Jennifer J. McGrath

A comprehensive view of sex-specific issues related to cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of mortality in women. In fact, CVD is responsible for a third of all deaths of women worldwide and half of all deaths of women over 50 years of age in developing countries. The prevalence of CVD risk factor precursors is increasing in children. Retrospective analyses suggest that there are some clinically relevant differences between women and men in terms of prevalence, presentation, management and outcomes of the disease, but little is known about why CVD affects women and men differently. For instance, women with diabetes have a significantly higher CVD mortality rate than men with diabetes. Similarly, women with atrial fibrillation are at greater risk of stroke than men with atrial fibrillation. Historically, women have been underrepresented in clinical trials. The lack of good trial evidence concerning sex-specific outcomes has led to assumptions about CVD treatment in women, which in turn may have resulted in inadequate diagnoses and suboptimal management, greatly affecting outcomes. This knowledge gap may also explain why cardiovascular health in women is not improving as fast as that of men. Over the last decades, mortality rates in men have steadily declined, while those in women remained stable. It is also becoming increasingly evident that gender differences in cultural, behavioural, psychosocial and socioeconomic status are responsible, to various degrees, for the observed differences between women and men. However, the interaction between sex-and gender-related factors and CVD outcomes in women remains largely unknown.

Do you see what I see? Weight status misperception and exposure to obesity among children and adolescents

Objective:Obesity prevention in childhood is important. However, changing childrens lifestyle behaviors to reduce overweight is a substantial challenge. Accurately perceiving oneself as overweight/obese has been linked to greater motivation to change lifestyle behaviors. Children and adolescents may be less likely to perceive themselves as overweight/obese if they are exposed to overweight/obese people in their immediate environments. This study examined whether youth who are exposed to overweight parents and schoolmates were more likely to misperceive their own weight status.Design:The Quebec Child and Adolescent Health and Social Survey was a provincially representative, school-based survey of children and adolescents conducted between January and May 1999.Subjects:3665 children and adolescents (age 9, n=1267; age 13, n=1186; age 16, n=1212) from 178 schools. Mean body mass index (BMI) was 17.5, 20.6 and 22.2 kg/m2, respectively.Measurements:The misperception score was calculated as the standardized difference between self-perception of weight status (Stunkard Body Rating Scale) and actual BMI (from measured height and weight). Exposure to obesity was based on parent and schoolmate BMI.Results:Overweight and obese youth were significantly more likely to misperceive their weight compared with non-overweight youth (P<0.001). Multilevel modeling indicated that greater parent and schoolmate BMI were significantly associated with greater misperception (underestimation) of weight status among children and adolescents.Conclusion:Children and adolescents who live in environments in which people they see on a daily basis, such as parents and schoolmates, are overweight/obese may develop inaccurate perceptions of what constitutes appropriate weight status. Targeting misperception may facilitate the adoption of healthy lifestyle behaviors and improve the effectiveness of obesity prevention interventions.

Perceived racial discrimination and hypertension: A comprehensive systematic review.

OBJECTIVE Discrimination is posited to underlie racial disparities in hypertension. Extant literature suggests a possible association between racial discrimination and blood pressure, although inconsistent findings have been reported. The aim of this comprehensive systematic review was to quantitatively evaluate the association between perceived racial discrimination with hypertensive status and systolic, diastolic, and ambulatory blood pressure. METHOD Electronic database search of PubMed and PsycINFO (keywords: blood pressure/hypertension/diastolic/systolic, racism/discrimination/prejudice/unfair treatment) was combined with descendancy and ascendancy approaches. Forty-four articles (N = 32,651) met inclusion criteria. Articles were coded for demographics, hypertensive diagnosis, blood pressure measurement, discrimination measure and constructs, study quality, and effect sizes. RESULTS Random effects meta-analytic models were tested based on Fishers Z, the derived common effect size metric. Overall, perceived racial discrimination was associated with hypertensive status, Zhypertension = 0.048, 95% CI [.013, .087], but not with resting blood pressure, Zsystolic = 0.011, 95% CI [-.006, .031], Zdiastolic = .016, 95% CI [-.006, .034]. Moderators that strengthened the relation included sex (male), race (Black), age (older), education (lower), and hypertensive status. Perceived discrimination was most strongly associated with nighttime ambulatory blood pressure, especially among Blacks. CONCLUSIONS Despite methodological limitations in the existing literature, there was a small, significant association between perceived discrimination and hypertension. Future studies should consider ambulatory nighttime blood pressure, which may more accurately capture daily variation attributable to experienced racial discrimination. Perceived discrimination may partly explain racial health disparities.

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.

Subjective socioeconomic status and adolescent health: a meta-analysis.

OBJECTIVE To comprehensively and quantitatively examine the association between subjective socioeconomic status (SES) and health outcomes during adolescence. METHODS Forty-four studies met criteria for inclusion in the meta-analysis. Information on study quality, demographics, subjective SES, health outcomes, and covariates were extracted from each study. Fishers Z was selected as the common effect size metric across studies. Random-effect meta-analytic models were employed and fail-safe numbers were generated to address publication bias. RESULTS Overall, subjective SES was associated with health during adolescence (Fishers Z = .10). The magnitude of the effect varied by type of health outcome, with larger effects observed for mental health outcomes, self-rated health, and general health symptoms; and nonsignificant effects observed for biomarkers of health and substance-use-related health behaviors. Of the measures of subjective SES employed in the reviewed studies, perception of financial constraints, was most strongly associated with adolescent health outcomes. Analysis of covariates indicated that inclusion of objective SES covariates did not affect the association between subjective SES and health. CONCLUSIONS This meta-analysis has implications for the measurement of subjective SES in adolescents, for the conceptualization of subjective and objective SES, and for the pathways between SES and health in adolescents.

Beyond sleep duration: distinct sleep dimensions are associated with obesity in children and adolescents.

Objective:Short sleep duration is recognized as a significant risk factor in childhood obesity; however, the question as to how sleep contributes to the development of obesity remains largely unknown. The majority of pediatric studies have relied on sleep duration as the exclusive measure of sleep; this insular approach may be misleading given that sleep is a dynamic multidimensional construct beyond sleep duration, including sleep disturbances and patterns. Although these sleep dimensions partly overlap, it is necessary to determine their independent relation with obesity, which in turn, may inform a more comprehensive understanding of putative pathophysiological mechanisms linking sleep and obesity. The aim of the present study was to investigate whether sleep dimensions including sleep duration, disturbances, and patterns were individually associated with obesity, independent of multiple covariates. The second objective was to examine whether sleep disturbances and patterns were independently associated with obesity, after adjusting for sleep duration.Methods:Participants included 240 healthy children and adolescents (Mage=12.60, s.d.=1.98; 45.8% females). Anthropometric measures included measured waist and hip circumference, body mass index Z-score, and percent body fat. Subjective sleep measures included sleep duration, sleep disturbances, sleep quality, and sleep patterns from youth- and parental report.Results:Youth with larger adiposity and body composition measures reported poorer sleep quality (βavg=−0.14, P<0.01), more sleep disturbances (βavg=0.13, P<0.05), and showed a delayed sleep phase pattern (βavg=0.15, P<0.05), independent of age, sex, pubertal status, physical activity, screen time, socioeconomic status, and sleep duration. Shorter sleep duration was significantly associated with obesity; however, this link was attenuated after adjustment of covariates.Conclusions:The results suggest that sleep measures beyond duration may more precisely capture influences that drive the negative association between sleep and obesity, and thus, yield more robust associations. As such, future studies are needed to better understand how distinct sleep dimensions confer risk for childhood obesity.

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

Association Between Cigarette Smoking and C-Reactive Protein in a Representative, Population-Based Sample of Adolescents

Although related to inflammatory markers in adults, little is known about the association between cigarette smoking and C-reactive protein (CRP) in adolescent smokers. We examined the association between high-sensitivity CRP (hs-CRP) concentrations and smoking in youth. We used data from a cross-sectional, province-wide survey of a representative sample of youth conducted in Quebec, Canada, in 1999. Data were collected in self-report questionnaires completed by participants and their parents. Participants provided a fasting blood sample, and anthropometric measures were undertaken by trained technicians. The present analysis pertains to 1,501 adolescents aged 13 and 16 years who completed questionnaires and for whom blood samples were available. The independent association between a six-category indicator of smoking status and elevated hs-CRP, defined as a value at least in the 90th percentile of the age- and sex-specific CRP distribution, was assessed in multiple logistic regression analyses controlling for potential confounders. Relative to never-smokers, the odds ratios (95% confidence intervals) for puffers (i.e., never smoked a whole cigarette), those who smoked but not in the past month, light past-month smokers, moderate past-month smokers, and heavy past-month smokers were 1.04 (0.55-1.98), 1.76 (1.06-2.94), 1.39 (0.70-2.76), 2.07 (0.96-4.42), and 2.40 (1.18-4.88), respectively. Our data suggest a positive association between smoking status and elevated CRP in adolescents, and in particular among heavier past-month smokers. Damage related to cigarette smoking may begin soon after tobacco use initiation, reinforcing the preventive message that no level of smoking is safe in youth.

Nicotine dependence symptoms among young never-smokers exposed to secondhand tobacco smoke

BACKGROUND To extend previous observations that secondhand tobacco smoke (SHS) is associated with nicotine markers in children, we investigated if SHS exposure is associated with self-reports of nicotine dependence (ND) symptoms among young never-smokers. METHOD Data on number of persons who smoke inside the home, number of days exposed to SHS in a motor vehicle in the past week, number of parents, siblings, and friends who smoke, and ND symptoms, were collected from 10-12 year-old students in self-report questionnaires. The association between SHS and ND symptoms among young never-smokers was assessed in logistic regression models. RESULTS Sixty-nine of 1488 never-smokers (5%) reported one or more ND symptom. After controlling for sibling and peer smoking, and susceptibility to initiating smoking, exposure to SHS in a motor vehicle was independently associated with ND symptoms (OR, 95% CI=1.2, 1.0-1.4). The OR for number of persons who smoke inside the home was 1.1 (0.9-1.4). CONCLUSION SHS exposure in motor vehicles may be associated with ND symptoms among young never-smokers. If replicated, this finding provides support for interventions that promote non-smoking in motor vehicles.

Stability of the diurnal cortisol profile in children and adolescents

The diurnal cortisol profile has been implicated in multiple physical and mental health conditions in children and adolescents; however, current knowledge regarding the stability of the diurnal cortisol profile is largely based on adults. Developmental changes throughout childhood and adolescence warrant examination of the stability of the diurnal cortisol profile during this stage in the lifecourse. The aim of the present study was to conduct a comprehensive evaluation of the diurnal cortisol profile in children and adolescents. Participants (N=233; M=12.40, SD=1.83; 44.2% girls) in the Healthy Heart Project collected saliva samples, completed demographic questionnaires, and recorded bed and waking time. Intra-class correlations were calculated to evaluate the stability of aggregate and single sample measures of the diurnal cortisol profile. Total cortisol concentration (AUC(TG), AUC(AG)) and maximum sample were the most stable cortisol measures (ICC(avg)=0.54). Dynamic measures (AUC(I), slope; ICC(avg)=0.22) and other single sample measures (awake, lunch, dinner, bedtime, morning random, day random; ICC(avg)=0.28) were less stable. Of the developmentally relevant covariates tested, sleep duration, adrenarche, and time of awakening were most associated with cortisol values. Altogether, the diurnal cortisol profile yielded moderate to high stability in children and adolescents. These findings can inform methodological decisions regarding cortisol sampling protocols for children and adolescents.