NEW YORK (Reuters Health) – Patients who undergo bariatric surgery should not expect it to cure their obstructive sleep apnea, according to results of a meta-analysis published in the June issue of The American Journal of Medicine.

Dr. David L. Greenburg of Walter Reed Army Medical Center in Washington, DC and colleagues analyzed 12 reports involving 342 patients, including 5 prospective trials. All but one study had fewer than 50 participants.

According to Dr. Greenburg’s team, the random-effects mean pooled body mass index was reduced from 55.3 to 37.7.

With regard to the mean apnea-hypopnea index (AHI), the researchers found that the baseline rate of 54.7 events per hour was reduced by 71%.

They point out, however, that despite this “substantial improvement,” the mean residual AHI was 15.8 events per hour, which “reflects moderate disease severity and may contribute to adverse medical sequelae, such as hypertension, heart disease, stroke, and difficulty with weight control.”

The investigators caution, “Given the limitations of the pooled studies and the finding that the mean follow-up body mass indices in both aggregate and individual patient analyses were still in the obese range, additional larger, prospective studies are needed to better define patients for whom follow-up polysomnograms are warranted.”

Until then, Dr. Greenburg and colleagues conclude, “clinicians should have low thresholds” for re-evaluating patients for obstructive sleep apnea after bariatric surgery.

Reference:
Am J Med 2009;122:535-542.