To investigate the effect of weight loss by gastric balloon insertion on parameters of obstructive sleep apnea.

Most of the patients with obstructive sleep apnea (OSA) are obese. It has been noted that significant weight loss could improve the severity of sleep apnea. Significant weight loss is difficult to achieve especially in morbidly obese patients. Endoscopic gastric balloon insertion is minimally invasive procedure is employed by surgeon for weight reduction for morbidly obese patients. This study would assess the parameters of sleep which could be affected by weight reduction. If results are positive, this procedure might be considered as treatment for obstructive sleep apnea in morbidly obese patients.

Patient population would be selected from patients who would undergo gastric balloon insertion in the surgical department. There would be no sex or age limit. Patient recruited would have BMI > 35. Consent would be signed for sleep studies. Baseline sleep study, lung function, Epworth Sleepiness Scale (ESS) and quality of life would be assessed in patients who have symptoms suggestive of OSA. If a patient is confirmed to have OSA, a continuous positive airway pressure (CPAP) titration would be offered if the patient is willing to try CPAP. Otherwise patients would be discharged home and wait for balloon insertion. The same assessment would be repeated 3 months and 6 months after the surgical procedure. All sleep studies would be done as in-patient.

Leptin and ghrelin are hormones control satiety, which are also related to the degree of obesity. Blood for plasma leptin and ghrelin would be taken before and 6 months after gastric balloon insertion to assess the relationship of weight reduction by reducing appetite and plasma level of the hormones

Inclusion Criteria:

• morbidly obese patients with BMI > 30
• confirmed obstructive sleep apnea with RDI > 10/hr
• able to sign consent

Exclusion Criteria:

• patients undergoing weight reduction surgery
• sleep apnea other than obstructive sleep apnea
• untreated endocrine disorder
• patient refusal