Lisa Kakinami

Identifying the best body mass index metric to assess adiposity change in children

Objective Although dual-energy X-ray absorptiometry (DEXA) is the preferred method to estimate adiposity, body mass index (BMI) is often used as a proxy. However, the ability of BMI to measure adiposity change among youth is poorly evidenced. This study explored which metrics of BMI change have the highest correlations with different metrics of DEXA change. Methods Data were from the Quebec Adipose and Lifestyle Investigation in Youth cohort, a prospective cohort of children (8–10 years at recruitment) from Québec, Canada (n=557). Height and weight were measured by trained nurses at baseline (2008) and follow-up (2010). Metrics of BMI change were raw (ΔBMIkg/m2), adjusted for median BMI (ΔBMIpercentage) and age-sex-adjusted with the Centers for Disease Control and Prevention growth curves expressed as centiles (ΔBMIcentile) or z-scores (ΔBMIz-score). Metrics of DEXA change were raw (total fat mass; ΔFMkg), per cent (ΔFMpercentage), height-adjusted (fat mass index; ΔFMI) and age-sex-adjusted z-scores (ΔFMz-score). Spearmans rank correlations were derived. Results Correlations ranged from modest (0.60) to strong (0.86). ΔFMkg correlated most highly with ΔBMIkg/m2 (r = 0.86), ΔFMI with ΔBMIkg/m2 and ΔBMIpercentage (r = 0.83–0.84), ΔFMz-score with ΔBMIz-score (r = 0.78), and ΔFMpercentage with ΔBMIpercentage (r = 0.68). Correlations with ΔBMIcentile were consistently among the lowest. Conclusions In 8–10-year-old children, absolute or per cent change in BMI is a good proxy for change in fat mass or FMI, and BMI z-score change is a good proxy for FM z-score change. However change in BMI centile and change in per cent fat mass perform less well and are not recommended.

Risk of cardiovascular disease in HIV, Hepatitis C, or HIV/Hepatitis C patients compared to the general population

Background:  As a result of effective antiretroviral therapy HIV patients are living longer, and their risk of cardiovascular disease (CVD) is a growing concern. It remains unknown whether coinfection with hepatitis C (HCV) changes an HIV person’s CVD risk, and how the risks compare to the general population. The objective of this study was to compare the Framingham Risk Score (FRS) and vascular age differences in persons with HIV, HCV or HIV/HCV disease to the general population.

Parenting style and obesity risk in children

BACKGROUND Parents play a critical role in their childrens lifestyle habits. The objective was to assess the effect of parenting style on the risk of childhood obesity, and to determine whether poverty was a moderator of the association. METHODS Participants were from the 1994-2008 cross-sectional samples of the National Longitudinal Survey of Children and Youth (NLSCY), a nationally representative survey of Canadian youth. Factor and cluster analyses identified four parenting styles consistent with Baumrinds parenting style prototypes. Multivariable logistic regression assessed the risk of obesity based on parenting style after adjusting for covariates. Analyses were stratified by age (preschool: 2-5years of age, n=19,026; school-age: 6-11years of age, n=18,551) and the moderating effect of poverty (household income<low income cut-offs adjusted for household size and geographic region) was assessed. Analyses used sampling and bootstrap weights. RESULTS In multivariable analyses, compared to authoritative parenting, preschool- and school-age children with authoritarian parents were 35% (95% CI: 1.2-1.5) and 41% (CI: 1.1-1.8) more likely to be obese, respectively. In preschool children, poverty moderated this association: authoritarian and negligent parenting was associated with 44% (CI: 1.3-1.7) and 26% (CI: 1.1-1.4) increased likelihood of obesity, respectively, but only among the children not living in poverty. In school-age children, poverty was not a moderator. CONCLUSIONS Parenting style is associated with childhood obesity, but may be moderated by poverty. Successful strategies to combat childhood obesity should reflect the independent and interactive associations of sociodemographic and social-familial influences on health especially in early childhood.

Cohort Profile: The Nicotine Dependence in Teens (NDIT) Study

The Nicotine Dependence in Teens (NDIT) study is a prospective cohort investigation of 1294 students recruited in 1999-2000 from all grade 7 classes in a convenience sample of 10 high schools in Montreal, Canada. Its primary objectives were to study the natural course and determinants of cigarette smoking and nicotine dependence in novice smokers. The main source of data was self-report questionnaires administered in class at school every 3 months from grade 7 to grade 11 (1999-2005), for a total of 20 survey cycles during high school education. Questionnaires were also completed after graduation from high school in 2007-08 and 2011-12 (survey cycles 21 and 22, respectively) when participants were aged 20 and 24 years on average, respectively. In addition to its primary objectives, NDIT has embedded studies on obesity, blood pressure, physical activity, team sports, sedentary behaviour, diet, genetics, alcohol use, use of illicit drugs, second-hand smoke, gambling, sleep and mental health. Results to date are described in 58 publications, 20 manuscripts in preparation, 13 MSc and PhD theses and 111 conference presentations. Access to NDIT data is open to university-appointed or affiliated investigators and to masters, doctoral and postdoctoral students, through their primary supervisor (www.nditstudy.ca).

Trying to Lose Weight: The Association of Income and Age to Weight-Loss Strategies in the U.S.

BACKGROUND Two thirds of the U.S. population is overweight or obese, but those living in poverty are disproportionately affected. Although 30%-50% of Americans report currently trying to lose weight, some strategies may be counterproductive. Little is known about how income may be associated with weight-loss strategies. PURPOSE This study aims to determine the association between income and weight-loss strategies in the general U.S. population. METHODS Cross-sectional data from the National Health and Nutrition Examination Survey were collected in 1999-2010 and analyzed in 2012. Annual household income was categorized as <

Influence of Dairy Product Consumption on Children's Blood Pressure: Results from the QUALITY Cohort

20,000,

Association between different growth curve definitions of overweight and obesity and cardiometabolic risk in children

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Poverty's latent effect on adiposity during childhood: evidence from a Québec birth cohort

44,999,

Comparison of three lifecourse models of poverty in predicting cardiovascular disease risk in youth

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Correlates of HIV testing uptake among kothi-identified men who have sex with men in public sex environments in Chennai, India.

74,999, ≥