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Objectives. To describe the recent global prevalence of e-cigarette use and to investigate its associated factors among youths aged 12 to 16 years in 68 countries and territories (hereafter “countries”). Methods. We analyzed 485 746 youths aged 12 to 16 years from the population-based cross-sectional Global Youth Tobacco Survey conducted in 67 countries between 2012 and 2019 and the 2019 National Youth Tobacco Survey in the United States. We defined past-30-day e-cigarette use as using e-cigarettes on 1 or more days during the past 30 days. Results. The global prevalence of past-30-day e-cigarette use among youths was 9.2%, ranging from 1.9% in Kazakhstan to 33.2% in Guam. Maternal smoking (adjusted odds ratio [AOR] = 1.40; 95% confidence interval [CI] = 1.29, 1.52), paternal smoking (AOR = 1.13; 95% CI = 1.07, 1.19), secondhand smoke exposure (AOR = 1.74; 95% CI = 1.64, 1.84), youth cigarette smoking (AOR = 7.18; 95% CI = 6.84, 7.54), and youth other tobacco use (AOR = 3.88; 95% CI = 3.62, 4.15) were positively associated with e-cigarette use. Conclusions. E-cigarette use was moderately frequent among youths aged 12 to 16 years globally. Several important factors were associated with youth e-cigarette use. Public Health Implications. Our findings highlight the need for countries worldwide to develop policies to address e-cigarette use among youths. (Am J Public Health. 2022;112(4):650–661. https://doi.org/10.2105/AJPH.2021.306686 )

Few studies have examined access to cigarettes among adolescents. To address this, we aimed to examine cigarette access and purchase patterns among adolescent cigarette smokers based on the most recent data from the Global Youth Tobacco Surveys (GYTS).We used the most recent school-based GYTS data (2010-2018) on 49 856 adolescent cigarette smokers aged 12-16 years in 140 countries/territories (hereafter "countries") to examine cigarette access and purchase patterns among adolescent smokers.Over half (51.2%) of adolescent smokers bought cigarettes from commercial vendors (ie, stores/shops/street vendors/kiosks) and one-third of smokers (32.7%) got cigarettes from private persons (ie, peers or adults). Males (vs females), older adolescents (vs younger ones), and adolescent smokers from low-income countries (vs those from middle- or high-income countries) were more likely to buy cigarettes from commercial vendors. Younger adolescents (vs older ones) and adolescent smokers from low-income countries (vs those from middle- or high-income countries) were more likely to get cigarettes from private persons. As many as 39.6% of adolescent smokers reported that they were not denied buying cigarettes from commercial vendors due to age restrictions, especially among males (vs females), among older adolescents (vs younger ones), and among adolescent smokers from upper-middle-income or high-income countries (vs those from low-income countries). Purchasing cigarettes as single sticks was more likely to occur in males (vs females), in older adolescents (vs younger ones), and in adolescent smokers from low-income countries (vs those from upper-middle-income or high-income countries), with inverse findings for purchasing cigarettes in full packs.Adolescent smokers often obtained cigarettes from commercial vendors or private persons. Additionally, adolescent smokers often purchased cigarettes in packs and as individual sticks. These findings emphasize the need to strengthen measures to reduce the supply of cigarettes to minors.

BACKGROUND It is well-known that secondhand smoke exposure in childhood or adolescence is positively associated with morbidity and mortality. However, less is known about the current status of and most recent trends in secondhand smoke exposure among adolescents in China. OBJECTIVE We aimed to assess recent changes in the prevalence of secondhand smoke exposure among adolescents in China using nationally representative data. METHODS We used data from 2 repeated national cross-sectional surveys conducted in 2013-2014 and 2019. A total of 155,117 students (median age 13.5 years) in 2013-2014 and 147,270 students (median age 13.1 years) in 2019 were included in this study. Sociodemographic factors and secondhand smoke exposure information were collected via a standardized questionnaire. Exposure was defined as secondhand smoke exposure ≥1 day during the past 7 days at home or in public places. Other frequencies of secondhand smoke exposure (ie, ≥3 days, ≥5 days, and every day) during the past 7 days were also assessed. The weighted prevalence of secondhand smoke exposure was calculated according to the complex sample design for surveys. RESULTS The prevalence of secondhand smoke exposure in any place (home or public places ≥1 day during the past 7 days) decreased from 2013-2014 (72.9%, 95% CI 71.5%-74.3%) to 2019 (63.2%, 95% CI 62%-64.5%), as did exposure at home (2013-2014: 44.4%, 95% CI 43.1%-45.7%; 2019: 34.1%, 95% CI 33.1%-35.2%) and in public places (2013-2014: 68.3%, 95% CI 66.9%-69.6%; 2019: 57.3%, 95% CI 56%-58.6%). The prevalence of secondhand smoke exposure decreased with increased gross domestic product per capita in each of the 2 survey years irrespective of exposure frequency or location. The prevalence of exposure at other frequencies (ie, ≥3 days, ≥5 days, or every day during the past 7 days) also decreased in any place, at home, and in public places. Secondhand smoke exposure was associated with higher school grade level (ninth vs seventh grade: odds ratio [OR] 1.76, 95% CI 1.68-1.84), gender (boys vs girls: OR 1.18, 95% CI 1.15-1.22), urban status (urban vs rural: OR 1.10, 95% CI 1.01-1.19), and cigarette smoking (yes vs no: OR 6.67, 95% CI 5.83-7.62). CONCLUSIONS Although the prevalence of secondhand smoke exposure among Chinese adolescents declined from 2013-2014 to 2019, it remains unacceptably high. More effective strategies and stronger action are needed in China to further, and dramatically, curb secondhand smoke exposure among adolescents.

Sleep deprivation may cause depressive disorders in both children and adults. However, the effects of sleep duration change from childhood to adulthood on adult depressive disorders are poorly documented. Using the China Family Panel Study (CFPS) data, we aimed to examine the association between sleep duration change from childhood to adulthood and adult depressive disorders in the Chinese population.Data were from 1172 children aged 10-15 years in 2010 who were followed up through 2018 based on the nationally representative and population-based CFPS. According to sleep duration in childhood and early adulthood, the sleep duration change was categorized into four groups: persistently insufficient sleep, sleep duration loss, sleep duration gain and persistently sufficient sleep.After adjustment for potential covariates, compared with individuals with persistently sufficient sleep duration, those with sleep duration loss (OR = 1.98, 95% CI = 1.14-3.46) and persistently insufficient sleep (OR = 2.35, 95% CI = 1.43-3.88) had higher odds of depressive disorders in adulthood. In contrast, the odds of adult depressive disorders did not significantly increase in those with sleep duration gain (OR = 1.46, 95% CI = 0.88-2.41).Information on sleep duration was obtained through a questionnaire; the sample size of this study was not large; the generalizality of our findings to other populations should be caucious.Persistently insufficient sleep duration and sleep duration loss from childhood to adulthood were associated with higher odds of adult depressive disorders, while those who were able to change their sleep duration from insufficient status to sufficient status didn't have an increased odds of adult depressive disorders.

Dynamic Vision Sensor (DVS) is a new type of neuromorphic event-based sensor, which has an innate advantage in capturing fast-moving objects. Due to the interference of DVS hardware itself and many external factors, noise is unavoidable in the output of DVS. Different from frame/image with structural data, the output of DVS is in the form of address-event representation (AER), which means that the traditional denoising methods cannot be used for the output (i.e., event stream) of the DVS. In this paper, we propose a novel event stream denoising method based on probabilistic undirected graph model (PUGM). The motion of objects always shows a certain regularity/trajectory in space and time, which reflects the spatio-temporal correlation between effective events in the stream. Meanwhile, the event stream of DVS is composed by the effective events and random noise. Thus, a probabilistic undirected graph model is constructed to describe such priori knowledge (i.e., spatio-temporal correlation). The undirected graph model is factorized into the product of the cliques energy function, and the energy function is defined to obtain the complete expression of the joint probability distribution. Better denoising effect means a higher probability (lower energy), which means the denoising problem can be transfered into energy optimization problem. Thus, the iterated conditional modes (ICM) algorithm is used to optimize the model to remove the noise. Experimental results on denoising show that the proposed algorithm can effectively remove noise events. Moreover, with the preprocessing of the proposed algorithm, the recognition accuracy on AER data can be remarkably promoted.

Assisted reproductive technology (ART) is the most widely used treatment for infertility and has resulted in millions of births worldwide. The safety of the offspring has been of the utmost concern. Previous studies suggested an increase in metabolic disorders in offspring later in life. The aim of the present study was to investigate metabolic changes at age 6–10 years in offspring conceived as a result of in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI). A total of 380 children born from IVF/ICSI and a matched control group of 380 naturally conceived children, all aged 6–10 years, were recruited. Anthropometric measures, ultrasound and serum tests were performed for body mass, glucose metabolism and lipid profiles, and examination of vasculature structure. The children conceived by ART showed significantly higher fasting blood glucose and serum insulin levels and HOMA-IR (adjusted β [95% CI]: fasting blood glucose 0.49 [0.42, 0.55]; loge-transformed insulin 0.28 [0.20, 0.35]; loge-transformed HOMA-IR 0.38 [0.30, 0.46]), as well as a lower HOMA-B and serum apolipoprotein A (ApoA) levels (adjusted β [95% CI]: loge-transformed HOMA-B −0.19 [−0.27, −0.11]; ApoA −0.17 [−0.21, −0.13]), when compared with the control group. Furthermore, the ultrasound scan indicated elevated carotid intima–media thickness in children conceived by ART (β 0.13 [95% CI 0.12, 0.13]). Children conceived by IVF/ICSI have a less favourable glucose and cardiovascular metabolic profile in childhood when compared with naturally conceived children. The underlying mechanisms and potential long-term consequences need to be elucidated in future studies.

Long non-coding RNAs (LncRNAs), lacking protein-coding function, modulate immune function by regulating the expression of genes or the function of protein molecules. They participate in epigenetic regulation, interfere with downstream gene transcription acting as a molecular sponge to affect miRNA function, and can combine with proteins to form nucleic acid protein complexes that affect protein function or cell location to regulate genes and regulate immune function. LncRNAs are differentially expressed in immune cells. They affect the maturity, differentiation and activation of immune cells and regulate cytokine release and immune phenotype. They are closely related to immune tolerance and cell migration. Dendritic cells (DCs) are important immune cells with the most robust antigen-presenting function, and have irreplaceable roles in human innate immunity and adaptive immunity. Emerging evidence over the past few years has suggested that LncRNAs influence the differentiation and maturation of DCs and serve as a critical role in the cell phenotype and immune function of DCs. To further understand the role of LncRNAs in the occurrence and development of DC-related diseases, we elaborated the role of LncRNAs in DC immune function, including antigen presentation, T cell activation and proliferation, DC migration. Furthermore, we summarized the impact of pathological factors (tumors, inflammation, autoimmune disease, viral infection) and physiological factors (e.g., age) on the LncRNAs in DCs, and how the changed LncRNAs altered the function and behavior of DCs resulting from the intervention. We hope this review give us have a better understanding of multiple effects of LncRNA on cell function in DCs.

Background: Maternal height has been confirmed to be associated with offspring stunting in low- and middle-income countries (LMICs), but only limited studies have examined the paternal-offspring association, and few studies have examined the joint effect of maternal and paternal height on stunting.Objective: To investigate the association between parental height and stunting of children aged under five in LMICs.Methods: We obtained data from the Demographic and Health Surveys (DHS) conducted in 14 LMICs from 2006 to 2016. The association between maternal and paternal height and height-for-age z score (HAZ) of children aged under five was analyzed using a linear regression model in consideration of complex survey design, and regression coefficients (β) with 95% confidence intervals (CIs) were reported. Then, the association between maternal and paternal height quintile and child stunting was analyzed using a modified Poisson regression approach with robust error variance in consideration of complex survey design with adjustment for covariates. The effect estimates were expressed as relative risks (RRs) with 95% CIs.Results: A total of 50,372 singleton children were included and the weighted prevalence of stunting was 34.5%. Both maternal height and paternal height were associated with child HAZ (β = 0.047; 95% CI, 0.043, 0.050; and β = 0.022; 95% CI, 0.018, 0.025, respectively). Compared with those born to the tallest mothers and fathers, children from the shortest mothers and the shortest fathers had higher risks of stunting (adjusted RR = 1.89; 95% CI, 1.78, 2.01; adjusted RR = 1.56; 95% CI, 1.47, 1.65, respectively). The mother-offspring associations are substantively larger than the father-offspring associations for each corresponding height quintile. Children from the shortest parents had the highest risk of stunting compared with children from the tallest parents (adjusted RR = 3.23; 95% CI, 2.83, 3.68).Conclusions: Offspring born to short parents are at increased risk of stunting in LMICs, and this intergenerational effect is partly driven by maternal intrauterine influence. This suggests the importance of improving the nutritional status of children and adults in LMICs, especially female caregivers.

Background The dose-response association between sedentary time and suicidal ideation and planning among adolescents is unclear. This study examined the association between leisure sedentary time and suicidal ideation, planning and attempts among adolescents in low- and middle-income countries (LMICs). Methods We used the most recent data (2009–2016) from the Global School-based Student Health Survey (GSHS) in 54 LMICs. Leisure sedentary time and suicidal ideation, planning and attempts were assessed using a standardized questionnaire. A total of 146,345 young adolescents aged 12–15 years were included. Results Among adolescents in the 54 LMICs, the prevalence of suicidal ideation was 14.8%, planning was 14.5%, and attempts was 13.0%. Compared with those who had less than 1 h/day of sedentary time, those who had 3, 4 h/day sedentary time were at higher odds ratio (OR) of suicidal ideation OR=1.21 (95% confidence interval (CI) =1.14–1.29), planning OR=1.15 (95%CI=1.07–1.22) and attempts OR=1.17 (95%CI=1.09–1.26), and those who had more than 8 h/day sedentary time were at OR=1.58 (95%CI=1.44–1.72), OR=1.44 (95%CI=1.31–1.58) and OR=1.27 (95%CI=1.16–1.40), respectively. Limitations Suicidal behaviors and sedentary time were assessed by a self-reported questionnaire, which might be prone to recall bias. Conclusions Higher amounts of leisure sedentary time are associated with suicidal ideation, planning and attempts among adolescents. Adolescents should spend less than 2 h/day of their sedentary time to reduce the likelihood of suicide.

It is unclear whether physical activity and sedentary behavior are associated with economic development in low- and middle-income countries (LMICs). We aimed to assess the association between these two behaviors and country economic development among young adolescents in LMICs. Data came from the Global School-based Student Health Survey (GSHS) conducted between 2009 and 2016 in 68 LMICs. A total of 180,298 adolescents aged 12&ndash, 15 years were included, 15.3% of young adolescents achieved the recommended level for sufficient physical activity (&ge, 60 min/day of physical activity of any kind per week according to WHO) and 64.6% achieved a low sedentary behavior (&le, 2 h of sitting activities/day according to some guidelines, not accounting for sitting time at school or for doing homework). However, only 9.1% of young adolescents met the recommended levels of both behaviors. Comparing the lowest to the highest quintiles of a country&rsquo, s purchasing power parity per capita (PPP), mean values of both physical activity (boys: 2.55 to 2.96 days/week, girls: 2.10 to 2.31 days/week) and sedentary behavior(boys: 1.86 to 3.13 h/day, girls: 1.83 to 3.53 h/day) increased. The prevalence of having both recommended behaviors decreased among boys (12.0% to 10.0%) and girls (9.6% to 4.9%) (p &lt, 0.001). Although there might be an ecological fallacy, the findings emphasize the need for interventions to increase physical activity and reduce sedentary behavior among children and young adolescents.

Summary Background Tobacco use is a leading preventable cause of morbidity and mortality worldwide. Little is known about recent prevalence and trends in tobacco use among adolescents globally. We aimed to assess the recent global prevalence of tobacco use in young adolescents and the secular trends in prevalence between 1999 and 2018. Methods We used the most recent Global Youth Tobacco Surveys data on adolescents aged 13–15 years from 143 countries or territories that had done at least one survey between Jan 1, 2010, and Dec 31, 2018, to assess the recent prevalence of tobacco use; and data from 140 countries that had done two or more surveys between Jan 1, 1999, and Dec 31, 2018, to assess the trends in the prevalence of tobacco use. Findings 530 234 adolescents were included from the 143 countries that had done at least one survey between 2010 and 2018. 1 192 312 adolescents were included from the 140 countries that had done two or more surveys between 1999 and 2018. The most recent global prevalence of cigarette smoking was 11·3% (95% CI 10·3–12·3) in boys and 6·1% (5·6–6·6) in girls, based on cigarette smoking on at least 1 day during the past 30 days, 6·0% (5·5–6·6) and 2·6% (2·4–2·9) based on smoking on at least 3 days, and 4·2% (3·8–4·6) and 1·6% (1·4–1·8) based on smoking on at least 6 days. The most recent prevalence of the use of tobacco products other than cigarettes (eg, chewing tobacco, snuff, dip, cigars, cigarillos, pipe, electronic cigarettes) on at least 1 day during the past 30 days was 11·2% (9·9–12·6) in boys and 7·0% (6·4–7·7) in girls. The most recent prevalence of any tobacco use on at least 1 day during the past 30 days was 17·9% (16·1–19·6) in boys and 11·5% (10·5–12·4) in girls. The prevalence of cigarette smoking on at least 1 day during the past 30 days decreased between the first and last surveys in 80 (57·1%) of 140 countries, was unchanged in 39 countries (27·9%), and increased in 21 countries (15·0%). However, the prevalence of the use of tobacco products other than cigarettes was unchanged or increased in 81 (59·1%) of 137 countries. Interpretation The global prevalence of tobacco use among adolescents aged 13–15 years was substantial. Although the prevalence of cigarette smoking decreased over time in the majority of countries, the prevalence of the use of other tobacco products increased or did not change in the majority of countries during the past two decades. These findings re-emphasise the need to strengthen tobacco control efforts among young adolescents globally. Funding Shandong University.

Summary Background Alcohol use remains a major public health problem worldwide because of its harmful effects on physical and mental health. Few studies have used a standardised methodology to assess alcohol use among adolescents in low-income and middle-income countries (LMICs). In the present study, we aimed to compare the prevalence of alcohol use, drunkenness episodes, and drin king-related problems among young adolescents in LMICs. Methods For this population-based study, we used individual data from the Global School-based Student Health Surveys (GSHS) from between 2006 and 2013 in adolescents aged 12–15 years in LMICs. Data were collected using an anonymous self-reported questionnaire. This report is based on four questions assessing alcohol use, drunkenness episodes, alcohol-related drinking problems (ever had a hangover, felt sick, got into trouble with family or friends, missed school, or got into fights, as a result of drinking alcohol), and, in those who reported drinking, how alcohol was purchased. We calculated the overall and regional estimates using a meta-analysis with random-effects. Findings GSHS data from 57 countries, corresponding to a total of 139 649 young adolescents, were included in this study. The prevalence of the variables varied largely according to country and region. The overall prevalence of having at least one drink during the past 30 days was 25·0% (95% CI 19·3–30·7), and was higher among boys (27·5%, 21·9–33·2) than girls (22·5%, 18·8–26·2), and at age 14–15 years (29·0%, 23·1–34·8) than at age 12–13 years (18·9%, 15·3–22·5). The overall prevalence of having been drunk at least once during the lifetime was 17·9% (13·6–22·1); and was higher among boys (21·3%, 16·8–25·7) than girls (14·5%, 12·1–16·9), and at age 14–15 years (21·5%, 17·0–26·0) than at age 12–13 years (12·2%, 9·5–15·0). The overall prevalence of drinking-related problems was 10·6% (8·9–12·2), and was higher among boys (12·5%, 10·4–14·5) than girls (8·9%, 7·5–10·2), and at age 14–15 years (12·3%, 10·4–14·2) than at age 12–13 years (7·8%, 6·6–9·1). Among those reporting drinking, 27·8% (24·8–30·7) accessed alcohol from their friends, 23·2% (19·5–26·9) got it from family, 19·5% (17·5–21·6) bought it in a store, 9·1% (8·0–10·2) gave someone money to buy some, 2·8% (2·3–3·3) stole it, and 14·4% (12·2–16·5) got it by some other way. Interpretation Alcohol use, lifetime drunkenness, and alcohol-related problems were frequent among young adolescents in LMICs; however, with differences by country, region, sex, and age group. These findings emphasise the need for interventions to reduce alcohol use targeting young adolescents in LMICs with high prevalence of use and alcohol-related problems. Funding Shandong University.

Blood pressure-to-height ratio (BPHR) has been reported to perform well for identifying hypertension (HTN) in adolescents but not in young children. Our study was aimed to evaluate the performance of BPHR and modified BPHR (MBPHR) for screening HTN in children. A total of 5268 Chinese children (boys: 53.1%) aged 6–12 years and 5024 American children (boys: 48.1%) aged 8–12 years were included in the present study. BPHR was calculated as BP/height (mmHg/cm). MBPHR7 was calculated as BP/(height + 7*(13-age)). MBPHR3 was calculated as BP/(height + 3*(13-age)). We used receiver-operating characteristic curve analysis to assess the performance of the three ratios for identifying HTN in children as compared to the 2017 U.S. clinical guideline as the “gold standard”. The prevalence of HTN in Chinese and American children was 9.4% and 5.4%, respectively, based on the 2017 U.S. guideline. The AUC was larger for MBPHR3 than BPHR and MBPHR7. All three ratios had optimal negative predictive value (~100%). The positive predictive value (PPV) was higher for MBPHR3 than BPHR in both Chinese (43.9% vs. 37.9%) and American (39.1% vs. 26.3%) children. In contrast, the PPV was higher for MBPHR7 than BPHR in Chinese children (47.4% vs. 37.9%) but not in American children (24.8% vs. 26.3%). In summary, MBPHR3 overall performed better than MBPHR7 and BPHR for identifying HTN in children. However, the three ratios had low PPV (

Previous studies have revealed inconsistent findings regarding the association of light to moderate alcohol consumption with cardiovascular disease (CVD) and cancer mortality.The aim of this study was to examine the association between alcohol consumption and risk of mortality from all causes, cancer, and CVD in U.S. adults.Data were obtained by linking 13 waves of the National Health Interview Surveys (1997 to 2009) to the National Death Index records through December 31, 2011. A total of 333,247 participants ≥18 years of age were included. Self-reported alcohol consumption patterns were categorized into 6 groups: lifetime abstainers; lifetime infrequent drinkers; former drinkers; and current light, moderate, or heavy drinkers. Secondary exposure included participants' binge-drinking status. The main outcome was all-cause, cancer, or CVD mortality.After a median follow-up of 8.2 years (2.7 million person-years), 34,754 participants died of all causes (including 8,947 CVD deaths and 8,427 cancer deaths). Compared with lifetime abstainers, those who were light or moderate alcohol consumers were at a reduced risk of mortality for all causes (light-hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.76 to 0.82; moderate-HR: 0.78; 95% CI: 0.74 to 0.82) and CVD (light-HR: 0.74; 95% CI: 0.69 to 0.80; moderate-HR: 0.71; 95% CI: 0.64 to 0.78), respectively. In contrast, there was a significantly increased risk of mortality for all causes (HR: 1.11; 95% CI: 1.04 to 1.19) and cancer (HR: 1.27; 95% CI: 1.13 to 1.42) in adults with heavy alcohol consumption. Binge drinking ≥1 d/week was also associated with an increased risk of mortality for all causes (HR: 1.13; 95% CI: 1.04 to 1.23) and cancer (HR: 1.22; 95% CI: 1.05 to 1.41).Light and moderate alcohol intake might have a protective effect on all-cause and CVD-specific mortality in U.S. adults. Heavy or binge drinking was associated with increased risk of all-cause and cancer-specific mortality.

Objectives. To compare consumption of carbonated soft drinks among young adolescents in 53 low- and middle-income countries (LMICs). Methods. We used 2009 to 2013 Global School-based Student Health Survey data to assess 137 449 young adolescents aged 12 to 15 years with available data (via a standardized questionnaire) on frequency of carbonated soft drink consumption. Results. Overall, young adolescents reported having consumed carbonated soft drinks 1.39 times per day (95% confidence interval [CI] = 1.26, 1.51), and 54.3% of adolescents reported consuming a carbonated soft drink at least once per day. Frequency (times per day) varied greatly across countries, ranging from 0.52 (95% CI = 0.43, 0.60) in Kiribati to 2.39 (95% CI = 2.25, 2.53) in Suriname. Conclusions. Our data confirm that consumption of carbonated soft drinks is frequent among young adolescents in LMICs. Our findings highlight the need for interventions in these countries to reduce adolescents’ carbonated soft drink consumption.

The US Fourth Report (2004) recommended that elevated blood pressure (BP) on at least three occasions should be used to define hypertension in children and adolescents. However, there is no sufficient evidence to support this decision. This study aimed to assess the change in the prevalence of elevated BP obtained on three separate visits in children and adolescents worldwide using a meta-analysis. The PubMed database was searched for eligible studies published in English until 20 April 2016. Included studies were population based and reported on the prevalence of elevated BP measured on two or three separate occasions in pediatric populations. A meta-analysis was performed to calculate a summary prevalence of elevated BP over three different visits. A total of 21 studies with 179 561 participants aged 3-20 years were included in the present meta-analysis. The summary prevalence of elevated BP decreased across visits, from 12.1% (95% confidence interval (CI)=10.1-14.0%) during the first visit to 5.6% (95% CI=4.3-7.0%) during the second visit and to 2.7% (95% CI=2.1-3.3%) during the third visit. These findings were independent of sex, age group, ethnicity/race and the definition of elevated BP. When compared with visit 1, the prevalence of elevated BP decreased by 53.7% during visit 2 and by 77.7% during visit 3. Our study suggested that the prevalence of elevated BP decreased substantially from the first visit to the subsequent visits. Worldwide, the true prevalence of hypertension in children and adolescents is ~3% over three different visits.

The aim of this study was to assess the performance of the blood pressure-to-height ratio (BPHR) for screening elevated blood pressure (BP) in children and adolescents using a meta-analysis of eligible published studies. We retrieved studies that investigated the performance of the BPHR for identifying elevated BP from Pubmed and other databases. We performed meta-analyses by subgroups of sex, age and ethnicity using a fixed or random effect model based on whether there was between-study heterogeneity. A total of 13 publications including 262 830 children and adolescents aged 6-18 years on BPHR and a total of three publications including 95 343 children on the modified BPHR were included in this meta-analysis. The summary results suggested that BPHR performed well to identify pre-high BP and high BP for children aged 6-11 years and adolescents aged 12-18 years. The performance of BPHR was perfect for identifying severe high BP in adolescents aged 12-18 years. However, the modified BPHR did not improve accuracy for screening high BP in children aged 6-12 years. In summary, BPHR performed well for identifying elevated BP in children and adolescents, independently of sex, age and ethnicity group. In addition, the modified BPHR performed similarly with BPHR for screening high BP in childhood.

This study aims to compare the performance of body mass index (BMI), waist circumference (WC), and waist-to-height-ratio (WHtR) to predict the presence of at least 3 main CV risk factors in US adolescents. A total of 3621 adolescents (boys: 49.9%) aged 12–17 years from the US National Health and Nutrition Examination Survey (1999–2012) were included in this study. Measured CV risk factors included systolic/diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and fasting plasma glucose. The AUC of BMI-z score, WC-z score and WHtR-z score to predict at least three CV risk factors were similar (~0.85), irrespective of criteria used to define abnormal levels of CV risk factors. A 1-SD increase in any of three indices to predict CV risk was also similar for the three adiposity scores. For instance, a 1-SD increase risk in BMI-z score, WC-z score and WHtR-z score was 3.32 (95%CI 2.53–4.36), 3.43 (95%CI 2.64–4.46), and 3.45 (95%CI 2.64–4.52), respectively, in the total population using the International Diabetes Federation definition. In addition, the most efficient WHtR cut-off for screening CV risk was ~0.50 in US adolescents. In summary, BMI, WC and WHtR performed similarly well to predict the presence of at least 3 main CV risk factors among US adolescents.

Summary Background Tobacco use is an important risk factor for non-communicable diseases worldwide. However, the global extent and prevalence of tobacco use in adolescents is poorly described. Using previously collected survey data, we aimed to assess tobacco use and second-hand smoke exposure in young adolescents aged 12–15 years in 68 low-income and middle-income countries. Methods We used data from the Global School-based Student Health Survey (2006–13) and the China Global Tobacco Youth Survey (2013), which are school-based surveys of young adolescents aged 12–15 years that assess health behaviours using a standardised, anonymous, self-reported questionnaire. We calculated the prevalence of current tobacco use and exposure to second-hand smoke in young adolescents from 68 low-income and middle-income countries that collected these data in the surveys. We used a multilevel model to estimate the association between parental tobacco use, second-hand smoke, and adolescent tobacco use, adjusting for sex, age, school, school class, country's purchasing power parity, smoking initiation age, national prevalence of tobacco use among adults, year the WHO FCTC was ratified for each country, proxy of socioeconomic status, and survey year. Findings The mean prevalence of current tobacco use was 13·6%, ranging from 2·8% in Tajikistan to 44·7% in Samoa. In most countries, the prevalence of tobacco use was higher for boys than girls, and higher for adolescents aged 14–15 years than for those aged 12–13 years. The overall prevalence of second-hand smoke exposure was 55·9%, ranging from 16·4% in Tajikistan to 85·4% in Indonesia. Parental tobacco use (as reported by the young adolescents), especially maternal use, was associated with tobacco use in young adolescents (odds ratio 2·06, 95% CI 1·93–2·19, for maternal and 1·29, 1·23–1·35 for paternal use). Second-hand smoke exposure was also a risk factor for young adolescents' tobacco use (2·56, 2·43–2·69). However, the prevalence of tobacco use was not associated with a country's purchasing power parity. Interpretation Tobacco use and second-hand smoke exposure were frequent among young adolescents aged 12–15 years in low-income and middle-income countries. Parental tobacco use and second-hand smoke exposure were strongly associated with young adolescents' tobacco use. The data emphasise the need to strengthen tobacco control interventions and programmes in young adolescents from low-income and middle-income countries. Funding This work was partly supported by the Young Scholars Program of Shandong University (2015WLJH51), the Shandong Provincial Natural Science Foundation (ZR2012HQ033), and the National Natural Science Foundation (81302496).

Objective China is the largest producer of tobacco worldwide. We assessed secular trends in prevalence of smoking, average cigarettes per day, mean age of initiation, and mortality attributable to smoking among the Chinese population between 1991 and 2011. Design Data came from the China Health and Nutrition Survey, conducted eight times between 1991 and 2011. A total of 83,447 participants aged 15 years or older were included in this study. Trends in smoking were stratified by sex, age, and region (urban vs. rural). Results In 2011, 311 millions individuals were current smokers in China, with 295 million men and 16 million women, respectively. Between 1991 and 2011, the prevalence of current smoking decreased from 60.6% to 51.6% in men, and from 4.0% to 2.9% in women. However, during this period, the average number of cigarettes smoked per day per smoker increased from 15.0 to 16.5 in males, and from 8.5 to 12.4 in females. Further, age of smoking initiation decreased from 21.9 to 21.4 years in men and from 31.4 to 28.4 years in women. In 2011, 16.5% of all deaths in men and 1.7% in women were due to smoking. Between 1991 and 2011, the total number of deaths caused by smoking increased from 800,000 to 900,000. Conclusions During the past 20 years, a slight decrease in smoking prevalence was observed in the Chinese population. However, cigarette smoking remains a major cause of death in China, especially in men.

The identification of elevated blood pressure (BP) in children and adolescents relies on complex percentile tables. The present study compares the performance of 11 simplified methods for assessing elevated or high BP in children and adolescents using individual-level data from 7 countries. Data on BP were available for a total of 58 899 children and adolescents aged 6 to 17 years from 7 national surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. Performance of the simplified methods for screening elevated or high BP was assessed with receiver operating characteristic curve (area under the curve), sensitivity, specificity, positive predictive value, and negative predictive value. When pooling individual data from the 7 countries, all 11 simplified methods performed well in screening high BP, with high area under the curve values (0.84–0.98), high sensitivity (0.69–1.00), high specificity (0.87–1.00), and high negative predictive values (≥0.98). However, positive predictive value was low for most simplified methods, but reached ≈0.90 for each of the 3 methods, including sex- and age-specific BP references (at the 95th percentile of height), the formula for BP references (at the 95th percentile of height), and the simplified method relying on a child’s absolute height. These findings were found independently of sex, age, and geographical location. Similar results were found for simplified methods for screening elevated BP. In conclusion, all 11 simplified methods performed well for identifying high or elevated BP in children and adolescents, but 3 methods performed best and may be most useful for screening purposes.