Background Obstructive Sleep Apnoea (OSA) is prevalent in obese patients and has substantial impact on health and society1. We undertook this analysis to examine changes in Sleep Apnoea severity by studying the Apnoea-Hypopnoea Index (AHI) pre and post bariatric surgery in a London District General Hospital.
Methods We retrospectively reviewed patients with a history of OSA who underwent a laparoscopic bariatric procedure between 2011 and 2012, preceded by a sleep study. Repeat sleep studies were performed in those patients who reported significant symptom reduction as part of the assessment to withdraw CPAP therapy. Following this, data concerning changes in BMI and corresponding AHI values were analysed as were Epworth Sleepiness Scale scores.
Results Twenty patients reported significant improvement in sleep apnoea symptoms and requested to come off CPAP therapy. Nineteen of them underwent a repeat sleep study. The mean age of the patients was 45 years (SEM = 2.1) with 14 of them being females. The mean pre and post-surgery BMI were 49 kg/m2 (SEM = 1.4) and 40 kg/m2 (SEM = 1.8)respectively (p = 0.000, paired t-test). The mean Epworth sleepiness scale scores were 13.3 and 7.4 (p = 0.001, paired t test) respectively for the same patients. The average time period for repeat sleep studies was 7 months (range 2 - 19). The mean baseline AHI pre surgery was 41 (SEM = 6.5) and the corresponding value post-surgery was 12.4 (SEM = 2.7) (p = 0.000, paired t-test). The correlation co-efficient corresponding to percentage decrease in BMI and AHI was 0.44 (Spearman’s correlation). The majority of patients included in this analysis discontinued the use of CPAP and continue to remain well.
Conclusion This analysis demonstrates the positive outcome on AHI and Epworth sleepiness scale scores following laparoscopic bariatric surgery. The correlation between percentage changes in BMI and AHI suggest there may be factors other than weight reduction alone contributing to the outcome.
1Scottish Intercollegiate Guidelines Network (2003). Management of Obstructive Sleep Apnoea/Hypopnoea Syndrome in Adults:73. Edinburgh: Scottish Intercollegiate Guidelines Network.