The effect of weight loss on OSA severity and position dependence in the bariatric population.

BACKGROUND: The aims of this study were to determine the prevalence of positional obstructive sleep apnea (POSA) in patients undergoing bariatric surgery and to evaluate the effect of weight loss brought about by bariatric surgery on POSA. Furthermore, the authors investigated whether body mass index (BMI), neck circumference, apnea-hypopnea index (AHI), and age are predictors for POSA. METHOD: A retrospective cohort study was conducted with data collected from patients who were screened for OSA pre-bariatric surgery and completed a follow-up polysomnography post bariatric surgery from August 2008 to November 2012. Descriptive statistics were used to characterize the prevalence of POSA patients, and the Mann-Whitney and Wilcoxon signed-rank tests were used to examine differences between the POSA and non-POSA groups. A logistic regression model was used to determine predictors for POSA. RESULTS: Thirty-four percent of patients had POSA, which is significantly lower (p<0.001) than in the general population. BMI, neck circumference, and AHI were significantly lower in POSA patients. AHI was the only significant independent predictor for POSA. Of the 91 patients analyzed following bariatric surgery, 35.2% (n=32) no longer had OSA. CONCLUSION: The prevalence of POSA in patients undergoing bariatric surgery is significantly lower than the prevalence noted in the general population. A low AHI was shown to be the only significant independent predictor for the presence of POSA.

Evaluation of position dependency in non-apneic snorers.

The aims of this study are to determine the prevalence of position dependency in non-apneic snorers, as defined by the American Academy of Sleep Medicine (AASM) guidelines, and to investigate the influence of various factors such as BMI, neck circumference, age, gender, and sleep efficiency on sleeping position. A cohort of consecutive patients was screened for complaints of excessive snoring or symptoms suspicious for sleep disordered breathing. Overnight polysomnographic data were collected and non-apneic snorers who met all the inclusion criteria were selected for statistical analysis. To assess position-dependent snoring, the snore index (total snores/h) was used. Supine-dependent patients were defined as having a supine snore index higher than their total non-supine snore index. 76 patients were eligible for statistical analysis. Prevalence of position dependency in non-apneic snorers was 65.8% (p < 0.008). A stepwise regression showed that only BMI had a significant effect (p < 0.003) on the supine snore index. This is the first study that uses the AASM guidelines to accurately define non-apneic snorers (AHI < 5) and provides scientific evidence that the majority of non-apneic snorers are supine dependent. Furthermore, these results show that non-apneic snorers with a higher BMI snore more frequently in supine position. The use of sleep position therapy therefore, has the potential to play a significant role in improving snoring and its associated physical and psychosocial health outcomes in this population.

Sleep-disordered breathing in pregnancy: a review of the physiology and potential role for positional therapy.

BACKGROUND: Sleep disordered breathing (SDB) has been shown to be associated with negative clinical sequelae such as systemic hypertension and cardiovascular disease. It has been reported in the literature that approximately 53-56 % of patients with obstructive sleep apnea (OSA) have positional OSA, known as POSA. POTENTIAL TREATMENT FOR SDB IN PREGNANCY: These findings have led to a resurgence of positional therapy as an effective treatment for select patients with SDB. Pregnant patients can also be diagnosed with SDB, the negative consequences of which not only pertain to the patient but to the unborn fetus as well. Despite this, however, SDB is under-diagnosed in pregnant patients and research looking at SDB in pregnant patients and potential therapies are scarce. CONCLUSIONS: This article reviews the literature regarding the physiologic respiratory changes that occur during pregnancy, SDB in pregnancy, supine hypotensive syndrome (SHS), complications and current treatments for these events and potential roles for positional therapy in pregnant women whose problems may be specifically position dependent.