Thesis (M.S.)--Boston University

Background: The major activity components that make up the 24 hours of daily life, the so-called 'movement continuum' are sleep, comprising ~40% of time, sedentary behaviour (~40%), low intensity physical activity (LPA) (~15%), and moderate-to-vigorous physical activity (MVPA) (~5%). To address fully the impact of movement behaviour on children's health, it is necessary to study the relationship between each of these components of the 'movement continuum' and children's health. Asthma is a chronic childhood disease that impacts children's activity and alters the balance between movement continuum components. Few studies have attempted to investigate the association between asthma and movement continuum components. The relationship between asthma in children and physical activity and sedentary behaviour is conflicting. Some studies suggested that asthmatic children are less physically active and more sedentary; others suggested that they are more active and less sedentary or that there are no differences between asthmatic and healthy children. The factors that led to this conflict are not clear. We conducted a systematic review that reviewed available published evidence regarding the association between objectively measured physical activity, sedentary behaviour and asthma in school aged children. The effect of asthma attacks on the movement continuum components is unclear, especially in the Middle East area. We hypothesized that in the acute stage following an asthma attack; children are less physically active, more sedentary and have sleep disturbances compared to the recovery stage. During recovery from asthma attack, there is inter individual variability in changes of movement continuum components. We conducted an observational study to measure levels of asthma control and movement continuum components of Kuwaiti school aged children week 1 and week 4 following an asthma attack. The study also compared movement continuum components of asthmatics at week 4 following an asthma attack with the same measurements in healthy controls. Methods: In our systematic review, a literature search of EMBASE, Medline, CINHAL, Cochrane library and PubMed was performed to identify articles published in English between 2000-2017 in which either physical activity or sedentary behaviour or both were assessed objectively in 6-12 years old school aged children with asthma in case-control, cross-sectional or longitudinal (cohort) studies. In our prospective study we recruited 23 asthmatic children admitted to Kuwaiti hospitals following an asthma attack (mean age of 8.1 (SD 2.02) yrs). For the control group, 23 healthy children from Kuwait youth centres (mean age of 9.0 (1.72) yrs) were recruited. Measurements of asthmatic children at week 1 (acute stage) were compared to those at week 4 after discharge from hospital (recovery stage). Measurements of asthmatic children at the recovery stage were compared to those in healthy controls. Asthma symptoms were assessed by Childhood Asthma Control Test (CACT) questionnaire. Pulmonary function testing was carried out using a portable spirometer. Physical activity, sedentary behaviour and sleeping behaviour were investigated using ActivPAL™ accelerometers. Results: In the systematic review, the literature search identified 71 publications. Of the studies identified, nine met the inclusion criteria (total subjects n= 2996 (asthmatics (n=839), and wheezers (n=37)). In eight studies (total subjects n=2644) there was no significant difference in physical activity between children with and without asthma. Only one study (n=352) reported that asthmatic children were less physically active. No study found that asthmatic children were more physically active. Sedentary behaviour was assessed objectively in 3 studies (n=609); one study suggested that asthmatic children were less sedentary; and two studies showed no differences in sedentary behaviour between children with and without asthma. Our prospective study showed that CACT score improved significantly from week one to week four (week 1, 19.1 ± 4.39; week 4, 22.7 ± 3.77, P=0.000). The number of steps at week four was significantly higher than at week one (week 4, 11876 ± 3924; week 1, 10087 ± 2720, P=0.02). Total sitting time at week 4 was significantly lower than at week 1 (week 4, 7.7 ± 1.10 h/day; week 1, 8.7 ± 1.13 hours/day, P=0.001). During recovery from asthma attack changes in measures of activity continuum varied between individuals. Physical activity duration was increased in 14, but decreased in nine asthmatic children. Number of steps was increased in 16, decreased in six and remained the same in one asthmatic child. Total sitting time was decreased in 19, and increased in four asthmatic children. Sleeping time was increased in 13, decreased in eight and remained the same in two asthmatic children. Physical activity parameters of asthmatic children at week four were significantly higher than those of healthy controls; duration of physical activity (asthmatics, 7.40 ± 1.12 hours/day; healthy, 6.63 ± 2.04 hours/day, P=0.038); total activity counts (asthmatics, 840 ± 271; healthy, 650 ± 157, P=0.006); and number of steps (asthmatics, 11876 ± 3924; healthy, 8602 ± 2128, P=0.001). Sedentary behaviour parameters of asthmatic children at week four were significantly better than those of healthy controls; total sitting time (asthmatics, 7.7 ± 1.10hours; healthy, 8.3 ± 1.56 hours, P=0.05); number of breaks in sitting (asthmatics, 247 ± 97; healthy, 199 ± 65, P=0.05); number of sedentary bouts (asthmatics, 254 ± 89; healthy, 209 ± 54, P=0.045); and fragmentation index (asthmatics, 33.5 ± 13.0; healthy, 26.2 ± 9.6, P=0.001). In the summer in Kuwait, at the hottest time of the year, bed time shifted eight hours (0400 vs 2100) and wake up time shifted to late in the afternoon (1300-1400 vs 0500-0600).The summer sleep duration was ten hours, one hour longer than at other times of the year. Conclusions: The balance of available evidence in the literature strongly suggests that asthmatic and healthy children were of similar physical activity. This study showed that during recovery from asthma attack, asthma symptoms improved, physical activity increased and sedentary behaviour reduced. There were inter-individual variability changes in the activity continuum during recovery. In Kuwait, asthmatic children admitted with an asthma attack were physically active, not sedentary and had no difference in sleep time compared to healthy controls. During the period of very high external environmental temperature in the summer in Kuwait, there was a significant association changes in children's sleeping time and pattern.

Introduction Children with cerebral palsy (CP) often have to wear orthoses to help them walk. There is a growing body of evidence that orthotic tuning, that is, optimisation of the ground reaction forces in the lower limbs during walking, is recommended to ensure the maximum potential benefit for each child. Research demonstrates that orthoses can reduce the energy cost of walking for children with CP, but to-date there is no evidence as to whether this tuning process results in further energy efficiency or not [1]. Aim The aim of this research programme was to validate a method that would help to determine when an orthosis was optimised for each child; and then to investigate whether the use of orthoses that were optimally tuned for each child allowed a further reduction in energy cost during walking, compared with orthoses that had not been optimally tuned. Method A video vector system was used to allow visualisation of the alignment of ground reaction forces in relation to the lower limbs during walking. A simple measurement tool was validated that allowed quantification of the moment arm at the knee in stance, which was used to confirm when optimal alignment had occurred following orthotic tuning. The energy cost of walking was measured using the Total Heart Beat Index (THBI). Data were collected barefoot, with the original ‘un-tuned’ orthosis and with the final ‘tuned’ orthosis. Results Analysis of energy cost showed that for some children, energy cost was further reduced through orthotic tuning, but that this was not the case for all children. Preliminary findings suggest the influence of underlying level of disability, as determined by the GMFCS. Conclusion Orthotic tuning may help to reduce the energy cost of walking for some children with CP, especially those with greater levels of disability. Further studies with large participant numbers are warranted to further investigate this area.

Coeliac disease (CD) is an autoimmune condition of the gastrointestinal tract. In untreated patients, an inflammatory response to gluten results in destruction of the gut mucosa resulting in villus atrophy. This often presents with overt clinical symptoms but can also be silent in nature. Continual gluten insult can inevitably lead to a range of complications including nutritional problems from poor growth to deficits in bone mineral density (BMD). The CHIC study aimed to create a comprehensive picture of CD in children, taking into account growth and nutritional status, bone health, micronutrient status and further assessing children with the dual diagnosis of type 1 diabetes mellitus and CD. It is well established that early diagnosis of CD and the prompt initiation of gluten free dietary treatment (GFD) reduces the manifestation of complications. Yet in many previous studies the quality of a GFD and children's compliance to it have not been accounted for. This study assessed nutritional status and body composition in paediatric patients with newly diagnosed CD and found that the presentation of CD has changed, with the majority of patients presenting with normal and even over nutrition. Furthermore, the introduction of GFD with good compliance supports normal growth velocities and enables catch up growth in children presenting with short stature. When considering bone health in paediatric patients with CD the results remain inconclusive. Many previous studies have used the widely available DXA to assess bone mineral content, but in paediatric patients this may not accurately determine bone health. This study used peripheral quantitative computed tomography to distinguish changes in bone mineral density and investigate any alterations in bone microarchitecture. Thus, for the first time in paediatric CD patients identifying disruption to the remodelling mechanisms of trabecular bone, which may be particularly sensitive to resorption and mineral loss in patients with active CD. Furthermore, restoration of BMD was evident with good compliance to dietary treatment. Investigations into micronutrient status revealed that newly diagnosed children are vulnerable to micronutrient deficiency, this is likely due to malabsorption in the gut in patients with active CD. Deficiencies in zinc and magnesium were also identified in children treated with a GFD. This may be due to the inadequate micronutrients intakes with consumption levels of riboflavin, vitamin A, vitamin K, calcium, iron, magnesium and zinc lower than expected in treated CD children.

Background: A better understanding of the nutritional status of infants and young children who are HIV-Exposed-Uninfected (HEU) and HIV-Unexposed-Uninfected (HUU) during their first 1000 days is a key to improving population health, particularly in sub-Saharan Africa. Methods: A mixed-methods approach (explanatory sequential design) was utilised to compare the nutritional status, feeding practices and determinants of nutritional status of HEU and HUU infants and young children residing in representative selected districts in Botswana. In addition, themes associated with perceptions of caregivers, older family figures and healthcare workers in achieving optimal nutritional outcomes in these infants and young children were identified. In the quantitative strand (413 infants and young children, 37.3% HIV-exposed) aged 6-24 months attending routine child health clinics were recruited. In the qualitative strand 25 caregivers, 9 older family figures and 10 healthcare workers were interviewed using a semi-structured questionnaire. Quantitative data including anthropometric, 24-hour dietary intake and socio-demographic data was collected. Anthropometric z-scores were calculated using 2006 WHO growth standards. Modelling of the determinants of malnutrition was undertaken using logistic regression. Qualitative data was analysed using an inductive, interpretive/latent thematic analysis approach. Results: Overall, prevalence of stunting, wasting and underweight were 10.4%, 11.9% and 10.2% respectively. HEU infants and young children were significantly more likely to be underweight (15.6% vs. 6.9%), (p < 0.01) and stunted (15.6% vs. 7.3%), (p < 0.05) but not wasted (p= 0.14) than HUU infants and young children. HEU infants and young children tended to be formula fed (89.4%) whereas HUU infants and young children tended to breastfeed (89.6%) for the first six months (p < 0.001). In multivariate analysis, significant predictors of nutritional status were HIV exposure, birthweight, birth length, Apgar score and mother/caregiver’s education with little influence of socioeconomic status (p < 0.05). Qualitative thematic analysis revealed four themes; when “free choice” is an illusion: mother’s infant feeding decisions; “These people are dangerous.” negotiating access to healthcare services; “caring is how I show my baby love”; “our culture, our heritage”. Conclusions: HEU infants and young children aged 6-24 months had worse nutritional status compared to HUU infants and young children. Notably, birthweight was the main predictor of undernutrition in this population and, therefore optimisation of infants and young children’ nutritional status should focus on the nutrition and health of women in the pre- and antenatal period. These interventions should focus on equipping caregivers with skills and knowledge but also address external factors such as influence of the older family figure, community norms and cultures and experiences associated with accessing healthcare services.

digitalisering@umu.se

digitalisering@umu.se

Introduction: Exposure to maternal obesity during early development can have profound consequences for health and programme for obesity and type-2 diabetes. However, the mechanisms of programming during gestation and lactation are poorly understood. Aim: To assess the relative contributions of exposure to maternal obesity, induced by a cafeteria diet, during gestation and lactation on rat offspring growth, behaviour, metabolic and cardiovascular health. Methods: A cross-fostering study was piloted and then implemented to assess the relative contributions of maternal obesity during pregnancy and lactation. Female Wistar rats were fed either a control (C) or cafeteria diet (O) for two weeks before mating in the pilot study and eight weeks in the second experiment, throughout pregnancy and lactation. Offspring were cross-fostered at birth to a dam on the same or alternate diet to before birth and weaned on a chow diet. The pilot study also compared offspring cross-fostered (CF) against those that were not (NCF). Endpoints measured in offspring comprised weight and body composition, blood pressure, circulating and hepatic lipids, glucose tolerance, locomotor behaviour and gene expression. Results: The pilot study identified no difference between CF and NCF groups in offspring body composition, blood pressure, glucose tolerance, or plasma TAG and cholesterol concentrations at eight weeks of age. Therefore, cross-fostering was an effective method for a larger scale experiment. Feeding female dams a highly varied cafeteria diet resulted in greater weight and 3.4 times greater adiposity than animals fed a control chow diet throughout pregnancy and lactation (P < 0.05). Exposure to maternal obesity during pregnancy was associated with lower birth weight in offspring, reduced locomotor behaviour in female offspring at eight weeks of age, and elevated hepatic omega 3 fatty acid composition in male offspring at twelve weeks of age. Exposure to maternal obesity in lactation was associated with reduced locomotor behaviour in male offspring at twelve weeks of age. It was also associated with greater adiposity. Compared to control offspring, male offspring had 40% greater perirenal adiposity at two weeks of age (P=0.043) and female offspring had 26% greater gonadal adiposity at twelve weeks of age (P=0.030). Fasting blood glucose concentrations were 8% greater in offspring exposed to maternal obesity during lactation (P=0.031) and male offspring demonstrated slower glucose clearance during a two-hour intraperitoneal glucose tolerance test, despite no differences in circulating insulin between groups. This indicated insulin resistance, which was further confirmed by reduced adipose tissue and hepatic mRNA expression of genes which code for the regulatory and catalytic subunits of PI3K, in the insulin signalling cascade. However, male offspring exposed to maternal obesity during gestation demonstrated up-regulation of insulin signalling genes in skeletal muscle and perirenal adipose tissue. An insulin resistance PCR array confirmed an mRNA expression profile favouring insulin sensitivity in offspring exposed to maternal obesity during gestation (key genes included ALOX5, APOE, CASP1, CCL12, STAT3, TNF P < 0.001) and resistance in offspring exposed to maternal obesity during lactation (CXCR4, OLR1, CCR5, TNF, P < 0.05). Conclusions: Cross-fostering successfully teased apart the relative contributions of exposure to maternal obesity before birth and during lactation. Maternal obesity during lactation has a greater influence in programming for insulin resistance and adiposity than maternal obesity in pregnancy.

No description available.

Submitted in partial fulfillment of the requirements for the degree of Master of Science (Child Health) in the Department of Paediatrics, University of the Witwatersrand, Gauteng, South Africa, 2017 / Background: The incidence and morbidity of childhood tuberculosis (TB) in South Africa is high. Objectives: We evaluated the incidence of childhood TB in a regional hospital, the proportion of cases with a delayed diagnosis, and the determinants and outcomes thereof. Method: We conducted a retrospective cross-sectional review of hospital records of paediatric cases that were diagnosed with probable or confirmed TB at Addington Hospital, eThekwini, KwaZulu-Natal (KZN) from July through December 2013. Caregiver delays in diagnosis were based on history taking atinitial presentation, while health care worker or systems delays were calculated fromthe time from first presentation to diagnosis.Healthcare worker and health system delays were classified asbeing of 2-4 weeks and >4 weeksduration. Delays related to health policy implementation were also determined. Results: Fifty nine (74%) of the 80 children who werediagnosed with TBhad their recordsretrieved.The overall childhood TB incidence for Addington Hospital during the study period was 2.5%. Caregiver-related factors impacting on delay in TB diagnosis were observed in 25 (42%) of the 59 cases.Nineteen (32%)childrenhad a delay from initial presentation to TB diagnosis related to healthcare worker and health systems issues.Airway reactivity occurred more frequently in the group ofchildren who had a delay in diagnosis of>4 weeks (8/11, 73%)as compared to the non-delayed group (15/40, 38%), P=0.038. Conclusion: The diagnosis of TB in childrenis delayed in a substantial proportion of children. Significant improvements in healthcare that is provided to these childrenare required to avoid missed opportunities for diagnosis and treatment. / XL2018