Jennifer O’Loughlin

Blood Pressure and Adiposity in Children and Adolescents

Background—Although obesity is associated with important hemodynamic disturbances, there are few data on population-wide blood pressure (BP) distribution in children and adolescents in this era of endemic pediatric obesity. Methods and Results—We conducted a school-based survey of a representative sample of youth aged 9, 13, and 16 years in Quebec, Canada. Resting BP was measured with an oscillometric device in 3589 subjects (80% response). Additional measures included height, weight, and subscapular and triceps skinfold thickness, an age-appropriate questionnaire, and a fasting blood draw. Mean (SD) systolic/diastolic BP (SBP/DBP) levels in 9-, 13-, and 16-year-olds were 103 (9)/57 (6), 113 (12)/58 (7), and 124 (14)/61 (7) mm Hg in males and 103 (10)/57 (6), 111 (11)/60 (7), and 114 (11)/62 (7) mm Hg in females. The prevalence of high-normal or elevated SBP was 12%, 22%, and 30% among 9-, 13-, and 16-year-old males, respectively, and 14%, 19%, and 17% among same-aged females. The prevalence of high-normal or elevated DBP was <1%. In multiple linear regression analysis, body mass index was consistently associated with SBP and DBP in all age-gender groups. Conclusions—Mean SBP and the prevalence of high-normal and elevated SBP are elevated in children and adolescents. Public policy, public health programs, and clinical preventive measures are urgently needed to address the obesity epidemic and its hemodynamic consequences.

Distribution of Fasting Plasma Insulin, Free Fatty Acids, and Glucose Concentrations and of Homeostasis Model Assessment of Insulin Resistance in a Representative Sample of Quebec Children and Adolescents

BACKGROUND Plasma fasting insulin and the homeostasis model assessment of insulin resistance (HOMA-IR) are markers of IR, which, at least in part, mediates the relation of obesity to increased cardiovascular risk. Increased free fatty acids (FFAs) may be involved in the pathogenesis of IR. Our objectives were to describe the distributions of fasting plasma insulin, glucose, and FFAs and HOMA-IR in youth and to assess the relationship between FFAs and markers of IR. METHODS Fasting plasma insulin, glucose, and FFAs were measured in a representative sample of Quebec youth comprising 2244 individuals 9, 13, and 16 years of age. RESULTS In all age and sex groups, glucose exhibited remarkably tight distributions (median CV, 7.1%) in contrast to insulin, HOMA-IR, and FFAs (median CVs, 52%, 54% and 45%, respectively). For every percentile examined, 9-year-olds had lower insulin concentrations and HOMA-IR values than 13- and 16-year-olds. We observed strong correlations between insulin concentrations and HOMA-IR values, as well as close similarity in their rankings of individuals. The mean concentrations of glucose were higher in our population than in other Caucasian pediatric populations. No positive correlations were detected between FFAs and markers of IR. CONCLUSIONS We report some of the first data on the distributions of fasting plasma insulin, HOMA-IR, and FFAs from a representative sample of youth. HOMA-IR does not appear more informative than fasting insulin as a marker of IR. Our findings on higher mean glucose concentrations in this population require confirmation in other representative samples of youth to assess whether the North American distribution of glucose concentrations is shifting positively.

Emergence of sex differences in prevalence of high systolic blood pressure : Analysis of a longitudinal adolescent cohort

Background— High systolic blood pressure (SBP) occurs more frequently both among men and boys than among women and girls. No longitudinal study has investigated whether the impact of SBP determinants differ according to sex in youth. Methods and Results— Between 1999 and 2005, an adolescent cohort (n=1267) completed a questionnaire survey and underwent biannual blood pressure and anthropometric assessment (grades 7, 9, and 11). Boys accounted for ≈50% of those with high SBP at grade 7 and 9 assessments but 67% of those with high SBP at the grade 11 assessment. As computed through a generalized estimating equations logistic regression model (sex, age, sex and age interaction term, overweight, physical activity, sedentary behavior, heart rate, household income, tobacco use, and 4 language categories), the likelihood of high SBP values among boys compared with girls was 1.29 (95% CI, 0.77 to 2.16) in grade 7, 1.98 (95% CI, 1.35 to 2.93) in grade 9, and 2.74 (95% CI, 1.52 to 4.94) in grade 11. Although there was a significant interaction between sex and age, interaction terms of sex with overweight, sedentary behavior, and physical activity were not statistically significant. Overweight (odds ratio [OR], 2.63; 95% CI, 1.76 to 3.92) and sedentary behavior (OR, 1.17 for increment of 5 hours weekly; 95% CI 1.04 to 1.33) demonstrated positive associations with high SBP values. Physical activity was inversely associated with the presence of high SBP (OR, 0.92 for increment of 5 activities in 7 days; 95% CI, 0.84 to 1.00). Conclusions— Boys are more likely than girls to develop high SBP as they approach adulthood. Even among overweight adolescents, reducing sedentary behavior and increasing physical activity may lower the risk of high SBP.

Associations of sedentary behavior, sedentary bouts and breaks in sedentary time with cardiometabolic risk in children with a family history of obesity.

Background Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children. Purpose To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8–11 years with a family history of obesity. Methods Data from 286 boys and 236 girls living in Quebec, Canada, with at least one biological parent with obesity (QUALITY cohort) were collected from 2005–2008, and analyzed in 2013. Sedentary behavior, light and moderate-to-vigorous physical activity were measured over 7 days using accelerometry. Leisure time computer/video game use and TV viewing over the past 7 days were self-reported. Outcomes included waist circumference, body mass index Z-score, fasting insulin, fasting glucose, triglycerides, HDL-cholesterol, C-reactive protein and a continuous cardiometabolic risk score. Results After adjustment for confounders, breaks in sedentary time and the number of sedentary bouts lasting 1–4 minutes were associated with reduced cardiometabolic risk score and lower BMI Z-score in both sexes (all p<0.05). The number of sedentary bouts lasting 5–9 minutes was negatively associated with waist circumference in girls only, while the number of bouts lasting 10–14 minutes was positively associated with fasting glucose in girls, and with BMI Z-score in boys (all p<0.05). Leisure time computer/video game use was associated with increased cardiometabolic risk score and waist circumference in boys, while TV viewing was associated with increased cardiometabolic risk, waist circumference, and BMI Z-score in girls (all p<0.05). Conclusions These results suggest that frequent interruptions in sedentary time are associated with a favourable cardiometabolic risk profile and highlight the deleterious relationship between screen time and cardiometabolic risk among children with a family history of obesity.

Physical activity vs. sedentary time: independent associations with adiposity in children

To investigate the independent associations between objectively measured levels of movement intensity (i.e. time spent sedentary and at light, moderate and vigorous intensities) and indicators of adiposity in a cohort of Canadian children.

Prevalence of cardiometabolic risk factors by weight status in a population-based sample of Quebec children and adolescents

BACKGROUND There are few data on the prevalence of cardiometabolic risk factors in population-based samples of overweight and obese youth. OBJECTIVES To compare the prevalence of individual and multiple cardiometabolic risk factors across body mass index (BMI) categories in a population-based sample of youth. METHODS In 1999, a school-based survey of a provincially representative sample of youth nine, 13 and 16 years of age was conducted in Quebec (1778 boys, 1835 girls). Overweight was defined as BMI in the 85th percentile or higher and lower than the 95th percentile of the Centers for Disease Control and Prevention 2000 growth charts, and obesity was defined as BMI in the 95th percentile or higher. Levels of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure were categorized as desirable, borderline or unfavourable. RESULTS The proportions of overweight and obese participants were 14% and 10% in boys, and 14% and 7% in girls, respectively. With the exception of total cholesterol and low-density lipoprotein cholesterol in girls, and glucose in both sexes, the prevalence of all investigated risk factors (borderline or unfavourable) was significantly higher among overweight and obese participants. Almost one-third of obese participants had unfavourable levels of at least two of seven risk factors (apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure) compared with 3% of normal weight participants (adjusted OR 15 and 18 in boys and girls, respectively). Thirty-four per cent of obese youth did not have unfavourable levels of any risk factor. CONCLUSION There is marked heterogeneity in the association between excess weight and cardiometabolic risk factors. Nonetheless, the present study highlights a high prevalence of multiple risk factors in a population-based sample of overweight and obese youth.

Cohort Profile: The Quebec Adipose and Lifestyle Investigation in Youth Cohort

Departement de pediatrie, Universite de Montreal, Montreal, Quebec, Canada, Centre de recherche du Centre Hospitalier Universitaire (CHU) Sainte-Justine, Montreal, Quebec, Canada, Departement de medecine sociale et preventive, Universite de Montreal, Montreal, Quebec, Canada, Centre de Recherche du Centre Hospitalier de l’Universite de Montreal, Montreal, Quebec, Canada, Division of Kinesiology, Faculty of Medicine, Universite Laval, Quebec, Canada, Departement d’education physique, Universite Laval, Quebec, Canada, Departement de radiologie, CHU Sainte-Justine, Montreal, Quebec, Canada, School of Dietetics and Human Nutrition, McGill University, Montreal, Quebec, Canada, Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada, Department of Psychiatry, McGill University, Montreal, Quebec, Canada, Office of Senior Medical Advisor, First Nations Inuit Health Branch, Health Canada, Vancouver, British-Columbia, Canada, Departement de kinesiologie, Universite de Montreal, Montreal, Quebec, Canada, School of Public Health, University of Alberta, Edmonton, Alberta, Canada, Department of Psychology, Concordia University, Montreal, Quebec, Canada, Epidemiology and Biostatistics Unit, INRS-Institut Armand-Frappier, Laval, Quebec, Canada, Institut universitaire de cardiologie et de pneumologie de Quebec, Faculte de pharmacie, Universite Laval, Quebec, Canada, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada, McGill University Health Center Research Institute, Montreal, Quebec, Canada and Institut national de sante publique du Quebec, Montreal, Quebec, Canada

Common stressful life events and difficulties are associated with mental health symptoms and substance use in young adolescents

BackgroundStressful life events are associated with mood disorders in adults in clinical settings. Less described in the literature is the association between common life stressors and a wide range of psychopathology in young adolescents. This study uses a large non-clinical sample of young adolescents to describe the associations among worry or stress about common life events/difficulties, mental health and substance use.MethodsData on lifetime stress or worry about common life events/difficulties (i.e., romantic breakups, family disruption, interpersonal difficulties, and personal stress (health, weight, school work)), symptoms of depression, conduct disorder symptoms, and substance use were collected from 1025 grade 7 students (mean age 12.9 years; 45% male). The association between each source of stress and each mental health and substance use indicator was modeled in separate logistic regression analyses.ResultsThe proportion of adolescents reporting worry or stress ranged from 7% for new family to 53% for schoolwork. Romantic breakup stress was statistically significantly associated with all the mental health and substance use indicators except illicit drug use. Family disruption was statistically significantly associated with depression symptoms, marijuana use, and cigarette use. Interpersonal difficulties stress was statistically significantly associated with depression symptoms. All sources of personal stress were statistically significantly related to depression symptoms. In addition, health-related stress was inversely related to binge drinking.ConclusionYoung adolescents may benefit from learning positive coping skills to manage worry or stress about common stressors and in particular, worry or stress related to romantic breakups. Appropriate management of mental health symptoms and substance use related to common stressful life events and difficulties may help reduce emerging psychopathology.

Prevalence and Correlates of Overweight among Elementary Schoolchildren in Multiethnic, Low Income, Inner-City Neighbourhoods in Montreal, Canada

PURPOSE Increased understanding of the early determinants of obesity is essential because of the increasing prevalence of obesity in many industrialized countries. METHOD As part of the evaluation of a school-based heart health promotion intervention, we measured height, weight, and triceps skinfold thickness at baseline in 2108 students aged 9-12 years (80.5% of eligible students) in 24 inner-city elementary schools located in multiethnic, low income neighbourhoods in Montreal, Canada. Data on students socio-demographic and lifestyle characteristics were collected in classroom-administered questionnaires, and parents completed an at-home self-administered questionnaire. RESULTS Overall, 35.2% of boys and 33.0% of girls were overweight (> or = 85th age and gender-specific percentiles from NHANES 11, for body mass index and triceps skinfold thickness); 15.1% of boys and 13.3% of girls were obese (> or = 95th age and gender-specific percentiles for body mass index and triceps skinfold thickness). Younger age, having lived all ones life in Canada, and being of European or Central American/Caribbean family origin were independent correlates of obesity in boys. Younger age, ever smoked, mother obese and father obese were independent correlates of obesity in girls. Girls of Asian family origin were protected. CONCLUSIONS The very high prevalence of overweight students in this low income, multiethnic population suggests an important need for preventive intervention.

Do the correlates of smoking cessation counseling differ across health professional groups

INTRODUCTION Smoking cessation counseling by health professionals is an effective approach to increase cessation rates among smokers. To guide the development of training and educational interventions, we surveyed six health professional groups including general practitioners (GPs), pharmacists, dentists, dental hygienists, nurses, and respiratory therapists, in order to describe current practices and identify the correlates of smoking cessation counseling. METHODS Self-administered questionnaires were mailed to 500 persons randomly selected from the membership lists of active licensed professionals in each health professional group in Québec. RESULTS Response proportions ranged from 52% (nurses) to 70% (dental hygienists). Compared with other groups, GPs and pharmacists undertook more counseling with patients ready to quit. GPs and respiratory therapists undertook more counseling with patients not ready to quit. Three factors emerged consistently across most groups as positively associated with counseling, including the belief that counseling is the role of health professionals, perceived self-efficacy to engage in effective counseling, and knowledge of community cessation resources. DISCUSSION The correlates of cessation counseling are similar across health professional groups. Interventions that address beliefs that cessation counseling is the role of health professionals, self-efficacy to provide effective counseling, and knowledge of community resources may result in improved cessation counseling practices among health professionals.