Associations between severity of obesity in childhood and adolescence, obesity onset and parental BMI: a longitudinal cohort study

Objective: To explore the relationship between severity of obesity at age 7 and age 15, age at onset of obesity, and parental body mass index (BMI) in obese children and adolescents. Design: Longitudinal cohort study.Subjects:Obese children (n231) and their parents (n462) from the Swedish National Childhood Obesity Centre. Methods: Multivariate regression analyses were applied with severity of obesity (BMI standard deviation score (BMI SDS)) and onset of obesity as dependent variables. The effect of parental BMI was evaluated and in the final models adjusted for gender, parental education, age at onset of obesity, severity of obesity at age 7 and obesity treatment. Results: For severity of obesity at age 7, a positive correlation with maternal BMI was indicated (P<0.05). Severity of obesity at this age also showed a strong negative correlation with the age at onset of obesity. Severity of obesity at age 15 was significantly correlated with both maternal and paternal BMI (P≥0.01). In addition, BMI SDS at age 15 differed by gender (higher for boys) and was positively correlated with severity of obesity at age 7 and negatively correlated with treatment. Also, a negative correlation was indicated at this age for parental education. No correlation with age at onset was found at age 15. For age at onset of obesity there was no relevant correlation with parental BMI. Children within the highest tertile of the BMI SDS range were more likely to have two obese parents. Conclusion: The impact of parental BMI on the severity of obesity in children is strengthened as the child grows into adolescence, whereas the age at onset is probably of less importance than previously thought. The influence of parental relative weight primarily affects the severity of childhood obesity and not the timing. © 2011 Macmillan Publishers Limited All rights reserved.link_to_subscribed_fulltex

Waist circumference and risk of elevated blood pressure in children: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Increasing childhood obesity has become a major health threat. This cross-sectional study reports associations between schoolchildren's waist circumference (WC) and risk of elevated blood pressure.</p> <p>Methods</p> <p>We measured height, weight, neck and waist circumference, and blood pressure in regular health examinations among children in grade 1 (ages 6-7 years) at six elementary schools in Taipei County, Taiwan. Elevated blood pressure was defined in children found to have mean systolic or diastolic blood pressure greater than or equal to the gender-, age-, and height-percentile-specific 95th-percentile blood pressure value.</p> <p>Results</p> <p>All 2,334 schoolchildren were examined (response rate was 100% in the six schools). The mean of systolic and diastolic blood pressure increased as WC quartiles increased (p < 0.0001). The prevalence of elevated blood pressure for boys and girls within the fourth quartile of waist circumference was 38.9% and 26.8%, respectively. In the multivariate logistic regression analyses, the adjusted odds ratios of elevated blood pressure were 1.78 (95% confidence interval [CI] = 1.13-2.80), 2.45 (95% CI = 1.56-3.85), and 6.03 (95% CI = 3.59-10.1) for children in the second, third, and fourth waist circumference quartiles compared with the first quartile. The odds ratios for per-unit increase and per increase of standard deviation associated with elevated blood pressure were 1.14 (95% CI = 1.10-1.18) and 2.22 (95% CI = 1.76-2.78), respectively.</p> <p>Conclusions</p> <p>Elevated blood pressure in children was associated with waist circumference. Not only is waist circumference easier to measure than blood pressure, but it also provides important information on metabolic risk. Further research is needed on effective interventions to identify and monitor children with increased waist circumference to reduce metabolic and blood pressure risks.</p

'Be active, eat right', evaluation of an overweight prevention protocol among 5-year-old children: design of a cluster randomised controlled trial

BACKGROUND: The prevalence of overweight and obesity in children has at least doubled in the past 25 years with a major impact on health. In 2005 a prevention protocol was developed applicable within Youth Health Care. This study aims to assess the effects of this protocol on prevalence of overweight and health behaviour among children. METHODS AND DESIGN: A cluster randomised controlled trial is conducted among 5-year-old children included by 44 Youth Health Care teams randomised within 9 Municipal Health Services. The teams are randomly allocated to the intervention or control group. The teams measure the weight and height of all children. When a child in the intervention group is detected with overweight according to the international age and gender specific cut-off points of BMI, the prevention protocol is applied. According to this protocol parents of overweight children are invited for up to three counselling sessions during which they receive personal advice about a healthy lifestyle, and are motivated for and assisted in behavioural change.The primary outcome measures are Body Mass Index and waist circumference of the children. Parents will complete questionnaires to assess secondary outcome measures: levels of overweight inducing/reducing behaviours (i.e. being physically active, having breakfast, drinking sweet beverages and watching television/playing computer games), parenting styles, parenting practices, and attitudes of parents regarding these behaviours, health-related quality of life of the children, and possible negative side effects of the prevention protocol. Data will be collected at baseline (when the children are aged 5 years), and after 12 and 24 months of follow-up. Additionally, a process and a cost-effectiveness evaluation will be conducted. DISCUSSION: In this study called 'Be active, eat right' we evaluate an overweight prevention protocol for use in the setting of Youth Health Care. It is hypothesized that the use of this protocol will result in a healthier lifestyle of the children and an improved BMI and waist circumference. TRIAL REGISTRATION: Current Controlled Trials ISRCTN04965410

Whole-body protein turnover and resting energy expenditure in obese, prepubertal obese children

Background: Obesity is becoming more frequent in Children; understanding the extent to which this condition affects not only carbohydrate and lipid metabolism but also protein metabolism is of paramount importance. Objective: We evaluated the kinetics of protein metabolism in obese, prepubertal children in the static phase of obesity. Design: In this cross-sectional study, 9 obese children (x̄ ± SE: 44 ± 4 kg, 30.9 ± 1.5% body fat) were compared with 8 lean (28 ± 2 kg, 16.8 ± 1.2% body fat), age-matched (8.5 ± 0.2 y) control children. Whole-body nitrogen flux, protein synthesis, and protein breakdown were calculated postprandially over 9 h from 15N abundance in urinary ammonia by using a single oral dose of [15N]glycine; resting energy expenditure (REE) was assessed by indirect calorimetry (canopy) and body composition by multiple skinfold-thickness measurements. Results: Absolute rates of protein synthesis and breakdown were significantly greater in obese children than in control children (x̄ ± SE: 208 ± 24 compared with 137 ± 14 g/d, P < 0.05, and 149 ± 20 compared with 89 ± 13 g/d, P < 0.05, respectively). When these variables were adjusted for fat- free mass by analysis of covariance, however, the differences between groups disappeared. There was a significant relation between protein synthesis and fat-free mass (r = 0.83, P <0.001) as well as between protein synthesis and REE (r = 0.79, P < 0.005). Conclusions: Obesity in prepubertal children is associated with an absolute increase in whole-body protein turnover that is consistent with an absolute increase in fat-free mass, both of which contribute to explaining the greater absolute REE in obese children than in control children

Substrate metabolism, nutrient balance and obesity development in children and adolescents: a target for intervention?

Obesity results from the organism's inability to maintain energy balance over a long term. Childhood obesity and its related factors and pathological consequences tend to persist into adulthood. A cluster of factors, including high energy density in the diet (high fat intake), low energy expenditure, and disturbed substrate oxidation, favour the increase in fat mass. Oxidation of three major macronutrients and their roles in the regulation of energy balance, particularly in children and adolescents, are discussed. Total glucose oxidation is not different between obese and lean children; exogenous glucose utilization is higher whereas endogenous glucose utilization is lower in obese compared with lean children. Carbohydrate composition of the diet determines carbohydrate oxidation regardless of fat content of the diet. Both exogenous and endogenous fat oxidation are higher in obese than in lean subjects. The influence of high fat intake on accumulation of fat mass is operative rather over a long term. Several future directions are addressed, such that a combination of increased physical activity and modification in diet composition, in terms of energy density and glycemic index, is recommended for children and adolescents