OBJECTIVE:The autonomic nervous system (ANS) is a key factor in the regulation of energy balance and body fat storage; however, to what extent the physical activity during the childhood years contributes to variations in ANS function is still unclear. The present study was designed to investigate the ANS activity in lean and obese children, focusing on the differences in physical activity levels. SUBJECTS: This study was performed on 1080 school children initially recruited to the present study. In all, 24 physically active and 24 inactive obese children (Z120% of the standard body weight) were chosen as samples. Then, 24 lean-active and 24 lean-inactive children, who were matched individually in age, gender, height, and the amount of sports activity, were carefully selected from the remaining children. MEASUREMENTS: Physical activity was classified as the frequency of participation in after-school sports activities (active; Z3 times per week, inactive; nothing). The ANS activities were measured during the resting condition by means of heart rate (HR) variability power spectral analysis, which enables us to identify separate frequency components, that is, low frequency (LF; 0.03-0.15 Hz), reflecting mixed sympathetic (SNS) and parasympathetic nervous system (PNS) activity, high frequency (HF; 0.15-0.5 Hz), mainly associated with PNS activity, and total power (TP; 0.03-0.5 Hz), evaluating the overall ANS activity. The spectral powers were log transformed for statistical testing. RESULTS:The lean-active group demonstrated lower resting HR as well as significantly higher TP, LF, and HF powers compared to the remaining groups. In contrast, the obese-inactive group showed significantly lower TP (Po0.05 vs the remaining groups), LF (Po0.05 vs the lean groups), and HF power (Po0.05 vs the lean groups), respectively. The obese-active and lean-inactive groups were nearly identical in all spectral parameters. The correlation analysis revealed that TP among 48 inactive children was significantly and negatively associated with the percentage of body fat (r ¼ À0.53, Po0.001); however, such correlation among 48 active children was modest (r ¼ À0.33, P ¼ 0.02). CONCLUSION: Our data suggest that obese children possess reduced sympathetic as well as parasympathetic nervous activities as compared to lean children who have similar physical activity levels. Such autonomic reduction, associated with the amount of body fat in inactive state, might be an etiological factor of onset or development of childhood obesity. On the other hand, regular physical activities could contribute to enhance the overall ANS activity in both lean and obese children. These findings further imply that regular physical activity might be effective in preventing and treating obesity beginning in the childhood.

NAGAI, NARUMI, TAMAKI MATSUMOTO, HIROKO KITA, AND TOSHIO MORITANI. Autonomic nervous system activity and the state and development of obesity in Japanese school children. Obes Res. 2003;11:25-32. Objective: The autonomic nervous system (ANS) plays an important role in regulating energy expenditure and body fat content; however, the extent to which the ANS contributes to pediatric obesity remains inconclusive. The aim of this study was to evaluate whether sympathetic and/or the parasympathetic nerve activities were altered in an obese pediatric population. We further examined a physiological association between the duration of obesity and the sympatho-vagal activities to scrutinize the nature of ANS alteration as a possible etiologic factor of childhood obesity. Research Methods and Procedures: Forty-two obese and 42 non-obese healthy sedentary school children were carefully selected from 1080 participants initially recruited to this study. The two groups were matched in age, gender, and height. The clinical records of physical characteristics and development of the obese children were retrospectively reviewed to investigate the onset and progression of obesity. The ANS activities were assessed during a resting condition by means of heart rate variability power spectral analysis, which enables us to identify separate frequency components, i.e., total power (TP), low-frequency (LF) power, and high-frequency (HF) power. The spectral powers were then logarithmically transformed for statistical testing. Results:The obese children demonstrated a significantly lower TP (6.77 Ϯ 0.12 vs. 7.11 Ϯ 0.04 ln ms 2 , p Ͻ 0.05), LF power (6.16 Ϯ 0.12 vs. 6.42 Ϯ 0.05 ln ms 2 , p Ͻ 0.05), and HF power (5.84 Ϯ 0.15 vs. 6.34 Ϯ 0.07 ln ms 2 , p Ͻ 0.01) compared with the non-obese children. A partial correlation analysis revealed that the LF and HF powers among 42 obese children were negatively associated with the duration of obesity independent of age (LF: partial r ϭ Ϫ0.55, p Ͻ 0.001; HF: partial r ϭ Ϫ0.40, p Ͻ 0.01). The obese children were further subdivided into two groups based on the length of their obesity. All three spectral powers were significantly reduced in the obese group with obesity of Ͼ3 years (n ϭ 18) compared to the group with obesity of Ͻ3 years. Discussion: Our data indicate that obese children possess reduced sympathetic as well as parasympathetic nerve activities. Such autonomic depression, which is associated with the duration of obesity, could be a physiological factor promoting the state and development of obesity. These findings further imply that preventing and treating obesity beginning in the childhood years could be an urgent and crucial pediatric public health issue.

Physical exercise exerts favourable effects on brain health and quality of life of the elderly; some of these positive health effects are induced by the modulation of microbiota composition. We therefore conducted a randomised, double blind, placebo-controlled trial that assessed whether a combination of Bifidobacterium spp. supplementation and moderate resistance training improved the cognitive function and other health-related parameters in healthy elderly subjects. Over a 12-week period, 38 participants (66-78 years) underwent resistance training and were assigned to the probiotic Bifidobacterium supplementation (n=20; 1.25×10 cfu each of Bifidobacterium longum subsp. longum BB536, B. longum subsp. infantis M-63, Bifidobacterium breve M-16V and B. breve B-3) or the placebo (n=18) group. At baseline and at 12 weeks, we assessed the cognitive function, using the Japanese version of the Montreal Cognitive Assessment instrument (MoCA-J); modified flanker task scores; depression-anxiety scores; body composition; and bowel habits. At 12 weeks, the MoCA-J scores showed a significant increase in both the groups, while the flanker task scores of the probiotic group increased more significantly than those of the placebo group (0.35±0.9 vs -0.29±1.1, P=0.056). Only the probiotic group showed a significant decrease in the depression-anxiety scores (5.2±6.3 to 3.4±5.5, P=0.012) and body mass index (24.0±2.8 to 23.5±2.8 kg/m, P<0.001), with a significant increase in the defecation frequency (5.3±2.3 to 6.4±2.3 times/5 days, P=0.023) at 12 weeks. Thus, in healthy elderly subjects, combined probiotic bifidobacteria supplementation and moderate resistance training may improve the mental condition, body weight and bowel movement frequency.

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Bis(phenoxyimine)Zr complexes 1 − 8 containing a series of cycloalkyl groups on the imine-N's were synthesized (1:  cyclopropyl; 2, 3:  cyclobutyl; 4:  cyclopentyl; 5, 7:  cyclohexyl; 6, 8:  2-methylcyclohexyl). X-ray crystallographic analyses suggested that complexes 3, 5, and 8 assume an octahedral coordination geometry with a trans-phenoxy-O, cis-imine-N, and cis-Cl disposition and that the cycloalkyl groups on the imine-N's influence steric environments around the chlorine bound sites (i.e., potential polymerization sites). Upon activation with MAO at 25 °C, these complexes produced low-to-high molecular weight polyethylenes (PEs) (M w 1900−960000, M w/M n 1.6−4.9) with very high efficiency (22−290 kg of PE/(mmol of cat. h)), which is comparable to or exceeds that seen with Cp2ZrCl2/MAO (28 kg of PE/(mmol of cat. h)). The cycloalkyl group has a profound effect on both catalytic activity and product molecular weight, indicating the critical importance of the substituent on the imine-N for polymerization catalysis. The catalytic activity increased with an increase in the steric bulk of the cycloalkyl substituent, albeit too much steric bulk reduced the activity. The product molecular weight was also related to the steric bulk of the cycloalkyl group, in that increased steric bulk normally resulted in higher molecular weight PEs. The PEs produced with complexes 1 − 5/MAO (Al/Zr molar ratio = 1250) possess a high degree of vinyl unsaturation at one of the two polymer chain ends (M w 2000−14000, vinyl selectivity, 90−96 mol %). Polymerizations performed at a much higher Al/Zr molar ratio of 12500 confirmed the marked preference of these complexes for β-H transfer as the chain termination mechanism (M w 1900−14000, vinyl selectivity, 90−95 mol %). The vinyl-terminated PEs were readily transformed to the corresponding epoxy- and diol-terminated PEs, which are valuable materials for PE- and polar polymer-based block and graft copolymers. Ethylene pressure studies on complexes 1, 2, 4, and 5 revealed a first-order dependence on ethylene for both the rate of chain propagation and the rate of chain transfer. On the basis of this polymerization behavior together with X-ray analyses and DFT calculation studies, we concluded that β-H transfer to an incoming monomer is responsible for the formation of vinyl-terminated PEs. The calculations revealed that the complexes disfavor β-H transfer to the Zr metal due to the extreme instability of a metal hydride species that is produced in such a chain transfer process. Therefore, the unique polymerization catalysis and distinctive polymer formation with phenoxycycloalkylimine ligated Zr complexes were demonstrated.