Improvement in BMI z-score following Adenotonsillectomy in Adolescents Aged 12-18 Years: A Retrospective Cohort Study

Background : obstructive sleep apnea (OSA) is associated with different patient characteristics according to age groups. OSA in babies and in prepubertal children is usually accompanied by a failure to thrive (FTT) and underweight. Adenotonsillectomy (T&A) is the first line of treatment for obstructive sleep apnea (OSA) in childhood. In the adult population and partly in adolescents OSA is commonly associated with obesity and the metabolic syndrome. In adolescents with OSA managed with a T&A the change in BMI was only occasionally studied. Thus, we peruse to examine the BMI z-score change following T&A in adolescents. Methods: in Israel, Clalit Health Services is the largest health care organization with the largest patient registry (more than 50% of the population). From the Clalit registry, 242 adolescents aged 12-18 who underwent T&A between 2006-2015 were retrospectively studied. BMI z-score changes from up to 3 months prior to T&A were compared to BMI measures in the following 3 years post T&A. Results: there were changes to all directions with overall small increase, not statistically significant (P=0.26) in BMI Z-score with a median of 0.79 prior to and 0.835 following T&A. Overweight children (n=74) tended to reduce their BMI z-score from 1.508 to 1.48 following T&A (p=NS), and in obese children (n=33) BMI z-score decreased from 2.288 to 2.000 accordingly (P=0.06, 2 tailed). Interestingly thin individuals (n=6) increased their BMI z-score following T&A from -2.4 to -0.59 (p=0.046). Conclusions: adolescents managed with T&A show variable changes in their BMI z-score following the procedure. In this regard their BMI z-score change is closer to the change seen in adults treated for OSA and not young children. The changes observed show trend to normalize the BMI z-score such that overweight children tend to decrease their BMI z-score while thin individuals tend to increase it.