Height development trends among 7-18-year-old school-age children in central plains of China between 2000 and 2019: A serial cross-sectional surveillance study in China.

Objective: The aim of this study was to analyze changes in height of 7-18-year-old school-age children in China during the year of 2000-2019.

Methods: We used the survey data from the Chinese National Survey on Students' Constitution and Health in Henan Province for the years 2000, 2005, 2010, 2014, and 2019. Data were categorized into subgroups based on geographic location, gender, and age; mean, standard deviation, and Pearson's correlation coefficient were used to analyze trends in height change among children and adolescents and the correlation between socioeconomic indicators and height change.

Secular Trends in the Median Age at Menarche and Spermarche Among Chinese Children From 2000 to 2019 and Analysis of Physical Examination Indicators Factor.

Objectives: This research aimed to understand the long-term trends in the age of menarche among girls and spermarche among boys, and to analyze the factors that may influence the onset of menarche and first spermarche.

Methods: The study was based on data from 49 566 students in Henan Province collected from the Chinese National Surveys on Students' Constitution and Health (CNSSCH) conducted between 2000 and 2019. Median age at menarche and spermarche was estimated by probit analysis.