Rebecca Abbott

Environmental correlates of children's active transportation: a systematic literature review

This systematic review investigated the environmental (physical, economic, socio-cultural and political) correlates of active transportation (AT) among young people aged 5-18 years to better inform the promotion of active living. Greater distance, increasing household income and increasing car ownership are consistently associated with lower rates of AT among children. Having a non-white ethnic background has a convincing positive association with AT. Having recreation facilities and walk or bike paths present are possibly associated with higher rates of AT. Further research requires longitudinal and intervention studies, utilizing multi-level design methodologies and objective measures of environmental attributes.

Efficacy and safety of long-chain polyunsaturated fatty acid supplementation of infant-formula milk: A randomised trial

BACKGROUND We tested whether addition of n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFA) to infant-formula milk during the first 6 months promotes long-term cognitive and motor development, without adverse consequences. METHODS We did a double-blind, randomised, controlled, efficacy and safety trial of formula with and without LCPUFAs, with an additional breastfed reference group, in four hospitals in two cities in the UK. The participants were 447 healthy full-term babies. 309 were fed formula (155 without LCPUFAs) and 138 were breastfed for at least 6 weeks. The main outcome measures were: Bayley Mental and Psychomotor Development Indices (MDI, PDI) at 18 months (primary efficacy outcome) and Knobloch, Passamanick, and Sherrards test at 9 months (secondary outcome). Principal safety outcomes were: infection, atopy, growth, and gastrointestinal tolerance. FINDINGS Babies fed formula with and without LCPUFA did not differ in cognitive or motor development, growth, infection, atopy or tolerance. The mean (95% CI) MDI was 0.5 (-2.7 to 3.8) units and the PDI 0.6 (-1.8 to 3.0) units higher in the supplementation group. Formula-fed infants had similar developmental scores to the breastfed reference group after adjustment for higher social class and maternal education in the latter. INTERPRETATION There was no evidence of a beneficial or adverse effect on cognitive and motor development or growth up to 18 months. Although no significant differences in safety outcomes were observed, we suggest such data should be collected in future LCPUFA trials. Our trial does not provide support for addition of LCPUFA to standard infant formula but we are now doing further follow-up of this cohort.

Habitual physical activity and physical activity intensity: their relation to body composition in 5.0-10.5-y-old children

Background: Concerns of a decrease in physical activity levels (PALs) of children and a concurrent increase in childhood obesity exist worldwide. The exact relation between these two parameters however has as yet to be fully defined in children.Objective: This study examined the relation in 47 children, aged 5–10.5 y (mean age 8.4±0.9 y) between habitual physical activity, minutes spent in moderate, vigorous and hard intensity activity and body composition parameters.Design: Total energy expenditure (TEE) was calculated using the doubly labelled water technique and basal metabolic rate (BMR) was predicted from Schofields equations. PAL was determined by PAL=TEE/BMR. Time spent in moderate, vigorous and hard intensity activity was determined by accelerometry, using the Tritrac-R3D. Body fatness and body mass index (BMI) were used as the two measures of body composition.Results: Body fat and BMI were significantly inversely correlated with PAL (r=−0.43, P=0.002 and r=−0.45, P=0.001). Times spent in vigorous activity and hard activity were significantly correlated to percentage body fat (r=−0.44, P=0.004 and r=−0.39, P=0.014), but not BMI. Children who were in the top tertiles for both vigorous activity and hard activity had significantly lower body fat percentages than those in the middle and lowest tertiles. Moderate intensity activity was not correlated with measures of body composition.Conclusions: As well as showing a significant relation between PAL and body composition, these data intimate that there may be a threshold of intensity of physical activity that is influential on body fatness. In light of world trends showing increasing childhood obesity, this study supports the need to further investigate the importance of physical activity for children.

Iron fortified follow on formula from 9 to 18 months improves iron status but not development or growth: a randomised trial

AIMS Iron deficiency anaemia is associated, in observational studies, with developmental disadvantage. This study tested the hypothesis that feeding iron supplemented formula from 9 to 18 months of age would improve developmental performance. SUBJECTS AND METHODS 493 healthy children aged 9 months being fed pasteurised cows’ milk were recruited from three UK centres. They were randomised to: cows’ milk as before, formula containing 0.9 mg/litre iron, or formula containing 1.2 mg/litre iron, until 18 months of age. Bayley mental and psychomotor developmental indices were measured at 18 months, as were growth and haematological indices. RESULTS Children fed iron fortified formula had higher plasma ferritin concentrations, but there were no significant intergroup differences in development or growth. CONCLUSIONS There are no developmental or growth advantages in children given iron supplemented formula, but a benefit for a minority who were anaemic, or the possibility that a benefit may emerge at a later age, cannot be excluded.

Effectiveness of mindfulness-based stress reduction and mindfulness based cognitive therapy in vascular disease: A systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE To determine the effectiveness of mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) on psychological and physical outcomes for people with vascular disease. DESIGN Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES AMED, CINAHL, EMBASE, British Nursing Index, Medline, Web of Science, PsycINFO, Cochrane Database of Systematic Reviews, Central, Social Sciences Citation Index, Social Policy and Practice, and HMIC from inception to January 2013. REVIEW METHODS Articles were screened for inclusion independently by two reviewers. Data extraction and quality appraisal were performed by one reviewer and checked by a second with discrepancies resolved by discussion with a third if necessary. Random-effects meta-analyses were performed. RESULTS Nine articles (from eight original randomised controlled trials) met eligibility criteria and were included in the final review. In total, 578 participants were enrolled across the trials, with participants presenting with prehypertension/hypertension (n=3 trials), type 1 or 2 diabetes (n=2), heart disease (n=2) and stroke (n=1). Meta-analyses, using standardised mean differences, showed evidence of reductions in stress (-0.36; 95% CI -0.67 to -0.09; p=0.01), depression (-0.35; 95% CI -0.53 to -0.16; p=0.003) and anxiety (-0.50; 95% CI -0.70 to -0.29; p<0.001). Effects on physical outcomes (blood pressure, albuminuria, stress hormones) were mixed. CONCLUSION Whilst populations with vascular disease appear to derive a range of psychological benefits from MBSR/MBCT intervention, the effects on physical parameters of disease are not yet established. More robust studies, with longer term follow-up, are required to ascertain full effectiveness of such intervention.

Correlation of habitual physical activity levels with flow-mediated dilation of the brachial artery in 5–10 year old children

Endothelial dysfunction is an early key event of atherogenesis. Both fitness level and exercise intervention have been shown to positively influence endothelial function. In a cross-sectional study of 47 children, the relationship between habitual physical activity and flow-mediated dilation (FMD) of the brachial artery was explored. Habitual physical activity levels (PALs) were assessed using a validated stable isotope technique, and FMD of the brachial artery was measured via high-resolution ultrasound. The results showed that habitual physical activity significantly correlated with FMD (r=0.39, P=0.007), and remained the most influential variable on dilation in multivariate analysis. Although both fitness level and exercise intervention have previously been shown to positively influence FMD, this is the first time that a relationship with normal PALs has been investigated, especially, at such a young age. These data support the concept that physical activity exerts its protective effect on cardiovascular health via the endothelium and add further emphasis to the importance of physical activity in childhood.

Validity of BMI as a measure of obesity in Australian white Caucasian and Australian Sri Lankan children

Background: Body mass index (BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (%FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. Aim: This study is focused on determining the ability of BMI-based cut-off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. Subjects and methods: Height and weight was measured and BMI (W/H2) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender-specific constants. A %FM of 30% for girls and 20% for boys was considered as the criterion cut-off level for obesity. BMI-based obesity cut-offs described by the International Obesity Task Force (IOTF), CDC/NCHS centile charts and BMI-Z were validated against the criterion method. Results: There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 (36%) girls and 29 (66%) boys, and of the Sri Lankans 7 (46%) girls and 16 (63%) boys, were obese based on %FM. The FM and BMI were closely associated in both Caucasians (r = 0.81, P<0.001) and Sri Lankans (r = 0.92, P<0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut-off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI-Z cut-offs detected cases of obesity with low sensitivity. Conclusions: BMI is a poor indicator of percentage fat and the commonly used cut-off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut-off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %FM should be explored.

Validating the waist‐height ratio and developing centiles for use amongst children and adolescents

Aim: To assess the statistical validity of the waist‐height ratio (WHtR) as an appropriate method of adjusting waist circumference (WC) for height in children and adolescents.

Effectiveness of mealtime interventions on nutritional outcomes for the elderly living in residential care: A systematic review and meta-analysis

The need to improve the nutrition of the elderly living in long term care has long been recognised, but how this can best be achieved, and whether (and which) intervention is successful in reducing morbidity is less well understood. The aim of this systematic review was to determine the effectiveness of mealtime interventions for the elderly living in residential care. Mealtime interventions were considered as those that aimed to change/improve the mealtime routine, practice, experience or environment. Following comprehensive searches, review and appraisal, 37 articles were included. Inadequate reporting in over half of the articles limited data quality appraisal. Mealtime interventions were categorised into five types: changes to food service, food improvement, dining environment alteration, staff training and feeding assistance. Meta-analysis found inconsistent evidence of effects on body weight of changes to food service (0.5 kg; 95% CI: -1.1 to 2.2; p=0.51), food improvement interventions (0.4 kg; 95% CI: -0.8 to 1.7; p=0.50) or alterations to dining environment (1.5 kg; 95% CI: -0.7 to 2.8; p=0.23). Findings from observational studies within these intervention types were mixed, but generally positive. Observational studies also found positive effects on food/caloric intake across all intervention types, though meta-analyses of randomised studies showed little evidence of any effects on food/caloric intake in food improvement studies (-5 kcal; 95% CI: -36 to 26; p=0.74). There was some evidence of an effect on daily energy intakes within dining environment studies (181 kcal/day, 95% CI: -5 to 367, p=0.06). The need to improve the nutrition of the elderly living in residential long term care is well recognised. This review found some evidence that simple intervention around various aspects of mealtime practices and the mealtime environment can result in favourable nutritional outcomes. Further large scale pragmatic trials, however, are still required to establish full efficacy of such interventions.

‘I could do with a pair of wings’: perspectives on physical activity, bodies and health from young Australian children

There is little research that reports childrens perspectives on physical activity, bodies and health. This paper, drawn from a larger multi-method study on physical activity in the lives of seven- and eight-year-old Australian children, attempts to ‘give a voice’ to 13 childrens views. Interviews focused on childrens activity preferences and related decision making and motivations pertaining to these activities, as well as how they thought about the relationships between physical activity, health and their bodies. Data suggest some tensions surrounding the importance of fun for children alongside their awareness of ‘healthist’ discourses that require self-monitoring and improvement.