Long-term effects of comprehensive school health on health-related knowledge, attitudes, self-efficacy, health behaviours and weight status of adolescents.

BACKGROUND: APPLE Schools is a Comprehensive School Health (CSH) project, started in schools in socioeconomically disadvantaged areas where dietary habits are poor, physical activity (PA) levels are low, and obesity rates are high. Earlier research showed program effects whereby energy intake, PA and weight status of students in APPLE Schools had reached similar levels as that of students in other schools. However, it is unknown whether the effects of CSH are sustained when children grow into adolescents. Effects of APPLE Schools on health-related knowledge, attitudes, self-efficacy, diet, PA, and weight status, seven years after the start of the project, when students were in junior high and high school were assessed. We hypothesised that APPLE School graduates and comparison school graduates will remain at similar levels for these indicators. METHODS: In the 2015/16 school year, junior high and high school graduates (grades 7-12) in Northern Alberta, Canada participated in a Youth Health Survey. Participants included graduates from APPLE elementary schools (n = 202) and comparison elementary schools (n = 338). Health-related knowledge, attitudes, self-efficacy, diet (24-h dietary recall), PA (pedometer step count) and weight status were assessed. Mixed effects regression was employed to assess differences in these outcomes between APPLE School graduates and comparison school graduates. Comparisons between elementary school (2008/09) and junior high/high school (2015/16) of self-efficacy, PA and weight status were also conducted. RESULTS: APPLE School graduates did not significantly differ from comparison school graduates on any outcomes (i.e. knowledge, attitudes, self-efficacy, diet, PA, and weight status). Additionally, no significant differences existed in the comparisons between 2008/09 and 2015/16. CONCLUSION: Our findings of no difference between the APPLE School graduates and comparison school graduates suggest that the effects of APPLE Schools may continue into adolescence or the new school environment may have an equalizing effect on the students. Since lifestyle practices are adopted throughout childhood and adolescence, and the school environment has an important influence on development, an extension of CSH initiatives into junior high/high schools should be considered. This will help to consolidate and support the continuance of healthy lifestyle messages and practices throughout childhood and adolescence.

The use of entertainment and communication technologies before sleep could affect sleep and weight status: a population-based study among children.

BACKGROUND: Short sleep duration and poor sleep quality have been demonstrated to be associated with childhood obesity. It has been suggested that electronic entertainment and communication devices (EECDs) including TVs, computers, tablets, video games and cell phones interfere with sleep in children and youth. The aim of this study was to assess the impact that the use of EECDs in the hour before bedtime has on sleep and weight status to inform sleep promotion interventions and programs to prevent childhood obesity. METHODS: A provincially representative sample of 2334 grade 5 children and their parents in Alberta, Canada was surveyed. Parents reported their child's bedtime and wake-up time along with how often their child snored, felt sleepy during the day, woke-up at night and woke-up in the morning feeling unrefreshed. Sleep duration, sleep quality and sleep efficiency were derived from these indicators. Parents also reported on the presence of EECDs in their child's bedroom, while children reported use of EECDs during the day and frequency of using each of these devices during the hour before sleep. The height and weight of children were measured. Multivariable mixed effect linear and logistic regression models were used to determine how sleep duration, sleep quality, sleep efficiency and weight status are influenced by (i) access to EECDs in children's bedrooms, (ii) use of EECDs during the hour before sleep, and (iii) calming activities specifically reading during the hour before sleep. RESULTS: Sleep duration was shorter by -10.8 min (cell phone), -10.2 min (computer) and -7.8 min (TV) for those with bedroom access to and used these EECDs during the hour before sleep compared to no access and no use. Good sleep quality was hindered by bedroom access to and use of all EECDs investigated during the hour before sleep, particularly among users of cell phones (OR = 0.64, 95% CI: 0.58-0.71) and computers (OR = 0.72, 95% CI: 0.65-0.80). Very good sleep efficiency was decreased by access to and frequent use of a TV (54%), cell phone (52%), tablet (51%) and video games (51%). Odds of obesity were doubled by bedroom access to and use of a TV and computer during the hour before sleep. Children who rarely read a printed book in the bedroom during the hour before sleep had a shorter sleep duration and poorer sleep quality and sleep efficiency compared to their peers. Having access to an EECD in the bedroom was associated with increased obesity despite frequently reading during the hour before sleep. CONCLUSIONS: Our findings suggest that sleep duration, sleep quality, sleep efficiency and weight status are better among children who do not have EECDs in the bedroom and frequently read a book during the hour before sleep as opposed to those who use EECDs during this hour. Education of limits against EECD use by parents may improve sleep outcomes. These findings will inform health promotion messages and may give rise to national recommendations regarding EECD use. TRIAL REGISTRATION: ClinicalTrials.gov NCT01914185 . Registered 31 July 2013 Retrospectively registered.

The Association of Serum 25-Hydroxyvitamin D Concentrations and Elevated Glycated Hemoglobin Values: A Longitudinal Study of Non-Diabetic Participants of a Preventive Health Program.

The prevalence of Type 2 Diabetes (T2D) is sharply on the rise, both in Canada and worldwide. As addressing its root causes, i.e., promotion of healthy lifestyles and weight management, has been largely unsuccessful, new clues for primary prevention seem essential to curbing the increasing public health burden of T2D. In the present study, we examined whether improvements in vitamin D status, i.e., serum 25-hydroxyvitamin D [25(OH)D] concentrations, are paralleled by a reduction in the risk for reaching adverse glycated hemoglobin (HbA1c) levels in a community sample of non-diabetic volunteers participating in a preventive health program that encourages the use of vitamin D. Repeated observations on 6565 participants revealed that serum 25(OH)D concentrations increased from 90.8 to 121.3 nmol/L, HbA1c values decreased from 5.6% to 5.5%, and the prevalence of having HbA1c values ≥ 5.8% decreased from 29.5% to 17.4% while in the program. Compared to participants who did not increase their 25(OH)D concentrations during follow-up, those who increased their 25(OH)D concentrations with 50 nmol/L or more were 0.74 times as likely to achieve elevated HbA1c values at follow-up (p = 0.03). These findings suggest that public health initiatives that promote vitamin D status along with healthy lifestyles in the population at large may alleviate the future public health burden associated with T2D.

Breast-feeding duration for the prevention of excess body weight of mother-child pairs concurrently: a 2-year cohort study.

OBJECTIVE: To examine the association between breast-feeding duration and the risk of excess body weight (children >85th percentile, mothers BMI≥25·0 kg/m2) concurrently in mother-child pairs two years after delivery. DESIGN: Prospective cohort study in Joinville, Brazil. Multivariable logistic regression was used to examine the independent relationship between breast-feeding duration and risk of excess body weight. SETTING: Brazilian public maternity hospital. SUBJECTS: Three hundred and five mother-child pairs. RESULTS: At 2-year follow-up, 23·6 % of mother-child pairs had excess body weight. Children breast-fed for <2 months were more likely to have excess body weight than children breast-fed for ≥6 months (OR=2·4; 95 % CI 1·1, 5·1). Breast-feeding for <2 months was also associated with a greater likelihood of maternal excess body weight compared with those who breast-fed for ≥6 months (OR=2·9; 95 % CI 1·1, 8·1). There was a progressive increase in the likelihood of mother-child pairs having excess body weight as breast-feeding duration decreased. In addition to breast-feeding duration, other independent determinants of excess body weight were pre-pregnancy weight, gestational weight gain and number of pregnancies in mothers, and birth weight in children. CONCLUSIONS: Breast-feeding for a longer duration has a parallel protective effect on the risk of excess body weight in mother-child pairs two years after birth. Since members of the same family could be influenced by the same risk factors, continued promotion and support of breast-feeding may help to attenuate the rising prevalence of overweight in mother-child pairs.

The Independent Importance of Pre-pregnancy Weight and Gestational Weight Gain for the Prevention of Large-for Gestational Age Brazilian Newborns.

Objectives To study the independent effect of pre-pregnancy weight, gestational weight gain (GWG), and other important risk factors on newborn birth weight. Methods Baseline data of 435 adult women and their singletons born between January and February 2012 at a public hospital in Brazil were used. Logistic regression was applied to determine the independent importance of pre-pregnancy weight and GWG for large for gestational age (LGA) newborns. Results Among all mothers, 37.9 % were overweight and obese before pregnancy and 45.3 % experienced excessive GWG. Among the newborns, 24.4 % were classified as LGA. Univariate analysis showed an association of family income, GWG, pre-pregnancy BMI and excessive GWG with LGA newborns. Smoking before and during pregnancy was associated with a decreased likelihood of giving birth to an LGA newborn compared to mothers who did not smoke. After adjustment for confounding variables, age at birth of first child, GWG, HbA1c and pre-pregnancy weight-GWG were significant and independent determinants of giving birth to an LGA newborn. Mothers with pre-pregnancy overweight and excessive GWG were more likely to deliver an LGA newborn (OR 2.54, P < 0.05) compared to mothers who were normal weight and experienced adequate GWG. Conclusions for Practice Age at first birth of child, GWG, HbA1c and pre-pregnancy overweight combined with excessive GWG are independent determinants of LGA newborns. The results of this study suggest that both primary prevention of overweight in women of childbearing age and management of GWG may be important strategies to reduce the number of LGA newborns and, consequently, the long-term public health burden of obesity.

The economic burden of inadequate consumption of vegetables and fruit in Canada.

OBJECTIVE: Public health decision makers not only consider health benefits but also economic implications when articulating and issuing lifestyle recommendations. Whereas various estimates exist for the economic burden of physical inactivity, excess body weight and smoking, estimates of the economic burden associated with our diet are rare. In the present study, we estimated the economic burden attributable to the inadequate consumption of vegetables and fruit in Canada. DESIGN: We accessed the Canadian Community Health Survey to assess the inadequacy in the consumption of vegetables and fruit and published meta-analyses to assemble risk estimates for chronic diseases. Based on these inadequacy and risk estimates, we calculated the population-attributable fraction and avoidable direct and indirect costs to society. Direct costs include those for hospital care, physician services and drugs in 2015. RESULTS: About 80 % of women and 89 % of men consume inadequate amounts of vegetables and fruit. We estimated this to result in an economic burden of $CAN 3·3 billion per year, of which 30·5 % is direct health-care costs and 69·5 % is indirect costs due to productivity losses. A modest 1 percentage point annual reduction in the prevalence of inadequate vegetables and fruit consumption over the next 20 years would avoid approximately $CAN 10·8 billion, and an increase of one serving of vegetables and fruit per day would avoid approximately $CAN 9·2 billion. CONCLUSIONS: Further investments in the promotion of vegetables and fruit will prevent chronic disease and substantially reduce direct and indirect health-care costs.

The Effect of Serum 25-Hydroxyvitamin D Concentrations on Elevated Serum C-Reactive Protein Concentrations in Normal Weight, Overweight and Obese Participants of a Preventive Health Program.

The hypothesized effect of vitamin D on C-reactive protein (CRP) has received substantial attention as a potential means to alleviate the risk for cardiovascular disease. However, observational studies have been inconsistent in their reporting of associations between serum 25-hydroxyvitamin D (25(OH)D) and CRP concentrations, and trials and meta analyses have been inconsistent in their conclusions regarding the effect of vitamin D supplementation on CRP concentrations. These supplementation trials were mostly conducted among patients with more or less inflammatory complications and did not consider potential distinctive effects by weight status. To further our understanding of the potential influences of vitamin D on CRP, we analyzed longitudinal observations of 6755 participants of a preventative health program. On average, serum 25(OH)D concentrations increased from 88.3 to 121.0 nmol/L and those of CRP decreased from 1.7 to 1.6 mg/L between baseline and follow up. Relative to obese participants without temporal increases in 25(OH)D, those who showed improvements of <25, 25-50, 50-75, and more than 75 nmol/L at follow up were 0.57 (95% confidence interval: 0.37-0.88), 0.54 (0.34-0.85), 0.49 (0.30-0.80), and 0.48 (0.29-0.78) times as likely to have elevated CRP concentrations (≥1 mg/L), respectively. These associations were less pronounced and not statistically significant for normal weight and overweight participants. Herewith, the findings suggest that promotion of adequate serum 25(OH)D concentrations among obese individuals along with healthy lifestyles may alleviate the public health burden associated with cardiovascular disease.

The Effect of Serum 25-Hydroxyvitamin D on Elevated Homocysteine Concentrations in Participants of a Preventive Health Program.

Both lower serum 25-hydroxyvitamin D [25(OH)D] and elevated homocysteine concentrations are potential risk factors for cardiovascular disease (CVD). A recent analysis of the National Health and Nutrition Examination Survey reported an inverse association of serum 25(OH)D with homocysteine, however, the longitudinal relationship has yet to be investigated. We hypothesized and examined whether a temporal increase in 25(OH)D concentrations is paralleled by a reduction in the risk for elevated homocysteine. We analyzed data of 4475 participants with repeated assessments of serum 25(OH)D and homocysteine concentrations who enrolled in a preventive health program that encourages vitamin D supplementation and monitors serum 25(OH)D and homocysteine concentrations. We defined elevated homocysteine as concentrations greater than 13 micromoles per liter. Logistic regression was applied to assess the association of temporal changes in serum 25(OH)D with the risk of elevated homocysteine. We observed an inverse gradient whereby greater increases in 25(OH)D concentrations were associated with a lower prevalence of elevated homocysteine. Relative to those without temporal increases in 25(OH)D, participants who showed improvements in their serum 25(OH)D concentrations of "<25", "25-50", "50-75", and "≥75" nanomoles per liter at follow up were 0.92 (95% confidence interval: 0.62-1.37), 0.52 (0.33-0.80), 0.34 (0.20-0.58), and 0.32 (0.19-0.54) times as likely to have elevated homocysteine, respectively. These observations suggest that temporal improvements in vitamin D status reduce serum homocysteine concentrations, and therefore may potentially contribute to the primary prevention of CVD.

The Relationship of Serum 25-Hydroxyvitamin D and Insulin Resistance among Nondiabetic Canadians: A Longitudinal Analysis of Participants of a Preventive Health Program.

Observational and intervention studies have revealed inconsistent findings with respect to the relationship between vitamin D and insulin resistance. No intervention studies have been conducted in community samples whereas this may be particularly relevant to the primary prevention of type 2 diabetes (T2D) and cardiovascular disease (CVD). In the present study we examined whether temporal improvements in vitamin D status, measured as serum 25-hydroxyvitamin D [25(OH)D], reduce the risk of insulin resistance among individuals without T2D. We accessed and analyzed data from 5730 nondiabetic participants with repeated measures of serum 25(OH)D who enrolled in a preventive health program. We used the homeostatic model assessment for insulin resistance (HOMA-IR) and applied logistic regression to quantify the independent contribution of baseline serum 25(OH)D and temporal increases in 25(OH)D on HOMA-IR. The median time between baseline and follow up was 1.1 year. On average serum 25(OH)D concentrations increased from 89 nanomoles per liter (nmol/L) at baseline to 122 nmol/L at follow up. Univariate analyses showed that relative to participants with baseline serum 25(OH)D less than 50 nmol/L, participants with baseline concentrations of "50-<75", "75-<100", "100-<125", and ≥125 nmol/L were 0.76 (95% confidence intervals: 0.61-0.95), 0.54 (0.43-0.69), 0.48 (0.36-0.64) and 0.36 (0.27-0.49) times as likely to have insulin resistance at follow up, respectively. More importantly, relative to participants without temporal increases in 25(OH)D, those with increases in serum 25(OH)D of "<25", "25-<50", "50-<75", "≥75" nmol/L were 0.92 (0.72-1.17), 0.86 (0.65-1.13), 0.66 (0.47-0.93), and 0.74 (0.55-0.99) times as likely to have insulin resistance at follow up, respectively. In the subgroup of participants without insulin resistance at baseline, this was 0.96 (0.72-1.27), 0.78 (0.56-1.10), 0.66 (0.44-0.99), and 0.67 (0.48-0.94), respectively. These observations suggest that improvements in vitamin D status reduce the risk for insulin resistance and herewith may contribute to the primary prevention of T2D and CVD.

Use of micronutrient supplements among pregnant women in Alberta: results from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.

Maternal nutrient intake in the prenatal period is an important determinant of fetal growth and development and supports maternal health. Many women, however, fail to meet their prenatal nutrient requirements through diet alone and are therefore advised to consume nutrient supplements. The purpose of this study was to describe the use of natural health products (NHP) by pregnant women in each trimester of pregnancy. Women (n = 599) participating in the first cohort of the Alberta Pregnancy Outcomes and Nutrition (APrON) study completed an interviewer-administered supplement intake questionnaire during each trimester of pregnancy. NHP use was high, with >90% taking multivitamin/mineral supplements, and nearly half taking at least one additional single-nutrient supplement. Compliance with supplementation guidelines was high for folic acid (>90%), vitamin D (∼70%) and calcium (∼80%), but low for iron (<30%) and for all four nutrients together (≤11%). On average, women met or exceeded the recommended dietary allowance for folic acid, vitamin D and iron from NHPs alone, with median daily intakes of 1000 µg, 400 IU and 27 mg, respectively. The median calcium intake was 250 mg d(-1) . Up to 26% of women exceeded the tolerable upper intake level for folic acid and up to 19% did so for iron at some point of their pregnancy. Findings highlight the need to consider both dietary and supplemental sources of micronutrients when assessing the nutrient intakes of pregnant women.

Test-retest reliability of a continuous glucose monitoring system in individuals with type 2 diabetes.

AIMS: This study determined the test-retest reliability of a continuous glucose monitoring system (CGMS) (iPro™2; Medtronic, Northridge, CA) under standardized conditions in individuals with type 2 diabetes (T2D). SUBJECTS AND METHODS: Fourteen individuals with T2D spent two nonconsecutive days in a calorimetry unit. On both days, meals, medication, and exercise were standardized. Glucose concentrations were measured continuously by CGMS, from which daily mean glucose concentration (GLU(mean)), time spent in hyperglycemia (t(>10.0 mmol/L)), and meal, exercise, and nocturnal mean glucose concentrations, as well as glycemic variability (SD(w), percentage coefficient of variation [%cv(w)], mean amplitude of glycemic excursions [MAGEc, MAGE(ave), and MAGE(abs.gos)], and continuous overlapping net glycemic action [CONGA(n)]) were estimated. Absolute and relative reliabilities were investigated using coefficient of variation (CV) and intraclass correlation, respectively. RESULTS: Relative reliability ranged from 0.77 to 0.95 (P<0.05) for GLU(mean) and meal, exercise, and nocturnal glycemia with CV ranging from 3.9% to 11.7%. Despite significant relative reliability (R=0.93; P<0.01), t(>10.0 mmol/L) showed larger CV (54.7%). Among the different glycemic variability measures, a significant between-day difference was observed in MAGEc, MAGE(ave), CONGA6, and CONGA12. The remaining measures (i.e., SD(w), %cv(w), MAGE(abs.gos), and CONGA1-4) indicated no between-day differences and significant relative reliability. CONCLUSIONS: In individuals with T2D, CGMS-estimated glycemic profiles were characterized by high relative and absolute reliability for both daily and shorter-term measurements as represented by GLUmean and meal, exercise, and nocturnal glycemia. Among the different methods to calculate glycemic variability, our results showed SD(w), %cv(w), MAGE(abs.gos), and CONGAn with n ≤ 4 were reliable measures. These results suggest the usefulness of CGMS in clinical trials utilizing repeated measured.

The most effective strategy for recruiting a pregnancy cohort: a tale of two cities.

BACKGROUND: Pregnant women were recruited into the Alberta Pregnancy Outcomes and Nutrition (APrON) study in two cities in Alberta, Calgary and Edmonton. In Calgary, a larger proportion of women obtain obstetrical care from family physicians than from obstetricians; otherwise the cities have similar characteristics. Despite similarities of the cities, the recruitment success was very different. The purpose of this paper is to describe recruitment strategies, determine which were most successful and discuss reasons for the different success rates between the two cities. METHODS: Recruitment methods in both cities involved approaching pregnant women (< 27 weeks gestation) through the waiting rooms of physician offices, distributing posters and pamphlets, word of mouth, media, and the Internet. RESULTS: Between May 2009 and November 2010, 1,200 participants were recruited, 86% (1,028/1,200) from Calgary and 14% (172/1,200) from Edmonton, two cities with similar demographics. The most effective strategy overall involved face-to-face recruitment through clinics in physician and ultrasound offices with access to a large volume of women in early pregnancy. This method was most economical when clinic staff received an honorarium to discuss the study with patients and forward contact information to the research team. CONCLUSION: Recruiting a pregnancy cohort face-to-face through physician offices was the most effective method in both cities and a new critically important finding is that employing this method is only feasible in large volume maternity clinics. The proportion of family physicians providing antenatal and post-natal care may impact recruitment success and should be studied further.