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: STUDY OBJECTIVES To investigate the efficacy of tongue-muscle training by electrical neurostimulation of the upper-airway muscles as an alternative therapy option for  obstructive sleep apnea syndrome .  DESIGN A r and omized , placebo-controlled , double-blind study . SETTING Department of pneumology and sleep laboratory , University of Witten/Herdecke , Germany . PATIENTS 67 patients with an apnea-hypopnea index of 10 to 40 per hour were r and omly assigned to 2 groups : a  treatment group of 33 patients ( mean age , 50.8 + /- 12.1 years ; mean body mass index , 29.1 + /- 4.4 kg/m2 ) and a placebo group of 34 patients ( mean age , 53.3 + /- 11.3 years ; mean body mass index , 28.9 + /- 4.9 kg/m2 ) . Fifty-seven patients completed the study . INTERVENTIONS Tongue-muscle training during the daytime for 20 minutes twice a day for 8 weeks . MEASUREMENTS AND RESULTS Treatment efficacy was examined by polysomnography . Snoring , but not apnea-hypopnea index , improved with stimulation ( snoring baseline , 63.9 + /- 23.1 epochs per hour ; stimulation training , 47.5 + /- 31.2 ; P < .05 ) but not with placebo training ( snoring baseline , 62.4 + /- 26.1 epochs per hour ; placebo , 62.1 + /- 23.8 ; NS . ) . CONCLUSIONS Although tongue-muscle training can not generally be recommended for the treatment of sleep apnea , the method has proven to be effective in the treatment of snoring RATIONALE Cross-sectional epidemiologic studies show an association between sleep-disordered breathing and hypertension , but only one cohort study has examined sleep-disordered breathing as a risk factor for incident hypertension . OBJECTIVES To examine whether sleep-disordered breathing increases the risk of incident hypertension among persons 40 years of age and older . METHODS In a prospect i ve cohort study , we analyzed data from 2,470 participants who at baseline did not have hypertension , defined as blood pressure of at least 140/90 mm Hg or taking antihypertensive medication . The  apnea-hypopnea index ( AHI ) , the number of apneas plus hypopneas per hour of sleep , was measured by overnight in-home polysomnography . We estimated odds ratios for developing hypertension during 5 years of follow-up according to baseline AHI . MEASUREMENTS AND MAIN RESULTS The odds ratios for incident hypertension increased with increasing baseline AHI ; however , this relationship was attenuated and not statistically significant after adjustment for baseline body-mass index . Although not statistically significant , the observed association between a baseline AHI greater than 30 and future hypertension ( odds ratio , 1.51 ; 95 % confidence interval , 0.93 - 2.47 ) does not exclude the possibility of a modest association . CONCLUSIONS Among middle-aged and older persons without hypertension , much of the relationship between AHI and risk of incident hypertension was accounted for by obesity . After adjustment for body mass index , the AHI was not a significant predictor of future hypertension , although a modest influence of an AHI greater than 30 on hypertension could not be excluded Contraction of the genioglossus ( GG ) has been shown to improve upper airway patency . In the present study , we evaluated responses in upper airway pressure-flow relationships during sleep to electrical stimulation ( ES ) of the GG in patients with obstructive sleep apnea . Five patients with chronically implanted hypoglossal nerve ( HG ) electrodes and nine patients with fine-wire electrodes inserted into the GG were studied . Airflow was measured at multiple levels of nasal pressure , and upper airway collapsibility was defined by the nasal pressure below which airflow ceased [ " critical " pressure ( Pcrit ) ] . ES shifted the pressure-flow relationships toward higher flow levels in all patients over the entire range of nasal pressure applied . Pcrit decreased similarly during both HG-ES and GG-ES ( deltaPcrit was 3.98 + /- 2.31 and 3.18 + /- 1.70 cmH2O , respectively ) without a significant change in upstream resistance . The site of collapse ( velo- vs. oropharynx ) did not influence the response to GG-ES . Moreover , ES-induced reductions in the apnea-hypopnea index of the HG-ES patients were associated with substantial decreases in Pcrit . Our findings imply that responses in apnea severity to HG-ES can be predicted by characterizing the patient 's baseline pressure-flow relationships and response to GG-ES The tongue plays a significant role in the maintenance of a patent airway . The purpose of this study was to examine the effects of tongue musculature contraction on the static mechanical properties of the pharynx in patients with obstructive sleep apnoea ( OSA ) . During hyperventilation-induced apnoea in seven OSA patients anaesthetized with sevoflurane  , the static pressure/area relationships of the oropharynx were obtained by means of step changes in airway pressure while endoscopically measuring cross-sectional area . At each airway pressure , the tongue was electrically stimulated via electrodes placed bilaterally . Tongue electrical stimulation ( TES ) did not further dilate the oropharyngeal area at higher airway pressure ( 3.2+/-1.9 versus 3.0+/-2.1 cm2 ) , although the narrowed oropharyngeal area at lower airway pressures increased during TES ( 0.8+/-9.0 ) versus 1.7+/-1.8 cm2 , p<0.05 ) . Accordingly , the slope of the pressure/area relationship decreased during TES ( 0.24+/-0.20 versus 0.12+/-0.09 cm2 x cm H2O(-1 ) , p<0.05 ) . In conclusion , electrical stimulation of the tongue stiffens the retroglossal airway wall in patients with obstructive sleep apnoea The influence of lingual muscle activity on airflow dynamics in the upper airway was examined in nine patients with obstructive sleep apnea . Muscles that retract the tongue ( hyoglossus and styloglossus ) and protrude the tongue ( genioglossus ) were selectively stimulated electrically during sleep with fine wire electrodes placed intramuscularly transorally . We confirmed that stimulation with 50 Hz and 40-microseconds pulse duration did not elicit changes in electroencephalographic patterns or heart rate or alter airflow after the stimulation burst had ceased . The highest stimulus intensity that did not arouse patients from sleep was then utilized to examine the effect of lingual muscle recruitment on airflow dynamics during steady-state periods of inspiratory airflow limitation . When applying a stimulus burst during single inspirations , maximal inspiratory airflow decreased by 239 + /- 177 ml/s ( P < 0.05 ) during retractor stimulation , whereas maximal inspiratory airflow increased by 217 + /- 93 ml/s during protrusor stimulation ( P < 0.001 ) compared with breaths immediately before and after the stimulated breath . When consecutive inspirations were stimulated repeatedly , protrusor stimulation decreased the frequency of obstructive breathing episodes in four patients breathing at 3.9 + /- 3.4 ( SD ) cmH2O nasal pressure . The findings suggest that stimulation of the lingual muscles can increase or decrease airflow depending on the specific muscles stimulated without arousing patients from sleep The prevalence of sleep-disordered breathing has not been well studied in women , especially in terms of the effects of age , body mass index ( BMI ) , and menopause . We evaluated this question using a two-phase r and om sample from the general population . In Phase I , 12,219 women and 4,364 men ranging in age from 20 to 100 yr were interviewed ; and in Phase II , 1,000 women and 741 men of the Phase I subjects were selected for one night of sleep laboratory evaluation .  The results of our study indicated that , for clinical ly defined sleep apnea ( apnea/hypopnea index > or = 10 and daytime symptoms ) , men had a prevalence of 3.9 % and women 1.2 % , result ing in an overall ratio of sleep apnea for men to women of 3.3:1 ( p = 0.0006 ) . The prevalence of sleep apnea was quite low in premenopausal women ( 0.6 % ) as well as postmenopausal women with hormone replacement therapy ( HRT )  ( 0.5 % ) . Further , in these women the presence of sleep apnea appeared to be associated exclusively with obesity ( BMI > or = 32.3 kg/m2 ) . Postmenopausal women without HRT had a prevalence of sleep apnea that was significantly higher than the prevalence in premenopausal women with HRT ( 2.7 versus 0.6 % , p = 0.02 ) and was more similar to the prevalence in men ( 3.9 % ) , although it remained significantly less when controlling for age and BMI ( p = 0.001 ) . These data combined indicate that menopause is a significant risk factor for  sleep apnea in women and that hormone replacement appears to be associated with reduced risk BACKGROUND Sleep-disordered breathing is prevalent in the general population and has been linked to chronically elevated blood pressure in cross-sectional epidemiologic studies . We performed a prospect i ve , population -based study of the association between objective ly measured sleep-disordered breathing and hypertension ( defined as a laboratory-measured blood pressure of at least 140/90 mm Hg or the use of antihypertensive medications ) . METHODS We analyzed data on sleep-disordered breathing , blood pressure , habitus , and health history at base line and after four years of follow-up in 709 participants of the Wisconsin Sleep Cohort Study ( and after eight years of follow-up in the case of 184 of these participants ) . Participants were assessed overnight by 18-channel polysomnography for sleep-disordered breathing , as defined by the apnea-hypopnea index ( the number of episodes of apnea and hypopnea per hour of sleep ) . The odds ratios for the presence of hypertension at the four-year follow-up study according to the apnea-hypopnea index at base line were estimated after adjustment for base-line hypertension status , body-mass index , neck and waist circumference , age , sex , and weekly use of alcohol and cigarettes . RESULTS Relative to the reference category of an apnea-hypopnea index of 0 events per hour at base line , the odds ratios for the presence of hypertension at follow-up were 1.42 ( 95 percent confidence interval , 1.13 to 1.78 ) with an apnea-hypopnea index of 0.1 to 4.9 events per hour at base line as compared with none , 2.03 ( 95 percent confidence interval , 1.29 to 3.17 ) with an apnea-hypopnea index of 5.0 to 14.9 events per hour , and 2.89 ( 95 percent confidence interval , 1.46 to 5.64 ) with an apnea-hypopnea index of 15.0 or more events per hour . CONCLUSIONS We found a dose-response association between sleep-disordered breathing at base line and the presence of hypertension four years later that was independent of known confounding factors . The findings suggest that sleep-disordered breathing is likely to be a risk factor for hypertension and consequent cardiovascular morbidity in the general population RATIONALE Upper airway muscle function plays a major role in maintenance of the upper airway patency and contributes to the genesis of obstructive sleep apnea syndrome ( OSAS ) . Preliminary results suggested that oropharyngeal exercises derived from speech therapy may be an effective treatment option for patients with moderate OSAS . OBJECTIVES To determine the impact of oropharyngeal exercises in patients with moderate OSAS . METHODS Thirty-one patients with moderate OSAS were r and omized to 3 months of daily ( approximately 30 min ) sham therapy ( n = 15 , control ) or a set of oropharyngeal exercises ( n = 16 ) , consisting of exercises involving the tongue , soft palate , and lateral pharyngeal wall . MEASUREMENTS AND MAIN RESULTS Anthropometric measurements , snoring frequency ( range 0 - 4 ) , intensity ( 1 - 3 ) , Epworth daytime sleepiness ( 0 - 24 ) and Pittsburgh sleep quality ( 0 - 21 ) question naires , and full polysomnography were performed at baseline and at study conclusion . Body mass index and abdominal circumference of the entire group were 30.3 + /- 3.4 kg/m(2 ) and 101.4 + /- 9.0 cm , respectively , and did not change significantly over the study period . No significant change occurred in the control group in all variables . In contrast , patients r and omized to oropharyngeal exercises had a significant decrease ( P < 0.05 ) in neck circumference ( 39.6 + /- 3.6 vs. 38.5 + /- 4.0 cm ) , snoring frequency ( 4 [ 4 - 4 ] vs. 3 [ 1.5 - 3.5 ] ) , snoring intensity ( 3 [ 3 - 4 ] vs. 1 [ 1 - 2 ] ) , daytime sleepiness ( 14 + /- 5 vs. 8 + /- 6 ) , sleep quality score ( 10.2 + /- 3.7 vs. 6.9 + /- 2 
    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: STUDY OBJECTIVES To investigate the efficacy of tongue-muscle training by electrical neurostimulation of the upper-airway muscles as an alternative therapy option for  obstructive sleep apnea syndrome .  DESIGN A r and omized , placebo-controlled , double-blind study . SETTING Department of pneumology and sleep laboratory , University of Witten/Herdecke , Germany . PATIENTS 67 patients with an apnea-hypopnea index of 10 to 40 per hour were r and omly assigned to 2 groups : a  treatment group of 33 patients ( mean age , 50.8 + /- 12.1 years ; mean body mass index , 29.1 + /- 4.4 kg/m2 ) and a placebo group of 34 patients ( mean age , 53.3 + /- 11.3 years ; mean body mass index , 28.9 + /- 4.9 kg/m2 ) . Fifty-seven patients completed the study . INTERVENTIONS Tongue-muscle training during the daytime for 20 minutes twice a day for 8 weeks . MEASUREMENTS AND RESULTS Treatment efficacy was examined by polysomnography . Snoring , but not apnea-hypopnea index , improved with stimulation ( snoring baseline , 63.9 + /- 23.1 epochs per hour ; stimulation training , 47.5 + /- 31.2 ; P < .05 ) but not with placebo training ( snoring baseline , 62.4 + /- 26.1 epochs per hour ; placebo , 62.1 + /- 23.8 ; NS . ) . CONCLUSIONS Although tongue-muscle training can not generally be recommended for the treatment of sleep apnea , the method has proven to be effective in the treatment of snoring RATIONALE Cross-sectional epidemiologic studies show an association between sleep-disordered breathing and hypertension , but only one cohort study has examined sleep-disordered breathing as a risk factor for incident hypertension . OBJECTIVES To examine whether sleep-disordered breathing increases the risk of incident hypertension among persons 40 years of age and older . METHODS In a prospect i ve cohort study , we analyzed data from 2,470 participants who at baseline did not have hypertension , defined as blood pressure of at least 140/90 mm Hg or taking antihypertensive medication . The  apnea-hypopnea index ( AHI ) , the number of apneas plus hypopneas per hour of sleep , was measured by overnight in-home polysomnography . We estimated odds ratios for developing hypertension during 5 years of follow-up according to baseline AHI . MEASUREMENTS AND MAIN RESULTS The odds ratios for incident hypertension increased with increasing baseline AHI ; however , this relationship was attenuated and not statistically significant after adjustment for baseline body-mass index . Although not statistically significant , the observed association between a baseline AHI greater than 30 and future hypertension ( odds ratio , 1.51 ; 95 % confidence interval , 0.93 - 2.47 ) does not exclude the possibility of a modest association . CONCLUSIONS Among middle-aged and older persons without hypertension , much of the relationship between AHI and risk of incident hypertension was accounted for by obesity . After adjustment for body mass index , the AHI was not a significant predictor of future hypertension , although a modest influence of an AHI greater than 30 on hypertension could not be excluded Contraction of the genioglossus ( GG ) has been shown to improve upper airway patency . In the present study , we evaluated responses in upper airway pressure-flow relationships during sleep to electrical stimulation ( ES ) of the GG in patients with obstructive sleep apnea . Five patients with chronically implanted hypoglossal nerve ( HG ) electrodes and nine patients with fine-wire electrodes inserted into the GG were studied . Airflow was measured at multiple levels of nasal pressure , and upper airway collapsibility was defined by the nasal pressure below which airflow ceased [ " critical " pressure ( Pcrit ) ] . ES shifted the pressure-flow relationships toward higher flow levels in all patients over the entire range of nasal pressure applied . Pcrit decreased similarly during both HG-ES and GG-ES ( deltaPcrit was 3.98 + /- 2.31 and 3.18 + /- 1.70 cmH2O , respectively ) without a significant change in upstream resistance . The site of collapse ( velo- vs. oropharynx ) did not influence the response to GG-ES . Moreover , ES-induced reductions in the apnea-hypopnea index of the HG-ES patients were associated with substantial decreases in Pcrit . Our findings imply that responses in apnea severity to HG-ES can be predicted by characterizing the patient 's baseline pressure-flow relationships and response to GG-ES The tongue plays a significant role in the maintenance of a patent airway . The purpose of this study was to examine the effects of tongue musculature contraction on the static mechanical properties of the pharynx in patients with obstructive sleep apnoea ( OSA ) . During hyperventilation-induced apnoea in seven OSA patients anaesthetized with sevoflurane  , the static pressure/area relationships of the oropharynx were obtained by means of step changes in airway pressure while endoscopically measuring cross-sectional area . At each airway pressure , the tongue was electrically stimulated via electrodes placed bilaterally . Tongue electrical stimulation ( TES ) did not further dilate the oropharyngeal area at higher airway pressure ( 3.2+/-1.9 versus 3.0+/-2.1 cm2 ) , although the narrowed oropharyngeal area at lower airway pressures increased during TES ( 0.8+/-9.0 ) versus 1.7+/-1.8 cm2 , p<0.05 ) . Accordingly , the slope of the pressure/area relationship decreased during TES ( 0.24+/-0.20 versus 0.12+/-0.09 cm2 x cm H2O(-1 ) , p<0.05 ) . In conclusion , electrical stimulation of the tongue stiffens the retroglossal airway wall in patients with obstructive sleep apnoea The influence of lingual muscle activity on airflow dynamics in the upper airway was examined in nine patients with obstructive sleep apnea . Muscles that retract the tongue ( hyoglossus and styloglossus ) and protrude the tongue ( genioglossus ) were selectively stimulated electrically during sleep with fine wire electrodes placed intramuscularly transorally . We confirmed that stimulation with 50 Hz and 40-microseconds pulse duration did not elicit changes in electroencephalographic patterns or heart rate or alter airflow after the stimulation burst had ceased . The highest stimulus intensity that did not arouse patients from sleep was then utilized to examine the effect of lingual muscle recruitment on airflow dynamics during steady-state periods of inspiratory airflow limitation . When applying a stimulus burst during single inspirations , maximal inspiratory airflow decreased by 239 + /- 177 ml/s ( P < 0.05 ) during retractor stimulation , whereas maximal inspiratory airflow increased by 217 + /- 93 ml/s during protrusor stimulation ( P < 0.001 ) compared with breaths immediately before and after the stimulated breath . When consecutive inspirations were stimulated repeatedly , protrusor stimulation decreased the frequency of obstructive breathing episodes in four patients breathing at 3.9 + /- 3.4 ( SD ) cmH2O nasal pressure . The findings suggest that stimulation of the lingual muscles can increase or decrease airflow depending on the specific muscles stimulated without arousing patients from sleep The prevalence of sleep-disordered breathing has not been well studied in women , especially in terms of the effects of age , body mass index ( BMI ) , and menopause . We evaluated this question using a two-phase r and om sample from the general population . In Phase I , 12,219 women and 4,364 men ranging in age from 20 to 100 yr were interviewed ; and in Phase II , 1,000 women and 741 men of the Phase I subjects were selected for one night of sleep laboratory evaluation .  The results of our study indicated that , for clinical ly defined sleep apnea ( apnea/hypopnea index > or = 10 and daytime symptoms ) , men had a prevalence of 3.9 % and women 1.2 % , result ing in an overall ratio of sleep apnea for men to women of 3.3:1 ( p = 0.0006 ) . The prevalence of sleep apnea was quite low in premenopausal women ( 0.6 % ) as well as postmenopausal women with hormone replacement therapy ( HRT )  ( 0.5 % ) . Further , in these women the presence of sleep apnea appeared to be associated exclusively with obesity ( BMI > or = 32.3 kg/m2 ) . Postmenopausal women without HRT had a prevalence of sleep apnea that was significantly higher than the prevalence in premenopausal women with HRT ( 2.7 versus 0.6 % , p = 0.02 ) and was more similar to the prevalence in men ( 3.9 % ) , although it remained significantly less when controlling for age and BMI ( p = 0.001 ) . These data combined indicate that menopause is a significant risk factor for  sleep apnea in women and that hormone replacement appears to be associated with reduced risk BACKGROUND Sleep-disordered breathing is prevalent in the general population and has been linked to chronically elevated blood pressure in cross-sectional epidemiologic studies . We performed a prospect i ve , population -based study of the association between objective ly measured sleep-disordered breathing and hypertension ( defined as a laboratory-measured blood pressure of at least 140/90 mm Hg or the use of antihypertensive medications ) . METHODS We analyzed data on sleep-disordered breathing , blood pressure , habitus , and health history at base line and after four years of follow-up in 709 participants of the Wisconsin Sleep Cohort Study ( and after eight years of follow-up in the case of 184 of these participants ) . Participants were assessed overnight by 18-channel polysomnography for sleep-disordered breathing , as defined by the apnea-hypopnea index ( the number of episodes of apnea and hypopnea per hour of sleep ) . The odds ratios for the presence of hypertension at the four-year follow-up study according to the apnea-hypopnea index at base line were estimated after adjustment for base-line hypertension status , body-mass index , neck and waist circumference , age , sex , and weekly use of alcohol and cigarettes . RESULTS Relative to the reference category of an apnea-hypopnea index of 0 events per hour at base line , the odds ratios for the presence of hypertension at follow-up were 1.42 ( 95 percent confidence interval , 1.13 to 1.78 ) with an apnea-hypopnea index of 0.1 to 4.9 events per hour at base line as compared with none , 2.03 ( 95 percent confidence interval , 1.29 to 3.17 ) with an apnea-hypopnea index of 5.0 to 14.9 events per hour , and 2.89 ( 95 percent confidence interval , 1.46 to 5.64 ) with an apnea-hypopnea index of 15.0 or more events per hour . CONCLUSIONS We found a dose-response association between sleep-disordered breathing at base line and the presence of hypertension four years later that was independent of known confounding factors . The findings suggest that sleep-disordered breathing is likely to be a risk factor for hypertension and consequent cardiovascular morbidity in the general population RATIONALE Upper airway muscle function plays a major role in maintenance of the upper airway patency and contributes to the genesis of obstructive sleep apnea syndrome ( OSAS ) . Preliminary results suggested that oropharyngeal exercises derived from speech therapy may be an effective treatment option for patients with moderate OSAS . OBJECTIVES To determine the impact of oropharyngeal exercises in patients with moderate OSAS . METHODS Thirty-one patients with moderate OSAS were r and omized to 3 months of daily ( approximately 30 min ) sham therapy ( n = 15 , control ) or a set of oropharyngeal exercises ( n = 16 ) , consisting of exercises involving the tongue , soft palate , and lateral pharyngeal wall . MEASUREMENTS AND MAIN RESULTS Anthropometric measurements , snoring frequency ( range 0 - 4 ) , intensity ( 1 - 3 ) , Epworth daytime sleepiness ( 0 - 24 ) and Pittsburgh sleep quality ( 0 - 21 ) question naires , and full polysomnography were performed at baseline and at study conclusion . Body mass index and abdominal circumference of the entire group were 30.3 + /- 3.4 kg/m(2 ) and 101.4 + /- 9.0 cm , respectively , and did not change significantly over the study period . No significant change occurred in the control group in all variables . In contrast , patients r and omized to oropharyngeal exercises had a significant decrease ( P < 0.05 ) in neck circumference ( 39.6 + /- 3.6 vs. 38.5 + /- 4.0 cm ) , snoring frequency ( 4 [ 4 - 4 ] vs. 3 [ 1.5 - 3.5 ] ) , snoring intensity ( 3 [ 3 - 4 ] vs. 1 [ 1 - 2 ] ) , daytime sleepiness ( 14 + /- 5 vs. 8 + /- 6 ) , sleep quality score ( 10.2 + /- 3.7 vs. 6.9 + /- 2 
    Output:
    