[Associations between puberty timing and cardiovascular metabolic risk factors among primary and secondary students].

Objective: To explore the relationship between puberty timing and cardiovascular metabolic risk factors among primary and secondary students with different genders in Beijing.

Methods: Using the method of stratified cluster sampling by urban and rural areas and school sections, 3 067 students from 16 primary and secondary schools in Fangshan District of Beijing were selected in October 2012, with questionnaire survey, physical examination and serum laboratory testing. In this study, we controlled for confounding factors such as school segments, current residence of the family, birth weight, feeding method, only child, highest educational level of parents, and monthly family income, and then the associations between cardiovascular metabolic risk factors and puberty timing among the primary and secondary students was analyzed by multivariate Logistic analysis. To ensure the reliability of the data, this study adopted strict quality control.

Results: A total of 3 067 primary and middle school students aged 7 to 16 years were included in this study, including 1 575 boys and 1 492 girls. The prevalence of premature puberty was 14.73% among the boys and 12.89% among the girls, respectively. The prevalence of delayed puberty was 9.49% among the boys and 10.99% among the girls, respectively. The detection rates of central obesity, hypertension, hyperglycemia, and dyslipidemia among the primary and secondary students were 35.87%, 19.95%, 2.54% and 26.31%, respectively. The detection rates of 1 risk factor clustering, 2 risk factors clustering and more than 3 risk factors clustering were 29.21%, 16.17% and 9.36%, respectively. The difference in the detection rate of cardiovascular and metabolic risk factors in different youth stages was insignificant (P>0.05), the detection rate of risk factor aggregation of 0 was lower than that of the timely group and delayed group, and the detection rate of risk factors aggregation of 2 was higher than that of the timely group (P < 0.05).After adjusting the effects of learning stage, region, birth weight, feeding patterns, one-child, family income and the parents' educational levels, multivariate Logistic regression analysis showed that, compared with the on-time puberty group, the risk of 1 risk factor clustering, 2 risk factors clustering and more than 3 risk factors clustering increased by 1.94 times (95% CI=1.29-2.91), 2.97 times (95% CI=1.89-4.67) and 2.02 times (95% CI= 1.13-3.63) among the girls; It had not been found that the relationship between puberty timing and cardiovascular risk factor clustering among the boys (P>0.05).

Conclusion: Premature puberty is an independent risk factor for the clustering of cardiometabolic risk factors in girls, and primary prevention strategies should be implemented to reduce the burden of cardiovascular metabolic diseases in the population.