Associations of central precocious puberty with blood pressure trajectories: prospective cohort study.

BACKGROUND: Sex differences in blood pressure (BP) appear during childhood and adolescence, but the role of central precocious puberty (CPP) remains unclear. In this study, we aimed to examine the association of CPP with the risk of early hypertension and BP trajectories in girls and boys. METHODS: We analyzed trajectories of BP before and after puberty in girls aged 6-13 years (n = 305) and boys aged 10-15 years (n = 153) in the Taiwan Pubertal Longitudinal Study. The timing of puberty onset was defined as the month at which the children reached Tanner stage 2. We examined the association of CPP with the risk of early hypertension and BP trajectories before and after puberty onset. RESULTS: Among boys, CPP was found to be associated with early hypertension (odds ratio, 7.45 [95% CI, 1.15-48.06]), whereas no such association was observed among girls. Boys with CPP had higher systolic BP than did those with normal puberty onset before puberty onset (mean difference, 6.51 [95% CI, 0.58-12.43]) and after puberty onset (mean difference, 8.92 [95% CI, 8.58-15.26]). CONCLUSION: A large proportion of the higher systolic BP observed in boys with CPP compared with in those with normal puberty onset is accrued after puberty. IMPACT: We examined the sex-specific association of central precocious puberty with blood pressure trajectories to better understand whether central precocious puberty was associated with early hypertension. Central precocious puberty was associated with differences in systolic blood pressure trajectories, especially after puberty onset in boys. For boys only, central precocious puberty was associated with early hypertension. A large proportion of the higher systolic blood pressure observed in boys with central precocious puberty compared with in those with normal puberty onset was accrued after puberty. Interventions targeting central precocious puberty are likely to influence systolic blood pressure in early adulthood.

Comparative efficacy of digitally assisted interventions for glycated haemoglobin levels among patients with type 2 diabetes: A systematic review and component network Meta-Analysis.

AIMS: To compare the efficacy of digitally assisted interventions on the glycated haemoglobin (HbA1c) levels of patients with type 2 diabetes by performing a systematic review, network meta-analysis and component network meta-analysis. METHODS: Six databases were searched to identify eligible articles from the inception of each database until 17 March 2023. We included randomized controlled trials evaluating HbA1c levels. Data were pooled with a random-effects model under a frequentist framework. The evidence certainty was assessed using Confidence in Network MetaAnalysis (CINeMA). The PROSPERO registration number was CRD42021283815. RESULTS: In total, 75 trials involving 9764 participants were included. Results from standard network meta-analyses of 17 interventions revealed that compared with standard care, a mobile application (MA) combined with a professional education programme and peer support education (PSE; -1.98, 95% confidence interval = -2.90 to -1.06, CINeMA score: moderate to high) significantly reduced HbA1c levels. The component analysis found that PSE (-1.50, -2.36 to -0.64), SMS (-0.33, -0.56 to -0.11), MA (-0.30, -0.56 to -0.04) and telephone calls (-0.30, -0.53 to -0.06) most effectively reduced HbA1c levels among patients with type 2 diabetes. CONCLUSIONS: SMS and MA are the optimal digitally assisted interventions for reducing HbA1c levels. Educators can integrate digitally assisted interventions complemented by educational programmes, particularly MA combined with professional education programme and PSE, into daily care to control HbA1c. The limitations of included trials include a lack of information on allocation concealment and blinding and the fact that long-term follow-up effects were not investigated.

Predictors of time to relapse following ustekinumab withdrawal in patients with psoriasis who had responded to therapy: An 8-year multicenter study.

BACKGROUND: Data on predictors and time to relapse in patients with psoriasis who discontinue therapy in a real-world setting are scarce. OBJECTIVE: To investigate predictors of relapse after withdrawal of ustekinumab in patients with psoriasis. METHOD: This study screened 500 patients with psoriasis who received ustekinumab (669 treatment episodes) between 2011 and 2018. Overall, 202 patients (accounting for 304 treatment episodes) who had responded to therapy and were withdrawn from ustekinumab treatment were included. RESULTS: The cumulative probabilities of being relapse-free at 6, 12, 18, 24, and 36 months after withdrawal from ustekinumab treatment were 49.3%, 12.6%, 5.3%, 4.7%, and 1.6%, respectively. Multivariate regression analyses with a generalized estimating equation showed that after adjustments, biologic-naive status, maximum improvement in Psoriasis Area and Severity Index during ustekinumab treatment, time to achieve a 50% improvement in baseline Psoriasis Area and Severity Index score after initiation of ustekinumab, family history of psoriasis, chronic kidney disease, and immunosuppressant use while not taking ustekinumab were significant predictors of time to relapse following discontinuation of ustekinumab. LIMITATION: Nonrandomized allocation of duration of treatment and follow-up. CONCLUSION: Given the high rates of relapse, withdrawal of ustekinumab from patients with well-controlled psoriasis cannot be recommended.

Effects of Testosterone Replacement Therapy on Muscle Strength in Older Men with Low to Low-Normal Testosterone Levels: A Systematic Review and Meta-Analysis.

BACKGROUND: Previous studies and meta-analyses have explored the relationship among testosterone, muscle strength, and physical function, to the best of our knowledge, no meta-analysis has investigated the effects of testosterone replacement therapy (TRT) on subgroup of relatively hypogonadal older men. OBJECTIVE: The aim of this study was to evaluate the effect of TRT in older men with low testosterone levels. METHODS: PubMed, Embase, and Web of Science were systematically searched for articles published between January 1990 and April 2020. We included randomized controlled studies that investigated the effect of TRT and included older men (age >60 years) with relatively low testosterone levels. Studies were extracted following the PRISMA flowchart, and the included randomized controlled trials were evaluated using RoB 2.0. Our main outcome was muscle strength changes after TRT evaluated using a metaregression of confounding factors. Secondary outcomes included changes in physical performance and the risk ratio of adverse events. Random-effects meta-analyses of TRT on muscle strength and physical function were performed. RESULTS: Thirteen studies with 2,043 patients were included. The mean age of subjects in various studies ranged from 65.9 years to 76 years. Transdermal testosterone dosages ranged from 5 to 10 g/day, while intramuscular options were 125 mg/week or 200 mg every 2 weeks. Oral testosterone supplementation was given at 160 mg/day in one study. Pooled meta-analyses revealed greater muscle strength improvement after TRT compared with placebo (Hedges' g = 0.21; 95% CI: = 0.15-0.28). Intramuscular administration of TRT had greater efficacy (Hedges' g = 0.74; 95% CI: = 0.34-1.14) than transdermal and oral TRT (p < 0.001). A metaregression revealed that baseline serum total testosterone was associated with muscle strength improvement (ß = -0.004, p = 0.002). The risk ratios of adverse events, including elevated prostate-specific antigen, acute coronary syndrome, and prostate cancer, were not significantly different. CONCLUSION: TRT improved muscle strength in older, relatively hypogonadal men. The effect was more pronounced in populations with lower baseline testosterone levels.

Investigating obesity-related risk factors for childhood asthma.

BACKGROUND: We tested the hypothesis that multiple obesity-related risk factors (obesity, physical activity, cardiopulmonary physical fitness, sleep-disorder breathing (SDB), and sleep quality) are associated with childhood asthma using a Mendelian randomization (MR) design. Furthermore, we aim to investigate whether these risk factors were associated with incident asthma prospectively. METHODS: In total, 7069 children aged 12 from the Taiwan Children Health Study were enrolled in the current study. Cross-sectional logistic regression, one-sample MR, summary-level MR sensitivity analyses, and prospective survival analyses were used to investigate each causal pathway. RESULTS: In MR analysis, three of the five risk factors (obesity, SDB, and sleep quality) were associated with asthma, with the highest effect sizes per inter-quartile range (IQR) increase observed for sleep quality (odds ratio [OR] = 1.42; 95% confidence interval [CI]: 1.06 to 1.92) and the lowest for obesity (OR = 1.08; 95% CI: 1.00-1.16). In the prospective survival analysis, obesity showed the highest risk of incident asthma per IQR increase (hazard ratio [HR] = 1.28; 95% CI: 1.05 to 1.56), followed by SDB (HR = 1.18; 95% CI: 1.08 to 1.29) and sleep quality (HR = 1.10; 95% CI: 1.03 to 1.17). CONCLUSION: Among the examined factors, the most plausible risk factors for asthma were obesity, SDB, and poor sleep quality. For the prevention of childhood asthma, relevant stakeholders should prioritize improving children's sleep quality and preventing obesity comorbidities such as SDB.

Mediators linking obesity to childhood asthma.

BACKGROUND: Obesity and asthma are highly associated, but the mechanisms underlying the association remain unknown. We examined five mediators linking obesity with childhood asthma: (1) pulmonary function impairment, (2) airway inflammation, (3) physical fitness, (4) sleep-disordered breathing (SDB), and (5) early puberty. METHODS: A Mendelian randomization (MR) study with mediation analysis of data obtained from 5965 children as part of the Taiwan Children Health Study. Observational analysis, MR two-stage least-squares method, and MR sensitivity analysis were carried out to investigate each causal pathway. Prospective cohort analyses were used to strengthen the findings. RESULTS: The increased asthma risk associated with obesity was found to be mostly mediated through impaired pulmonary function, low physical fitness, and early puberty. In the MR analysis, body mass index was negatively associated with FEV1/FVC and physical fitness index (ß = -2.17 and -0.71; 95% CI, -3.92 to -0.42 and -1.30 to -0.13, respectively) and positively associated with early puberty (OR, 1.09; 95% CI, 1.02-1.17). High FEV1/FVC and physical fitness index reduced asthma risk (OR, 0.98 and 0.93; 95% CI, 0.97-0.99 and 0.88-0.98, respectively), whereas SDB and early puberty increased the risk of asthma (OR, 1.03 and 1.22; 95% CI, 1.01-1.05 and 1.05-1.42, respectively). Temporal causality was strengthened in prospective cohort analyses. The three main mediators were low physical fitness, impaired pulmonary function, and early puberty, with mediation proportions of 73.76%, 61.63%, and 27.66%, respectively. CONCLUSIONS: Interventions promoting physical fitness and pulmonary function might effectively reduce obesity-induced asthma risk.

Development and Validation of the Chinese Version Non-Nutritive Sweetener Food Frequency Questionnaire with Urinary Biomarker in Children and Adolescents.

OBJECTIVE: The purpose of this study was to develop a validated food frequency questionnaire (FFQ) to evaluate the intake of non-nutritive sweeteners (NNSs) in child and adolescent Asian populations. DESIGN: Intensive and overall market research was performed to create the applicable NNS-FFQ with 13 food categories and 305 items. Six intense sweeteners, including acesulfame potassium, aspartame, sucralose, glycyrrhizin, steviol glycosides and sorbitol, were investigated. The validity and reproducibility of the NNS-FFQ were evaluated. The validity was further assessed by examining the consistency of reported NNS intake compared with urinary biomarkers using Cohen's κ analysis. SETTINGS: This work was considered to be relevant in Asian societies. PARTICIPANTS: One hundred and two children and adolescents recruited from several clinics were invited to participate in this study. RESULTS: High content validity indices and high content validity ratio levels were revealed for each sweetener and food category. Reproducibility among subjects was satisfactory. Significant moderate correlations between estimated steviol glycoside/sucralose consumption and sensitive urinary biomarker levels were demonstrated (κ values were 0.59 and 0.45 for steviol glycosides and sucralose, respectively), indicating that the NNS-FFQ can be used to assess an individual's NNS intake. The dietary intense sweetener consumption pattern evaluated in this measurement was similar to those observed in other Asian countries but differed from those observed in Western populations with respect to types and amounts of NNSs. CONCLUSIONS: This validated NNS-FFQ can be an applicable and useful tool to evaluate NNS intake in future epidemiological and clinical studies.

Aspartame Consumption, Mitochondrial Disorder-Induced Impaired Ovarian Function, and Infertility Risk.

Frequent consumption of diet drinks was associated with oocyte dysmorphism, decreased embryo quality, and an adverse effect on pregnancy rate. We investigated the harmful effects of aspartame and potential mechanisms through which it increases infertility risk through clinical observations and in vivo and in vitro studies. Methods: We established a cohort of 840 pregnant women and retrospectively determined their time to conceive. We assessed the estrus cycle, the anti-Mullerian hormone level, ovarian oxidative stress, and ovarian mitochondrial function in an animal study. We also evaluated mitochondria function, mitochondrial biogenesis, and progesterone release with in vitro studies. Aspartame consumption was associated with increased infertility risk in the younger women (Odds ratio: 1.79, 95% confidence interval: 1.00, 3.22). The results of the in vivo study revealed that aspartame disrupted the estrus cycle and reduced the anti-Mullerian hormone level. Aspartame treatment also suppressed antioxidative activities and resulted in higher oxidative stress in the ovaries and granulosa cells. This phenomenon is caused by an aspartame-induced decline in mitochondrial function (maximal respiration, spare respiratory capacity, and ATP production capacity) and triggered mitochondrial biogenesis (assessed by examining the energy depletion signaling-related factors sirtuin-1, phosphorylated adenosine monophosphate-activated protein kinase, peroxisome proliferator-activated receptor-gamma coactivator-1α, and nuclear respiratory factor 1 expression levels). Aspartame may alter fertility by reserving fewer follicles in the ovary and disrupting steroidogenesis in granulosa cells. Hence, women preparing for pregnancy are suggested to reduce aspartame consumption and avoid oxidative stressors of the ovaries.

Early pubertal maturation and risk of childhood asthma: A Mendelian randomization and longitudinal study.

BACKGROUND: Studies on early puberty and incident asthma have reported inconsistent results and are mainly performed in females. In this longitudinal study, we investigated the causal relationship between pubertal maturation and asthma through Mendelian randomization (MR) and explored the joint effect of overweightness and early pubertal maturation on asthma. METHODS: We used data from the Taiwan Children Health Study with longitudinal follow-ups of 2991 children aged 11-17 years. Six puberty-related single-nucleotide polymorphisms (combined into a weighted allelic score) were used to yield genetic instrumental variables for early puberty. Early pubertal maturation was defined as reaching a certain pubertal stage earlier than the median age for that stage. Incident asthma cases were calculated by excluding children with a history of asthma prior to that age. RESULTS: The results of MR analysis revealed that early pubertal maturation was associated with active asthma (OR = 1.18; 95% CI: 1.08-1.28); this effect was significant in male children. Early pubertal maturation significantly increased the risk of incident asthma outcomes at 12 and 17 years of age in both sexes (hazard ratio = 2.15; 95% CI: 1.21-3.84). Taking non-overweight and non-early puberty children as the reference group, we observed a synergistic effect of overweightness and early pubertal maturation on asthma risk (OR = 1.08; 95% CI: 1.04-1.11) in children of both sexes. CONCLUSIONS: Early screening and intervention for obesity are recommended to prevent future early pubertal onset and asthma occurrence.

Body mass index growth trajectories, early pubertal maturation, and short stature.

BACKGROUND: Childhood body mass index (BMI) trajectory classes are rarely linked to early puberty risk, particularly among Chinese children. We estimated early puberty risk across BMI trajectory classes, investigated factors contributing to pubertal development, and examined differences in final adult height between children exhibiting early and nonearly pubertal maturation across the classes. METHODS: The Taiwan Children Health Study recruited 10-year-old children in 2010 from 14 Taiwanese communities and resurveyed them at age 11, 12, and 18 years. The study comprised 3109 children (50.4% boys) with available data for BMI (age 6-11 years) and pubertal stages (age 11, 12, and 18 years). RESULTS: Classes 1-4 were persistently healthy weight, rapid BMI growth, chronically overweight/obese, and early transient overweight/obese. Children in class 3 exhibited the highest risk of early pubertal maturation. Puberty genetic score, low sleep quality, and high fat-free mass collectively explained 15% of the variance in Tanner stages among class 3 children. Early pubertal maturation was considered to cause short and tall stature in boys and girls, respectively. CONCLUSIONS: Modifying sleep quality and fat-free mass may reduce early puberty risk in children with chronic overweight/obesity. Vigorous physical activity may reduce adiposity and increase the final adult height in the children.

Causal relationships between adiposity and childhood asthma: bi-directional Mendelian Randomization analysis.

BACKGROUND/OBJECTIVES: Obesity and asthma are common chronic diseases and have been reported to be mutually causative. We investigated the causal direction of the relationship between adiposity and asthma using genetic markers as instrumental variables (IVs) in bi-directional Mendelian randomization (MR) analysis. SUBJECTS/METHODS: We used data from the Taiwan Children Health Study with 24 body mass index (BMI)-single-nucleotide polymorphisms (SNPs, combined into a weighted allelic score) and 16 asthma-SNPs (combined into two weighted allelic scores, separately for asthma inflammatory and antioxidative genes) to yield genetic IVs for adiposity and asthma, respectively. RESULTS: The weighted allele score for BMI was strongly associated with adiposity (p = 2 × 10-16) and active asthma (p = 0.03). The two-stage least square regression risk ratio (RR) for the effect of BMI on asthma was 1.04 (95% confidence interval: 1.00-1.07, p = 0.03). Although the weighted asthma genetic scores were significantly associated with asthma (p = 8.4 × 10-3), no association was seen for genetically instrumented asthma with BMI using MR. Central obesity was the most accurate predictor of asthma. Adiposity showed higher causal effects on asthma in boys and children with non-atopic asthma. Sensitivity analysis for MR revealed no directional genetic pleiotropy effects. The causal effect RRs of BMI on asthma were 1.04, 1.08, and 1.03 for inverse-variance weighted, MR-Egger regression (slope), and weighted median methods, respectively, all in accordance with the MR estimates. CONCLUSIONS: High adiposity may lead to asthma, whereas the effects of asthma on adiposity accumulation are likely to be small.

Growth trajectories and asthma/rhinitis in children: a longitudinal study in Taiwan.

Studies have reported the effect of body weight in early childhood on asthma. However, the effect of growth patterns during school age on asthma and rhinitis has yet to be explored. We sought to investigate whether various growth patterns predict incident asthma and rhinitis.We conducted a nationwide longitudinal study (Taiwan Children Health Study) in 14 Taiwanese communities. Body mass index (BMI) z-scores of 4422 children aged 6-11 years were collected annually and distinct growth trajectory classes were identified using a latent generalised mixture model. Pulmonary function and exhaled nitric oxide fraction (FeNO) levels were also measured. Whether different growth trajectory classes predict incident asthma and rhinitis at age 12, 15 and 18 years was determined using a discrete time hazard model.Four growth trajectory classes were identified. Persistently overweight children exhibited significantly increased risks of asthma and rhinitis at age 12 years. Furthermore, being persistently overweight had a long-term effect on incident asthma (hazard ratio 2.47, 95% CI 1.18-5.12) and rhinitis (hazard ratio 1.44, 95% CI 1.12-1.84) in adolescence and early adulthood. Children in high BMI classes exhibited significantly lower pulmonary functions compared with normal growth children. FeNO levels were lower in children in the high BMI classes and higher in children showing declining obesity compared with normal growth children.Persistently overweight children exhibited incident asthma and rhinitis in adolescence and early adulthood.

Determinants of Receiving Palliative Care and Ventilator Withdrawal Among Patients With Prolonged Mechanical Ventilation.

OBJECTIVES: Increasing numbers of patients with prolonged mechanical ventilation generates a tremendous strain on healthcare systems. Patients with prolonged mechanical ventilation suffer from long-term poor quality of life. However, no study has ever explored the willingness to receive palliative care or terminal withdrawal and the factors influencing willingness. DESIGN: Cross-sectional study. SETTING: Five different hospitals of Taipei City Hospital system. PATIENTS: Adult patients with ventilatory support for more than 60 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We identified the family members of 145 consecutive patients with prolonged mechanical ventilation in five hospitals of Taipei City Hospital system and enrolled family members for 106 patients (73.1%). We collected information from patient families' regarding concepts (knowledge, attitude, and experiences) of palliative care, caregiver burden, family function, patient quality of life, and physician-family communications. From the medical record, we obtained duration of hospitalization, consciousness level, disease severity, medical cost, and the presence of do-not-resuscitate orders. The vast majority of family members agreed with the concept of palliative care (90.4%) with 17.3% of the family members agreeing to ventilator withdrawal currently and 67.5% terminally in anticipation of death. Approximately half of the family members regretted having chosen prolonged mechanical ventilation (56.7%). Reduced patient quality of life and increased family understanding of palliative care significantly associated with increased caregiver willingness to endorse palliative care and withdraw life-sustaining agents in anticipation of death. Longer duration of ventilator usage and hospitalization was associated with increased feelings of regret about choosing prolonged mechanical ventilation. CONCLUSIONS: During prolonged mechanical ventilation, physicians should thoroughly discuss its benefits and burdens. Families should be given the opportunity to discuss the circumstances under which they might request the implementation of palliative care or withdrawal of mechanical ventilation in order to avoid prolonging the dying process.

Mediating pathways from central obesity to childhood asthma: a population-based longitudinal study.

The mediating pathways linking obesity and asthma are largely unknown. We aimed to investigate the mediating pathways and to search for the most prominent pathological mechanism between central obesity and childhood asthma.In the Taiwan Children Health Study, we collected data on an open cohort of children aged 9-13 years. Children's respiratory outcomes, atopic conditions, obesity measures and pulmonary function were surveyed annually between 2010 and 2012. Exhaled nitric oxide fraction concentrations were recorded in 2012. Generalised estimating equations and general linear models were used to examine the associations between central obesity, possible mediators and asthma. Structural equation models were applied to investigate the pathways that mediate the link between central obesity and asthma.Central obesity (waist-to-hip ratio) most accurately predicted childhood asthma. In the active asthma model, the percentage of mediation was 28.6% for pulmonary function, 18.1% for atopy and 5.7% for airway inflammation. The percentage of mediation for pulmonary function was 40.2% in the lifetime wheeze model. Pulmonary function was responsible for the greatest percentage of mediation among the three mediators in both models.Decline in pulmonary function is the most important pathway in central obesity related asthma. Pulmonary function screening should be applied to obese children for asthma risk prediction.

Associations between allergic diseases and attention deficit hyperactivity/oppositional defiant disorders in children.

BACKGROUND: We aim to investigate the detailed associations between allergic diseases with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) among children. METHODS: Clinical information from 2,896 children enrolled in the Taiwan Children Health Study was obtained for analyses. Allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis, have been evaluated based on the questions adjusted from International Study of Asthma and Allergies in Childhood. The Swanson, Nolan, and Pelham questionnaire was used to assess symptoms of ADHD and ODD. Symptoms of depression, stress, and poor sleep quality were evaluated as the interactive risk factors. RESULTS: Children having symptoms of allergic diseases within the past 1 y were associated with having all dimensions of symptoms of ADHD and ODD. Children with ever having a physician-diagnosed atopic dermatitis were associated with inattentive and hyperactive-impulsive symptoms of ADHD. Ever diagnosed asthma was associated with ADHD and ODD. Ever diagnosed allergic rhinitis was associated with inattentive and combined symptoms of ADHD and ODD. CONCLUSION: Children with allergic diseases, such as atopic dermatitis, asthma, and allergic rhinitis, were associated with exhibiting ADHD and ODD.

Associations between Respiratory Diseases and Dietary Patterns Derived by Factor Analysis and Reduced Rank Regression.

BACKGROUND/AIMS: The study aims to identify children's dietary patterns and explore the relationship between dietary patterns and respiratory diseases. METHODS: Subjects were 2,397 fourth graders in 14 Taiwanese communities who participated in the Taiwan Children Health Study. This study is based on an evaluation of dietary patterns, performed from April until June 2011. Information pertaining to respiratory disease was obtained by The International Study of Asthma and Allergies in Childhood questionnaire, and dietary intake data obtained by food frequency questionnaire. Factor analysis and reduced rank regression (RRR) were both used to analyze dietary patterns. RESULTS: Using factor analysis, it was found that children on a high-protein, high-fat, Western diet had a significantly higher risk of allergic rhinitis (OR 1.10, 95% CI 1.01-1.20). Lower ORs were noted for current wheezing, ever asthma and bronchitis in children eating a healthy diet than those on a high-protein, high-fat, Western diet. Using RRR, it was found that children on a high-protein, high-fat diet had significantly higher risks of allergic rhinitis (OR 1.17, 95% CI 1.07-1.27), current wheezing (OR 1.23, 95% CI 1.04-1.45) and bronchitis (OR 1.26, 95% CI 1.09-1.46). CONCLUSIONS: A diet rich in fat and protein may increase the risk of respiratory disease in children.

Pathway from central obesity to childhood asthma. Physical fitness and sedentary time are leading factors.

RATIONALE: Available prospective studies of obesity and asthma have used only body mass index (BMI) as an indicator for adiposity; studies using detailed obesity measures are lacking, and the role of physical fitness level and sedentary time remains unexplored in the link between obesity and asthma. OBJECTIVES: To compare various anthropometric measures of obesity in relation to childhood asthma, and to further characterize the interrelations among central obesity, physical fitness level, sedentary time, and asthma. METHODS: The nationwide Taiwan Children Health Study followed 2,758 schoolchildren from fourth to sixth grade, annually collecting data regarding physical fitness, sedentary time, obesity measures (comprising body weight and height, abdominal and hip circumference, skin fold thickness, and body composition), asthma, and pulmonary function tests. The generalized estimating equation was used for 3 years of repeated measurements to analyze the interrelation among obesity, sedentary time, physical fitness level, and asthma; a structural equation model was used to explore the pathogenesis among these factors. Asthma incidence was analyzed during a 2-year follow-up among centrally obese and nonobese groups in baseline children without asthma. MEASUREMENTS AND MAIN RESULTS: Central obesity most accurately predicts asthma. Low physical fitness levels and high screen time increase the risk of central obesity, which leads to asthma development. Obesity-related reduction in pulmonary function is a possible mechanism in the pathway from central obesity to asthma. CONCLUSIONS: Central obesity measures should be incorporated in childhood asthma risk predictions. Children are encouraged to increase their physical fitness levels and reduce their sedentary time to prevent central obesity-related asthma.

Active smoking, environmental tobacco smoke and bronchitic symptoms among adolescents in Taiwan: a prospective cohort study.

OBJECTIVE: The study investigates the association between active smoking, exposure to environmental tobacco smoke (ETS) and the development of bronchitis and bronchitic symptoms among adolescents. METHODS: A prospective cohort study was conducted with 4134 adolescents aged 12-14 from the Taiwan Children Health Study in 14 communities in Taiwan since 2007. Parents or guardians completed written questionnaires regarding demographic information, household ETS and respiratory symptoms at baseline. The adolescents themselves completed identical questionnaires on respiratory outcomes in the 2009 survey. Associations between active smoking, exposure to ETS and the 2-year incidence of respiratory outcomes were analyzed by multiple Poisson regression models, taking overdispersion into account. RESULTS: Active smoking was associated with an increased risk of developing chronic cough and chronic phlegm. We found significant dose-response associations between the duration of smoking, the numbers of cigarettes and the onset of bronchitic symptoms. Exposure to ETS was a significant risk factor for the development of chronic cough. Among asthmatic adolescents, exposure to ETS was associated with an additional risk for the onset of chronic phlegm. CONCLUSION: This study demonstrates that active smoking and exposure to ETS are associated with higher risks for developing bronchitic symptoms among adolescents.