Clinical research study
Effects of Surgical Weight Loss on Measures of Obstructive Sleep Apnea: A Meta-Analysis

https://doi.org/10.1016/j.amjmed.2008.10.037Get rights and content

Abstract

Objective

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.

Methods

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.

Results

Twelve studies representing 342 patients were identified. The pooled mean body mass index was reduced by 17.9 kg/m2 (95% confidence interval [CI], 16.5-19.3) from 55.3 kg/m2 (95% CI, 53.5-57.1) to 37.7 kg/m2 (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).

Conclusion

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.

Section snippets

Search Strategy

With the assistance of a reference librarian, we performed an online search of the MEDLINE and EMBASE databases to identify potentially relevant studies. Search terms included obstructive sleep apnea, obstructive sleep apnoea, sleep-disordered breathing, bariatric surgery, surgical weight loss, gastric bypass, and obesity. All databases were searched from inception to March 17, 2008. The search was limited to case series reporting data on patients who underwent a clinical assessment and

Results

A total of 2309 references were retrieved by the search. The flow of studies is shown in Figure 1. Review of the titles allowed for exclusion of 2249 publications. We reviewed the abstracts for 60 publications. Of the abstracts reviewed, 22 articles were reviewed. After excluding duplicate studies and studies that did not meet the inclusion criteria, we identified 12 studies representing 342 patients for inclusion.

The characteristics of the included studies are shown in Table 1. Most studies

Discussion

The results of our meta-analysis corroborate previously reported improvements in AHI after bariatric surgery. The overall effect size of the pooled, weighted data shows a reduction of 38.2 events per hour in the combined study results, a combined reduction in AHI of 71%. This is a substantial improvement for obese patients with sleep apnea. However, residual disease is seen in the majority of patients (62%) after bariatric surgery with a mean residual AHI of more than 15 events per hour. A

Conclusions

Given the limitations of the pooled studies and the finding that the mean follow-up BMIs of patients in both aggregate and individual patient data analyses were still in the obese range, additional larger, prospective studies are needed to better define patients for whom follow-up polysomnograms are warranted. The high prevalence of clinically unsuspected OSA identified in patients before bariatric surgery has led some bariatric surgical centers to universally screen all patients with baseline

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  • Cited by (0)

    Funding: None.

    Conflict of Interest: All authors are employees of the Department of Defense. Expressed opinions represent those of the authors and do not represent those of the Department of Defense.

    Authorship: All authors had access to the data and played a role in writing this manuscript.

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