Pediatrics

Exercise leads to simultaneous increases in mediators signaling apparently antagonistic functional responses such as growth factors and inflammatory mediators. The aim of the present study was to demonstrate the physiological effect of IL-6 on circulating components of the growth hormone (GH) -insulin-like growth factor-I (IGF-I) axis. Twelve men (ages 26±2 yrs) were divided into two groups (n=6 in each group), receiving either albumin or rhIL-6 infusion. IL-6 was infused via an antecubital vein, and a contra-lateral antecubital vein was used for blood sampling. The IL-6 dose was chosen to reach plasma levels of IL-6 characteristic of intense exercise (5 µg/h, for 3h, resulting in plasma levels of 100 pg/ml). Blood samples for GH, GH binding protein (GHBP), IGF-I, and IGFBP-1 and -3 were collected at baseline, 30min, 1h, 2h, 3h, 4h, 5h and 8h after the beginning of the rhIL-6 infusion. IL-6 levels increased only in the rhIL-6 infused group (p<0.0005), and returned to baseline after the infusion was stopped. IL-6 infusion led to a significant increase in GH, peaking one hour after the beginning of infusion (p<0.001). A decrease in total IGF-I levels was noted only in the rhIL-6 infused group (p<0.027). An initial decrease in IGFBP-1 levels was noted in both groups during infusion (P<0.03).

Studies have previously demonstrated that brief (4 weeks) passive range-of-motion exercise is beneficial for bone development in very low birth weight (VLBW) preterm infants. However, the optimal duration of exercise for bone development in preterm infants is yet unknown. The aim of the present study was to examine the effect of 8 weeks of assisted exercise on bone strength and metabolism in VLBW premature infants. Sixteen infants (mean ± standard error of the mean birth weight 1,009 ± 55 g and gestational age 27.3 ± 0.3 weeks) were randomly assigned into exercise (n = 8) and control (n = 8) groups. The intervention started at the first week of life and involved 8 weeks of daily passive extension and flexion range-of-motion exercise of the upper and lower extremities. Biochemical markers of bone turnover were measured at enrollment and after 8 weeks. Bone strength was measured weekly by quantitative ultrasound measurement of tibial bone speed of sound (SOS). Bone SOS decreased significantly in the control group ()108.1 ± 33.7 m/second, P < 0.0001) during the study period, while remaining stable in the exercise group (11.3 ± 22.8 m/second). The main beneficial effect of exercise occurred in the first 4 weeks of the intervention. There were no significant differences in the bone turnover marker changes between the groups. There is a significant postnatal decrease in bone SOS in VLBW preterm infants. Eight weeks of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia in premature infants.

We evaluated the eVect of cold ice-pack application following a brief sprint-interval training on the balance between anabolic mediators [growth hormone (GH), insulin-like growth factor-I (IGF-I), testosterone], catabolic markers (cortisol, IGFBP-1), and circulating pro [Interlukin-6 (IL-6) and IL-1 ]-and anti-inXammatory cytokines [IL-1 receptor antagonist (IL-1ra)]. Twelve males, elite junior handball players performed 4 £ 250 m treadmill run, at 80% of each individual's maximal speed, followed by a rest period with and without local cold-pack application. Pre, immediately post, and 60-min post-exercise blood samples were drawn. Exercise was associated with a signiWcant increase in IL-6, GH, IGFBP-3, and testosterone levels. Local cold-pack application was associated with signiWcant decreases in IL-1 , IL-1ra, IGF-I, and IGFBP-3 and a greater increase of IGFBP-1 during recovery. Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro-and anti-inXammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative eVects on athletic performance.

We assessed the effect of a weight management programme on body weight, body mass index (BMI), and fitness in obese children and adolescents. The study was designed as a longitudinal, non-randomised, clinical experience of a 3 and 6 month combined dietarybehavioural-exercise intervention. A total of 177 obese children (age 6-16 years) participated in the 3 month programme, of whom 65 completed the 6 month intervention. A group of 25 age-and maturity-matched obese children who did not participate in the structured programme served as controls. Body weight, BMI, and fitness were evaluated at baseline, and after the 3 and 6 months intervention. Body weight and BMI were significantly reduced (P<0.05), and endurance time significantly increased (P<0.0005) following the 3 months intervention. Obese children who continued the programme for 6 months maintained the decrease in BMI and further improved endurance time. In contrast, obese children who did not participate in the structured programme gained weight, increased their BMI, and improved fitness less significantly. Gender, pubertal status, and the degree of obesity had no influence on BMI changes. Children without parental overweight had significantly greater decreases in BMI compared to children of obese parents. Conclusion: a combined, structured multidisciplinary intervention for childhood obesity results in decreased body weight, decreased body mass index and improved fitness.

We measured bone speed of sound in premature infants by quantitative ultrasound. A total of 44 neonates participated in the study including 29 premature infants (median birth weight 1264 g, range 578±2420 g; median gestational age 31 weeks, range 24±36 weeks) and 15 full-term infants (median birth weight 3360 g, range 2700±3730 g; median gestational age 40 weeks, range 37±41 weeks). The left tibial speed of sound (SOS) was measured by quantitative ultrasound. Bone SOS was successfully measured in all infants. We found a signi®cant correlation between tibial SOS and gestational age (r=0.78, P<0.0005), but a signi®cant inverse correlation between tibial SOS and post-natal age (r=±0.78, P<0.0005). Bone SOS was signi®cantly (P<0.05) higher in full-term infants (3101 m/s, range 2899±3314 m/s) compared to premature infants (2821 m/ s, range 2516±3139 m/s), and compared to a subgroup of the premature infants who reached corrected age of fullterm infants (2706 m/s, range 2516±2892 m/s, n=13). Bone SOS was lower (2745 m/s, range 2533±3036 m/s, n=16) in very low birth weight premature infants (birth weight <1500 g). Conclusion: the results indicate that tibial speed of sound was reduced in premature infants (in particular very low birth weight) compared to fullterm infants even when premature infants reached the corrected age of their full-term peers. The potential role of this technique in assessing osteopenia in premature infants warrants further exploration.

Objective: The aim of the present study was to determine physical activity (PA) and nutrition knowledge and preferences in low socio-economic status kindergarten children. Methods: Following height and weight measurement, 795 low socio-economic status kindergarten children (age 3.8-6.8 y.o) completed a photo-pair knowledge and preferences food and exercise questionnaire. Results: No difference was found between nutrition and PA knowledge scores (52.3 ± 0.9 versus 52.6 ± 0.8%, respectively). There was no difference between the nutrition knowledge and preference score (52.3 ± 0.9 versus 50.9 ± 0.9%, respectively). PA preference was significantly higher than knowledge (56.9 ± 1.5 versus 52.6 ± 0.8%, respectively; p < 0.0001). Significant correlations were found between nutrition knowledge and preferences (r = 0.55, p < 0.0001), physical activity knowledge and preferences (r = 0.46, p < 0.0001), and nutrition and PA preferences (r = 0.46, p < 0.001). Nutrition preference scores were significantly lower in overweight compared to normal weight kindergartners 48.1 ± 1.7 versus 52.0 ± 1.0%; p < 0.05). PA knowledge and preference scores were significantly higher among male compared to the female kindergartners (p < 0.001 for both). Conclusion: Our data demonstrate diversities in physical activity and nutrition knowledge and preferences among low socio-economic status kindergarten children. These findings may be important for the development of health promotion programs in low socioeconomic kindergarten children.

Obesity blunts catecholamine and growth hormone responses to exercise in adults, but the effect of obesity on these exercise-associated hormonal responses in children is unclear. Therefore, the aim of the present study was to asses the effect of childhood obesity on the counter-regulatory hormonal response to acute exercise. Twenty-five obese children (Ob, BMI> 95%), and 25 age, gender and maturity matched normal weight controls (NW) participated in the study. Exercise consisted of ten two-min bouts of constant cycle-ergometry above the anaerobic threshold, with one-min rest intervals between each bout. Pre, post and 120-min post exercise blood samples were collected for circulating components of the GH-IGF-I axis and catecholamines. There were no differences in peak exercise heart rate, serum lactate and peak VO 2 normalized to lean body mass between the groups. Obesity attenuated the GH response to exercise (8.9±1.1 versus 3.4±0.7 ng/ml in NW and Ob participants, respectively; p<0.02). No significant differences in the response to exercise were found for other components of the GH-IGF-I axis. Obesity attenuated the catecholamine response to exercise (epinephrine: 52.5±12.7 versus 18.7±3.7 pg/ml, p<0.02; norepinephrine: 479.5±109.9 versus 218.0±26.0 pg/ml, p<0.04; dopamine: 17.2±2.9 versus 3.5±1.9 pg/ml, p<0.006 in NW and Ob, respectively). Insulin levels were significantly higher in the obese children, and dropped significantly after exercise in both groups. Despite the elevated insulin levels and the blunted counter-regulatory response, none of the participants developed hypoglycemia. Childhood obesity was associated with attenuated GH and catecholamine response to acute exercise. These abnormalities were compensated for, so that exercise was not associated with hypoglycemia despite increased insulin levels in obese children.

A relatively brief range of motion daily movement intervention was associated with greater weight gain and increased leptin levels in very -lowbirth -weight premature infants. This may suggest that at least part of the daily movements associated with increase in body weight resulted from an increase in adipose tissue.

We report the athletic, physiological and mitochondrial-related genomic data of an Israeli endurance runner. He is holding the Israeli record in 10,000, 5000, 1500 and 800 m run, along with being one of the best Israeli 400 m runners. We tested the ACTN3 R577X, and six polymorphisms in the PPARGC1A-NRF-TFAM pathway genes. The case athlete was heterozygous for the ACTN3 R577X variation and had five out of six 'enduranceoriented' genotypes, scoring significantly high in endurance 'optimal' genotype profile. In conclusion, we suggest that the case athlete is favoured by polygenic profile that is more suitable for mitochondrial biogenesis, regardless of his good phenotypic accomplishments in short-term running events.

Submariners taking part in prolonged missions are exposed to environmental factors that may adversely affect bone health. Among these, relatively high levels of CO2, lack of sunlight exposure affecting vitamin D metabolism, limited physical activity, and altered dietary habits. The aims of this study were to examine the effect of a prolonged submersion (30 days) on changes in bone strength using

OBJECTIVE: Determination of bone strength of lower extremities in very low birth weight (VLBW) premature infants with central nervous system pathology resulting in reduced unilateral spontaneous leg movements.STUDY DESIGN: Quantitative ultrasound (QUS) measurements of speed of sound (SOS) of the tibiae of both legs in three VLBW premature infants with brain insult and unilateral reduced spontaneous activity. Results were compared

Objective: To determine the effects of obesity on baseline levels of circulating granulocytes, monocytes, and lymphocyte subtypes in otherwise healthy children. Design: Two group comparison of leukocytes in normal weight control and overweight children. Subjects: In total, 38 boys and girls, ages 6-18 years, divided in two groups: normal weight, (NW, BMIo85th %tile, n ¼ 15) and overweight (OW, body mass index (BMI)485th %tile, n ¼ 23). Measurements: BMI obtained from direct measures of height and body mass. Body fat was assessed by DEXA. Complete blood counts (CBC) were obtained by standard clinical hematology methods and surface antigen staining by flow cytometry. Results: The OW group compared to the NW group had increased total leukocytes counts (P ¼ 0.011), neutrophils (P ¼ 0.006), monocytes (P ¼ 0.008), total T (CD3) lymphocytes (P ¼ 0.022), and Helper T (CD4 þ ) cells (P ¼ 0.003). Significant correlations were evident between leukocytes, and BMI percentile, BMI, or percent body fat. Neither lean body mass nor VO 2peak per unit lean body mass were significantly related to any of the leukocytes. Percent body fat and BMI percentile were positively correlated (Po0.05) to total T cells (CD3) and/or helper T cells (CD4 þ ). Conclusion: A group of 23 overweight children displayed elevated counts in most types of circulating immune cells, suggesting the presence of low-grade systemic inflammation, a known pathogenetic mechanism underlying most long-term complications of obesity. Our data provide an additional rationale for the importance of avoiding or correcting pediatric obesity.

We hypothesized that brief exercise of a small muscle group would lead to local rather than systemic alterations in cytokines, peripheral blood mononuclear cells, and mediators of angiogenesis. Fifteen men and eight women (age range 22-36 yr old) performed 10 min of unilateral wrist flexion exercise. Blood was sampled from venous catheters in the resting and exercising arm at baseline, at the end of exercise, and at 10, 30, 60, and 120 min after exercise. Lactate was significantly elevated in the exercising arm (+276 +/- 35%; P &lt; 0.0005) with no change in the resting arm. In contrast, increases in both arms were observed for interleukin-6 (+139 +/- 51%; P &lt; 0.0005), growth hormone (+1,104 +/- 284%; P &lt; 0.003), natural killer cells (+81 +/- 9%; P &lt; 0.0005), and lymphocytes expressing CD62L, CD11a, and CD54. There were no significant differences in these increases between the resting and exercising arm. Catecholamines increased in both arms [epinephrine peak increase, +226...

To examine the immediate effect of three different types of popular exercise activities on food intake and preferences in normal weight and overweight children. Forty-four (22 overweight) age and gender matched, pre-pubertal children participated in four separate visits. All performed three typical, 45 min, aerobic, indoor resistance and swimming exercise sessions and a control visit (no exercise). A similar buffet lunch was served immediately after each visit to both groups. The total energy intake and relative consumption of carbohydrates, fat and protein were recorded. In the normal weight children, total energy intake was reduced following exercise. This difference reached statistical significance only following the resistance-type exercise (14.0 + or - 1.4 [58.6 + or - 5.9] versus 19.4 + or - 1.7 [81.2 + or - 7.1] kcal/kg [kJ/ kg], in resistance exercise and control, respectively; p&lt;0.008). The different types of exercise were associated with increased relative consumption o...

We determined relationships between aerobic fitness and performance indices (fastest sprint time -FS, total sprint time -TS, and performance decrement -PD) of repeated sprint tests (RST) in normal and overweight children (BMI%: 59.8±12.9 versus 96.4±1.9%, respectively). Aerobic fitness, FS, and TS were significantly higher in normal weight children. Significant negative correlations were found between aerobic fitness and TS (r=-0.802), FS (r=-0.762) and PD (r=-0.670) in normal weight children. Significant negative correlations between aerobic fitness and TS (r=-0.767) and FS (r=-0.738), but not with PD were found in overweight children. While aerobic and anaerobic capabilities were significantly higher in normal weight children, strong relationships were found between aerobic fitness and RST indices in both normal and overweight children.