Effects of a palaeolithic diet on obstructive sleep apnoea occurring in females who are overweight after menopause-a randomised controlled trial.

BACKGROUND/OBJECTIVES: Obesity is the main risk factor for obstructive sleep apnoea, commonly occurring in females who are overweight after menopause. We aimed to study the effect of a palaeolithic diet on sleep apnoea in females with overweight after menopause from the population. METHODS: Seventy healthy, non-smoking females with a mean age of 60 years and a mean BMI of 33 kg/m2 were randomised to a palaeolithic diet or to a control low-fat diet according to Nordic Nutritional Recommendations, for 2 years. The apnoea-hypopnoea index was measured and daytime sleepiness was estimated during the intervention. RESULTS: The mean apnoea-hypopnoea index at baseline was 11.6 (95% CI 8.6-14.5). The mean weight loss was 7.2 kg (95% CI 5.3-9.2 kg) in the palaeolithic diet group and 3.9 kg in the control group (95% CI 1.9-5.9 kg); p < 0.021 for the group difference. The reduction in weight corresponded to a reduction in the apnoea-hypopnoea index in the palaeolithic diet group (r = 0.38, p = 0.034) but not in the control group (r = 0.08, p = 0.69). The apnoea-hypopnoea index was reduced in the palaeolithic diet group when the weight was reduced by more than 8 kg. Daytime sleepiness according to the Epworth Sleepiness Scale score and the Karolinska Sleepiness Scale score was unaffected by dietary group allocation. CONCLUSIONS: A substantial decrease in body weight of 8 kg was needed to achieve a reduction in sleep apnoea in this small trial of women who are overweight after menopause. The palaeolithic diet was more effective for weight reduction than a control low-fat diet and the reduction in sleep apnoea was related to the degree of weight decrement within this diet group. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00692536.

Positive Expiratory Pressure Therapy on Oxygen Saturation and Ventilation After Abdominal Surgery: A Randomized Controlled Trial.

Objective: To evaluate the immediate effects of positive expiratory pressure therapy on oxygen saturation and ventilation after abdominal surgery. Background: Positive expiratory pressure therapy to treat postoperative hypoxia is widespread, despite a lack of evidence of effect. Methods: This randomized, sham-controlled, crossover trial investigated adults 1-2 days after abdominal surgery at Umeå University Hospital, Sweden. The intervention was positive expiratory pressure of 10-15 cm H2O. The control was a sham device. The investigations were ended with deep-breathing maneuvers. Outcomes were the gradient of changes in peripheral oxygen saturation and transcutaneous carbon-dioxide partial pressure (PtcCO2). Results: Eighty patients were included and randomized and 76 patients were analyzed. Oxygen saturation increased from a baseline mean of 92% to 95%, P < 0.001, during positive expiratory pressure breathing, while PtcCO2 decreased from a mean of 36 to 33 mm Hg, P < 0.001. This was followed by apnea, oxygen desaturations to a mean of 89%, P < 0.001, and increased PtcCO2 before returning to baseline values. The changes in oxygen saturation and PtcCO2 did not differ from sham breathing or deep-breathing maneuvers. Conclusions: Positive expiratory pressure breathing after abdominal surgery improves oxygen saturation during the maneuver because of hyperventilation, but it is followed by apnea, hypoventilation, and oxygen desaturation. The effect is not different from the expiration to a sham device or hyperventilation. It is time to stop positive expiratory pressure therapy after abdominal surgery, as there is no evidence of effect in previous trials, apart from the adverse effects reported here.

Association between proteomics and obstructive sleep apnea phenotypes in a community-based cohort of women.

Proteomic-based technologies offer new opportunities to identify proteins that might reflect the cardiometabolic stress caused by different aspects of sleep-disordered breathing. We aimed to investigate whether severe obstructive sleep apnea and severe obstructive sleep apnea during rapid eye movement sleep are associated with changed levels of inflammatory and cardiac disease-related proteins in a population-based cohort of women. In the community-based "Sleep and Health in Women" (SHE) cohort study, 400 women underwent polysomnography, anthropometric measurements and blood sampling. Two proteomic assays (Olink Proseek® Inflammation panel and Olink Proseek® Cardiovascular II panel), each measuring 92 proteins, were analysed in a subsample of 253 women. p-Values were adjusted for multiple testing, with false discovery rate set at 10%. In unadjusted models, 57 proteins were associated with apnea-hypopnea index, 56 proteins with oxygen desaturation index and 64 proteins with rapid eye movement-apnea-hypopnea index. After adjustment for age, body mass index and plate, there were no significant associations between apnea-hypopnea index or oxygen desaturation index and any of the proteins. Severe obstructive sleep apnea during rapid eye movement sleep (rapid eye movement-apnea-hypopnea index ≥ 30) was associated with decreased levels of two anti-inflammatory proteins; Sirt2 (q-value .016) and LAP-TGF-ß1 (q-value .016). There was also a negative association between rapid eye movement-apnea-hypopnea index of ≥ 30 and Axin1 (q-value .095), a protein thought to facilitate TGF-ß-signalling. We conclude that severe obstructive sleep apnea during rapid eye movement sleep is associated with low levels of Sirt2, LAP-TGF-ß1 and Axin1, anti-inflammatory proteins involved in metabolic regulation and in the atherosclerotic process. For obstructive sleep apnea based on a whole night, the associations with cardiac and inflammatory proteins are weaker, and explained to a large extent by age and body mass index.

Can STOP-Bang and Pulse Oximetry Detect and Exclude Obstructive Sleep Apnea?

BACKGROUND: Obstructive sleep apnea (OSA) is related to postoperative complications and is a common disorder. Most patients with sleep apnea are, however, undiagnosed, and there is a need for simple screening tools. We aimed to investigate whether STOP-Bang and oxygen desaturation index can identify subjects with OSA. METHODS: In this prospective, observational multicenter trial, 449 adult patients referred to a sleep clinic for evaluation of OSA were investigated with ambulatory polygraphy, including pulse oximetry and the STOP-Bang questionnaire in 4 Swedish centers. The STOP-Bang score is the sum of 8 positive answers to Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index >35 kg/m, Age >50 years, Neck circumference >40 cm, and male Gender. RESULTS: The optimal STOP-Bang cutoff score was 6 for moderate and severe sleep apnea, defined as apnea-hypopnea index (AHI) ≥15, and the sensitivity and specificity for this score were 63% (95% CI, 0.55-0.70) and 69% (95% CI, 0.64-0.75), respectively. A STOP-Bang score of <2 had a probability of 95% (95% CI, 0.92-0.98) to exclude an AHI >15 and a STOP-Bang score of ≥6 had a specificity of 91% (95% CI, 0.87-0.94) for an AHI >15. The items contributing most to the STOP-Bang were the Bang items. There was a positive correlation between AHI versus STOP-Bang and between AHI versus oxygen desaturation index, Spearman ρ 0.50 (95% CI, 0.43-0.58) and 0.96 (95% CI, 0.94-0.97), respectively. CONCLUSIONS: STOP-Bang and pulse oximetry can be used to screen for sleep apnea. A STOP-Bang score of <2 almost excludes moderate and severe OSA, whereas nearly all the patients with a STOP-Bang score ≥6 have OSA. We suggest the addition of nightly pulse oximetry in patients with a STOP-Bang score of 2-5 when there is a need for screening for sleep apnea (ie, before surgery).

Nocturnal Blood Pressure Is Reduced by a Mandibular Advancement Device for Sleep Apnea in Women: Findings From Secondary Analyses of a Randomized Trial.

BACKGROUND: Obstructive sleep apnea is associated with high blood pressure. The magnitude of blood pressure effects from sleep apnea treatment is unclear. We aimed to determine the effect of mandibular advancement device therapy on ambulatory nighttime and daytime blood pressure in women and men with daytime sleepiness and snoring or mild to moderate sleep apnea (apnea-hypopnea index, <30). METHODS AND RESULTS: In this 4-month, double-blind, randomized controlled trial comprising 96 untreated patients, 27 women and 58 men, aged 31 to 70 years, completed the study. The active group received individually made adjustable mandibular advancement devices, and the control group was given individually made sham devices, to be used during sleep. Polysomnographic sleep recordings and ambulatory 24-hour blood pressure measurements were performed at baseline and at follow-up. In women with mandibular advancement devices, the mean nighttime systolic blood pressure was 10.8 mm Hg (95% confidence interval, 4.0-17.7 mm Hg; P=0.004) lower than in the women in the sham group, adjusted for baseline blood pressure, age, body mass index, and the apnea-hypopnea index. The mean nighttime adjusted diastolic blood pressure was 6.6 mm Hg (95% confidence interval, 2.7-10.4 mm Hg; P=0.002) lower in the mandibular advancement device group. In men, there were no significant differences in blood pressure at night or during the daytime between the intervention groups. CONCLUSIONS: A mandibular advancement device for obstructive sleep apnea reduces nocturnal blood pressure in women. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00477009.

Cardioversion of atrial fibrillation does not affect obstructive sleep apnea.

BACKGROUND: Sleep apnea is common in patients with atrial fibrillation, but the effect of the cardioversion of atrial fibrillation to sinus rhythm on central and obstructive apneas is mainly unknown. The primary aim of the study was to analyze the association between cardioversion of atrial fibrillation and sleep apneas, to investigate whether obstructive or central sleep apneas are reduced following cardioversion. A secondary objective was to study the effect on sleep quality. METHODS: Twenty-three patients with atrial fibrillation were investigated using overnight polysomnography, including esophagus pressure monitoring and ECG, before and after the cardioversion of persistent atrial fibrillation. RESULTS: Obstructive sleep apnea occurred in 17/23 patients (74%), and central sleep apnea in 6/23 patients (26%). Five patients had both obstructive and central sleep apnea. Sinus rhythm at follow-up was achieved in 16 patients. The obstructive apnea-hypopnea index, central apnea-hypopnea index, and the number of patients with obstructive or central sleep apnea did not differ before and after restoration of sinus rhythm. Sleep time, sleep efficiency, time in different sleep stages, and subjective daytime sleepiness were normal and unaffected by cardioversion. CONCLUSIONS: Both obstructive and central sleep apneas are highly prevalent in patients with persistent atrial fibrillation. Obstructive sleep apneas are unaffected by the cardioversion of atrial fibrillation to sinus rhythm. The sleep pattern is normal and unaffected by cardioversion in patients with atrial fibrillation. CLINICAL TRIAL REGISTRATION: Trial number NCT00429884.

Atrial fibrillation among patients under investigation for suspected obstructive sleep apnea.

STUDY OBJECTIVES: Obstructive sleep apnea is common among patients with atrial fibrillation, but the prevalence and risk factors for atrial fibrillation among patients who are being investigated on suspicion of sleep apnea are not well known. The aim of the study was to estimate the prevalence of atrial fibrillation among patients investigated for suspected obstructive sleep apnea and to identify risk factors for atrial fibrillation among them. METHODS: The prevalence of atrial fibrillation was investigated among 201 patients referred for suspected obstructive sleep apnea. Patients without known atrial fibrillation were investigated with a standard 12-lead ECG at hospital and short intermittent handheld ECG recordings at home, during 14 days. RESULTS: Atrial fibrillation occurred in 13 of 201 subjects (6.5%), and in 12 of 61 men aged 60 years and older (20%). The prevalence of atrial fibrillation increased with sleep apnea severity (p = 0.038). All patients with atrial fibrillation were men and all had sleep apnea. Age 60 or older, the occurrence of central sleep apnea and diabetes mellitus were independent risk factors for atrial fibrillation after adjustments for body mass index, gender, sleep apnea and cardiovascular disease. CONCLUSIONS: Atrial fibrillation is common among subjects referred for sleep apnea investigation and the prevalence of atrial fibrillation increases with sleep apnea severity. Independent risk factors for atrial fibrillation among patients investigated for suspected obstructive sleep apnea include the occurrence of coexisting central sleep apnea, age 60 years or older and diabetes mellitus.

Tonsillectomy in adults with obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: To study whether tonsillectomy is effective on obstructive sleep apnea (OSA) in adults with large tonsils. STUDY DESIGN: A multicenter prospective interventional study. METHODS: The study comprised 28 patients with OSA, an apnea-hypopnea index of > 10, large tonsils (Friedman tonsil size 3 and 4), and age 18 to 59 years. They were derived from 41 consecutive males and females with large tonsils referred for a suspicion of sleep apnea to the ear, nose, and throat departments in Umeå, Skellefteå, and Sunderbyn in northern Sweden. The primary outcome was the apnea-hypopnea index, measured with polygraphic sleep apnea recordings 6 months after surgery. Secondary outcomes included daytime sleepiness, as measured with the Epworth Sleepiness Scale, and swallowing function, using video-fluoroscopy. RESULTS: The apnea-hypopnea index was reduced from a mean of 40 units per hour (95% confidence interval [CI] 28-51) to seven units per hour (95% CI 3-11), P < 0.001, at the 6-month follow-up after surgery. The apnea-hypopnea index was reduced in all patients and 18 (64%) were cured. The Epworth Sleepiness Scale was reduced from a mean of 11 (95% CI 8-13) to 6.0 (95% CI 4-7), P < 0.001. A swallowing dysfunction was found in seven of eight investigated patients before surgery. Of those, swallowing function improved in five patients after surgery, whereas no one deteriorated. CONCLUSION: Tonsillectomy may be effective treatment for adult patients with OSA and large tonsils. Tonsillectomy may be suggested for adults with OSA and large tonsils. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2859-2862, 2016.

Sleep apnoea is a common occurrence in females.

Obstructive sleep apnoea (OSA) is primarily regarded as a male disorder, presenting with snoring, daytime sleepiness and cardiovascular disease. We aimed to determine the frequency of sleep apnoea among females in the general population. We investigated 400 females from a population-based random sample of 10,000 females aged 20-70 yrs. They answered a questionnaire and performed overnight polysomnography. OSA (apnoea/hypopnoea index (AHI) ≥5) was found in 50% (95% CI 45-55%) of females aged 20-70 yrs. Sleep apnoea was related to age, obesity and hypertension, but not to daytime sleepiness. Severe sleep apnoea (AHI ≥30) was present in 14% (95% CI 8.1-21%) of females aged 55-70 yrs and in 31% (95% CI 12-50%) of obese females with a body mass index of ≥30 kg·m(-2) aged 55-70 yrs. Sleep apnoea with daytime sleepiness and sleep apnoea with hypertension were observed as two different phenotypes of OSA. OSA occurs in 50% of females aged 20-70 yrs. 20% of females have moderate and 6% severe sleep apnoea. Sleep apnoea in females is related to age, obesity and hypertension, but not to daytime sleepiness. When searching for sleep apnoea in females, females with hypertension or obesity should be investigated.

Ambient temperature and obstructive sleep apnea: effects on sleep, sleep apnea, and morning alertness.

STUDY OBJECTIVES: The aim of the study was to investigate the effect of ambient temperature on sleep, sleep apnea, and morning alertness in patients with obstructive sleep apnea. DESIGN: Randomized controlled trial. SETTING: In-hospital investigations. PARTICIPANTS: Forty patients with obstructive sleep apnea naïve to treatment, with an apnea-hypopnea index of 10-30. INTERVENTIONS: Three different nights in room temperatures of 16°C, 20°C, and 24°C. MEASUREMENTS: Overnight polysomnography and Karolinska Sleepiness Scale. RESULTS: The obstructive apnea-hypopnea index was 30 ± 17 at 16°C room temperature, 28 ± 17 at 20°C, and 24 ± 18 at 24°C. The obstructive apnea-hypopnea index was higher at 16°C room temperature versus 24°C (P = 0.001) and at 20°C room temperature versus 24°C (P = 0.033). Total sleep time was a mean of 30 min longer (P = 0.009), mean sleep efficiency was higher (77 ± 11% versus 71 ± 13% respectively, P = 0.012), and the patients were significantly more alert according to the Karolinska Sleepiness Scale (P < 0.028) in the morning at 16°C room temperature versus 24°C. The amount of sleep in different sleep stages was not affected by room temperature. CONCLUSIONS: Untreated patients with obstructive sleep apnea sleep longer, have better sleep efficiency, and are more alert in the morning after a night's sleep at 16°C room temperature compared with 24°C, but obstructive sleep apnea is more severe at 16°C and 20°C compared with 24°C. CLINICAL TRIAL INFORMATION: This study is registered in ClinicalTrials.gov number NCT00544752.

Associations between short sleep duration and central obesity in women.

STUDY OBJECTIVES: The aim was to assess associations between sleep duration, sleep stages, and central obesity in women. DESIGN: Cross-sectional study. SETTING: City of Uppsala, Sweden. PARTICIPANTS: Population-based sample of 400 women (range 20-70 years). INTERVENTIONS: Full-night polysomnography and measurement of anthropometric variables. MEASUREMENTS AND RESULTS: Sleep duration was inversely related to both waist circumference and sagittal abdominal diameter. Sleep duration remained inversely related to waist circumference (adj. beta = -1.22 cm/h; P = 0.016) and sagittal abdominal diameter (adj. beta = -0.46 cm/h; P = 0.001) after adjusting for potential confounders. Duration of slow wave sleep (SWS, adj. beta = -0.058 cm/min; P = 0.025) and REM sleep (adj. beta = -0.062 cm/min; P = 0.002) were both inversely related to waist circumference afteradjustments. Moreover,duration of REM sleep was inversely related to sagittal abdominal diameter (adj. beta = -0.021 cm/min; P < 0.0001). These associations were stronger in young women (age < 50 years). CONCLUSION: An inverse relationship between short sleep duration and central obesity was found in women after adjusting for confounders. Loss of SWS and REM sleep may be important factors in the association between sleep loss and central obesity.

Heart rate variability during sleep and sleep apnoea in a population based study of 387 women.

Increased sympathetic activity during sleep has been suggested as a link between obstructive sleep apnoea syndrome and cardiovascular disease. Heart rate variability (HRV) is a measure of autonomic effect on the heart. Different parameters have been associated with sympathetic and parasympathetic activity. We have studied HRV in different sleep stages and related the HRV-pattern to sleep apnoea in a population-based sample of 387 women. We investigated the HRV-parameters standard deviation of all R-R intervals (SDNN), root of the averaged square of successive differences (RMSSD), low frequency component (LF), high frequency component (HF), ratio of low frequency component to high frequency component LF/HF and VSAI [variation in sympathetic activity between rapid eye movement (REM) and slow wave sleep, defined as LF(REM)-LF(SWS)]. The HRV-parameters were compared with the results of a full-night polysomnography. Hourly incidence of obstructive episodes was used for classifying the subjects into four apnoea-hypopnoea index (AHI)-groups (<5, > or =5 and <15, 15-30 and >30 events). Individual sleep stages were analysed by pooling all recordings. Women with high AHI had higher heart rate and LF/HF ratio. In subjects with AHI >30, LF/HF ratio however dropped to same level as with AHI <5. Subjects with high AHI had low VSAI. Levels of SDNN, LF and LF/HF ratio during REM and light sleep were similar to wakefulness. In slow wave sleep the parameters decreased. In conclusion, moderately increased prevalence of obstructive apnoeas was associated with signs of higher sympathetic activity. High AHI was however associated with a HRV-pattern suggestive of depressed sympathetic drive and lowered ability to increase it during REM.

Sleep in women: Normal values for sleep stages and position and the effect of age, obesity, sleep apnea, smoking, alcohol and hypertension.

OBJECTIVES: To define normal values for total sleep time, sleep latency, sleep efficiency, sleep stages and sleeping positions in women and to investigate how sleep is affected by age, obesity, sleep apnea, smoking, alcohol dependency and hypertension. METHODS: In a population-based study, 400 Swedish women aged 20-70 years with over-sampling of snorers were investigated using overnight in-home polysomnography. All results are weighted. RESULTS: The mean normal total sleep time was 392 min, sleep latency 22 min and sleep efficiency 82%. Women spent 31 min in sleep stage 1, 244 min in stage 2, 41 min in stage 3/4 and 76 min in rapid eye movement (REM) sleep. They spent 41% of their sleep time in the supine position, 50% in the lateral position and 9% in the prone position. Multivariate analyses revealed that sleep efficiency was lower in older women and in women with hypertension. Sleep latency was short in women with severe sleep apnea and long in smokers, alcohol-dependent and hypertensive women. Sleep stage 3/4 was inversely related to age and body mass index. Less REM sleep occurred in alcohol-dependent women. Women younger than 45 years old slept a mean of 42% in the lateral position while women of 45 years and older slept 57% in the lateral position (p<0.001). CONCLUSIONS: In this population-based study of women, we present normal values for sleep stages and sleeping position. We conclude that age, body mass index, obstructive sleep apnea, smoking, alcohol and hypertension reduce sleep quality. With age, women spend more time sleeping in the lateral position.

Obstructive sleep apnea is a risk factor for death in patients with stroke: a 10-year follow-up.

BACKGROUND: Sleep apnea occurs frequently among patients with stroke, but it is still unknown whether a diagnosis of sleep apnea is an independent risk factor for mortality. We aimed to investigate whether obstructive or central sleep apnea was related to reduced long-term survival among patients with stroke. METHODS: Of 151 patients admitted for in-hospital stroke rehabilitation in the catchment area of Umeå from April 1, 1995, to May 1, 1997, 132 underwent overnight sleep apnea recordings at a mean (SD) of 23 (8) days after the onset of stroke. All patients were followed up prospectively for a mean (SD) of 10.0 (0.6) years, with death as the primary outcome; no one was lost to follow-up. Obstructive sleep apnea was defined when the obstructive apnea-hypopnea index was 15 or greater, and central sleep apnea was defined when the central apnea-hypopnea index was 15 or greater. Patients with obstructive and central apnea-hypopnea indexes of less than 15 served as control subjects. RESULTS: Of 132 enrolled patients, 116 had died at follow-up. The risk of death was higher among the 23 patients with obstructive sleep apnea than controls (adjusted hazard ratio, 1.76; 95% confidence interval, 1.05-2.95; P = .03), independent of age, sex, body mass index, smoking, hypertension, diabetes mellitus, atrial fibrillation, Mini-Mental State Examination score, and Barthel index of activities of daily living. There was no difference in mortality between the 28 patients with central sleep apnea and controls (adjusted hazard ratio, 1.07; 95% confidence interval, 0.65-1.76; P = .80). CONCLUSIONS: Patients with stroke and obstructive sleep apnea have an increased risk of early death. Central sleep apnea was not related to early death among the present patients.

Sleep apnea and Down's syndrome.

OBJECTIVE: Obstructive sleep apnea has been reported to occur in 20-50% of children with Down's syndrome in case series of patients referred for evaluation of suspected sleep apnea. In this population-based controlled study, we aimed to investigate whether sleep apnea is related to Down's syndrome. MATERIAL AND METHODS: Every child aged 2-10 years with Down's syndrome residing in the Umeå healthcare district (n = 28) was invited to participate in the study, with their siblings acting as controls. Successful overnight sleep apnea recordings and echocardiography were performed in 17/21 children with Down's syndrome and in 21 controls. RESULTS: Obstructive sleep apnea could not be diagnosed, either in children with Down's syndrome or in the control children. The apnea-hypopnea index in the children with Down's syndrome was 1.2 +/- 1.5 and did not differ from that in controls. Snoring and hypertrophy of the tonsils were more common in children with Down's syndrome than in controls. Children with Down's syndrome slept for a shorter time (p < 0.001) and changed body position more often (p < 0.05) than the control children. CONCLUSIONS: Snoring, restless sleep and hypertrophy of the tonsils were common among children with Down's syndrome. Obstructive sleep apnea was, however, not related to Down's syndrome in the present population-based controlled study.