Subjective sleepiness and daytime functioning in bariatric patients with obstructive sleep apnea.

PURPOSE: The purpose of this study was to evaluate associations between obstructive sleep apnea (OSA) severity and self-reported sleepiness and daytime functioning in patients considering bariatric surgery for treatment of obesity. METHODS: Using a retrospective cohort design, we identified 342 patients who had sleep evaluations prior to bariatric surgery. Our final sample included 269 patients (78.6 % of the original cohort, 239 females; mean age = 42.0 ± 9.5 years; body mass index = 50.2 ± 7.7 kg/m(2)) who had overnight polysomnography and completed the Epworth Sleepiness Scale (ESS) and the Functional Outcomes of Sleep Questionnaire (FOSQ). Patients' OSA was classified as none/mild (apnea-hypopnea index (AHI) < 15, n = 112), moderate (15 ≤ AHI < 30, n = 77), or severe (AHI ≥ 30, n = 80). We calculated the proportion of unique variance (PUV) for the five FOSQ subscales. ANOVA was used to determine if ESS and FOSQ were associated with OSA severity. Unpaired t tests compared ESS and FOSQ scores in our sample with published data. RESULTS: The average AHI was 29.5 ± 31.5 events per hour (range = 0-175.8). The mean ESS score was 6.3 ± 4.8, and the mean global FOSQ score was 100.3 ± 18.2. PUVs for FOSQ subscales showed moderate-to-high unique contributions to FOSQ variance. ESS and global FOSQ score did not differ by AHI group. Only the FOSQ vigilance subscale differed by OSA severity with the severe group reporting more impairment than the moderate and none/mild groups. Our sample reported less sleepiness and daytime impairment than previously reported means in patients and controls. CONCLUSIONS: Subjective sleepiness and functional impairment were not associated significantly with OSA severity in our sample of patients considering surgery for obesity. Further research is needed to understand individual differences in sleepiness in patients with OSA. If bariatric patients underreport symptoms, self-report measures are not an adequate substitute for objective assessment and clinical judgment when evaluating bariatric patients for OSA. Patients with severe obesity need evaluation for OSA even in the absence of subjective complaints.

Predicting obstructive sleep apnea among women candidates for bariatric surgery.

BACKGROUND: More women than men pursue bariatric surgery for treatment of obesity. Untreated obstructive sleep apnea (OSA) in bariatric patients increases perioperative morbidity and mortality, and, therefore, most bariatric surgeons screen for OSA with polysomnography (PSG). We sought to develop a model for predicting OSA in women seeking bariatric surgery in order to use this diagnostic resource most efficiently. METHODS: We identified 296 women who had PSG in preparation for bariatric surgery. Regression and logistic regression analyses were used to assess the relationship between history and physical examination findings and OSA severity. After developing best statistical models, we constructed a summary index to identify patients exceeding clinical thresholds for mild (apnea-hypopnea index [AHI] ≥ 5) and moderate to severe disease (AHI ≥ 15). RESULTS: In our sample, most women (86%) had OSA, and more than half (53%) had moderate to severe disease. Multiple logistic regression showed that age, body mass index (BMI), neck circumference, hypertension, witnessed apneas, and snoring predicted AHI. Diabetes mellitus and daytime sleepiness measured with the Epworth Sleepiness Scale (ESS) were not significant predictors of OSA. Prediction models were statistically significant but had poor specificity for predicting OSA severity. CONCLUSIONS: OSA is highly prevalent in symptomatic and asymptomatic women planning bariatric surgery for obesity. Best prediction models based on clinical characteristics did not predict disease severity under conditions superior to those in which they might be applied. In light of the perioperative risks associated with OSA in bariatric patients, all women considering bariatric surgery for obesity should be evaluated for OSA with PSG.

The impact of cardiac resynchronization therapy on obstructive sleep apnea in heart failure patients: a pilot study.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been shown to improve cardiac function and reduce Cheyne-Stokes respiration but has not been evaluated in patients with obstructive sleep apnea (OSA). In this pilot study, we investigated the impact of both CRT and CRT plus increased rate pacing in heart failure (ie, congestive heart failure [CHF]) patients with OSA. We hypothesized that through increased cardiac output CRT/pacing would reduce obstructive events and daytime symptoms of sleepiness. METHODS: Full polysomnograms were performed on CHF patients who were scheduled for CRT, and those patients with an apnea-hypopnea index (AHI) of > 5 events per hour were approached about study enrollment. Patients had a pre-CRT implant baseline echocardiogram and an echocardiogram a mean (+/- SEM) duration of 6.6 +/- 1.4 months post-CRT implant; polysomnography; and responded to the Minnesota Living with Heart Failure questionnaire, the Epworth sleepiness scale, and the Functional Outcomes of Sleep Questionnaire. An additional third polysomnography was performed combining CRT with a pacing rate of 15 beats/min above the baseline sleeping heart rate within 1 week of the second polysomnography. Assessments for the change in cardiac output during the polysomnography were performed using circulation time to pulse oximeter as a surrogate. RESULTS: Twenty-four patients were screened, and 13 patients (mean age, 68.6 years; body mass index, 28.7 kg/m(2)) had evidence of OSA. The mean AHI decreased from 40.9 +/- 6.4 to 29.5 +/- 5.9 events per hour with CRT (p = 0.04). The mean baseline ejection fraction was 22 +/- 1.7% and increased post-CRT to 33.6 +/- 2.0% (p < 0.05). The reduction in AHI with CRT closely correlated with a decrease in circulation time (r = 0.89; p < 0.001) with CRT. Increased rate pacing made no additional impact on the AHI or circulation time. CRT had a limited impact on sleep architecture or daytime symptom scores. CONCLUSIONS: CRT improved cardiac function and reduced the AHI. Reduced circulatory delay likely stabilized ventilatory control systems and may represent a new therapeutic target in OSA.