Key words: bed partners; polysomnography; questionnaires; rhinomanometry; sleep apnea

Transcription

1 Patient- and Bed Partner-Reported Symptoms, Smoking, and Nasal Resistance in Sleep-Disordered Breathing* Paula Virkkula, MD, PhD; Adel Bachour, MD, PhD; Maija Hytönen, MD, PhD; Henrik Malmberg, MD, PhD; Tapani Salmi, MD, PhD; and Paula Maasilta, MD, PhD, FCCP Objectives: Nocturnal and daytime symptoms are important determinants in clinical decision making in patients suspected of having sleep-disordered breathing (SDB). We compared patients and bed partners reporting of symptoms associated with SDB in a clinical sample of snoring men. The bed partners view on snoring disturbance was assessed. The relationship between sleep parameters, anthropometric data, and selected subjective symptoms was assessed. Additionally, we evaluated the relationship between smoking, nasal resistance, and habitual snoring. Design: A cross-sectional, prospective study. Setting: University teaching hospital. Patients: Thirty-seven consecutive snoring men referred to ENT Hospital because of a snoring problem or suspicion of sleep apnea, and scheduled for surgical treatment of nasal obstruction. Interventions: The patients completed a sleep questionnaire, a questionnaire on nasal history, and the Epworth sleepiness scale. The bed partners were asked to complete a separate sleep questionnaire of the patient s daytime and nocturnal symptoms. Both patients and bed partners evaluated the intensity of snoring on a visual analog scale. The patients underwent polysomnography and anterior rhinomanometry. Results: Agreement of patients and bed partners reports on symptoms related to SDB was good in this material. One half of the bed partners were disturbed by snoring every night or almost every night, and one third of the bed partners reported disharmony in the relationship from time to time or repeatedly due to snoring. The combination of current smoking and total nasal resistance in a supine position higher than the median value in this patient sample was associated with history of habitual snoring. Conclusions: Male patients and their bed partners seem to give congruent reports of snoring and symptoms related to SDB in a clinical population with mild SDB. One half of the bed partners found their sleep constantly disturbed. The combination of current smoking and high nasal resistance was related with habitual snoring. (CHEST 2005; 128: ) Key words: bed partners; polysomnography; questionnaires; rhinomanometry; sleep apnea Abbreviations: AHI apnea-hypopnea index; BMI body mass index; ESS Epworth sleepiness scale; ODI oxygen desaturation index; OSA obstructive sleep apnea; Sao 2 arterial oxygen saturation; SDB sleepdisordered breathing; VAS visual analog scale Sleep-disordered breathing (SDB) develops gradually in susceptible individuals and presents with symptoms both during wakefulness and sleep. Sleepiness is the most important daytime consequence of *From the Department of Otorhinolaryngology, Peijas Hospital (Dr. Virkkula) and ENT Hospital (Drs. Hytönen and Malmberg), Departments of Clinical Neurophysiology (Dr. Salmi) and Pulmonary Medicine (Drs. Bachour and Maasilta), Helsinki University Central Hospital, Helsinki, Finland. The work was performed at the ENT Hospital, Helsinki University Central Hospital. The patients underwent polysomnography at the Department of Pulmonary Medicine, Helsinki University Central Hospital. fragmented sleep in these patients, causing increased risk of vehicular crashes and occupational accidents. Obstructive sleep apnea (OSA) or hypopnea can This study was supported financially by The Helsinki University Hospital Special Funds. Manuscript received December 8, 2004; revision accepted March 1, Reproduction of this article is prohibited without written permission from the American College of Chest Physicians ( org/misc/reprints.shtml). Correspondence to: Paula Virkkula, MD, PhD, Department of Otorhinolaryngology, Peijas Hospital, Helsinki University Central Hospital, Sairaalakatu 1, FIN Vantaa, Finland; paula.virkkula@hus.fi 2176 Clinical Investigations

2 result in impaired quality of life in patients and their bed partners. 1 Systemic hypertension may develop, and cardiovascular disease and increased mortality have been associated with OSA. 2,3 Nocturnal symptoms, such as snoring, apneas, gasping/choking, and restless sleep, are mostly unconscious for the patient, and the snorer will determine his or her view of the matter from the reports of the bed partner. Habitual snoring and/or some kind of a description of obstructed breathing during sleep can be found in most prediction rules developed for sleep apnea, 4 and a history of these symptoms has been found a useful tool for evaluation of need of an overnight sleep study in clinical practice. Measurement of different parameters of breathing and sleep will define the degree of the disorder, but the number of apneas and hypopneas is not always consistent with symptoms. Moreover, current knowledge about treatment outcomes in prevention of cardiovascular consequences of SDB is limited. 2 Therefore, symptoms and especially daytime sleepiness are considered as the main reasons to treat OSA. 5 Understanding the possible differences in reporting of symptoms by the patient and bed partner is important in decision making of further investigations and treatment in clinical work. Previous recommendations for clinical practice include asking the bed partner s view of nocturnal breathing and sleep. 6 However, there is not much evidence in the literature to support this practice. Previous studies 7,8 on the comparison of snoring and other associated symptoms in patient and spouse reports have been based on population studies. These results have been useful in evaluation of snoring prevalence based on self-reports, but they may not be applicable to clinical materials. Patients seeking help for the symptoms of SDB may be more conscious and better informed of their nocturnal breathing and sleep than the population in general. Moreover, since these earlier studies, awareness of snoring and its related symptoms and consequences has increased in the population. The purpose of this prospective study was to compare patients and bed partners reporting of the common daytime and nocturnal symptoms of SDB in a clinical material of snoring men. Additionally, we assessed to what extent snoring disturbed the bed partner. The relationships between body mass index (BMI) and sleep parameters, including snoring time and mouth breathing time, and some subjective symptom scores were evaluated. Further, we investigated the association between smoking, nasal resistance, and habitual snoring. Patients and Study Design Materials and Methods The study population consisted of 37 men and their bed partners. The patients were consecutive snoring men referred to the ENT Hospital, Helsinki University Central Hospital because of a snoring problem or suspicion of sleep apnea and scheduled for surgical treatment of nasal obstruction. 9,10 The patients underwent an otorhinolaryngologic examination and were referred for an attended in-laboratory polysomnography and active anterior rhinomanometry. The ethical committee of the ENT Hospital, Helsinki University Central Hospital approved the study. Informed consent was obtained from the study subjects. Questionnaires Prior to the sleep study, the patients kept a sleep diary for 2 weeks. During their stay in the sleep laboratory, the patients were asked to fill in a sleep questionnaire based on the Basic Nordic Sleep Questionnaire. 11 For the questionnaire administered to the bed partner, the same questions about snoring, apneas, and daytime sleepiness were structured so that the bed partner was reporting for the patient. The questionnaire for the bed partner was given to the patient from the sleep laboratory to be returned by mail. The patients and bed partners were asked to state the quality of snoring on a 5-point scale: 1 no snoring; 2 quiet regular snoring; 3 moderately loud regular snoring; 4 very loud snoring (can be heard in the next room); and 5 very loud irregular snoring. The frequency of snoring and how often the snoring was found disturbing by the bed partner were reported on a 5-point scale: 1 never or less than once per month; 2 less than once per week; 3 1 day or 2 days per week; 4 3 to 5 days per week; 5 every night or almost every night. The same scale was used in the assessment of the frequency of mouth breathing during sleep, apneas, daytime sleepiness, use of separate rooms during nights, and marital disharmony due to snoring. Patients and bed partners also reported about duration of snoring (score of 1 only part of the night; score of 2 most of the night; and score of 3 all night) and snoring position (score of 1 mainly on back; score of 2 in all body positions). Both patients and bed partners assessed the intensity of snoring on a visual analog scale (VAS). Additionally, the patients were asked to fill in a separate questionnaire about nasal history and symptoms, and the Epworth sleepiness scale (ESS). 12 Habitual snoring was defined as history of snoring every night or almost every night. Heavy snoring was defined as history of very loud snoring, which can be heard to the next room (scores 4 and 5). Polysomnography and Anterior Rhinomanometry As reported previously, 13 the overnight hospital recordings were performed using a computerized 24-channel polygraph (Alice 3; Healthdyne Technologies; Marietta, GA). It included a four-channel EEG (C3/A2, C4/A1, O1/A2, O2/A1), electrooculogram, and submental and leg electromyograms. Airflow was detected by monitoring with a nasal and oral thermistor (Healthdyne Technologies). In order to quantify mouth breathing, a 3-6-cm silicon transversal diaphragm was fixed at the nasal thermistor to prevent activation of the mouth thermistor during nose breathing. 14 Thoracic and abdominal belts (Healthdyne Effort Sensor; Healthdyne Technologies) were used for respiratory movement detection. Pulse oximetry (BCI Oximetry 3100; BCI International; Waukesha, WI) and a body position sensor (Healthdyne Technologies) were included in all recordings. A CHEST / 128 / 4/ OCTOBER,

3 calibrated skin microphone (Healthdyne Technologies) was attached to the throat for detection of snoring. To verify snoring, another microphone was attached to the ceiling, 2 m from the patient s head, to record sounds on videotape. Sleep stage was scored manually in 30-s epochs following the criteria of Rechtschaffen and Kales. 15 An apnea was defined as absence of nasal or buccal flow for 10 s. Hypopnea was scored as the diminution of flow amplitude of 50% and for 10 s associated with an arousal or an oxygen desaturation 3%. An arousal was defined as an EEG frequency shift to the range for at least 3 s. 16 AHI was defined as the number of apneas and hypopneas per hour of sleep. An oxygen desaturation index (ODI) was registered when there was a 4% drop in arterial oxygen saturation (Sao 2 ) during sleep. The analog signal of snoring was detected with a skin microphone and transferred to the monitor screen. A snoring event was scored visually if the signal was at least 50% of the calibration signal as described previously. 13 The time spent in snoring episodes was divided by total sleep time to give the percentile snoring time. A mouth breathing event was scored visually when at least one deviation from baseline was 10% of the calibrated signal as described previously. 14 Active anterior rhinomanometry was performed without nasal decongestion in a seated position and in a supine position after lying down for 5 min. Inspiratory nasal resistance at radius 200 was calculated according to the method of Broms et al. 17 Combined nasal resistance was calculated from the unilateral recordings. Statistical Analysis Pearson correlation analysis was used to evaluate the relationships between BMI, sleep parameters, intensity of snoring on the VAS, and ESS. Agreement between the symptom scales of the patients and the bed partners was tested using the Cramer V analysis. 2 test was used to evaluate the association between smoking status, nasal resistance, and habitual snoring. The computations were performed using commercial statistical packages (Statistica version 5.1; Statsoft; Tulsa, OK; and StatXact version with Cytel Studio; Cytel Software Corporation; Cambridge, MA); p values 0.05 were considered to indicate statistical significance. Results All patients were of Finnish origin. Mean age was 44.2 years, and mean BMI was 27.9 kg/m 2. Detailed patient characteristics are shown in Table 1. Thirteen patients had hypertension, two patients had experienced coronary disease, and one patient had a transient ischemic attack. One patient received medication for hypothyroidism, another patient used antidepressants, and a third patient was medicated with a low-dose corticosteroid due to sarcoidosis without any nasal involvement. None of the patients used sedatives regularly. Thirty-two percent of the patients reported daytime sleepiness every day or almost every day. All patients complained of nasal obstruction, and five of the patients had a history of allergic rhinitis (14%). Two of the patients used nasal corticosteroid sprays, and one patient used an antihistamine regularly. Table 1 Characteristics of the 37 Male Patients Variables Data Age, yr Mean (SD) 44.2 (9.4) Median (range) 44 (29 62) BMI, kg/m 2 Mean (SD) 27.9 (3.4) Median (range) 27.5 ( ) Marital status, No. (%) Marriage or common-law marriage 33 (83) Not married 4 (11) Education, No. (%) Less than senior high school 18 (49) Graduate from high school or 11 (30) institutional degree Academic degree 8 (21) Smoking status, No. (%) Smoker 19 (51) Ex-smokers 11 (30) Habitual snoring 28 (88) Heavy snoring 30 (94) Intensity of snoring (patient s rating; VAS) Mean (SD) 71 (16) Median (range) 74 (32 97) Intensity of snoring (bed partner s rating; VAS) Mean (SD) 80 (15) Median (range) 81 (34 100) Epworth sleepiness score (0 24) Mean (SD) 6.2 (3.8) Median (range) 5 (1 15) Intensity of snoring estimated by the patients and bed partners on the VAS was significantly correlated (r 0.51; p 0.05) [Table 1]. Eighty-eight percent of the patients and 70% of the bed partners reported habitual snoring. Ninety-four percent of the patients and 83% of the bed partners reported heavy snoring. Sixty-one percent of the patients and 71% of the bed partners reported apneas at least once a week. Daytime sleepiness in the snoring men was reported by 32% of the patients and 33% of the bed partners. Prevalences of these symptoms did not differ statistically. Figure 1 shows the scoring of each symptom by the patients and bed partners. In the estimation of snoring duration (part of the night, most of the night, all night) and the frequency of mouth breathing the agreement between the groups was moderate (Cramer V estimates, 0.35 and 0.39, respectively; p 0.05). The intensity of snoring assessed by the patients on VAS was not related to BMI, sleep parameters, or ESS, but it was significantly correlated with BMI, AHI, ODI, and ESS when assessed by the bed partner (r 0.40 to 0.52; p 0.05) [Tables 1, 2]. Self-reported sleepiness on ESS correlated with ODI and time with oxygen desaturation below 90% (r 0.35 and r 0.36, respectively; p 0.05) Clinical Investigations

4 Figure 1. The severity of each symptom or issue scored by the patients (P) and bed partners (BP). The area of the circle represents the number of patients, and answers have been graded from mild or rare (score of 1) to severe or frequent (score of 5). Duration of snoring (score of 1, only part of the night; score of 2, most of the night; score of 3, all night) and snoring position (score of 1, mainly on back; score of 2, in all body positions). Fifty-five percent of the bed partners found snoring disturbing every night or almost every night, and 40% of them slept in a separate room at least once a week. Twenty-six percent of the spouses used ear plugs, sleeping pills, or both. Thirty-five percent of the bed partners reported disharmony in the relationship from time to time or repeatedly due to snoring. Measured data on polysomnography and anterior rhinomanometry are presented in Table 2. Snoring Table 2 Polysomnography and Rhinomanometry Variables Mean (SD) Median (Range) AHI 13.7 (16.2) 6.0 (0 54) ODI 15.8 (19.6) 8.0 (0 70) Sao 2 90%, % 5.2 (13.2) 0.0 (0 73) Arousals per h 23.3 (16.0) 21.0 (4 68) Snoring, % 35 (24) 33 (0 85) Mouth breathing, % 48 (24) 52 (2 96) Total sleep time, min 387 (80) 395 ( ) Sleep efficiency, %* 82 (14) 87 (39 98) Wake after sleep onset, min 54 (49) 35 (5 226) Slow-wave sleep, % 15 (8) 14 (0 43) Rapid eye movement sleep, % 18 (6) 18 (3 34) Total nasal resistance, baseline, supine, Pa/cm 3 /s (0.571) ( ) *Total sleep time/time in bed. and mouth breathing time measured during the study night were both significantly correlated with BMI (r 0.58 and r 0.48, respectively; p 0.05). Snoring time was significantly correlated with AHI, ODI, and arousals (r 0.44 to 0.52; p 0.05). Mouth breathing time was correlated with AHI, ODI, arousals, and time with Sao 2 90% (r 0.41 to 0.50; p 0.05). However, these variables were not correlated with ESS or intensity of snoring on VAS assessed by the patients or bed partners. Current smoking and higher-than-the-median (0.300 Pa/cm 2 /s) total nasal resistance measured in a supine position were not separately related to selfreported habitual snoring, but the combination of the high nasal resistance and current smoking was associated with a history of habitual snoring (p 0.05). When this relationship was evaluated with nasal resistance measured in a seated position, no significant association was found. Discussion The primary objective of this study was to compare SDB symptoms provided by patients themselves with the assessments provided by bed partners on the patient s behalf. The agreement between snoring men and their bed partners appears to be CHEST / 128 / 4/ OCTOBER,

5 good in the scoring of the main symptoms of SDB. The ratings of snoring intensity on VAS were also significantly correlated. Previous studies 7,8 comparing patient and spouse reports of snoring and other symptoms associated with SDB have usually been based on population studies. Spouse reports have yielded higher prevalences of snoring and some other symptoms for men than self-reports in a survey of husband and wife pairs. 7 Another population study 8 observed modestto-excellent levels of agreement in scoring of snoring, some other nocturnal symptoms, and the reports of falling asleep while walking or driving, when no restrictions were placed on subjects abilities to confer with their bed partners. Predictability of OSA was not substantially improved with a separate roommate questionnaire. Recently, one clinical study 18 reported differences in assessment of quality of life between patients with more severe SDB than our patients had and their bed partners. In this study, we investigated the reliability of the main symptoms that have been found relevant in clinical decision making of patients suspected of having SDB. 19 As we had expected, male patients with habitual or heavy snoring seeking medical help seem to be well informed of snoring and other associated symptoms as well. However, this may not be true in patients investigated for other reasons, eg, hypertension or cardiac disease. Asking the bed partner s view is probably more important in these cases. Severity or frequency of the symptom is essential in prediction of OSA. However, grading of symptoms based on bed partner s reports may be difficult to self-assess. Especially habitual disruptive snoring has been found to be associated with OSA. 8,20,21 The ESS score has been found to rise with increasing frequency of snoring in the population. 22 Interestingly, the relationship between sleepiness and snoring has been found at each level of AHI, suggesting that snoring is associated with sleepiness independent of AHI. 22 It is possible that a reliable history of snoring gives a rather accurate measure of disease severity on a longer time span than a single overnight sleep study. Figure 1 shows that severity grading of the most important symptoms was congruent in this sample. Only assessment of snoring duration and frequency of mouth breathing seemed to differ to some degree in patients and bed partners reports. Snoring disturbed half of the bed partners every night or almost every night, and 40% of the bed partners had to leave the bedroom weekly. Use of sleeping pills and/or ear plugs was common. One third of the bed partners reported marital disharmony at least from time to time due to snoring. Greater marital dissatisfaction and higher divorce rates have been previously reported in spouses of men with OSA. 23,24 There are some studies 25,26 showing that snoring and nocturnal symptoms may indeed increase sleep fragmentation, daytime sleepiness, and fatigue in the bed partners. Recently, Parish and Lyng 1 reported improvement of daytime sleepiness and quality of life in bed partners of patients with OSA after treatment with nasal continuous positive airway pressure. In this study, bed partners reports of frequently disrupted sleep were rather common, although SDB was usually mild. We have previously shown that mouth breathing compromises adherence to nasal continuous positive airway pressure therapy. 14 Measured snoring time and mouth breathing time were significantly associated with BMI and sleep parameters in this study, suggesting that they are useful measures of SDB also in general. 14 However, these measurements were not associated with symptoms (snoring intensity on VAS or ESS). This finding is in accordance with previous reports 20,27,28 of measured data on polysomnography and daytime sleepiness, in which a poor relationship between AHI and sleepiness has been demonstrated. In this study, we only found a weak correlation between ESS and ODI and the time with Sao 2 90%. Smoking increases the risk of snoring and OSA. 29 A recent study 30 has demonstrated that even past smoking and to some extent passive smoking are contributors of habitual snoring. In this study, one half of the patients were smokers. The proportion of smokers was higher than in the Finnish population in general (28% in men). 31 Habitual snorers appear to have lower nasal airflow than nonsnorers. 32 Nasal obstruction has been recognized as a risk factor for habitual snoring, 33 but the relationship between nasal obstruction and OSA has remained controversial. 32 Earlier, we have reported a linear correlation between total nasal resistance measured in a supine position and both AHI and ODI. 9 Elevated total nasal resistance in a supine position and smoking together were associated with habitual snoring. Supine measurement of nasal resistance may assess nocturnal nasal congestion more closely than seated measurements. Questionnaire data on symptoms in SDB can be influenced by several factors. Self-evaluation of daytime sleepiness may be influenced by the habitual nature of gradually emerging symptoms, which may cause underreporting. A recent study 18 comparing self- and bed partner-assessed quality of life in SDB found that male patients with SDB gave better ratings than spouses reporting on their behalf. However, self-reported quality-of-life scores were generally lower in patients with SDB compared with ageand sex-adjusted normative values. 18 Male and female patients seem to report their symptoms differ Clinical Investigations

6 ently when compared with their bed partners. 7,18 The susceptibility of the spouse to be disturbed by snoring may also vary. Since quality of life may be impaired in both the patients and their bed partners, 1 reduction of the functional status may bias reporting. The patients in this material were consecutive men with a snoring problem. Mean ESS score was low, although one third of the patients complained habitual sleepiness. All our patients had nasal stuffiness, but symptoms of nasal obstruction are common in patients with OSA. 34,35 The results of this sample may be considered representative of a clinical population referred for evaluation of snoring and possibly of a population with an early stage of SDB in general. However, these findings may not apply to women or to patients with severe SDB. Conclusions Agreement between patients and bed partners reports of snoring and other common symptoms of SDB seems to be good in snoring male patients with mild SDB. 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7 33 Young T, Finn L, Palta M. Chronic nasal congestion at night is a risk factor for snoring in a population-based cohort study. Arch Intern Med 2001; 161: Brander PE, Soirinsuo M, Lohela P. Nasopharyngeal symptoms in patients with obstructive sleep apnea syndrome: effect of nasal CPAP treatment. Respiration 1999; 66: Lojander J, Brander PE, Ämmälä K. Nasopharyngeal symptoms and nasal continuous positive pressure therapy in obstructive sleep apnoea syndrome. Acta Otolaryngol (Stockh) 1999; 119: Clinical Investigations