The average weight loss resulting from bariatric surgical procedures is significantly greater than that attained using conservative measures (22
). In a meta-analysis of 22,094 patients undergoing bariatric surgery (5
), weight loss after gastric banding was reported to be 28.6 kg (range 24.5 kg to 32.8 kg) compared with 43.5 kg (range 38.8 kg to 48.1 kg) for gastric bypass, and 46.4 kg (41.2 kg to 51.6 kg) for biliopancreatic diversion. The corresponding changes in BMI were 10.4 kg/m2
(range 9.3 kg/m2
to 11.5 kg/m2
; 16.7 kg/m2
to 18.4 kg/m2
); and 18 kg/m2
to 19.4 kg/m2
) (). This compares very favourably with the use of the antiobesity medications orlistat, sibutramine and rimonabant, which achieve average weight losses of 5 kg or less (26
). Maximum weight loss is achieved one year postsurgery, which is followed by a minor weight gain; however, even 15 years after the date of surgery, a great majority of the weight loss is maintained (4
). The 30-day mortality rate associated with bariatric surgery is acceptably low, varying from 0% to 0.3% for laparoscopic procedures (including Roux-en-Y gastric bypass) to 2.1% for procedures performed by laparotomy (25
). Importantly, however, long-term mortality figures for morbidly obese individuals undergoing bariatric surgery are significantly lower than those who are managed conservatively (22
). Furthermore, obesity-related comorbidities other than sleep apnea (eg, hypertension, diabetes mellitus and hyperlipidemia) are also significantly reduced postbariatric surgery (4
). In a prospective, nonrandomized, controlled study (22
), mortality was improved in the bariatric surgical group, and sleep apnea severity (measured only on a crude, subjective basis) was reduced. An earlier meta-analysis (5
) of the impact of bariatric surgery on obstructive sleep apnea reported that 86% of patients “no longer needed CPAP treatment” after bariatric surgery; however, many of the studies included in that analysis did not report objective quantification of sleep apnea severity before and after the surgery. Indeed, although published studies in which sleep apnea severity was measured before and after bariatric surgery, substantial improvements in sleep apnea severity have generally been observed. However, there are exceptions, and the reported success rate for complete abolition of OSAS is quite variable. Furthermore, among patients who experienced abolition of OSAS postbariatric surgery, subsequent recurrence of OSAS without additional weight gain has been reported (20
). In a meta-analysis of 12 studies involving 342 patients with OSAS who underwent PSG before and after bariatric surgery (8
), the AHI fell from a mean of approximately 55 presurgery to 16 postsurgery, with a coincident mean reduction in BMI of approximately 18 kg/m2
. Thus, contrary to the implication from earlier systematic analyses that bariatric surgery obviated the need for continued treatment of OSAS, the most recent and comprehensive meta-analysis of bariatric surgical impact on sleep apnea severity suggests that the average AHI postbariatric surgery is consistent with moderately severe OSAS (8
). Thus, patients are advised to remain on treatment for OSA after bariatric surgery and, if asymptomatic from the sleep apnea perspective after weight loss, to undergo diagnostic PSG to objectively evaluate sleep apnea severity before discontinuation of treatment.
There are no RCTs comparing medical (ie, diet and medication) therapy versus bariatric surgery for the management of OSAS in obese patients. However, based on available data demonstrating substantially greater weight loss after bariatric surgery, it is likely that medical management would be less effective as a strategy for treating OSA through weight reduction than bariatric surgery.
Thus, limited available evidence suggests a survival benefit from bariatric surgery in morbidly obese individuals, and that the surgery is usually associated with improvement but not complete abolition of sleep disordered breathing.