescence in Greece from early life: the "National Action Plan for Public Health".

Early identification of infants being at high risk to become obese at their later childhood or adolescence can be of vital importance in any obesity prevention initiative. The aim of the present study was to examine the utility and applicability of the "Childhood Obesity Risk Evaluation (CORE)" index as a screening tool for the early prediction of obesity in childhood and adolescence. Anthropometric, socio-demographic data were collected cross-sectionally and retrospectively from a representative sample of 5946 children, and adolescents and were combined for calculating the CORE-index score. Logistic regression analyses were performed to examine the associations of the CORE-index score with obesity by gender and age group, and cut-off point analysis was also applied to identify the optimal value of the CORE-index score that differentiates obese from non-obese children. Mean CORE-index score in the total sample was 3.06 (sd 1.92) units (range 0-11 units). Each unit increase in the CORE-index score was found to be associated with a 30 % (95 % C.I. 1.24-1.36) increased likelihood for obesity in childhood or adolescence, while the optimal cut-off value of the CORE-index score that predicted obesity with the highest possible sensitivity and specificity was found to be 3.5. CONCLUSION: The present study supports the utility and applicability of the CORE-index as a screening tool for the early identification of infants that are potentially at a higher risk for becoming obese at their childhood and adolescence. This tool could be routinely used by health professionals to identify infants at high risk and provide appropriate counselling to their parents and caregivers so as to maximize the effectiveness of early obesity prevention initiatives. What is known? • Childhood obesity has reached epidemic proportions worldwide. • Certain perinatal and socio-demographic indices that were previously identified as correlates of childhood obesity in children were combined to develop the CORE-index, a screening tool that estimates obesity risk in 9-13 year-old children. What is new? • The utility and applicability of the CORE-index as screening tool can be extended to the age range of 6-15 years. • The CORE-index is a cost-effective screening tool that can assist health professionals in initiating obesity preventive measures from early life.

Associated autoimmune diseases in children and adolescents with type 1 diabetes mellitus (T1DM).

Type 1 diabetes (T1DM) is an autoimmune disease with aberrant immune responses to specific ß-cell autoantigens, resulting in insulin deficiency. Children and adolescents with T1DM may also develop organ-specific multiple autoimmunity in the context of APS (autoimmune polyendocrine syndrome) type 1, 2 or 3. The most frequently encountered associated autoimmune disorders in T1DM are autoimmune thyroid, followed by celiac, autoimmune gastric disease and other rare autoimmune conditions. There are limited previous studies on the prevalence of associated autoimmunity, especially multiple, in children with T1DM. The present review reports on the classification of autoimmune diabetes, and on the prevalence, pathogenesis, predictive factors and clinical presentation of pancreatic autoimmunity and of all associated autoimmune disorders in children with T1DM. The impact of associated autoimmunity on diabetes control and general health is also discussed, along with suggestions regarding screening strategies and follow-up for early detection and management of the autoimmunity.

Insulin resistance and cardiometabolic risk factors in obese children and adolescents: a hierarchical approach.

BACKGROUND: This study aims to globally assess the network of insulin resistance (IR)-related factors in a sample of overweight and obese Greek youths. METHODS: A total of 185 subjects were examined, and IR was quantified by homeostasis model assessment (HOMA-IR). Multivariate hierarchical approach was performed, and five distinct levels were recognized, namely, immutable demographic features and early life parameters, current anthropometric measures, IR, unfavorable clinical conditions, and social parameters. Two analyses were performed based on HOMA-IR cut-off values (3.16 and, as an alternative, 3.99). RESULTS: Obesity was associated with IR (adjusted OR=3.19, 95% CI: 1.12-9.09). IR steadily predicted low HDL (adjusted OR=5.75, 95% CI: 1.58-20.87), hypertriglyceridemia (adjusted OR=10.28, 95% CI: 1.18-89.55), and systolic hypertension. At the alternative analysis, IR was also associated with older age, older age at menarche, hyperuricemia, and low school grades. CONCLUSION: Emerging on the grounds of obesity, IR confers risks for dyslipidemia and hypertension at a relatively early age. Along with weight loss, interventions targeted at IR are required to prevent cardiometabolic risk in adolescence.

Evolution of sonographic appearance of the thyroid gland in children with Hashimoto's thyroiditis.

BACKGROUND: Although thyroid ultrasound is a valuable tool for the diagnosis and follow-up of patients with Hashimoto's thyroiditis (HT), classical sonographic findings are not always present. AIM: To calculate the time needed for children with HT and normal ultrasound at diagnosis to develop characteristic sonographic findings. PATIENTS AND METHODS: 105 children (23 male and 82 female) with HT (mean age 9.4 +/- 2.9 years) were studied. Physical examination and measurements of TSH and fT4 levels were performed at diagnosis, at 3-month intervals for the first year, and twice yearly thereafter. Thyroid ultrasound was performed at diagnosis and twice yearly thereafter. The median follow-up duration was 18 months (range: 6-61 months). RESULTS: The time needed for 30%, 50%, and 70% of children to demonstrate an abnormal thyroid sonographic pattern was 4, 7, and 14 months, respectively. Important factors accelerating sonographic changes were goiter (p = 0.023), hypothyroidism (p = 0.0255), and seropositivity for both thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg) autoantibodies (p = 0.0005). CONCLUSION: Sonographic findings of HT are present in 37% of children at diagnosis. Fifty percent of children with normal initial thyroid US will develop changes within 7 months; however, characteristic findings may not develop for over 4 years.

Herpes virus antibodies seroprevalence in children with autoimmune thyroid disease.

BACKGROUND: Elevated titers of antibodies against different herpes virus antigens have been reported in some immunodeficient and systemic autoimmune disorders. OBJECTIVE: To examine if Herpes Simplex Virus (HSV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) IgG and IgM antibodies are detected more frequently in children with autoimmune thyroid disease (AITD) compared to controls. SUBJECTS AND METHODS: Thirty-four children with AITD, aged 9.62 +/- 2.35 years, and 31 matched controls, aged 9.24 +/- 2.98 years, were studied. RESULTS: The percentage of EBV IgG+ children with AITD was statistically higher than the percentage of EBV IgG+ controls (82.35% versus 51.61%, P = 0.008). The percentage of EBV IgG+ children with AITD and hypothyroidism was statistically higher than the percentage of EBV IgG+ children with AITD, without hypothyroidism (100% versus 70%, P = 0.024). No other statistically significant differences were observed in HSV-1+2, and CMV IgG or IgM antibodies between the subgroups of children studied. CONCLUSIONS: EBV seroprevalence is higher in children with AITD compared to controls and the underlying pathology remains to be elucidated.

Malignant insulinoma in childhood.

Pancreatic tumors constitute a rare surgical problem in infancy and childhood. Insulinomas are rare in all age groups with an estimated incidence of one per 250,000 person-years and even rarer in childhood. We report a 10 year-old girl with malignant insulinoma. The presenting symptom was hypoglycemic attacks. Laboratory investigation demonstrated that the hypoglycemia was due to hyperinsulinism. MRI of the abdomen revealed a mass at the tail of the pancreas. Distal pancreatectomy with splenectomy was performed. Histological examination showed malignant insulinoma with peripancreatic lymph node metastases. One month later abdominal MRI revealed the existence of multiple small metastatic foci in the liver, which were confirmed by In111 octreoscan. Treatment with octreotide was started and the disease is stable after 12 months of therapy.