human
***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: Healthy subjects with normal nasal resistance  breathe almost exclusively through the nose during sleep . This study tested the hypothesis that a mechanical advantage might explain this preponderance of  nasal over oral breathing  during sleep . A r and omised , single-blind , crossover design was used to compare upper airway resistance during sleep in the nasal and oral breathing conditions in 12 ( seven male ) healthy subjects with normal nasal resistance , aged 30±4 ( mean±sem ) yrs , and with a body mass index of 23±1 kg·m2 . During wakefulness , upper airway resistance was similar between the oral and nasal breathing routes . However , during sleep ( supine , stage two ) upper airway resistance was much higher while breathing orally ( median 12.4 cmH2O·L−1·s−1 , range 4.5–40.2 ) than nasally ( 5.2 cmH2O·L−1·s−1 , 1.7–10.8 ) . In addition , obstructive ( but not central ) apnoeas and hypopnoeas were profoundly more frequent when breathing orally ( apnoea-hypopnoea index 43±6 ) than nasally ( 1.5±0.5 ) . Upper airway resistance during sleep and the propensity to obstructive sleep apnoea are significantly lower while breathing nasally rather than orally . This mechanical advantage may explain the preponderance of nasal breathing during sleep in normal subjects One thous and and one men , aged 35 - 65 years , were identified from the age-sex register of one group general practice . Over four years 900 men were visited at home and asked questions about symptoms potentially related to sleep apnoea and snoring . Height , weight , neck circumference , resting arterial oxygen saturation ( SaO2 ) , and spirometric values were also determined . All  night oximetry  was then performed at home and the tracing analysed for the number of dips in SaO2 of more than 4 % . Subjects with more than five dips of 4 % SaO2 or more per hour were invited for sleep laboratory polysomnography .  Seventeen per cent of the men admitted to snoring " often . " Multiple linear regression techniques identified and ranked neck circumference ( r2 = 7.2 % ) , cigarette consumption ( r2 = 3.4 % ) , and nasal stuffiness ( r2 = 2 % ) as the only significant independent predictors of snoring . Together these account for at least a sixfold variation in the likelihood of being an " often " snorer . Forty six subjects ( 5 % ) had greater than 4 % SaO2 dip rates of over five an hour and 31 of these had full sleep studies . Three subjects had clinical ly obvious and severe symptomatic obstructive sleep apnoea , giving a prevalence of three per 1001 men ( 0.3 % ; 95 % confidence interval 0.07 - 0.9 % ) . Eighteen men had  obstructive sleep apnoea  only when supine and in 10 the cause of the SaO2 dipping on the original home tracing was not eluci date d. The greater than 4 % SaO2 dip rates correlated with the history of snoring . Multiple linear regression techniques identified and ranked neck circumference ( r2 = 7.9 % ) , alcohol consumption ( r2 = 3.7 % ) , age ( r2 = 1 % ) and obesity ( r2 = 1 % ) as the only significant independent predictors of the rate of overnight hypoxic dipping . This study shows that snoring in this r and omly selected population correlates best with neck size , smoking , and nasal stuffiness . Obstructive sleep apnoea , defined by nocturnal hypoxaemia , correlates best with neck size and alcohol , and less so with age and general obesity Intranasal ipratropium bromide has been shown to significantly reduce  rhinorrhea .  Use of a freon-propelled intranasal preparation has result ed in side effects associated with the drying properties of the propellant . The purpose of the present trial was to study the safety and efficacy of a new isotonic aqueous ipratropium bromide nasal spray pump , specifically in patients with perennial nonallergic rhinitis . Two hundred thirty-three patients participated in an 8-week double-blind parallel comparison of ipratropium bromide nasal spray with its vehicle , a saline solution . Treatment with the ipratropium spray result ed in a 30 % reduction in rhinorrhea ; this reduction was significantly greater than that seen with the saline vehicle . There was a modest reduction in postnasal drip , sneezing , and congestion with both treatments , which may be attributable to the salutary effects of the saline solution . Patients also perceived a significant reduction in the degree to which rhinorrhea interfered with their daily activities and moods . Treatment was well tolerated , with no drug-related systemic adverse events and no evidence of nasal rebound on discontinuation of treatment . Minor , infrequent episodes of nasal dryness and epistaxis were the only significant adverse events reported ; these did not limit treatment BACKGROUND Limited data have suggested that sleep-disordered breathing , a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults . Data from the Wisconsin Sleep Cohort Study , a longitudinal study of the natural history of cardiopulmonary disorders of sleep , were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health . METHODS A r and om sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep ( the apnea-hypopnea score ) . We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score ( > or = 5 , > or = 10 , and > or = 15 ) ; we used logistic regression to investigate risk factors . RESULTS The estimated prevalence of sleep-disordered breathing , defined as an apnea-hypopnea score of 5 or higher , was 9 percent for women and 24 percent for men . We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome ( an apnea-hypopnea score of 5 or higher and daytime hypersomnolence ) . Male sex and obesity were strongly associated with the presence of sleep-disordered breathing . Habitual snorers , both men and women , tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher . CONCLUSIONS The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women . Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence OBJECTIVES The goal was to compare the effect of an improved nasal airway on obstructive sleep apnea ( OSA ) by use of subjective and objective measures . METHODS A prospect i ve study of 50 consecutive patients with nasal airway obstruction and OSA was carried out . RESULTS Subjectively , nasal breathing improved in 49 ( 98 % ) patients , whereas snoring decreased or disappeared in 17 ( 34 % ) ; the remaining 33 ( 66 % ) patients did not notice any significant change in their snoring . Daytime energy levels increased in 39 ( 78 % ) patients and remained unchanged or worsened in 11 ( 22 % ) . In review of the polysomno-graphic data , the group overall did not have significant changes in respiratory disturbance index ( RDI ) or lowest oxygen saturation levels ( LSaO2 ) . Continuous positive airway pressure ( CPAP ) levels required to correct OSA decreased after nasal surgery ( P < 0.01 ) . Patients with mild OSA showed significant worsening in RDI ( P < 0.05 ) , whereas LSaO2 levels were improved in the group with moderate OSA ( P < 0.05 ) . In patients with severe OSA neither the RDI levels nor the LSaO2 changed , but CPAP levels required to alleviate the obstruction after surgery were reduced ( P < 0.01 ) . CONCLUSIONS Most patients report improvement in nasal and sleep symptoms after correction of nasal airway obstruction . However , nasal surgery alone does not consistently improve OSA when measured objective ly . Depending on the severity of OSA , nasal airway reconstruction may contribute to a decrease in CPAP level and improvement in oxygen saturation . Correction of the obstructed nasal airway should certainly be included in the overall treatment plan for OSA . ( Otolaryngol Head Neck Surg 2000;122:71–4 . Chronic rhinitis patients often suffer from unrefreshing sleep and snoring , related to increased nasal resistance to airflow . Previous trials based on subjective assessment of snoring have demonstrated beneficial effects of Breathe Right ( BR ) , a noninvasive external nasal dilator . Polysomnography ( PSG ) was applied to objective ly assess the effects of BR on snoring . Twelve nonobese chronic rhinitis patients participated in the present study , which had a r and omized , placebo-controlled design . The presence of snoring and the absence of sleep apnoea was demonstrated during a baseline overnight sleep study . Patients were then r and omized for placebo or true nasal dilator treatment , which was also assessed by overnight PSG . The use of BR had no effect on sleep quality , arousal-index apnoea-hypopnoea-index or snoring loudness . Snoring frequency was significantly lowered by BR ( 173+/-29 snores x h(-l ) ) , compared with placebo ( 258+/-34 snores x h(-1 ) ; p=0.016 ) . The results support the hypothesis that Breathe Right is effective in reducing the amount of snoring in patients with chronic rhinitis . This objective finding is in line with some other reports on subjective improvement of snoring , based upon the judgement of bedpartners Recent data suggested that daytime somnolence in patients with allergic rhinitis was secondary to disrupted sleep caused by nasal congestion . Medications , which decreased congestion , would be expected to improve sleep and daytime somnolence . Previously , we showed that nasal steroids improved all three symptoms . Presently , we have not performed objective sleep testing to determine if there is a correlation between subjective improvement of congestion , sleep , and daytime somnolence . The objective of this 8-week , double-blind , placebo-controlled study was to determine if topical nasal fluticasone is effective at decreasing subjective congestion and daytime somnolence and improving sleep and if this improvement correlated with a change in overnight sleep testing ( polysomnography ) . We recruited 32 subjects with perennial allergic rhinitis and r and omized them in a double-blinded , cross-over fashion , to receive placebo or fluticasone ( 50 micrograms a spray ) , 2 sprays each side everyday , using Balaam 's design . Question naires , quality of life instruments , daily diary , Epworth Sleepiness Scale , and an overnight sleep test with polysomnograms were used as tools . The last 2 weeks of each 4-week treatment period were summarized , scored , and compared by PROC MIXED in SAS . Correlations between arousals on sleep tests and subjective tests were performed . Fluticasone improved subjective sleep when compared with placebo ( p = 0.04 ) ; however , there was no difference in the apnea/hypopnea index in those that were treated . Daytime sleepiness and fatigue were decreased by > 10 % in the treated group ; however , this was not statistically significant . However , fluticasone used at approved doses improves subjective sleep in patients with perennial allergic rhinitis without a change in the apnea/hypopnea index Anecdotal observations suggested that poor quality of sleep is a frequent complaint during upper respiratory infections ( URI ) . Nasal obstruction occurs frequently during URI and causes sleep apnea in some infants . Sleep apnea disrupts normal sleep and could explain the complaints of poor sleep quality during URI in adults . Accordingly , 10 normal men had full night recordings of sleep stages and breathing rhythm before and during nasal obstruction . The order of obstructed and nonobstructed nights was r and omized after a st and ard acclimatization night . During nasal obstruction , time spent in the deep sleep stages decreased from 90 + /- 11.2 ( SEM ) to 71 + /- 12.9 min ( p less than 0.05 ) , whereas significantly more time was spent in Stage 1 sleep ( p less than 0.03 ) . This loss of deep sleep during obstruction was associated with a twofold increase in sleep arousals and awakening ( p less than 0.01 ) result ing from an increased ( p less than 0.02 ) number of apneas ( 34 + /-19 during control sleep versus 86 + /- 34 during obstructed sleep ) . Apneas of 20 to 39 s in duration became 2.5 times more frequent ( p less than 0.05 ) during obstruction . Oxygen saturation was studied in the last 4 subjects using an ear oximeter .  Desaturation ( SaO2 less than 90 % ) occurred 27 times during control sleep compared with 255 times during obstructed sleep . These desaturation episodes occurred only during apneas . All men complained of poor sleep quality during nasal obstruction . We concluded that apneas , sleep arousals and awakenings , and loss of deep sleep occur during nasal obstruction and may explain complaints of poor sleep quality during URI An association between mouth breathing during sleep and increased propensity for upper airway collapse is well documented , but the effect of treatment for nasal obstruction on mouth breathing during sleep and simultaneous obstructive sleep apnoea ( OSA ) severity has not been described previously . A r and omised single blind placebo- and sham-controlled crossover study of treatment ( 
    Output:
    
agent
***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: Healthy subjects with normal nasal resistance  breathe almost exclusively through the nose during sleep . This study tested the hypothesis that a mechanical advantage might explain this preponderance of  nasal over oral breathing  during sleep . A r and omised , single-blind , crossover design was used to compare upper airway resistance during sleep in the nasal and oral breathing conditions in 12 ( seven male ) healthy subjects with normal nasal resistance , aged 30±4 ( mean±sem ) yrs , and with a body mass index of 23±1 kg·m2 . During wakefulness , upper airway resistance was similar between the oral and nasal breathing routes . However , during sleep ( supine , stage two ) upper airway resistance was much higher while breathing orally ( median 12.4 cmH2O·L−1·s−1 , range 4.5–40.2 ) than nasally ( 5.2 cmH2O·L−1·s−1 , 1.7–10.8 ) . In addition , obstructive ( but not central ) apnoeas and hypopnoeas were profoundly more frequent when breathing orally ( apnoea-hypopnoea index 43±6 ) than nasally ( 1.5±0.5 ) . Upper airway resistance during sleep and the propensity to obstructive sleep apnoea are significantly lower while breathing nasally rather than orally . This mechanical advantage may explain the preponderance of nasal breathing during sleep in normal subjects One thous and and one men , aged 35 - 65 years , were identified from the age-sex register of one group general practice . Over four years 900 men were visited at home and asked questions about symptoms potentially related to sleep apnoea and snoring . Height , weight , neck circumference , resting arterial oxygen saturation ( SaO2 ) , and spirometric values were also determined . All  night oximetry  was then performed at home and the tracing analysed for the number of dips in SaO2 of more than 4 % . Subjects with more than five dips of 4 % SaO2 or more per hour were invited for sleep laboratory polysomnography .  Seventeen per cent of the men admitted to snoring " often . " Multiple linear regression techniques identified and ranked neck circumference ( r2 = 7.2 % ) , cigarette consumption ( r2 = 3.4 % ) , and nasal stuffiness ( r2 = 2 % ) as the only significant independent predictors of snoring . Together these account for at least a sixfold variation in the likelihood of being an " often " snorer . Forty six subjects ( 5 % ) had greater than 4 % SaO2 dip rates of over five an hour and 31 of these had full sleep studies . Three subjects had clinical ly obvious and severe symptomatic obstructive sleep apnoea , giving a prevalence of three per 1001 men ( 0.3 % ; 95 % confidence interval 0.07 - 0.9 % ) . Eighteen men had  obstructive sleep apnoea  only when supine and in 10 the cause of the SaO2 dipping on the original home tracing was not eluci date d. The greater than 4 % SaO2 dip rates correlated with the history of snoring . Multiple linear regression techniques identified and ranked neck circumference ( r2 = 7.9 % ) , alcohol consumption ( r2 = 3.7 % ) , age ( r2 = 1 % ) and obesity ( r2 = 1 % ) as the only significant independent predictors of the rate of overnight hypoxic dipping . This study shows that snoring in this r and omly selected population correlates best with neck size , smoking , and nasal stuffiness . Obstructive sleep apnoea , defined by nocturnal hypoxaemia , correlates best with neck size and alcohol , and less so with age and general obesity Intranasal ipratropium bromide has been shown to significantly reduce  rhinorrhea .  Use of a freon-propelled intranasal preparation has result ed in side effects associated with the drying properties of the propellant . The purpose of the present trial was to study the safety and efficacy of a new isotonic aqueous ipratropium bromide nasal spray pump , specifically in patients with perennial nonallergic rhinitis . Two hundred thirty-three patients participated in an 8-week double-blind parallel comparison of ipratropium bromide nasal spray with its vehicle , a saline solution . Treatment with the ipratropium spray result ed in a 30 % reduction in rhinorrhea ; this reduction was significantly greater than that seen with the saline vehicle . There was a modest reduction in postnasal drip , sneezing , and congestion with both treatments , which may be attributable to the salutary effects of the saline solution . Patients also perceived a significant reduction in the degree to which rhinorrhea interfered with their daily activities and moods . Treatment was well tolerated , with no drug-related systemic adverse events and no evidence of nasal rebound on discontinuation of treatment . Minor , infrequent episodes of nasal dryness and epistaxis were the only significant adverse events reported ; these did not limit treatment BACKGROUND Limited data have suggested that sleep-disordered breathing , a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults . Data from the Wisconsin Sleep Cohort Study , a longitudinal study of the natural history of cardiopulmonary disorders of sleep , were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health . METHODS A r and om sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep ( the apnea-hypopnea score ) . We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score ( > or = 5 , > or = 10 , and > or = 15 ) ; we used logistic regression to investigate risk factors . RESULTS The estimated prevalence of sleep-disordered breathing , defined as an apnea-hypopnea score of 5 or higher , was 9 percent for women and 24 percent for men . We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome ( an apnea-hypopnea score of 5 or higher and daytime hypersomnolence ) . Male sex and obesity were strongly associated with the presence of sleep-disordered breathing . Habitual snorers , both men and women , tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher . CONCLUSIONS The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women . Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence OBJECTIVES The goal was to compare the effect of an improved nasal airway on obstructive sleep apnea ( OSA ) by use of subjective and objective measures . METHODS A prospect i ve study of 50 consecutive patients with nasal airway obstruction and OSA was carried out . RESULTS Subjectively , nasal breathing improved in 49 ( 98 % ) patients , whereas snoring decreased or disappeared in 17 ( 34 % ) ; the remaining 33 ( 66 % ) patients did not notice any significant change in their snoring . Daytime energy levels increased in 39 ( 78 % ) patients and remained unchanged or worsened in 11 ( 22 % ) . In review of the polysomno-graphic data , the group overall did not have significant changes in respiratory disturbance index ( RDI ) or lowest oxygen saturation levels ( LSaO2 ) . Continuous positive airway pressure ( CPAP ) levels required to correct OSA decreased after nasal surgery ( P < 0.01 ) . Patients with mild OSA showed significant worsening in RDI ( P < 0.05 ) , whereas LSaO2 levels were improved in the group with moderate OSA ( P < 0.05 ) . In patients with severe OSA neither the RDI levels nor the LSaO2 changed , but CPAP levels required to alleviate the obstruction after surgery were reduced ( P < 0.01 ) . CONCLUSIONS Most patients report improvement in nasal and sleep symptoms after correction of nasal airway obstruction . However , nasal surgery alone does not consistently improve OSA when measured objective ly . Depending on the severity of OSA , nasal airway reconstruction may contribute to a decrease in CPAP level and improvement in oxygen saturation . Correction of the obstructed nasal airway should certainly be included in the overall treatment plan for OSA . ( Otolaryngol Head Neck Surg 2000;122:71–4 . Chronic rhinitis patients often suffer from unrefreshing sleep and snoring , related to increased nasal resistance to airflow . Previous trials based on subjective assessment of snoring have demonstrated beneficial effects of Breathe Right ( BR ) , a noninvasive external nasal dilator . Polysomnography ( PSG ) was applied to objective ly assess the effects of BR on snoring . Twelve nonobese chronic rhinitis patients participated in the present study , which had a r and omized , placebo-controlled design . The presence of snoring and the absence of sleep apnoea was demonstrated during a baseline overnight sleep study . Patients were then r and omized for placebo or true nasal dilator treatment , which was also assessed by overnight PSG . The use of BR had no effect on sleep quality , arousal-index apnoea-hypopnoea-index or snoring loudness . Snoring frequency was significantly lowered by BR ( 173+/-29 snores x h(-l ) ) , compared with placebo ( 258+/-34 snores x h(-1 ) ; p=0.016 ) . The results support the hypothesis that Breathe Right is effective in reducing the amount of snoring in patients with chronic rhinitis . This objective finding is in line with some other reports on subjective improvement of snoring , based upon the judgement of bedpartners Recent data suggested that daytime somnolence in patients with allergic rhinitis was secondary to disrupted sleep caused by nasal congestion . Medications , which decreased congestion , would be expected to improve sleep and daytime somnolence . Previously , we showed that nasal steroids improved all three symptoms . Presently , we have not performed objective sleep testing to determine if there is a correlation between subjective improvement of congestion , sleep , and daytime somnolence . The objective of this 8-week , double-blind , placebo-controlled study was to determine if topical nasal fluticasone is effective at decreasing subjective congestion and daytime somnolence and improving sleep and if this improvement correlated with a change in overnight sleep testing ( polysomnography ) . We recruited 32 subjects with perennial allergic rhinitis and r and omized them in a double-blinded , cross-over fashion , to receive placebo or fluticasone ( 50 micrograms a spray ) , 2 sprays each side everyday , using Balaam 's design . Question naires , quality of life instruments , daily diary , Epworth Sleepiness Scale , and an overnight sleep test with polysomnograms were used as tools . The last 2 weeks of each 4-week treatment period were summarized , scored , and compared by PROC MIXED in SAS . Correlations between arousals on sleep tests and subjective tests were performed . Fluticasone improved subjective sleep when compared with placebo ( p = 0.04 ) ; however , there was no difference in the apnea/hypopnea index in those that were treated . Daytime sleepiness and fatigue were decreased by > 10 % in the treated group ; however , this was not statistically significant . However , fluticasone used at approved doses improves subjective sleep in patients with perennial allergic rhinitis without a change in the apnea/hypopnea index Anecdotal observations suggested that poor quality of sleep is a frequent complaint during upper respiratory infections ( URI ) . Nasal obstruction occurs frequently during URI and causes sleep apnea in some infants . Sleep apnea disrupts normal sleep and could explain the complaints of poor sleep quality during URI in adults . Accordingly , 10 normal men had full night recordings of sleep stages and breathing rhythm before and during nasal obstruction . The order of obstructed and nonobstructed nights was r and omized after a st and ard acclimatization night . During nasal obstruction , time spent in the deep sleep stages decreased from 90 + /- 11.2 ( SEM ) to 71 + /- 12.9 min ( p less than 0.05 ) , whereas significantly more time was spent in Stage 1 sleep ( p less than 0.03 ) . This loss of deep sleep during obstruction was associated with a twofold increase in sleep arousals and awakening ( p less than 0.01 ) result ing from an increased ( p less than 0.02 ) number of apneas ( 34 + /-19 during control sleep versus 86 + /- 34 during obstructed sleep ) . Apneas of 20 to 39 s in duration became 2.5 times more frequent ( p less than 0.05 ) during obstruction . Oxygen saturation was studied in the last 4 subjects using an ear oximeter .  Desaturation ( SaO2 less than 90 % ) occurred 27 times during control sleep compared with 255 times during obstructed sleep . These desaturation episodes occurred only during apneas . All men complained of poor sleep quality during nasal obstruction . We concluded that apneas , sleep arousals and awakenings , and loss of deep sleep occur during nasal obstruction and may explain complaints of poor sleep quality during URI An association between mouth breathing during sleep and increased propensity for upper airway collapse is well documented , but the effect of treatment for nasal obstruction on mouth breathing during sleep and simultaneous obstructive sleep apnoea ( OSA ) severity has not been described previously . A r and omised single blind placebo- and sham-controlled crossover study of treatment ( 
    Output:
    