Objective  To study the correlation between adenotonsillectomy and postoperative body mass index change.

  Methods  A total of 120 children with adenotonsillectomy meeting the inclusion criteria were selected as the study objects. Among them, 28 children with recurrent acute tonsillar infection and sleep apnea hypopnea index (AHI) < 1 were included in the recurrent tonsillar infection group, while 92 children with preoperative AHI≥1 were included in the obstructive sleep apnea hypopnea syndrome (OSAHS) group. Age, gender, AHI, body mass index z-scores (BMIzsc) at 3-to 6-month before and after operation were compared. According to a previous studies revealing that the mean age undergoing adenotonsillectomy was 5.6 years, these patients were divided into ≤6 years and >6 years. The changes of BMIzsc before and after operation were compared.

  Results  There were no significant differences in age, sex, height before operation, body mass before operation, BMIzsc before and after operation between the two groups (P>0.05), but a significant difference was found in postoperative BMIzsc scores compared with operation before in two groups (P < 0.05). Multiple linear regression analysis demonstrated that BMIzsc had no correlation with sex, and AHI, but was negatively correlated with age (P < 0.05).

  Conclusion  Adenotonsillectomy has a significant effect on the body mass of children under 6 years old.