Cohort Profile: Chongqing Pubertal Timing and Environment Study in China with 15 Follow-Ups since 2014

Abstract

Background: Puberty is a life milestone that marks the transition from childhood to adulthood. An ambispective Chongqing Pubertal Timing (CQPT) cohort was started in 2014 to understand pubertal timing and identify environmental risk factors. Methods: A total of 1429 children and adolescents were recruited and have been followed up once every 6 months for 8 years in a district of Chongqing, China. Data were collected via questionnaires for social and family environment, health conditions, gestational and maternal information, and in-person physical examinations by trained medical school graduate students in follow-ups. Environmental exposures of polycyclic aromatic hydrocarbons (PAHs), neonicotinoids, and heavy metals in urine samples were measured at different time points. Results: The mean ages at pubertal onset were 10.20 for thelarche, 11.62 for pubic hair development, and 11.84 for menarche in girls, and 11.16 for genital development, 11.66 for testicular enlargement, and 12.71 for first spermatorrhea in boys. Four OH-PAHs were associated with delayed timing of menarche, thelarche, pubic hair, and axillary hair development in girls, and thiacloprid was found to potentially impact genital stages in boys and axillary hair development in girls. Conclusions: We built a cohort to provide evidence of regional pubertal timing of boys and girls and the significant environmental factors. Further health outcomes, especially mental health and women’s health and its long-term health implications, will be followed.