[Study of relationship between dietary patterns and precocious puberty of school-age girls in Shenzhen]

Objective: To explore the daily dietary behaviors of girls under precocious puberty and provide targeted measures for the prevention of precocious puberty. Methods: A case control study was conducted in a hospital in Shenzhen between September 2016 and December 2018. Girls with diagnosed precocious puberty were selected as case group. A 1∶1 matching was conducted. The control group was from 26 primary schools in Shenzhen. Dietary survey was conducted in parents, completing a self-administered questionnaire. Frequencies of 12 kinds of food intakes were investigated and dietary patterns were analyzed. Conditional logistic regression was used to analyze the relationship between dietary patterns and precocious puberty. Results: A total of 568 girls were included in the study. Among them, those aged 8-year-old accounted for highest proportion (43.8%). The median of age was same in both case group and control group (8 years-old). There was no significant difference in ethnic group between two groups (P>0.05). The medians of height, weight and BMI of case group were 135.0 cm, 30.2 kg and 16.6 kg/m(2), respectively, which were all higher than those of the control group (129.2 cm, 25.0 kg and 15.3 kg/m(2)), the differences were significant (P<0.05). There was significant difference in nutritional assessment result between two groups (P< 0.05). Three dietary patterns were defined, i.e. balanced pattern, high calorie and fat pattern and high protein diet pattern. The cumulative rate of variance contribution of the three dietary patterns was 0.541 2. The differences in the prevalence of three dietary patterns between two groups were significant (χ(2)=4.41, χ(2)=49.24, χ(2)=39.68, P<0.05 respectively). Data from the multivariate regression analysis showed that both balanced dietary pattern (OR=0.633, 95%CI: 0.504-0.769) and high protein diet pattern (OR=0.622, 95%CI: 0.498-0.776) were protective factors for precocious puberty, while high calorie and fat pattern was risk factors (OR=1.850, 95%CI: 1.461-2.342). Conclusions: Balanced dietary pattern was common in school-aged girls. High calorie and fat pattern was risk factor for precocious puberty. Children should be encouraged to develop a balanced dietary habit and increasing the intake of legumes and fish since they are beneficial to normal growth and development.