Obese Sleep Apnea Patients Research Articles

A Two-Year Weight Reduction Program in Obese Sleep Apnea Patients

To evaluate the effects of a 2-year weight reduction program on respiratory disturbances, arousal index, daytime sleepiness, metabolic status, and quality of life in obese patients with obstructive sleep apnea syndrome (OSAS). Prospective intervention study of 33 consecutive obese OSAS patients (24 men, 9 women); 19 subjects used continuous positive airway pressure and 4 used mandibular retaining device, except during nights with sleep recording. The program consisted of 8 weeks of low calorie diet followed by group meetings with behavioral change support. Seventy percent of the patients completed the program; 67% completed the sleep recordings. The success rate for the apnea-hypopnea index (AHI) (< 20 and reduction > or = 50%) was 15% in the intention to treat (ITT) analysis. The AHI showed a nonsignificant decrease in mean values, from 43 to 28. The oxygen desaturation index (ODI) decreased from 42 to 23 (p = 0.010), arousal index from 24 to 11 (p = 0.019), body mass index from 40 to 35 (p = 0.003) and the Epworth Sleepiness Scale (ESS) from 9 to 5 (p = 0.026), all ITT. Metabolic status, physical functioning, and vitality evaluations improved only in the per protocol analysis. Reduction in weight correlated significantly to reductions in ESS (p = 0.038) and insulin levels (p = 0.002), respectively. There were no differences based on gender or use/non-use of OSAS treatment device. Our weight reduction program showed a limited success in reducing AHI. However, there were significant improvements in weight, ODI, arousal index, and subjective symptoms. We recommend the program as an adjunct treatment for well-motivated obese OSAS patients.

Weight reduction improves sleep, sleepiness and metabolic status in obese sleep apnoea patients

In this prospective intervention study, 33 obese patients with obstructive sleep apnoea syndrome (OSAS) (24 men, 9 women) were consecutively enrolled for a weight reduction program at the Obesity Unit, Karolinska University Hospital. 23 of 33 patients used OSAS-device, 19 with Continuous Positive Airway Pressure and 4 with Mandibular Retaining Device. The patients were investigated with questionnaires, blood tests and ambulant nocturnal polysomnography before and after a 6-month program. Patients with OSAS-device slept without it during the sleep studies. The intervention consisted of 8 weeks low calorie diet and group meetings, followed by a day-care program of behaviour change support. 27 of 33 patients (82%, 21 men and 6 women) completed the study. After the intervention there were highly significant decreases (p < 0.001) in Body Mass Index from mean(S.D.) 40(5) to 34(3), apnoea-hypopnoea index from 43(24) to 26(20) and Epworth Sleepiness Scale (ESS)-score from 9(4) to 6(4). Sleep quality (arousal index, sleep efficiency, percentage deep sleep) and metabolic status (blood pressure, blood glucose levels, lipidemia) were also significantly improved. There was a significant correlation between increased percentage deep sleep and reduced ESS-score. There were no differences due to gender or use/no use of OSAS-device. The results suggest that weight loss, induced by low calorie diet and behaviour change support, significantly improves nocturnal respiratory parameters, sleep quality, daytime sleepiness and metabolic status in obese OSAS patients after 6 months.

Prevalence of Sleep Apnea in Morbidly Obese Patients who Presented for Weight Loss Surgery Evaluation: More Evidence for Routine Screening for Obstructive Sleep Apnea before Weight Loss Surgery

The incidence of obstructive sleep apnea has been underestimated in morbidly obese patients who present for evaluation for weight loss surgery. This retrospective study shows that the incidence of obstructive sleep apnea in this patient population is greater than 70 per cent and increases in incidence as the body mass index increases. Obstructive sleep apnea (OSA) is a common comorbidity in obese patients who present for evaluation for gastric bypass surgery. The incidence of sleep apnea in obese patients has been reported to be as high as 40 per cent. A retrospective review of our prospectively collected database was performed. All patients being evaluated for weight loss surgery for obesity were screened preoperatively for OSA using a sleep study. The overall incidence of sleep apnea in our patients was 78 per cent (227 of 290). All 227 were diagnosed by formal sleep study. There were 63 (22%) males and 227 (78%) females. The mean age was 43 years (range, 17-75 years). The mean body mass index (BMI) was 52 kg/m2 (range, 31-94 kg/m2). The prevalence of OSA in the severely obese group (BMI 35-39.9 kg/m2) was 71 per cent. For the morbidly obese group (BMI 40-40.9 kg/m2), the prevalence was 74 per cent and for the superobese group (BMI 50-59.9 kg/m2) 77 per cent. Those with a BMI 60 kg/m2 or greater, the prevalence of OSA rose to 95 per cent. The incidence of sleep apnea in patients presenting for weight loss surgery was greater than 70 per cent in our study. Patients presenting for weight loss surgery should undergo a formal sleep study to diagnose OSA before bariatric surgery.

Weight reduction improves nocturnal respiration in obese sleep apnoea patients—A randomized controlled pilot study

Randomized controlled pilot study of the effect of weight reduction on nocturnal respiratory parameters in obese patients with obstructive sleep apnoea syndrome (OSAS). Twenty consecutive obese male patients fulfilling OSAS criteria at Karolinska University Hospital were randomized into two groups. Intervention with an 8-week weight reduction programme consisting of a low-calorie diet, together with group meetings, was evaluated compared to expectancy alone for the control group, followed by a crossover. Follow-up at 3 months included anthropometrics and ambulant sleep apnoea recordings. Eleven of twenty men completed the protocol. There were significant differences between the intervention group (n = 6) and the control group (n = 5) in changes of weight (p < 0.01) and oxygen desaturation index (ODI4) (p < 0.05). We also found a significant positive correlation in these 11 males after the crossover between their reduction in weight and their reduction in ODI4 (p < 0.05). This pilot study indicates that weight reduction improves nocturnal respiration in obese OSAS patients after 3 months' dietary treatment compared to expectancy.

P317 Weight reduction improves sleep quality, sleepiness, and nocturnal respiration in obese sleep apnea patients

Objectives:Toevaluate theeffectofweight reductiononsleep quality and respiratory parameters during sleep in obese patients with obstructive sleep apnea syndrome (OSAS). Materials and methods: Prospective intervention study. Patients from the waiting list at the Obesity unit, KarolinskaUniversity Hospital, fulfilling the criteria of OSAS, were consecutively asked to participate in the study. Thirty-four agreed and were divided into four groups. The weight reduction program started with an eightweek long low-calorie diet (LCD) 50% reduction), 43% were cured. No gender differences between were found, nor between patients treated with CPAP/dental device and those without. Conclusions: Intensive weight reduction and behaviour change support in groups may be an effective treatment with improved sleep quality, sleepiness, and nocturnal respiration in obese sleep apnea patients, however, resource-demanding.

Antihypertensive therapy in the obese hypertensive patient

Obesity is becoming recognized as one of the most important risk factors for the development of hypertension. The purpose of the review is to examine the latest evidence linking hypertension to obesity, summarize the benefits of weight reduction and present results of recent clinical trials evaluating antihypertensive treatment in obese patients. Adipose tissue has been directly implicated in the pathogenesis of hypertension. Obesity has been associated with unequivocal changes in cardiovascular structure and function. In contrast to earlier studies, several recent trials included overweight and obese patients. Evidence of potential benefits of angiotensin blockade in the management of obesity hypertension is growing. Hypertension management in obese individuals is complicated by poorer response to treatment, and the increased need for multiple medications. It is important to consider obstructive sleep apnea in obese patients with resistant hypertension. Several new lines of evidence suggest that drugs blocking the renin-angiotensin system might be considered as first-line therapy of obesity-related hypertension. Recent progress in understanding the mechanisms of obesity and associated disease processes might lead to development of novel therapeutic strategies. Further research in this area holds great promise for prevention of obesity-related cardiovascular disease.

Left ventricular dysfunction, pulmonary hypertension, obesity, and sleep apnea.

The purpose of this study was to determine the frequency of central and obstructive sleep apnea in adult patients who have echocardiographic evidence of left ventricular dysfunction and pulmonary hypertension. Subjects with left ventricular dysfunction, pulmonary hypertension (pulmonary artery systolic pressure >30 mm Hg) and no lung disease were evaluated for risk factors associated with pulmonary hypertension. Of eight eligible adults, six completed the study. Subjects were from suburban and inner city family practices. Spirometric assessment, pulse oximetry on room air, rheumatologic evaluation, polysomnography, and additional history were taken. All six subjects had sleep apnea (apnea-plus-hypopnea index, or AHI, > or = 20): obstructive, central, or mixed. All were obese, and almost all the subjects had a restrictive pattern on spirometry, which is consistent with obesity. All had a pulmonary artery systolic blood pressure of 35 mm Hg or greater. None had daytime hypoxemia or collagen vascular disease, and none had ever used appetite suppressants. This study found a strong association between pulmonary hypertension and obstructive or central sleep apnea in obese patients with congestive heart failure (CHF). We propose that a pulmonary artery systolic pressure of 35 mm Hg or greater in ambulatory patients with CHF may signify an increased risk of sleep apnea.

Value of Clinical, Functional, and Oximetric Data for the Prediction of Obstructive Sleep Apnea in Obese Patients

To evaluate the diagnostic value of clinical features, pulmonary function testing, blood gas tensions, and oximetric data for case finding of obstructive sleep apnea (OSA) before polysomnography (PSG) in a series of consecutive overweight patients. We studied a population of 102 consecutive patients referred by an obesity clinic for suspected OSA, in whom body mass index was > or = 25 kg/m(2). The following tests were performed: clinical score (CS), pulmonary function tests (PFTs), measurement of arterial blood gas tensions, nocturnal oximetry, and full-night PSG. Six of 34 women and 34 of 68 men had OSA, defined by an apnea-hypopnea index > or = 15. CS and the cumulative time spent below 80% arterial oxygen saturation (SaO(2)) were higher, and PaO(2), minimal SaO(2), and mean nocturnal SaO(2) (mSaO(2)) were lower in OSA patients than in non-OSA patients. Logistic regression showed that sex, CS, and the ratio of FEV(1) over forced expiratory volume in 0.5 s (an index of upper airway obstruction on flow-volume curves) and mSaO(2), expressed as categorical variables, were independent predictors of OSA. None of these individual variables had a satisfactory diagnostic value for the diagnosis of OSA. A logistic regression model including sex and all continuous variables would have allowed us to predict the presence or absence of OSA confidently in 72.5% of the population, in whom the positive predictive value of the model was 94% and the negative predictive value was 90%. In obese patients referred to a respiratory sleep laboratory and evaluated by CS, PFTs, arterial blood gases, and oximetry, no individual sign or symptom may accurately predict the presence or absence of OSA. Provided that it is validated in prospective studies, a logistic regression model using these variables may be useful for the prediction of OSA.

Inferior sagittal osteotomy with hyoid bone suspension for obese patients with sleep apnea.

An inferior sagittal osteotomy with a sliding mandibular osteotomy and hyoid bone suspension, combined with a uvulopalatopharyngoplasty, is advocated in patients with obstructive sleep apnea who fail to tolerate nasal continuous positive airway pressure. Some investigators have suggested that this surgical procedure may be less effective in obese patients. Preoperative and postoperative nocturnal polysomnograms and lateral cephalometric radiographs were obtained on 12 obese patients with obstructive sleep apnea who underwent these procedures. The mean +/- SD respiratory disturbance index during sleep decreased 53% +/- 11% after surgical procedures were performed (49 +/- 17 vs 23 +/- 11 events per hour, P < .001). Surgical outcome did not correlate with the body mass index, and 5 (71%) of 7 of the morbidly obese patients (body mass index, > or = 33) had greater than a 50% reduction in the respiratory disturbance index after the surgical procedures were done. An inferior sagittal osteotomy with a sliding mandibular osteotomy and hyoid bone suspension, combined with a uvulopalatopharyngoplasty, tends to improve obstructive sleep apnea in obese patients.

Sleep Apnea and Sleep Disruption in Obese Patients

To describe the frequency and severity of sleep apnea in obese patients without a primary sleep complaint and to assess the sleep patterns of obese patients without apnea and compare them with the sleep patterns of nonobese controls. Prospective case series with historical controls in an obesity and sleep disorders clinic. Two hundred obese women and 50 obese men (mean body mass index, 45.3) consecutively referred for treatment of their obesity and 128 controls matched for age and sex. Eight-hour sleep laboratory recording, including electroencephalogram, electro-oculogram, electromyogram, and respirations. Subjectively reported sleep-related symptoms and signs were also recorded. Twenty men (40%) and six women (3%) demonstrated sleep apnea warranting therapeutic intervention. Another four men (8%) and 11 women (5.5%) showed sleep apneic activity that warranted recommendation for evaluation in the sleep laboratory. In contrast, none of the 128 controls demonstrated sleep apneic activity severe enough for therapeutic intervention. The best clinical predictors of sleep apnea in the obese population were severity of snoring, subjectively reported nocturnal breath cessation, and sleep attacks. Obese patients, both men and women, without any sleep-disordered breathing demonstrated a significant degree of sleep disturbance compared with nonobese controls. Wake time after sleep onset, number of awakenings, and percentage of stage 1 sleep were significantly higher in obese patients than in controls, while rapid eye movement sleep was significantly lower. Severely or morbidly obese men are at extremely high risk for sleep apnea and should be routinely evaluated in the sleep laboratory for this condition, while for severely or morbidly obese women the physician should include a thorough sleep history in the clinical assessment.

Pulmonary Function and Respiratory Chemosensitivity in Moderately Obese Patients with Sleep Apnea

To determine whether moderately obese, normocapnic, sleep apnea patients are distinguished from normal obese individuals by differences in waking pulmonary function and respiratory chemosensitivity, we compared the waking pulmonary function, hypercapnic, and hypoxic ventilatory responses of 35 nonhypercapnic sleep apnea patients (32 men and 3 women) with those of 17 age-, sex-, weight-, and obesity-matched nonapneic control subjects (16 men and 1 woman). The waking ventilatory response to hypercapnia was lower among sleep apnea patients (mean +/- SD, 2.05 +/- 1.29 L/min/mm Hg) than control subjects (3.02 +/- 2.05 L/min/mm Hg, p < 0.05). Patients with sleep apnea demonstrated a higher waking PaCO2 (40.4 +/- 2.9 vs 37.0 +/- 2.7 mm Hg, p < 0.001), and a lower waking PaO2 (81.4 +/- 11.7 vs 89.7 +/- 10.4 mm Hg, p < 0.03). The waking hypoxic ventilatory response, however, was not significantly different between the groups. Moreover, control subjects had a higher total lung capacity than sleep apnea patients (6.99 +/- 1.12 L and 6.27 +/- 1.09 L, respectively, p < 0.05). The lower hypercapnic ventilatory response, higher waking PaCO2, and lower total lung capacity in the sleep apnea patients resemble the pattern observed in patients with pickwickian syndrome. This suggests that disturbances in pulmonary function and ventilatory control in moderately obese sleep apnea patients are intermediate along a continuum from normal obesity to the pickwickian syndrome.

Bariatric surgery in morbidly obese sleep-apnea patients: short- and long-term follow-up

Forty-seven obese sleep-apnea patients were investigated in the sleep laboratory before and after a massive weight reduction achieved by bariatric surgery. The first postoperative sleep investigations were performed approximately 1 y after surgery and revealed a highly significant decrease in the number of apneic episodes per hour of sleep and a significant improvement in all sleep-quality-related measures. A second postoperative sleep study was performed approximately 7 y postoperatively and revealed that regaining of weight was associated with the reappearance of sleep apnea syndrome, although the great majority of the patients still felt, subjectively, that they were well and did not suffer from recurrence of the sleep apnea syndrome.