Gita Wahi

Effectiveness of Interventions Aimed at Reducing Screen Time in Children: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE To evaluate the impact of interventions focused on reducing screen time. DATA SOURCES Medline, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, ERIC, and CINAHL through April 21, 2011. STUDY SELECTION Included studies were randomized controlled trials of children aged 18 years or younger with interventions that focused on reducing screen time. INTERVENTION Efforts to reduce screen time. MAIN OUTCOME MEASURES The primary outcome was body mass index (BMI); the secondary outcome was screen time (hours per week). RESULTS A total of 1120 citations were screened, and 13 studies were included in the systematic review. Study samples ranged in age (3.9-11.7 years) and size (21-1295 participants). Interventions ranged in length (1-24 months) and recruitment location (5 in schools, 2 in medical clinics, 1 in a community center, and 5 from the community). For the primary outcome, the meta-analysis included 6 studies, and the difference in mean change in BMI in the intervention group compared with the control group was -0.10 (95% confidence interval [CI], -0.28 to 0.09) (P = .32). The secondary outcome included 9 studies, and the difference in mean change from baseline in the intervention group compared with the control group was -0.90 h/wk (95% CI, -3.47 to 1.66 h/wk) (P = .49). A subgroup analysis of preschool children showed a difference in mean change in screen time of -3.72 h/wk (95% CI, -7.23 to -0.20 h/wk) (P = .04). CONCLUSIONS Our systematic review and meta-analysis did not demonstrate evidence of effectiveness of interventions aimed at reducing screen time in children for reducing BMI and screen time. However, interventions in the preschool age group hold promise.

Race/Ethnicity, Obesity, and Related Cardio-Metabolic Risk Factors: A Life-Course Perspective

The adoption of health behaviors characterized by minimal energy expenditure and overconsumption of energy has led to cardiometabolic risk factors in pregnancy, childhood, and youth, all of which increase the prevalence of cardiovascular disease in adulthood. The propensity to develop abdominal obesity and cardiometabolic risk factors appears to disproportionally affect non-white ethnic groups. While the majority of observational research has been conducted in populations of European origin, studies in non-white ethnic groups across the life-course are underway and there is evidence that unique ethnic-specific differences exist. This review will focus on the life-course determinants of obesity and its related cardio-metabolic risk factors among diverse ethnic groups including people of Afro-Caribbean origin, South Asian, East Asian, and indigenous ancestry.

Metabolic syndrome in children with and without developmental coordination disorder

Children with developmental coordination disorder (DCD) have higher rates of obesity compared to children with typical motor development, and, as a result may be at increased risk for developing metabolic syndrome (MetS). The purpose of this study was to determine the presence of MetS and its components among children with and without DCD. This nested case-control study classified 63 children scoring below the 16th percentile on the Movement Assessment Battery for Children (M-ABC-2) as probable DCD (pDCD), and 63 controls, all of whom scored above the 16th percentile. Metabolic syndrome was defined using the International Diabetes Federation (IDF) criteria. Eleven children met the criteria for MetS; 8 (72.3%) with pDCD and 3 (27.3%) controls (p = 0.115). Abdominal obesity was found in 39 (30.9%) of children, 29 (46.0%) with pDCD and 10 (15.9%) controls (p < 0.01). Serum triglycerides were higher in pDCD compared to controls, 91.9 mg/dl (63.1) vs. 67.7 mg/dl (33.3) in the control group, p = 0.001. Blood pressure was also significantly higher in the pDCD group, mean systolic BP (110 vs. 105 mmHg, p = 0.01) and mean diastolic BP (69 vs. 65 mmHg, p = 0.01). There were no statistically significant differences between the groups for other components of MetS. The higher prevalence of abdominal obesity and elevated triglycerides and blood pressure in children with pDCD may put them at risk of meeting all criteria of MetS earlier then their peers.

Aboriginal birth cohort (ABC): a prospective cohort study of early life determinants of adiposity and associated risk factors among Aboriginal people in Canada

BackgroundAboriginal people living in Canada have a high prevalence of obesity, type 2 diabetes, and cardiovascular disease (CVD). To better understand the pre and postnatal influences on the development of adiposity and related cardio-metabolic factors in adult Aboriginal people, we will recruit and follow prospectively Aboriginal pregnant mothers and their children – the Aboriginal Birth Cohort (ABC) study.Methods/designWe aim to recruit 300 Aboriginal pregnant mothers and their newborns from the Six Nations Reserve, and follow them prospectively to age 3 years. Key details of environment and health including maternal nutrition, glucose tolerance, physical activity, and weight gain will be collected. At birth, cord blood and placenta samples will be collected, as well as newborn anthropometric measurements. Mothers and offspring will be followed annually with serial measurements of diet and physical activity, growth trajectory, and adiposity.DiscussionThere is an urgent need to understand maternal and child factors that underlie the early development of adiposity and type 2 diabetes in Aboriginal people. The information generated from this cohort will assist the Six Nations community in developing interventions to prevent early adiposity in Aboriginal children.

Maternal and Newborn Health Profile in a First Nations Community in Canada

OBJECTIVES We sought to characterize maternal health profiles and birth outcomes among First Nations people living in Southern Ontario. METHODS We performed a retrospective chart review of all 453 women from the Six Nations Reserve, Ontario, who were pregnant between 2005 and 2010. Maternal health behaviours, past medical history, physical measurements, birth outcomes, and newborn characteristics were abstracted. Key maternal and newborn characteristics were compared with those of a cohort of non-First Nations women recruited from nearby Hamilton, Ontario. RESULTS The average age of women in the study cohort was 25.1 ± 6.2 (mean ± SD) years, and 75.8% were multiparous. The mean pre-pregnancy BMI was 28.3 ± 6.6 kg/m(2), and the average weight gain in pregnancy was 14.9 ± 8.3 kg. Mean weight gain during pregnancy was inversely associated with pre-pregnancy BMI, and 57.1% of women gained more than the recommended weight. The prevalence of type 2 diabetes or gestational diabetes was 4.7%, hypertension was present before or during pregnancy in 5.6%, and 35% used tobacco during pregnancy. The mean gestational age at delivery was 39.5 ± 1.7 weeks and the mean crude birth weight was 3619 ± 557 g. The main determinants of newborn weight included sex of the newborn, pre-pregnancy BMI, and weight gain during pregnancy. Compared with a contemporary cohort of 622 non-First Nations mothers and newborns, First Nations mothers were, on average, younger (25.1 vs. 32.1 years; P < 0.001), had a higher mean pre-pregnancy BMI (28.3 vs. 26.8 kg/m(2); P < 0.001), and were more likely to use tobacco during pregnancy (35.0% vs. 14.4%; P < 0.001). First Nations newborns had significantly higher mean birth weight (+176 grams) and length (+2.3 cm) than non-First Nations newborns. CONCLUSION First Nations mothers from the Six Nations Reserve tended to have a high pre-pregnancy BMI, tended to gain more than the recommended weight during pregnancy, and commonly used tobacco during pregnancy. Programs to prevent overweight/obesity and excess weight gain during pregnancy and to minimize smoking are required among women of child-bearing age in this community.

What accounts for ethnic differences in newborn skinfold thickness comparing South Asians and White Caucasians? Findings from the START and FAMILY Birth Cohorts.

Objective:South Asians are a high-risk group for type 2 diabetes and coronary heart disease. We sought to determine ethnic differences in newborn adiposity comparing South Asians (SA) to White Caucasians (Whites).Methods:Seven hundred ninety pregnant women (401 SA, 389 Whites) and their full-term offspring from two birth cohorts in Canada were analyzed. Pregnant women completed a health assessment including a 75-g oral glucose tolerance test to assess for dysglycemia. Birthweight, length, waist and hip circumference, and triceps and subscapular skinfold thickness (a surrogate measure of body adiposity) were measured in all newborns. Multivariate regression was used to identify maternal factors associated with newborn skinfold measurements.Results:South Asian women were younger (30.1 vs 31.8 years, P<0.001), their prepregnancy body mass index was lower (23.7 vs 26.2, P<0.0001) and gestational diabetes was substantially higher (21% vs 13%, P=0.005) compared with Whites. Among full-term newborns, South Asians had lower birthweight (3283 vs 3517 g, P=0.0001), had greater skinfold thickness (11.7 vs 10.6 mm; P=0.0001) and higher waist circumference (31.1 vs 29.9 cm, P=0.0001) compared with Whites. Risk factors for newborn skinfold thickness included South Asian ethnicity (standardized estimate (s.e.): 0.24; P<0.0001), maternal glucose (s.e.: 0.079; P=0.04) and maternal body fat (s.e.: 0.14; P=0.0002).Conclusions:South Asian newborns are lower birthweight and have greater skinfold thickness, compared with White newborns, and this is influenced by maternal body fat and glucose. Interventions aimed at reducing body fat prior to pregnancy and gestational diabetes during pregnancy in South Asians may favorably alter newborn body composition and require evaluation.

Body mass index among immigrant and non-immigrant youth: Evidence from the Canadian Community Health Survey

OBJECTIVES:The objectives of this study are to: i) examine differences in body mass index (BMI) and prevalence of overweight/obesity between immigrant versus non-immigrant youth aged 12–19 years, and ii) identify the extent to which lifestyle and socio-demographic factors account for between-group differences.METHODS: Data for analyses come from combining repeated, cross-sectional surveys of the Canadian Community Health Survey (CCHS) conducted between 2000 and 2008. The sample for analyses included 63,509 youth aged 12 to 19 years (mean 15.2, SD 2.3 years) with self-reported weight and height. Immigrant youth composed 6.4% of this sample. Multilevel linear and logistic regression analyses were used to address the study objectives.RESULTS: Approximately 22% of non-immigrant youth were overweight/obese, compared to 18% of immigrant youth (p<0.001). Immigrant youth had a lower zBMI by 0.44 compared to non-immigrant youth (p<0.001) and zBMI increased by 0.02 for every year an immigrant-respondent resided in Canada. Measures of lifestyle and socio-demographic factors did not account for differences in body composition between immigrant and nonimmigrant youth.CONCLUSION: Even after adjusting for lifestyle and socio-demographic factors, immigrant youth have a lower level of overweight/obesity and a lower zBMI, compared to non-immigrant youth. Further, for immigrant youth zBMI increases with time spent in Canada, which highlights an opportunity for primary preventative strategies for obesity aimed at newcomers to Canada.RésuméOBJECTIFS : Les objectifs de cette étude sont: i) d’examiner les différences dans l’indice de masse corporelle (IMC) et la prévalence du surpoids/de l’obésité entre les jeunes de 12 à 19 ans immigrants et non immigrants et ii) de déterminer la mesure dans laquelle le mode de vie et les facteurs sociodémographiques expliquent les différences entre ces groupes.MÉTHODE : Les données d’analyse ont été obtenues en combinant les enquêtes transversales répétées de l’Enquête sur la santé dans les collectivités canadiennes (ESCC) menées entre 2000 et 2008. L’échantillon d’analyse comprenait 63 509 jeunes de 12 à 19 ans (moyenne 15,2, déviation sensible [DS] 2,3 ans) ayant déclaré leur poids et leur taille. Les jeunes immigrants composaient 6,4 % de cet échantillon. Des analyses multiniveaux linéaires et des analyses de régression logistique ont servi à aborder les objectifs de l’étude.RÉSULTATS : Environ 22 % des jeunes non immigrants étaient en surpoids ou obèses, contre 18 % des jeunes immigrants (p<0,001). Le score-z de l’IMC des jeunes immigrants était inférieur de 0,44 à celui des jeunes non immigrants (p<0,001), et ce score augmentait de 0,02 pour chaque année de résidence au Canada d’un répondant immigrant. Les indicateurs du mode de vie et des facteurs sociodémographiques n’expliquaient pas les différences dans la composition corporelle des jeunes immigrants et non immigrants.CONCLUSION : Même après un rajustement des données pour tenir compte du mode de vie et des facteurs sociodémographiques, les jeunes immigrants ont un moindre niveau de surpoids/d’obésité et un score-z de l’IMC inférieur à celui des jeunes non immigrants. De plus, pour les jeunes immigrants, le score-z de l’IMC augmente avec le temps passé au Canada, ce qui présente la possibilité de mener des stratégies de prévention primaire de l’obésité axées sur les nouveaux arrivants au Canada.

A Case Study of a Methodological Approach to Cocreating Perinatal Health Knowledge Between Western and Indigenous Communities

This article describes the methods taken to create an understanding of the perinatal health beliefs of elder Indigenous women of the Six Nations of the Grand River in Ontario, Canada. Our study paired constructivist grounded theory data collection and analysis methods with an Indigenous epistemological framework. We aimed to create knowledge that was specific to an Indigenous context, which was useful and resonant with both Indigenous and Western readers. The multidisciplinary research team included Indigenous and non-Indigenous members and worked with a common appreciation for multiple knowledge sources. We offer an account of our process and methodological principles to serve as an illustrative case study of bringing together diverse approaches when working with Indigenous communities.

Does the impact of a plant-based diet during pregnancy on birth weight differ by ethnicity? A dietary pattern analysis from a prospective Canadian birth cohort alliance

Objective Birth weight is an indicator of newborn health and a strong predictor of health outcomes in later life. Significant variation in diet during pregnancy between ethnic groups in high-income countries provides an ideal opportunity to investigate the influence of maternal diet on birth weight. Setting Four multiethnic birth cohorts based in Canada (the NutriGen Alliance). Participants 3997 full-term mother–infant pairs of diverse ethnic groups who had principal component analysis-derived diet pattern scores—plant-based, Western and health-conscious—and birth weight data. Results No associations were identified between the Western and health-conscious diet patterns and birth weight; however, the plant-based dietary pattern was inversely associated with birth weight (β=−67.6 g per 1-unit increase; P<0.001), and an interaction with non-white ethnicity and birth weight was observed. Ethnically stratified analyses demonstrated that among white Europeans, maternal consumption of a plant-based diet associated with lower birth weight (β=−65.9 g per 1-unit increase; P<0.001), increased risk of small-for-gestational age (SGA; OR=1.46; 95% CI 1.08 to 1.54;P=0.005) and reduced risk of large-for-gestational age (LGA; OR=0.71; 95% CI 0.53 to 0.95;P=0.02). Among South Asians, maternal consumption of a plant-based diet associated with a higher birth weight (β=+40.5 g per 1-unit increase; P=0.01), partially explained by cooked vegetable consumption. Conclusions Maternal consumption of a plant-based diet during pregnancy is associated with birth weight. Among white Europeans, a plant-based diet is associated with lower birth weight, reduced odds of an infant born LGA and increased odds of SGA, whereas among South Asians living in Canada, a plant-based diet is associated with increased birth weight.

Causes and consequences of gestational diabetes in South Asians living in Canada: results from a prospective cohort study

BACKGROUND The reasons for the increased risk of gestational diabetes among South Asian women are not well understood. We sought to identify the determinants of gestational diabetes and its impact on newborn health in a prospective birth cohort of South Asian women and their babies. METHODS As part of the South Asian Birth Cohort (START) prospective birth cohort study in Ontario, we recruited 1012 South Asian women with singleton pregnancies in the second trimester of pregnancy between July 11, 2011, and Nov. 10, 2015. We collected health information and physical measurements and administered an oral glucose tolerance test. Birth weight and skinfold thickness measurements were obtained from their newborns, and cord blood glucose and insulin levels were measured. RESULTS The incidence of gestational diabetes was 36.3% (95% confidence interval [CI] 33.3%-39.3%); the age-standardized rate was 40.7%. Factors associated with gestational diabetes included maternal age (odds ratio [OR] 1.08 [95% CI 1.04-1.12]), family history of diabetes (OR 1.65 [95% CI 1.26-2.17]), prepregnancy weight (OR 1.025 [95% CI 1.01-1.04]) and low diet quality (OR 1.57 [95% CI 1.16-2.12]). Maternal height was protective against gestational diabetes (OR 0.97 [95% CI 0.95-0.99]). The population attributable risk due to prepregnancy body mass index and low diet quality was 37.3%. Compared to newborns of women without gestational diabetes, those of women with gestational diabetes had a significantly higher birth weight (3267 [standard error (SE) 23] g v. 3181 [SE 17] g, p = 0.005), greater skinfold thickness (11.7 [SE 0.1] mm v. 11.2 [SE 0.1] mm, p = 0.007) and lower insulin sensitivity (glucose/insulin ratio 0.092 [SE 0.009] mmol/pmol v. 0.129 [SE 0.006] mmol/pmol, p = 0.001). INTERPRETATION The modifiable risk factors of prepregnancy weight and low diet quality accounted for 37% of the population attributable risk of gestational diabetes in our cohort. Intervention studies to lower prepregnancy weight and to prevent gestational diabetes among South Asian women in high-income countries are needed.