Fitness levels below 42 and 35 mL/kg/min for boys and girls, respectively, should raise a red flag. These translate to 6 and 3 stages on the shuttle run test for a boy and a girl, both aged 15 years, respectively. These cut points identify children and adolescents who may benefit from primary and secondary cardiovascular prevention programming.

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Objective Risk factors for in-hospital mortality in confirmed COVID-19 patients have been summarized in numerous meta-analyses, but it is still unclear whether they vary according to the age, sex and health conditions of the studied populations. This study explored these variables as potential mortality predictors. Methods A systematic review was conducted by searching the MEDLINE, Scopus, and Web of Science databases of studies available through July 27, 2020. The pooled risk was estimated with the odds ratio (p-OR) or effect size (p-ES) obtained through random-effects meta-analyses. Subgroup analyses and meta-regression were applied to explore differences by age, sex and health conditions. The MOOSE guidelines were strictly followed. Results The meta-analysis included 60 studies, with a total of 51,225 patients (12,458 [24.3%] deaths) from hospitals in 13 countries. A higher in-hospital mortality risk was found for dyspnoea (p-OR = 2.5), smoking (p-OR = 1.6) and several comorbidities (p-OR range: 1.8 to 4.7) and laboratory parameters (p-ES range: 0.3 to -2.6). Age was the main source of heterogeneity, followed by sex and health condition. The following predictors were more markedly associated with mortality in studies with patients with a mean age ≤60 years: dyspnoea (p-OR = 4.3), smoking (p-OR = 2.8), kidney disease (p-OR = 3.8), hypertension (p-OR = 3.7), malignancy (p-OR = 3.7), diabetes (p-OR = 3.2), pulmonary disease (p-OR = 3.1), decreased platelet count (p-ES = -1.7), decreased haemoglobin concentration (p-ES = -0.6), increased creatinine (p-ES = 2.4), increased interleukin-6 (p-ES = 2.4) and increased cardiac troponin I (p-ES = 0.7). On the other hand, in addition to comorbidities, the most important mortality predictors in studies with older patients were albumin (p-ES = -3.1), total bilirubin (p-ES = 0.7), AST (p-ES = 1.8), ALT (p-ES = 0.4), urea nitrogen (p-ES), C-reactive protein (p-ES = 2.7), LDH (p-ES = 2.4) and ferritin (p-ES = 1.7). Obesity was associated with increased mortality only in studies with fewer chronic or critical patients (p-OR = 1.8). Conclusion The prognostic effect of clinical conditions on COVID-19 mortality vary substantially according to the mean age of patients. PROSPERO registration number CRD42020176595.

Higher levels of upper- and lower-body muscular strength are associated with a lower risk of mortality in adult population, regardless of age and follow-up period. Muscular strength tests can be easily performed to identify people with lower muscular strength and, consequently, with an increased risk of mortality.

PA, especially physical education, improves classroom behaviors and benefits several aspects of academic achievement, especially mathematics-related skills, reading, and composite scores in youth.

IMPORTANCE Studies of trends in excess weight among European children throughout the last few decades have rendered mixed results. Additionally, some studies were outdated, were based on self-reported weight and height, or included only a few European countries.OBJECTIVE To assess prevalence trends in measured overweight and obesity among children across Europe from 1999 to 2016 using a systematic methodology.DATA SOURCES MEDLINE, Embase, CINAHL, and Web of Science were searched from their inception until May 2018. Moreover, searches were conducted on health institutions' websites to identify studies not published in scientific journals. STUDY SELECTIONThe inclusion criteria were: (1) studies reporting the population-based prevalence of excess weight (overweight plus obesity) or obesity according to body mass index cutoffs proposed by the International Obesity Task Force; (2) cross-sectional or follow-up studies; and (3) studies including populations aged 2 to 13 years.DATA EXTRACTION AND SYNTHESIS Literature review and data extraction followed established guidelines. The Mantel-Haenszel method was used to compute the pooled prevalence estimates and their 95% CI whenever there was no evidence of heterogeneity (I 2 < 50%); otherwise, the DerSimonian and Laird random-effects method was used. Subgroup analyses by study year, country, or European region (Atlantic, Iberian, Central, and Mediterranean) were conducted. Prevalence estimates were calculated as an aggregate mean, weighted by the sample size and the number of individuals in each study. RESULTS A total of 103 studies (477 620 children aged 2 to 13 years) with data from 28 countries were included. The combined prevalence of overweight and obesity in the Iberian region tended to decrease from 30.3% (95% CI, 28.3%-32.3%) to 25.6% (95% CI, 19.7%-31.4%) but tended to increase in the Mediterranean region from 22.9% (95% CI, 17.9%-27.9%) to 25.0% (95% CI, 14.5%-35.5%). No substantial changes were observed in Atlantic Europe or Central Europe, where the overweight and obesity prevalence changed from 18.3% (95% CI, 14.0%-23.9%) to 19.3% (95% CI, 17.7%-20.9%) and from 15.8% (95% CI, 13.4%-18.5%) to 15.3% (95% CI, 11.6%-20.3%), respectively. CONCLUSIONS AND RELEVANCEThe prevalence of childhood overweight and obesity is very high, but trends have stabilized in most European countries. There are substantial between-country differences in the current levels and trends of overweight and obesity. The rising prevalence in some Mediterranean countries is worrisome.

The health consequences of excessive screen media use in children and adolescents are increasingly being recognized; however, the association between screen media use and academic performance remains to be elucidated. OBJECTIVES To estimate the association of time spent on screen-based activities with specific academic performance areas in children and adolescents and to examine this association separately in these populations. DATA SOURCES MEDLINE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, and ERIC were searched from database inception through September 2018. STUDY SELECTION Cross-sectional studies of the association between time or frequency of screen media use and academic performance in children and adolescents were independently screened by 2 researchers. A total of 5599 studies, published between 1958 and 2018 from 23 countries, were identified. DATA EXTRACTION AND SYNTHESIS Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size (ES). MAIN OUTCOMES AND MEASURES Academic performance areas included composite scores, language, and mathematics. Screen media measurements included time or frequency of computer, internet, mobile phone, television, video game, and overall screen media use. RESULTS In total, 58 cross-sectional studies (1.0%) of 5599 articles were included in the systematic review, of which 30 (52%) were included in the meta-analysis. The systematic review studies involved 480 479 participants aged 4 to 18 years, ranging from 30 to 192 000 people per study, and the meta-analysis studies involved 106 653 total participants, ranging from 70 to 42 041 people per study. Across studies, the amount of time spent on overall screen media use was not associated with academic performance (ES = −0.29; 95% CI, −0.65 to 0.08). Individually, television viewing was inversely associated with composite academic performance scores (ES = −0.19; 95% CI, −0.29 to −0.09), language (ES = −0.18; 95% CI, −0.36 to −0.01), and mathematics (ES = −0.25; 95% CI, −0.33 to −0.16). Video game playing was inversely associated with composite scores (ES = −0.15; 95% CI, −0.22 to −0.08). Subgroup analyses found that television viewing was inversely associated with language only in children (ES = −0.20; 95% CI, −0.26 to −0.15), whereas both television viewing (ES = −0.19; 95% CI, −0.30 to −0.07) and video game playing (ES = −0.16; 95% CI, −0.24 to −0.09) were inversely associated with composite scores only in adolescents. CONCLUSIONS AND RELEVANCE Findings from this study suggest that each screen-based activity should be analyzed individually for its association with academic performance, particularly television viewing and video game playing, which appeared to be the activities most negatively associated with academic outcomes. Education and public health professionals should consider supervision and reduction to improve the academic performance of children and adolescents exposed to these ...

ObjectiveTo examine the relationship between glycated haemoglobin A1c (HbA1c) levels and the risk of cardiovascular outcomes and all-cause mortality based on data from observational studies and to determine the optimal levels of HbA1c for preventing cardiovascular events and/or mortality in diabetic and non-diabetic populations.Review methodsWe systematically searched Medline, Embase, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews and Web of Science databases, from inception to July 2016, for observational studies addressing the association of HbA1c levels with mortality and cardiovascular outcomes. Random effects models were used to compute pooled estimates of HR and respective 95% CI for all-cause mortality, cardiovascular mortality and risk of cardiovascular events, separately for people with and without diabetes.ResultsSeventy-four published studies were included in the systematic review, but only 46 studies could be incorporated in the meta-analysis. In both diabetic and non-diabetic populations, there was an increase in the risk of all-cause mortality when HbA1c levels were over 8.0% and 6.0%, respectively. The highest all-cause mortality in people with diabetes was HbA1c above 9.0% (HR=1.69; 95% CI 1.09 to 2.66) and in those without diabetes was HbA1c above 6.0% (HR=1.74; 95% CI 1.38 to 2.20). However, both diabetic and non-diabetic populations with lower HbA1c levels (below 6.0% HR=1.57; 95% CI 1.14 to 2.17 and below 5.0% HR=1.19; 95% CI 1.04 to 1.36, respectively) had higher all-cause mortality. Similar pooled estimates were found when cardiovascular mortality was the outcome variable.ConclusionHbA1c is a reliable risk factor of all-cause and cardiovascular mortality in both diabetics and non-diabetics. Our findings establish optimal HbA1c levels, for the lowest all-cause and cardiovascular mortality, ranging from 6.0% to 8.0% in people with diabetes and from 5.0% to 6.0% in those without diabetes.