Objectives  

Sleep duration and sleep fragmentation have been proposed to play a role in the development and progression of obesity-associated morbidity. Weight loss results in resolution of obesity-associated morbidity. Our aim was to determine the effect of weight loss on sleep architecture in adolescents with severe obesity.

Methods  

Retrospective analysis of polysomnograhic data from all adolescents who underwent overnight sleep study before and after weight loss surgery was performed. Polysomnographic variables of sleep architecture after weight loss were compared to baseline by paired Student’s t test (normally distributed data) or Wilcoxon test (variables not meeting normality criteria).

Results  

The mean (±SEM) age of 19 subjects meeting inclusion criteria was 16.5 ± 0.35 years, mean body mass index was 60.3 ± 2.11 kg/m², and 66% were female. Obstructive sleep apnea was present in 14 subjects (74%). The average interval between the baseline and repeat polysomnograms was 0.91 ± 0.16 years, and average weight loss was 66.4 ± 8.8 kg. Surgical weight loss resulted in increased sleep efficiency (80.2% vs 73.1%, p = 0.01), reduced time in stage 1 sleep (3.0% vs 6.0%, p = 0.02), and reduced arousal index (7.6 ± 0.6/h vs 11.3 ± 1.2, p = 0.01).

Conclusion  

Our data demonstrate a marked improvement in sleep efficiency and sleep fragmentation with surgical weight loss. Given the emerging evidence that surgical weight loss results in resolution of obesity-associated psychosocial, metabolic, and cardiovascular morbidity, these results suggest that correction of sleep fragmentation could be an important but as yet underappreciated factor influencing changes in these other major comorbidities of obesity.