The Inverted U-Shaped Association between Serum Vitamin D and Serum Uric Acid Status in Children and Adolescents: A Large Cross-Sectional and Longitudinal Analysis.

BACKGROUND: Serum vitamin D is associated with hyperuricemia. However, previous studies have been controversial, with limited focus on children and adolescents. OBJECTIVE: This study aimed to examine the cross-sectional and longitudinal associations between serum vitamin D and serum uric acid (SUA) levels in children and adolescents. METHODS: The cross-sectional survey comprised 4777 participants aged 6 to 18 years, while the longitudinal survey involved 1641 participants aged 6 to 12 years, all derived from an ongoing cohort study in Shenzhen, China. Restricted cubic splines were used to visualize the dose-response relationship between vitamin D and SUA and the risk of higher SUA status. Two-segment generalized linear models (GLM) and logistic models were used to assess the association between vitamin D and SUA and higher SUA status, respectively. The longitudinal analysis used GLM. RESULTS: We observed an inverted U-shaped relationship between vitamin D and SUA (p-overall < 0.0001, p-nonlinear = 0.0002), as well as the risk of higher SUA status (p-overall = 0.0054, p-nonlinear = 0.0015), with the vitamin D inflection point at 24.31 and 21.29 ng/mL, respectively. A 10 ng/mL increment in 25(OH)D3 levels, when below 20.92 ng/mL, was associated with a 68% rise in the risk of higher SUA status (OR: 1.68, 95%CI: 1.07-2.66). Conversely, when 25(OH)D3 levels were above or equal to 20.92 ng/mL, a 10 ng/mL increment was associated with a 45% reduction risk of higher SUA status (OR: 0.55, 95%CI: 0.36-0.84). Longitudinal analysis indicated that the annual change of SUA was from -4.80 (ß, 95%CI: -10.74, 1.13) to -9.00 (ß, 95%CI: -15.03, -2.99) and then to -6.77 (ß, 95%CI: -12.83, -0.71, p for trend = 0.0212) µmol/L when increasing the quartile of vitamin D3. CONCLUSIONS: An inverse U-shaped relationship was observed between vitamin D and SUA as well as the risk of higher SUA status. Sufficient vitamin D levels appear to play a preventative role against the age-related increase in SUA. Ensuring adequate vitamin D levels may be beneficial in improving uric acid metabolism.

Abnormal Bone Turnover Observed in Obese Children Based on Puberty Stage -Specific Bone Turnover Marker Reference.

CONTEXT: Childhood and adolescence are critical periods for lifelong bone health. The impact of obesity on these phases is controversial, which may be due to the lack of standards for age-, sex-, and puberty-specific Bone turnover markers (BTMs) which could sensitively reflect bone metabolism. OBJECTIVE: To generate age-, sex, and puberty stage-specific BTMs reference curves in children and adolescents and to explore the effect of obesity on bone metabolism in the Chinese population. METHODS: Our study was part of the Evaluation and Monitoring on School-based Nutrition and Growth in Shenzhen study. 800 participants aged 6∼18 years with normal body mass index (BMI) were selected to establish BTM reference curves for boys and girls at different ages under different pubertal development stages. Additionally, 200 participants with obesity (BMI >P95th) were matched with healthy children from the original cohort at a 1:1 ratio. All participants underwent bone mineral density assessment, and serum levels of P1NP and ß-CTX were measured. RESULTS: The BTMs values presented significant age, sex, and puberty stage differences. Analysis of serum BTMs based on the established reference revealed a higher percentage of low-level P1NP in boys with obesity (P=0.005); no significant difference was observed in girls. However, the obese group showed a significantly higher proportion of high ß-CTX levels for girls, not boys (P=0.022). CONCLUSIONS: We provide age-, sex-, and puberty stage-specific P1NP and ß-CTX reference curve. According to these, obesity appeared to be a negative factor for bone formation in boys and for bone resorption in girls.

The Impact of New Regulations on Prevention and Control of E-Cigarettes on Adolescents in Middle Schools - A City in China, 2022-2023.

What is already known about this topic?: To protect the health of young people from the harmful impacts of electronic cigarettes (e-cigarettes), China has enacted various policies and regulations since 2018. As of October 1, 2022, the Electronic Cigarette Management Measures were put into action. They prohibited the sale of flavored e-cigarettes, permitting only those of plain tobacco flavor to be sold. What is added by this report?: The illegal market for flavored e-cigarettes, often disguised as milk tea cups, cola cans, and violent bear images, continues to flourish. There is an increased need to bolster support for the prohibition of flavored e-cigarettes and enhance public awareness of associated regulations. What are the implications for public health practice?: To advance the health of China's youth, it is crucial to improve the implementation and understanding of e-cigarette policies and guidelines.

Association between sugar-free beverage intake and childhood obesity among Chinese children and adolescents.

BACKGROUND: The relationship between sugar-free beverage (SFB) intake and childhood obesity among Chinese children is unknown. OBJECTIVES: To describe the status of SFB consumption among children and adolescents in China and assess the association between SFB intake and different types of obesity. METHODS: The study was based on the baseline data of an ongoing cohort project named Evaluation and Monitoring on School-based Nutrition and Growth in Shenzhen (EMSNGS). Food frequency questionnaires were used to collect information on SFB consumption in 3227 students aged 9-17. Physical and clinical examinations were conducted by trained investigators and clinicians. Multivariable binary logistic regression models were performed to assess the association between SFB intake and general obesity, overweight/obesity, abdominal obesity, metabolically unhealthy overweight (MUOW)/metabolically unhealthy obesity (MUO). RESULTS: The median age of the participants was 13.28 years. Among the participants, 55.2% were boys, and 66.1% were adolescents. The median SFB consumption was 16.67 mL/d. After adjusting for potential confounding factors, each 100 mL increase in daily SFB intake was associated with an increased risk of overweight/obesity (OR = 1.14; 95%CI: 1.06-1.23), abdominal obesity (OR = 1.12; 95%CI: 1.03-1.23), and MUOW/MUO (OR = 1.12; 95%CI: 1.02-1.21), respectively. Stratified analyses showed that family income may have an impact on the association between SFB intake and overweight/obesity (P for interaction = 0.021) and abdominal obesity (P for interaction = 0.031). CONCLUSION: SFB intake was positively associated with childhood obesity in Chinese children, particularly among individuals with high-income families.

Association of serum 25-hydroxyvitamin D with bone health measured by calcaneal quantitative ultrasound: a large cross-sectional analysis in children and adolescents.

Background: Vitamin D plays a crucial role in bone health; however, findings in children and adolescents remain inconsistent, and few studies have examined its impact on bone health measured by quantitative ultrasound (QUS). This study aims at assessing the relationship between serum vitamin D levels and bone health, as evaluated by QUS, across varying pubertal stages and genders. Methods: A baseline cross-sectional survey of an ongoing cohort study included 4682 children and adolescents aged 6 to 18 years from Shenzhen, China. Serum levels of 25-hydroxyvitamin D (25(OH)D), which is the sum of 25(OH)D2 and 25(OH)D3, were quantified using liquid chromatography-mass spectrometry. Bone health was measured through calcaneal QUS, utilizing the speed of sound (SOS) in the heel as a principal measure-a higher SOS indicating a denser bone structure. Generalized linear models were used to evaluate the association of serum 25(OH)D, 25(OH)D2, and 25(OH)D3 levels with the SOS. Results: Forty-one point-one percent of this population was vitamin D deficient (serum 25(OH)D < 20 ng ml-1), with only 11.1% being sufficient. In the fully adjusted model, we observed a significant positive association between increased serum 25(OH)D quartiles and SOS. Compared with the participants in the lowest quartiles of serum 25(OH)D, those in successive quartiles of 25(OH)D were 3.54 (95% CI: 0.81, 6.28) m s-1, 5.74 (95% CI: 2.87, 8.61) m s-1, and 8.83 (95% CI: 5.83, 11.84) m s-1, respectively (P for trend < 0.0001). The correlations observed for serum 25(OH)D2 and 25(OH)D3 with SOS were similar to those of serum 25(OH)D. Importantly, this association was primarily observed in post-pubertal children and adolescents but was absent in pre- and mid-pubertal participants (P for interaction = 0.0004). Conclusion: Elevated serum 25(OH)D levels were associated with better bone health, as measured through calcaneal QUS, in children and adolescents, particularly among those who had reached the post-pubertal stage. These findings highlight the crucial importance of maintaining sufficient vitamin D levels to support optimal bone health in this demographic.

Associations between High Protein Intake, Linear Growth, and Stunting in Children and Adolescents: A Cross-Sectional Study.

BACKGROUND AND AIMS: Childhood and adolescence are critical periods for linear growth and preventing stunting. Current evidence indicates that dietary protein intake in children and adolescents is often two to three times higher than the recommendations in many regions worldwide. However, few studies have focused on the association between high protein intake and linear growth and stunting in this population. We aim to investigate this association in children and adolescents aged 6 to 18 years in a population with relatively high protein consumption. METHODS: We conducted a large cross-sectional study involving 3299 participants from Shenzhen, a modern metropolis of China. Protein intake, including total protein, animal protein, and plant protein, was evaluated by a food-frequency questionnaire and expressed as grams per kilogram of body weight per day (g·kg-1·d-1) and as a percentage of total energy intake (%E). The primary outcomes were body height and height-for-age Z score (HAZ). Generalized linear models and logistic regression analyses were employed to examine the associations between protein intake and outcomes. We also conducted stratified analyses across different genders and pubertal stages in the aforementioned associations. RESULTS: The mean protein intake was 1.81 g·kg-1·d-1 (17% E). After adjusting for serum calcium, zinc, vitamin D3, vitamin A levels, birth outcomes, lifestyle, and parental characteristics, each standard deviation increase of 1 in protein intake (0.64 kg-1·d-1) is found to be associated with a -5.78 cm change in body height (95% CI: -6.12, -5.45) and a -0.79 change in HAZ (95% CI: -0.84, -0.74). Consistent results were observed when protein intake was expressed as %E or specifically as animal or plant protein. Moreover, the relationship between protein intake and linear growth remained consistent across genders in different pubertal stages, similar to that of the overall participants. CONCLUSIONS: Our findings highlight the potential hazards of high protein intake on linear growth in children and adolescents. Caution should be exercised when promoting increased protein consumption in children and adolescents who already have a high intake of protein.

Associations between dietary patterns and serum uric acid concentrations in children and adolescents: a cross-sectional study.

The serum uric acid (SUA) concentrations in children and adolescents in southeast coastal China are generally high. The relationship between diet and SUA in children and adolescents remains unclear. The objective of the study was to assess the associations between data-driven dietary patterns with SUA concentrations and hyperuricemia in Chinese children and adolescents and to explore the role of food components. This study involved 3383 participants aged 9 to 17 years from a representative nutrition and growth survey conducted in Shenzhen, a southeast coastal city in China. The dietary intake data, obtained from a validated food frequency questionnaire, were categorized into 19 food groups for factor analysis to derive dietary patterns. Weighted least squares regression was performed to examine the associations between dietary patterns and SUA concentrations, logistic regression was used to analyze the relationship between dietary patterns and hyperuricemia, and the relationship between food groups and food components with SUA concentrations was further analyzed. The potential dietary factors contributing to the associations between dietary patterns and SUA concentrations were explored by adjusting various food components. Six dietary patterns were identified by factor analysis, including an ultra-processed diet, plant-based nutritious diet, meat-based diet, soup/seafood/egg diet, vegetarian diet, and mushroom/animal organ diet. After adjusting for confounders, the meat-based diet exhibited a positive correlation with SUA concentrations (ß = 4.89; 95% confidence interval (CI): 0.60-9.18; P = 0.03), while the vegetarian diet could reduce the risk of hyperuricemia (odds ratio = 0.88; 95% CI: 0.80-0.98; P = 0.02). In addition, dietary intake of poultry (g per d) (ß = 0.09, 95% CI: 0.02, 0.16, P = 0.02), animal organs, blood (g per d) (ß = 0.32, 95% CI: 0.12, 0.51, P = 0.002) and hypoxanthine (mg per d) (ß = 0.03, 95% CI: 0.01, 0.06, P = 0.02) showed a significantly positive correlation with SUA concentrations, while that of vegetables (g per d) (ß = -0.02, 95% CI: -0.03, -0.01, P = 0.03) showed a significantly negative correlation. In summary, for children and adolescents, it is recommended to increase vegetable intake and reduce animal-based food intake in order to control SUA concentration and prevent hyperuricemia. This study was registered at the China Clinical Trials Registry (ChiCTR2100051722).

Effect of a two-phase tobacco control regulation on incidence from ischemic stroke and hemorrhagic stroke, Shenzhen, China, 2007-2016.

INTRODUCTION: The Shenzhen government is widely considered to be most efficiently implementing smoke-free legislation in China. We evaluated and compared the impact of Shenzhen's two-phase smoke-free regulation on the incidence rates for ischemic and hemorrhagic stroke. METHODS: An interrupted time series design was used to capture immediate and annual incidence changes from 2007 to 2016 for both ischemic and hemorrhagic stroke due to two-phase smoke-free regulation in Shenzhen, China, by using a generalized additive model. The first phase, implemented on 9 March 2010, required five main public places to be smoke-free. In the second phase, the comprehensive law was expanded to the whole city on 1 March 2014. RESULTS: The regulation implementation during phase I was associated with a strong immediate decline in the incidence rate of ischemic stroke (-14.2%, 95% CI: -19.6 - -8.4) and hemorrhagic stroke (-10.1%, 95% CI: -18.2 - -1.2), but without showing the annual changes (p>0.05). Following the implementation of the comprehensive law, the gradual annual effect showed a significant change in ischemic stroke, with a 6.3% (95% CI: 8.9 - -3.6) reduction. Neither the immediate nor gradual decreases in hemorrhagic stroke incidences associated with the comprehensive regulation were statistically significant during phase II (p>0.05). Subgroup analyses indicate that a much larger health effect of the regulation during phase I was greater among those aged ≥65 years than among those aged 35-64 years. CONCLUSIONS: Shenzhen's two-phase smoke-free regulation was well implemented. Even though the regulation did not extend to the whole city, the immediate health benefits on the incidence rates of ischemic stroke and hemorrhagic stroke could be seen. However, the health benefits brought by the implementation of comprehensive smoke-free legislation were attenuated by previous smoke-free regulations in five main public places, which were more evident in hemorrhagic stroke.

Assessing the Effectiveness of a Community-Based Smoking Cessation Intervention - Shenzhen City, Guangdong Province, China, 2022.

What is already known about this topic?: Research on community-based smoking cessation interventions in China is still in its early stages. Most existing studies have focused on a limited number of communities and have primarily examined interventions conducted by study teams rather than broader community initiatives. What is added by this report?: The three-month continuous abstinence rate for the intervention group (21.61%) was significantly higher than that for the control group (8.98%). Comprehensive community-based smoking cessation interventions, administered by trained physicians at community health service centers and supported by community workers, have shown effectiveness in improving a variety of outcomes among community smokers. What are the implications for public health practice?: The feasibility and effectiveness of comprehensive community-based smoking cessation interventions make them a valuable addition to existing cessation services in China. Wider implementation of these interventions should be pursued as a complementary approach to current efforts to reduce smoking rates in China.

Prevalence and associated factors of smoking among chinese adolescents: a school-based cross-sectional study.

BACKGROUND: Shenzhen has made great efforts to address the tobacco epidemic in the past decade. This study aims to evaluate the current status of the tobacco epidemic among adolescent in Shenzhen, China. METHODS: The multi-stage random cluster sampling method was used in the school-based cross-sectional study in 2019 and a total of 7,423 junior and high school (both senior and vocational) students were recruited. Information on cigarette use was collected by the electronic questionnaire. Logistic regression analysis was used to examine the associations between current cigarette use and associated factors. ORs with their 95% CIs were reported. RESULTS: The prevalence of current cigarette use among adolescents was 2.3%, with boys (3.4%) significantly higher than girls (1.0%). Smoking rates in junior high schools, senior high schools, and vocational senior high schools were 1.0%, 2.7%, and 4.1%, respectively. The results of multivariate logistic regression analysis indicated that gender, age, parental smoking, teachers smoking in schools, friends smoking, exposure to tobacco marketing, and misconceptions about cigarette use were associated factors for adolescent smoking behaviour. CONCLUSIONS: The prevalence of current smoking was relatively low among adolescent in Shenzhen, China. Personal characteristics, family, and school were associated with current adolescent smokers.

[The control study on risk factors of high-risk population in diabetes].

OBJECTIVE: To examine the significance of individual risk on diabetes to subjects who underwent diabetes screening. METHODS: 2003 asymptomatic diabetes subjects with high-risk factors of diabetes as family history, obesity, hypertension, and/or dyslipidemia, fetal giant history were screened. 5362 subjects having no risk factors but from the same community were allocated as controls. RESULTS: There were 131 (6.54%) diabetes identified in the screening group and 1547 (77.23%) subjects having 1 risk factor, 387 (19.27%) having 2 risk factors, 70 (3.49%) having 3 or more risk factors. There were 96 (1.79%) diabetes identified in the control group. Compared with control group, the OR (95% CI) value was 2.68 (2.20-3.25) after adjusted on age among the high risk group. The OR value of those having 1 risk factor was 2.89, but these having 3 or more risk factors increased to 4.68. CONCLUSION: The relation between the risk of high-risk group with diabetes and the number of risk factors of diabetes presented positive correlation. Early and regular screening for diabetes was essential in these individuals with high-risk factors.