***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Nocturnal gastroesophageal reflux ( nGER ) is common in patients with obstructive sleep apnea ( OSA ) . Small , short-term studies have shown that treatment with nasal continuous positive airway pressure ( CPAP ) decreases esophageal acid exposure . OBJECTIVE To examine the relationship between OSA and nGER , and the effect of CPAP on nGER , in a long-term follow-up study of a large cohort of patients with OSA and nGER . METHODS We prospect ively studied 331 patients diagnosed as having OSA between October 1 , 1993 , and November 30 , 2000 . At baseline , patients grade d their frequency of nGER symptoms on a scale of 1 ( never ) to 5 ( always ) . All patients were prescribed CPAP for their OSA . At follow-up , the frequency of nGER symptoms was obtained by telephone interview . RESULTS Of the 331 patients with OSA , nGER was present in 204 ( 62 % ) before treatment with CPAP . Follow-up was obtained in 181 patients ( 89 % ) . Of these 181 patients , 165 ( 91 % ) were still using CPAP and 16 ( 9 % ) were not , forming the treatment and control groups , respectively . The patients compliant with CPAP had a significant improvement in nGER score , from a mean of 3.38 before CPAP treatment to 1.75 after treatment ( 48 % improvement ; P<.001 ) , while patients not using CPAP ( control subjects ) showed no improvement ( mean , 3.56 to 3.44 ; P = .55 ) . There was a strong correlation between CPAP pressure and improvement in nGER score ( correlation , r = 0.70 ; P<.001 ) , with patients with higher CPAP pressures demonstrating a greater improvement in nGER score . CONCLUSIONS Nocturnal GER is common in patients with OSA . Treatment with nasal CPAP decreases the frequency of nGER symptoms by 48 % . Higher nasal CPAP pressures are associated with greater improvement in nGER BACKGROUND Patients with laryngopharyngeal reflux ( LPR ) undergoing treatment appear to have improvement in symptoms before the complete resolution of the laryngeal findings . OBJECTIVE To determine whether patients with LPR experience an improvement in symptoms before the complete resolution of the laryngeal findings . METHODOLOGY Forty consecutive patients with LPR documented by double-probe pH monitoring were evaluated prospect ively .  Symptom response to therapy with proton pump inhibitors was assessed at 2 , 4 , and 6 months of treatment with a  self-administered reflux symptom index ( RSI ) . In addition , transnasal fiberoptic laryngoscopy ( TFL ) was performed and a reflux finding score ( RFS ) was determined for each patient at each visit . RESULTS The mean RSI at entry was 19.3 ( + /- 8.9 st and ard deviation ) and it improved to 13.9 ( + /- 8.8 ) at 2 months of treatment ( P < .05 ) . No further significant improvement was noted at 4 months ( 13.1 + /- 9.8 ) or 6 months ( 12.2 + /- 8.1 ) of treatment . The RFS at entry was 11.5 ( + /- 5.2 ) , and it improved to 9.4 ( + /- 4.7 ) at 2 months , 7.3 ( + /- 5.5 ) at 4 months , and 6.1 ( + /- 5.2 ) after 6 months of treatment ( P < .05 with trend ) . CONCLUSIONS Symptoms of LPR improve over 2 months of therapy . No significant improvement in symptoms occurs after 2 months . This preliminary report demonstrates that the physical findings of LPR resolve more slowly than the symptoms and this continues throughout at least 6 months of treatment . These data imply that the physical findings of LPR are not always associated with patient symptoms , and that treatment should continue for a minimum of 6 months or until complete resolution of the physical findings Nocturnal gastro-oesophageal reflux has been observed in patients with obstructive sleep apnoea ( OSA ) . Negative intrathoracic pressure during apnoeas and arousal have been suggested as the underlying mechanisms . In order to evaluate this hypothesis , the coincidence and sequence in time of arousal , apnoea and reflux events were analysed . Fifteen patients with OSA or heavy snoring were studied by means of st and ard polysomnograpy with parallel recording of 24-h oesophageal pH.  Reflux events during the day were present in all patients , five of whom had symptoms of reflux . In three of these and in five other patients , a total of 69 nocturnal reflux events were found . In 68 events , arousal was found with the reflux event . Only one reflux without arousal was found ( sleep stage 2 ) . Seventeen events occurred during wakefulness after sleep onset . The percentage of time with a pH of < 4 during wakefulness after sleep onset was significantly higher than the percentage of time with a pH of < 4 during total sleep time ( p<0.05 ) . In 37 of the 52 reflux events which occurred during sleep , either an apnoea or a hypopnoea was found prior to the event . The investigation of sequence in time did not prove a causal relation between respiratory events and reflux events . The results indicate that gastro-oesophageal reflux and obstructive sleep apnoea are two separate disorders , which both have a high prevalence in obese patients OBJECTIVE : To determine the efficacy of pantoprazole therapy for daytime somnolence , psychomotor vigilance , and quality of life in patients with mild-moderate obstructive sleep disordered breathing ( OSDB ) and gastroesophageal reflux disease ( GERD ) . STUDY DESIGN : R and omized , double-blind , placebo-controlled crossover trial . METHODS : Sixty patients with daytime sleepiness , mildmoderate OSDB and GERD were r and omly assigned a 2-week treatment with pantoprazole 40 mg or placebo followed by a 2-week washout period and crossover respectively to 2-week treatment with placebo or pantoprazole . Outcomes included Epworth Sleepiness Score ( ESS ) , sleep-related quality -of-life ( FOSQ ) , and reaction time . RESULTS : With pantoprazole , patients reported statistically significantly greater improvement of overall reflux symptoms ( P = 0.0003 ) and in ESS ( P = 0.04 ) . A significant improvement was noted in FOSQ for both treatments with a trend toward greater improvement with pantoprazole ( P = 0.058 ) . No improvement in reaction times was observed . CONCLUSION : Patients with coexistent GERD and OSDB noted significant improvement in daytime sleepiness after treatment with pantoprazole over placebo likely related to a reduction in nocturnal reflux-related arousals OBJECTIVES To study the geographical variation in daytime sleepiness , snoring and disrupted breathing during sleep and to identify and compare risk factors using the same method in four European cities . DESIGN A cross-sectional , multicentre epidemiological survey . SETTING Reykjavik in Icel and , Uppsala and Göteborg in Sweden and Antwerp in Belgium . PARTICIPANTS A r and om population sample of 2202 subjects who participated in the European Community Respiratory Health Survey . MAIN OUTCOME MEASURES Sleep disturbances and daytime symptoms . RESULTS At all the centres , 5 % of the men and 2 - 3 % of the women reported snoring every night . Daytime sleepiness ( DS ) was more often reported in Uppsala [ odds ratio ( OR ) and 95 % confidence interval : 1.6 ( 1.2 - 2.1 ) ] than in the other centres , whilst daytime tiredness ( DT ) was most common in Reykjavik [ OR 1.8 ( 1.4 - 2.1 ) ] . Snoring was positively correlated with age , male gender and body-mass index in all areas . Symptoms of gastro-oesophageal reflux were associated with DS : OR 2.6 ( 1.5 4.4 ) and DT : OR 4.5 ( 2.7 - 7.6 ) and disrupted breathing : OR 3.8 ( 1.4 - 10 ) . DS and DT were reported more often by women than by men . CONCLUSION The prevalence of snoring was about the same in all four areas , whilst there was a geographical variation in daytime sleepiness and tiredness . As complaints of DS and DT and disrupted breathing were more common in subjects who reported symptoms of gastro-oesophageal reflux , we suggest that polysomnographic studies comparing sleep patterns in adult patients with and without reflux should be conducted Transient , nocturnal elevations of blood pressure have been observed during apneic episodes in the sleep apnea syndrome and may be caused by the acute consequences of sleep-disordered breathing such as arousals , high negative intrathoracic pressures , nocturnal desaturation of oxyhemoglobin , hypercapnia , or increased sympathetic nerve activity [ 1 ] . However , the mechanism by which these intermittent nocturnal events contribute to sustained , daytime hypertension is not known . It has been postulated that repetitive hemodynamic oscillations caused by frequent apneic episodes occurring in rapid succession may prevent systemic blood pressures from returning to baseline levels and that this may in turn result in neurohumoral or vascular changes leading to elevated waking pressures and sustained hypertension [ 2 ] . Several casecontrol and cross-sectional studies suggest that hypertension is highly prevalent ( 50 % to 90 % ) in patients with the sleep apnea syndrome [ 1 - 5 ] .  Sleep apnea has also been reported to occur frequently ( 22 % to 62 % ) in patients with essential hypertension [ 6 - 9 ] . However , in these studies blood pressure readings were collected at one time of day in the clinic [ 6 , 9 ] or from records of reported hypertension [ 7 , 8 ] in highly selected patient population s such as patients with severe obstructive sleep apnea [ 1 - 5 ] . Some studies found a strong association between sleep apnea and hypertension whereas others failed to do so . Inconsistencies in the results are probably caused by nonuniform definitions of hypertension and apnea , differences in methods and population s studied , lack of appropriate control participants , and failure to control for confounding factors such as age , sex , and obesity . Self-reported habitual , heavy snoring has also been associated with hypertension [ 10 - 13 ] . Because most people with sleep apnea snore , however , polysomnographic data are needed to separate participants with sleep apnea and to assess the association with snoring alone . In the earlier surveys , no objective data on breathing during sleep were available , so it was not possible to determine if any or all of the measured association was caused by the inclusion of apneic persons among snorers . In recent epidemiologic studies that included polysomnographic data , it was found that once sleep apnea was incorporated into the analysis , snoring did not contribute independently to the prediction of hypertension [ 14 ] . The most compelling evidence that sleep apnea can cause sustained high blood pressure comes from studies that have shown a reduction in blood pressure after sleep apnea was treated [ 6 , 15 - 22 ] . However , interpretation of these intervention studies is difficult because of the confounding effect of weight loss that occurred in several studies [ 17 - 19 , 22 ] or lack of data on weight change [ 6 , 12 , 16 , 20 , 23 ] . Weight loss alone has been shown to reduce blood pressure [ 23 ] . Collectively , these studies suggest the hypothesis that sleep-disordered breathing plays a causal role in hypertension . In view of recent estimates of sleep apnea prevalence of 9 % for women and 24 % for men [ 24 ] , there is a clear need to investigate how sleep-disordered breathing at the milder end of the severity spectrum , including habitual snoring without sleep apnea , is related to blood pressure . Our purpose was to determine how ambulatory blood pressure measurements obtained during an entire 24-hour period , while awake and asleep , differed among people with and without sleep-disordered breathing in the general population . To avoid previous problems of relying on casual blood pressure measurements , of difficulty in separating effects of snoring from those of sleep apnea , and of selection bias between groups , we studied 147 employed adults enrolled in a long-term study of risk factors , natural history , and health consequences of sleep-disordered breathing using 24-hour ambulatory blood pressure monitoring and overnight polysomnography . Methods One hundred and forty-seven persons were recruited from the Wisconsin Sleep Cohort Study , an ongoing prospect i ve study of sleep-disordered breathing . The details of the design and sampling scheme for the Sleep Cohort Study have been described previously [ 24 ] . We used a two-stage sampling scheme design ed to yield a cohort of men and women with a wide range of sleep-disordered breathing . For the first stage , all state employees , aged 30 to 60 years , from four large agencies were surveyed on sleep characteristics , health history , and sociodemographics by mailed question naire . For the second stage , all survey participants reporting habitual ( almost every night ) snoring , snorting , or breathing pauses , or extremely loud snoring ( design ated snorers ) and a r and om sample of the remaining participants ( design ated nonsnorers ) were recruited for laboratory sleep studies , with an overall ratio of one nonsnorer for every two snorers . During a 1-year period , 163 employees consecutively studied by overnight polysomnography in the Sleep Research Laboratory at the University of Wisconsin Clinical Research Center were asked to participate in the blood pressure  study : Of these , 147 participants agreed and were successfully studied ( 
    Output:
    
In conclusion , available studies do not provide enough evidence to make firm conclusions about the effects of PPI treatment on OSA symptoms and indices in patients with concomitant GERD .
This treatment may improve the quality of sleep without any effect on apnea-hypopnea indices