OBJECTIVETo evaluate the current status of penis and testicular development in boys and the effects of overweight/obesity on their development in the Zhengzhou area of Henan Province.

METHODSHeight, weight, waist circumference, hip circumference, penis length and testicular volume were measured in 3 546 4 to 12-year-old boys. The penis length and testicular volume were compared between the overweight/obesity and normal weight groups.

RESULTSBefore 9 years of age, the testicular volume was progressively smaller, and after 9 years old, it gradually increased. By the age of 11, it increased rapidly. The penis length increased gradually between 4 and 11 years of age, and after the age of 11 it increased rapidly. Phimosis was found in 144 cases (4.01%) and cryptorchidism was found in 18 cases (0.51%). A total of 639 (18.02%) boys were overweight or obese among 3 546 boys. At the ages of 6 and 7 years, the testicular volume in the overweight/obesity group was greater than in the normal control group (P<0.05). The penis length in the overweight/obesity group was significantly shorter than in the normal control group (P<0.05) by the age of 11 years. The correlation analysis showed that the testicular volume at the ages of 4 and 5 years was positively correlated with height, weight, BMI, waist circumference and hip circumference in overweight/obese boys. The penis length at the ages of 7 and 8 years was negatively correlated with weight, waist circumference and hip circumference. By the age of 12 years, the penis length was positively correlated with the height.

CONCLUSIONSThe development of penis and testicles in boys in the Zhengzhou area is in line with the level of sex development of Chinese boys. Overweight/obesity adversely affects the development of penis and testicles.