The association between income inequality and adolescent body mass index: findings from the COMPASS study (2016-2019).

OBJECTIVES: Income inequality has been linked to high and unhealthy body mass index (BMI), though there is a dearth of evidence in adolescents. Therefore, this study examines the association between income inequality and BMI in a large sample of Canadian adolescents. METHODS: A pooled cross-sectional design was used. Participants were adolescents (n = 101,901) from 157 Canadian secondary schools participating in the 2016-2017, 2017-2018, or 2018-2019 waves of the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study. BMI was calculated from self-reported height and weight and converted to World Health Organization (WHO) z-BMI scores. Gini coefficients were calculated at the census division level (n = 49) using data from the 2016 Canadian Census. Multilevel modelling was performed to account for the clustering of students nested within schools, which were nested within census divisions. Interactions were included to determine whether associations were heterogeneous for males and females. RESULTS: Income inequality demonstrated a non-linear association with WHO z-BMI score (z-Gini: ß = 0.05, 95%CI: 0.02, 0.08; z-Gini2: ß = -0.02, 95% CI: -0.04, -0.01) among adolescents after adjusting for student-, school-, and census division-level covariates. This association was more pronounced among females. CONCLUSION: The association between income inequality and BMI, being overweight, or having obesity appears to be non-linear. Public health units and schools may benefit from incorporating upstream factors such as income inequality into their interventions attempting to promote healthy weights.

RéSUMé: OBJECTIFS: L'inégalité des revenus a été liée à un indice de masse corporelle (IMC) élevé et malsain, bien qu'il y ait un manque de preuves chez les adolescents. Par conséquent, la présente étude examine l'association entre l'inégalité des revenus et l'IMC dans un vaste échantillon d'adolescents canadiens. MéTHODES: Un devis comprenant des études transversales groupées a été utilisé. Les participants étaient des adolescents (n = 101 901) de 157 écoles secondaires canadiennes participant aux vagues 2016-2017, 2017-2018 ou 2018-2019 de l'étude COMPASS (Cannabis, Obésité, Santé mentale, Activité physique, Alcool, Tabagisme et Comportement sédentaire). L'IMC a été calculé à partir de la taille et du poids auto-déclarés et convertis en scores z selon l'Organisation mondiale de la santé (OMS). Les coefficients de Gini ont été calculés à l'échelle du secteur de recensement (n = 49) en utilisant les données du Recensement canadien de 2016. Des modèles multiniveaux ont été effectués pour tenir compte du regroupement des élèves dans les écoles, qui elles-mêmes étaient incluses dans les secteurs de recensement. Des variables d'interactions ont été incluses dans les modèles afin de permettre une comparaison des paramètres estimés entre les hommes et les femmes. RéSULTATS: L'inégalité des revenus a démontré une association non linéaire avec le score de l'IMC z de l'OMS (z-Gini : ß = 0,05, IC à 95 % : 0,02, 0,08; z-Gini2 : ß = -0,02, IC à 95 % : -0,04, -0,01) chez les adolescents après ajustement pour tenir compte des covariables au niveau des élèves, de l'école et des divisions de recensement. Cette association était plus prononcée chez les femmes. CONCLUSION: L'association entre l'inégalité des revenus et l'IMC, l'embonpoint ou l'obésité semble être non linéaire. Les bureaux de santé publique et les écoles pourraient tirer profit de l'intégration de facteurs en amont comme l'inégalité des revenus dans leurs interventions visant à promouvoir le poids santé.

Sex-specific characteristics for the coexistence of asthma and COPD in the Canadian population: a cross-sectional analysis of CLSA data.

Objective: The coexistence of asthma and COPD (asthma + COPD) is a condition found among patients who present with clinical features of both asthma and COPD. Epidemiological evidence points to an increasingly disproportionate burden of asthma + COPD and COPD in females. The objective of this cross-sectional study is to identify female and male-specific epidemiological and clinical characteristics associated with asthma + COPD.Methods: Baseline data from the comprehensive cohort of Canadian Longitudinal Study on Aging (CLSA) were used in this cross-sectional study which included 30,097 subjects between the ages of 45- and 85-years Participants were categorized into four mutually exclusive groups: asthma + COPD, COPD-only, asthma-only and neither asthma nor COPD.Results: The prevalence was significantly greater in females than males for asthma + COPD (2.71% vs. 1.41%; p < 0.001), COPD-only (3.22% vs. 2.87%; p < 0.001) and asthma-only (13.31% vs. 10.11%; p < 0.001). The association between smoking and asthma + COPD was modified by age in females. Osteoporosis and underactive thyroid disease were significantly more prevalent in females than in males in asthma + COPD, COPD-only and asthma-only groups. In asthma + COPD group, a greater proportion of respiratory symptoms associated with asthma was observed in females whereas a greater proportion of respiratory symptoms associated with COPD was observed in males. Severity of airway obstruction determined by spirometry measurements was greater in males than females.Conclusions: In the Canadian adult population, several epidemiological and clinical characteristics in asthma + COPD varied between females and males. The findings in this study will help healthcare professional in the recognition and management of coexisting asthma and COPD in females and males.