Role of Physical Activity and Sedentary Behaviors on Vascular and Myocardial Structure and Function in Type 1 Diabetes.

OBJECTIVE: To estimate associations between physical activity and sedentary behaviors and early markers of cardiovascular diseases in adolescents with and without type 1 diabetes. STUDY DESIGN: Cross-sectional data stem from the CARdiovascular Disease risk in pEdiatric type 1 diAbetes (CARDEA) study, a study investigating early cardiovascular disease development in 100 adolescents with type 1 diabetes recruited at Sainte-Justine University Hospital Diabetes Clinic and 97 healthy adolescents without diabetes (14-18 years), in Montreal, Canada. Outcomes included arterial stiffness by pulse-wave velocity, endothelial function (velocity time integral) by flow-mediated dilation test, and cardiac magnetic resonance imaging markers. Moderate-to-vigorous physical activity (MVPA) and sedentary time were estimated by accelerometry and leisure screen time by questionnaire. We estimated multivariable linear regression models stratified by group. RESULTS: In adolescents with type 1 diabetes, 10-minutes daily increase in MVPA was associated with 3.69 g/m (95% CI: -1.16; 8.54) higher left ventricular (LV) mass/height and 1-hour increase in device-measured sedentary time with 0.68 mm (0.20; 1.16) higher wall thickness but only in those with glycated hemoglobin ≤7.5%. In healthy adolescents, a 10-minute increase in MVPA was associated with 1.32 g/m (-0.03; 2.66) higher LV mass/height. Every 1-hour increase in sedentary time was associated with -1.82 cm (-3.25; -0.39) lower velocity time integral, -2.99 g/m (-5.03; -0.95) lower LV mass/height, and -0.47 mm (-0.82; -0.12) lower wall thickness. CONCLUSIONS: Being active and limiting sedentary time appears beneficial for cardiac structure and endothelial function in healthy adolescents; however, adequate glycemic control combined with higher levels of MVPA may be required for adolescents with type 1 diabetes to overcome the impact of diabetes.

Body Mass Index Z Score vs Weight-for-Length Z Score in Infancy and Cardiometabolic Outcomes at Age 8-10 Years.

OBJECTIVES: To confirm that World Health Organization weight-for-length z scores (zWFL) and World Health Organization body mass index z scores (zBMI) in infancy are associated with adiposity and cardiometabolic measures at 8-10 years old and to compare the predictive ability of the 2 methods. STUDY DESIGN: zWFL and zBMI at 6, 12, and 18 months of age were computed using data extracted from health booklets, among participants in the Québec Adipose and Lifestyle InvesTigation in Youth prospective cohort (n = 464). Outcome measures at 8-10 years included adiposity, lipid profile, blood pressure, and insulin dynamics. The relationships between zWFL, zBMI, and each outcome were estimated using multivariable linear regression models. Outcome prediction at 8-10 years was compared between the 2 methods using eta-squared and the Lin concordance correlation coefficient. RESULTS: zWFL and zBMI were associated with all measures of adiposity at 8-10 years. Associations with other cardiometabolic measures were less consistent. For both zWFL and zBMI across infancy, eta-squared were highly similar and the Lin coefficients were markedly high (≥0.991) for all outcomes. CONCLUSIONS: There was no evidence that zBMI and zWFL in infancy differed in their ability to predict adiposity and cardiometabolic measures in childhood. This lends support to the sole use of zBMI for growth monitoring and screening of overweight and obesity from birth to 18 years. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03356262.

Lifestyle Habits, Dietary Factors, and the Metabolically Unhealthy Obese Phenotype in Youth.

OBJECTIVE: To determine whether lifestyle habits and dietary factors at age 8-10 years predict the development of metabolically unhealthy obesity 2 years later among children who were previously metabolically healthy obese. STUDY DESIGN: The QUebec Adipose and Lifestyle InvesTigation in Youth cohort comprises 630 youth with a parental history of obesity. Metabolically healthy obesity and metabolically unhealthy obesity were defined using cut-offs for the components of pediatric metabolic syndrome. Dietary factors, physical activity, fitness, sedentary behavior, screen time, and sleep duration were measured. Multivariable logistic regressions were used to examine associations. RESULTS: At baseline, 48 participants with metabolically healthy obesity were identified; 2 years later, 19 became metabolically unhealthy obese and 29 remained metabolically healthy obese. Every additional daily portion of fruits and vegetables decreased the risk of converting to metabolically unhealthy obesity by 39% (OR 0.61, 95% CI 0.40-0.94). Cumulating more hours of screen time and diets high in saturated fat and sugar-sweetened beverages and low in protein were associated with a tendency to develop metabolically unhealthy obesity. CONCLUSIONS: Fruit and vegetable intake and possibly screen time, saturated fat, sugar-sweetened beverages, and protein intake may be important targets for the prevention of cardiometabolic complications in obese children. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03356262.

Prediction of duration of breastfeeding among migrant and Canadian-born women: results from a multi-center study.

OBJECTIVE: To examine and compare predictors of breastfeeding duration among migrant and Canadian-born women. STUDY DESIGN: As part of a longitudinal study, a sample of 1503 mothers was recruited from 12 hospitals in Canada who completed questionnaires at 1 and 16 weeks postpartum. Following bivariate analysis, multivariate logistic regression analyses were completed to examine and compare predictors of continued breastfeeding at 16 weeks postpartum among migrant and Canadian-born women. RESULTS: Among migrant women, factors predictive of breastfeeding duration included maternal age ≥ 35 years, primiparity, and breast engorgement pain at 1 week postpartum. Factors predictive of discontinued breastfeeding in this group included maternal age <20 years, higher gender-related development index of country of origin, no previous breastfeeding experience, breastfeeding duration of peers <6 months, planned duration of exclusive breastfeeding <6 months, and not exclusively breastfeeding at 1 week postpartum. Among Canadian-born women, factors predictive of breastfeeding duration included residence in Vancouver and maternal age ≥ 35 years. Factors predictive of discontinued breastfeeding included residence in Toronto, maternal age <20 years, smoking at 16 weeks postpartum, primiparity, planned duration of exclusive breastfeeding <6 months, and not exclusively breastfeeding at 1 week postpartum. CONCLUSIONS: Although certain predictors for breastfeeding duration were similar between migrant and Canadian-born women, several were dissimilar, suggesting that these groups might benefit from different strategies to optimize breastfeeding outcomes.