Prevalence of concealed penis among school boys in Shanghai and its relationship with obesity

【Objective】 To describe the incidence rate of concealed penis among the primary and secondary school boys in Shanghai and preliminarily explore the correlation between concealed penis and Body Shape Index of school boys.【Methods】 Stratification sampling method was applied and then a total of 1 787 students were selected from primary school and secondary schools.Strict physical and genitalia examination were conducted to obtain the data of the participant boys at different ages and different pubertal stages in order to describe the general situation of concealed penis and the correlation was explored between concealed penis and obesity-related indicators based on the method of 1∶4 conditional Logistic regression analysis.【Results】 The incidence rate of concealed penis of the sample school boys was 2.5%.The higher incidence rate of concealed penis emerged at the age of 11 to 15.There were statistically significant correlations between the obesity-related indicators(BMI,weight and waistline,hip circumference,waist-hip ratio,subscapular,skinfold,triceps skinfold) and concealed penis(their ORs were 1.730,1.158,1.252,1.297,13.734,1.248,1.229 respectively).【Conclusion】 The prevalence of the concealed penis is higher than before.All the obesity-related indicators are risk factors of the concealed penis,moreover,the central obesity is attributed to the concealed penis among the boys.Actually,the influence of children obesity towards concealed penis should be paid high attention.