Limited evidence suggests bariatric surgery can result in high cure rates for obstructive
sleep apnea (OSA) in the morbidly obese. We performed a systematic review and meta-analysis
to identify the effects of surgical weight loss on the apnea-hypopnea index.
Relevant studies were identified by computerized searches of MEDLINE and EMBASE (from
inception to March 17, 2008), and review of bibliographies of selected articles. Included
studies reported results of polysomnographies performed before and at least 3 months
after bariatric surgery. Data abstracted from each article included patient characteristics,
sample size who underwent both preoperative and postoperative polysomnograms, types
of bariatric surgery performed, results of preoperative and postoperative measures
of OSA and body mass index, publication year, country of origin, trial perspective
(prospective vs retrospective), and study quality.
Twelve studies representing 342 patients were identified. The pooled mean body mass
index was reduced by 17.9 kg/m(2) (95% confidence interval [CI], 16.5-19.3) from 55.3
kg/m(2) (95% CI, 53.5-57.1) to 37.7 kg/m(2) (95% CI, 36.6-38.9). The random-effects
pooled baseline apnea hypopnea index of 54.7 events/hour (95% CI, 49.0-60.3) was reduced
by 38.2 events/hour (95% CI, 31.9-44.4) to a final value of 15.8 events/hour (95%
CI, 12.6-19.0).
Bariatric surgery significantly reduces the apnea hypopnea index. However, the mean
apnea hypopnea index after surgical weight loss was consistent with moderately severe
OSA. Our data suggest that patients undergoing bariatric surgery should not expect
a cure of OSA after surgical weight loss. These patients will likely need continued
treatment for OSA to minimize its complications.