Sedentary Behavior and Cardiometabolic Markers in Adolescents: A 4-Year Longitudinal Study.

PURPOSE: Analyzed the associations of sedentary behavior (SB) measured by questionnaire and accelerometer, with cardiometabolic markers in adolescents. METHODS: Longitudinal study with 4 years of follow-up with adolescents from João Pessoa, Brazil. SB was measured using a questionnaire (305 adolescents: 54.5% females; age 11.7 [SD = 0.7]) and use of accelerometer (136 adolescents: 54.8% females; age 11.5 [SD = 0.7]). The cardiometabolic markers were body mass index, waist circumference, systolic and diastolic blood pressure, fasting glucose, total cholesterol, triglycerides, low-density lipoproteins and high-density lipoproteins (HDL-C), total cholesterol/HDL ratio, triglycerides/HDL ratio, and non-HDL-C. Generalized Estimating Equation analysis was used to for analyses. RESULTS: The average time in SB by the accelerometer was greater (average 8.3 [SD = 1.5], 8.8 [SD = 1.6], and 8.4 [SD = 1.9] h/d/wk) than observed in the questionnaire (on average 6.0 [SD = 4.1], 7.2 [SD = 4.9], and 6.6 [SD = 5.4] h/d/wk), in all years of the study, but without a significant increasing trend (P > .05) over time for both measures. There was a significant and positive association between SB measured by the questionnaire and SBP (ß = 0.148; 95% CI, 0.021-0.274). CONCLUSIONS: The SB generally does not seem to contribute to significant changes in cardiometabolic markers in adolescents, despite it being associated with increased systolic blood pressure levels.

Longitudinal association between moderate to vigorous physical activity and lipid profile indicators in adolescents.

The objective of this study was to examine the association between time engaged in moderate (MPA), vigorous (VPA), and moderate-to-vigorous (MVPA) physical activity (PA) and indicators of lipid profile in adolescents. This longitudinal study with a four-year follow-up, and three collection points (2014, 2015 and 2017) analyzed the data of 136 adolescents (10-13 years old; 53.7% girls), in João Pessoa, Brazil. The time in MPA, VPA and MVPA times was measured by accelerometers. The lipid profile indicators analyzed were total cholesterol (TC), low-density (LDL-C) and high-density lipoproteins cholesterol (HDL-C), triglycerides (TG), non-HDL-C, TC/HDL-C and TG/HDL-c ratios. There was an inverse association between MPA time and TC values (ß = -0.560; 95%CI: -1.116; -0.004); VPA and LDL-C (ß = -0.962; 95%CI: -1.678; -0.246) and non-HDL-C (ß = -0.955; 95%CI: -1.708; -0.201); and MVPA and TC (ß = -0.436; 95%CI: -0.816; -0.055), TG (ß = -0.415; 95%CI: -0.712; -0.118), LDL-C (ß = -0.460; 95%CI: -0.823; -0.096), non-HDL-C (ß = -0.522; 95%CI: -0.908; -0.136) and TC/HDL-C (ß = -0.472; 95%CI: -0.889; -0.055). Adolescents more engaged in PA, especially in MVPA, exhibited better levels of TC, TG, LDL-C, non-HDL-C and TC/HDL-C; and AFV exerted a greater influence on LDL-c and non-HDL-c levels.HighlightsThis study is one of the first observational longitudinal studies to analyze the association between different PA intensities, measured by accelerometer, and lipid profile indicators, with a 4-year follow-up and 3 collection points in adolescents from a low-to-middle income country;Adolescents engaged in PA, especially MVPA intensity, obtained better TC, TG, LDL-c, non-HDL-C and TC/HDL-C levels;VPA was more strongly associated with LDL-C and non-HDL-C levels compared to MVPA.

Is Participation in Physical Education Classes Related to Physical Activity and Sedentary Behavior? A Systematic Review.

BACKGROUND: The aim of this systematic review was to summarize the results and assess the methodological quality of studies that analyzed the relation between physical education participation, physical activity, and sedentary behavior in schoolchildren. METHODS: Searches were conducted for original cross-sectional and longitudinal observational studies published in Portuguese, English, and Spanish between January 2007 and August 2020, on the PubMed, Web of Science, Scientific Electronic Library Online, Education Resources Information Center, and Scopus databases. RESULTS: A total of 60 articles (68 independent samples) were included in the revision (58 cross-sectional and 2 longitudinal observational studies). With regard to methodological quality, 27%, 52%, and 21% of the studies were classified as high, moderate, and low methodological quality, respectively. Physical activity was analyzed in 93% of the studies (n = 56) and sedentary behavior in 33% (n = 20). The higher frequency of physical education participation was associated with higher physical activity levels (56 of 68 results - 54/65 cross-sectional and 2/3 longitudinal studies) and less sedentary behavior (14 of 24 results), even after stratifying analyses by type and methodological quality. CONCLUSION: Physical education class participation may contribute to students being physically more active and less likely to engage in sedentary behavior.