Xin-Nan Zong

A twin-based chart of birth weight was useful to avoid overdiagnosis of small for gestational age (SGA) or large for gestational age (LGA) in twins comparing to the singleton-based chart. Several twin-based charts of birth weight were reported based on large data from nationwide, multiple cities or local regions in China. However, these twin-based charts showed inconsistent ranges across gestational age (GA) and not well-consistent growth trajectories, and may require further integration. We aimed to develop a set of smoothed percentile growth curves of twin birth weight in Chinese neonates that allows for continuous use from extremely preterm to full-term. We collected twin birth weight data through a procedure of systematic review by searching PubMed, Scopus, Web of science, Chinese national knowledge infrastructure (CNKI), and Wanfang from their inception to April 30, 2025. Finally, five studies that met the inclusion criteria were included in this present study. We used a two-stage proportionally weighted approach to generate initial integrated percentile data of twin birth weight, and then employed polynomial regression equation and the LMS method to establish the P₃, P₁₀, P₂₅, P₅₀, P₇₅, P₉₀, and P₉₇ reference values of twin birth weight that allowed for continuous use from GA of 22 to 42 weeks in Chinese male and female twins. Our established twin-based growth curves illustrated a distinct pattern comparing to the singleton-based growth curves in China. In conclusion, our established twin-based birth weight percentile references could be preferred over the use of singleton references when diagnosing SGA or LGA in twin newborns or monitoring the growth of twin newborns in China.

Background: Brachydactyly type A3 (BDA3), a common finger deformity, demonstrates an inverse epidemiological relationship with population height, suggesting a potential link with individual stature. We aimed to investigate the distribution of BDA3 and its association with shorter stature in Chinese children. Methods: From 2022 to 2023, we conducted a cross-sectional survey in 10 randomly selected schools in Beijing with children aged 3–18. We measured height on-site, obtained left hand-wrist X-rays, calculated predicted adult height (PAH) based on height and bone age, and diagnosed BDA3 deformity based on the X-ray images. And we compared the height and PAH between the BDA3 and Non-BDA3 groups by t-test or chi-square test, examined the association of BDA3 with shorter stature and shorter PAH using binary logistic regression model. Results: A total of 5,567 children participated, with 573 diagnosed with BDA3 (a detection rate of 10.3%). Notably, girls exhibited a significantly higher detection rate than boys (14.5% vs. 6.3%). The detection rate in children 12 years(15.3% vs. 7.6%). The average height and PAH were 0.30 SD and 0.22 SD lower, and the risk of shorter stature and shorter PAH were 1.57 times and 1.47 times higher in the BDA3 group than in the Non-BDA3 group, respectively. And, children >12 years in the BDA3 group had a significantly lower PAH than those in the Non-BDA3 group (about 2.0 cm). Conclusion: Children with BDA3 are more likely to have shorter stature and shorter PAH than those with no BDA3 in Chinese children aged 3–18 years.

Background: The aim of this study was to investigate the longitudinal associations between the body size trajectory and the cardio-renal-metabolic (CRM) conditions in adulthood, and evaluate the joint association between body size trajectory and polygenic risk scores (PRS) of CRM conditions. Methods: This prospective cohort study included 441 470 UK Biobank participants aged 40 to 70 years, recruited between March 2006 and July 2010. CRM conditions were defined as the occurrence of any of cardiovascular disease (CVD), chronic kidney disease (CKD), and type 2 diabetes (T2D). Cox regression models and Fine-Gray sub-distribution hazard models were used to estimate associations and competing risks of mortality. Mediation analysis and group-based trajectory modeling were performed to assess mediation effects and body size change trajectories. Additionally, interaction analyses were conducted to examine the combined effects of between the body size trajectories and PRS on CRM conditions. Results: The incidence density of CRM conditions was 128.9 per 1000 person-years. Adulthood overweight/obesity mediated the association between childhood plumper body size and CRM conditions (mediation proportion = 55.82%, P < 0.0001). Five trajectories of body size from birth to adulthood were identified, and the other four trajectories differing from the “normal-average-normal” trajectory were associated with increased risks of CRM conditions, with hazard ratio (HR) and 95% confidence interval (CI) ranging from 1.20 (1.15, 1.26) to 1.32 (1.28, 1.37). Intermediate and high genetic risk groups demonstrated elevated risks of CVD, CKD, and T2D, and the additive interactions were found between body size trajectories and PRS on CKD and T2D. Conclusions: Maintaining a normal body size across the life cycle, even with intermediate or high genetic risk, may help mitigate the impact of genetic risk. Early monitoring and interventions aimed at sustaining a normal body size throughout life could provide life-course benefits in preventing CRM conditions, particularly for individuals with elevated genetic risk. Graphical JOURNAL/ijos/04.03/01279778-202508000-00020/figure1/v/2026-10-30T033856Z/r/image-jpeg

Objectives: Insulin-like growth factor-1 (IGF-1) levels are affected by nutritional status, yet there is limited research exploring the association between body mass index (BMI) and IGF-1 levels among children. Methods: This cross-sectional study included 3227 children aged 2–18 years without specific diseases, whose height, weight, and pubertal stages were measured and assessed by pediatricians. BMI standard deviation scores (BMISDS) were used to categorize children as underweight (BMISDS < −2); normal-weight (−2 ≤ BMISDS ≤ 1); overweight (1 < BMISDS ≤ 2); and obese (BMISDS > 2). Children were divided into low-level (<−0.67 SD) and nonlow-level (≥−0.67 SD) groups based on IGF-1 standard deviation scores (IGF-1SDS). The association between IGF-1 and BMI as categorical and continuous variables was explored by Binary logistic regression, the restrictive cubic spline model, and the generalized additive model. Models were adjusted by height and pubertal development. Recursive algorithm and multivariate piecewise linear regression were further utilized to assess the threshold of the smooth curve. Results: IGF-1 levels varied by BMI categories, with the highest levels observed in the overweight group. The proportion of low IGF-1 levels in underweight, normal-weight, overweight, and obese groups was 32.1%, 14.2%, 8.4%, and 6.5%, respectively. The risk odds of low IGF-1 levels in underweight children were 2.86-, 2.20-, and 2.25-fold higher than in children with normal weight before adjustment, after adjustment for height, and after adjustment for height and puberty, respectively. When analyzing the association between BMI and low IGF-1 levels, dose-response analysis demonstrated an inverted J-shaped relationship between BMISDS and low IGF-1 levels. Lower or higher BMISDS increased the odds of low IGF-1 levels, and significance was retained in underweight children but not in obese children. When BMI and IGF-1 levels were used as continuous variables, the relationship between the BMISDS and IGF-1SDS followed a nonlinear inverted U shape. IGF-1SDS increased with the increase of BMISDS (β = 0.174, 95% CI: 0.141 to 0.208, p < 0.01) when BMISDS was less than 1.71 standard deviation (SD) and decreased with the increase of BMISDS (β = −0.358, 95% CI: −0.474 to −0.241, p < 0.01) when BMISDS was greater than 1.71 SD. Conclusions: The relationship between BMI and IGF-1 levels was found to depend on the type of variable, and extremely low or high BMI values could result in a tendency toward low IGF-1 levels, emphasizing the importance of maintaining a normal BMI range for normal IGF-1 levels.

A Proposal to Unify the Definition of the Metabolic Syndrome in Children and Adolescents

Background: Early postnatal growth monitoring and nutrition assessment for preterm infants is a public health and clinical concern. We aimed to establish a set of postnatal growth monitoring curves of preterm infants to better help clinicians make in-hospital and post-discharge nutrition plan of these vulnerable infants. Methods: We collected weight, length and head circumference data from a nationwide survey in China between 2015 and 2018. Polynomial regression and the modified LMS methods were employed to construct the smoothed weight, length and head circumference growth curves. Results: We established the P₃, P₁₀, P₂₅, P₅₀, P₇₅, P₉₀, P₉₇ reference curves of weight, length and head circumference that allowed for continuous use from 24 weeks of preterm birth to 50 weeks and developed a set of user-friendly growth monitoring charts. We estimated approximate ranges of weight gain per day and length and head circumference gains per week. Conclusions: Our established growth monitoring curves, which can be used continuously without correcting gestational age from 24 weeks of preterm birth to 50 weeks, may be useful for assessment of postnatal growth trajectories, definition of intrauterine growth retardation at birth, and classification of early nutrition status for preterm infants.