한대학병원에서철야수면다원검사를시행한환자들의수면설문조사결과분석 가톨릭대학교의과대학내과학교실, 1 예방의학교실강지호, 이상학, 권순석, 김영균, 김관형, 송정섭, 박성학, 문화식, 박용문 1 Analysis of Sleep Questionnaires of Patients who Performed Overnight Polysomnography at the University Hospital. Ji Ho Kang, M.D., Sang Haak Lee, M.D., Soon Seog Kwon, M.D., Young Kyoon Kim, M.D., Kwan Hyoung Kim, M.D., Jeong Sup Song, M.D., Sung Hak Park, M.D., Hwa Sik Moon, M.D., Yong Moon Park, M.D., Ph.D. 1 Department of Internal Medicine and 1 Preventive Medicine, The Catholic University of Korea, College of Medicine, Seoul, Korea Background : The objective of this study was to understand sleep-related problems, and to determine whether the sleep questionnaires is a clinically useful method in patients who need polysomnography. Methods : Subjects were patients who performed polysomnography and who asked to answer a sleep questionnaires at the Sleep Disorders Clinic of St. Paul s Hospital, Catholic University of Korea. Baseline characteristics, past medical illness, behaviors during sleep-wake cycle, snoring, sleep-disordered breathing and symptoms of daytime sleepiness were analyzed to compare with data of polysomnography. Results : The study population included 1081 patients(849 men, 232 female), and their mean age was 44.2±12.8 years. Among these patients, 38.9% had an apnea-hypopnea index(ahi)<5, 27.9% had 5 AHI<20, 13.2% had 20 AHI<40, and 20.0% had 40 AHI. The main problems for visiting our clinic were snoring(91.7%), sleep apnea(74.5%), excessive daytime sleepiness(8.0%), insomnia(4.3%), bruxism(1.1%) and attention deficit(0.5%). The mean value of frequency of interruptions of sleep was 1.6 and the most common reason was urination(46.3%). Epworth Sleepiness Scale(ESS) had a weak correlation with AHI(r=0.209, p<0.01). When we performed analysis of sleep questionnaires, there were significant differences in the mean values of AHI according to the severity of symptoms including snoring, daytime sleepiness, taking a nap and arousal state after wake(p<0.05). Conclusion : On the basis of statistical analysis of sleep questionnaires, the severity of subjective symptoms such as ESS, snoring, daytime sleepiness and arousal state after wake correlated with the AHI significantly. Therefore the sleep questionnaires can be useful instruments for prediction of the severity of sleep disorder, especially sleep-disordered breathing.(tuberc Respir Dis 2006; 60: 76-82) Key words : Sleep questionnaires, Polysomnography, Obstructive sleep apnea 서 수면무호흡증후군은과도한주간졸음증을주증상으로하면서수면중무호흡을반복적으로보이는질환으로심혈관계및정신신경학적합병증을유발할수있다 1. 최근비만인구의증가와관련되어유병률이 본논문은가톨릭대학교성바오로병원임상의학연구비의일부지원으로이루어졌음. Address for correspondence : Hwa Sik Moon, M.D., Division of Pulmonology, Department of Internal Medicine, St. Paul's Hospital, The Catholic University of Korea, 620-56, Jeonnong-dong, Dongdaemoon-gu, Seoul, 130-709, Republic of Korea Phone : +82-2-958-2463 Fax : +82-2-968-7250 E-mail : hsmoon@catholic.ac.kr Received : Nov. 2. 2005 Accepted : Dec. 14. 2005 론 급속히증가하고있으며 2 또한합병증으로인해사망률이증가할수있다는사실이알려지면서이질환의중요성이더욱강조되고있다 3. 수면다원검사는이질환의확진, 중증도판정및치료효과를평가하는데필수적인검사이며 4, 질환의중증도는수면다원검사에서의무호흡지수 (apnea index, AI), 무호흡-저호흡지수 (apnea-hypopnea index, AHI), 저산소증의정도, 고탄산증의발생여부및심혈관계질환의동반여부등을종합하여판정한다 5. 그러나수면다원검사결과가환자의주관적인임상증상과어느정도상관관계가있는지에대한연구자료는충분하지않은실정이다. 또한수면다원검사는시간과비용이많이소요되기때문에수면장애가의심되는모든환자에서시행하기에는어려움이많으며, 임상영역에서수면다원검사를시행할환자를선별할 76
Tuberculosis and Respiratory Diseases Vol. 60. No. 1, Jan. 2006 수있는유용성이입증된간편한검사법은현재까지없는실정이다. 이에저자들은수면장애를주소로내원한환자들에서시행한수면설문조사의여러항목중환자의주관적인임상증상과이들환자의철야수면다원검사결과를비교분석함으로써, 수면설문조사가환자의수면과관련된문제점을파악하고임상적유용성이있는지여부를알아보고자하였다. 연구대상및방법 1. 연구대상 1994년 6월부터 2004년 9월까지가톨릭대학교성바오로병원수면장애클리닉에의뢰되어철야수면다원검사 (overnight polysomnography) 를시행한환자들을대상으로하였다. 수면다원검사를두번이상시행한환자들의경우에는최초검사결과만을자료에포함시켰다. 수면설문조사는본수면장애클리닉이작성한수면설문지를이용하였고, 수면검사실기사의설명을들은후수면과관련된문제점들을환자가직접작성하게하였으며, 의사소통이원활하지않거나언어장애가있는환자는보호자를통해정보를얻었다. 수면설문지를작성하지않았거나부적절하게작성한경우는연구대상에서제외하였다. 2. 연구방법 1) 수면설문조사 (Sleep questionnaires) 수면설문지는 The Scripps Research Institute의수면설문지와 Stanford Sleep Questionnaires를기초로만들었으며, 여섯가지항목으로이루어져있다. 즉일반적인사항, 잠들기전행동, 수면시행동, 깨어난후행동, 낮동안의행동및기타행동으로구분되어있으며, 총 73개의문항으로구성되어있다. 전체적인내용은일반적인특성 (general description), 병력 (medical history), 수면 -각성주기 (sleep-arousal cycle) 동안의행동, 수면과관련된호흡장애 (sleep-disordered breathing), 주간졸음증 (daytime sleepiness) 과관계된증상등을포함하고있다. Epworth Sleepiness Scale (ESS) 은 1999년 9월부터작성하였으며여기에는 509명이포함되었다. 2) 수면다원검사 (Polysomnography) 수면다원분석기 (Alice 3 polysomnograph, Healthdyne Technologies, Atlanta, GA) 를이용하여전체수면기간동안실시하였으며, 검사에소요된시간은최소 6시간이상이었다. 수면다원기록 (polysomnographic data) 에는두개의뇌파 (C3/A2 & O2/A1 EEG), 좌측및우측안구운동 (EOG), 턱과다리의근전도, 흉부및복부호흡운동, 체위변동, 입과코로부터공기의흐름, 코골이기록, 심전도, 동맥혈산소포화도 (Healthdyne 930 pulse oximeter, Atlanta, GA) 를포함시켰으며, 환자의수면중영상과음향을동시에기록하였다. 전체수면기간의수면다원기록에서수면단계 (sleep stage) 는 Rechtschaffen 과 Kales의판독기준에따라분석하였다 6. 수면다원검사의분석항목중무호흡 (apnea) 은호흡이 10초이상정지된경우로정의하였고, 저호흡 (hypopnea) 은기류가기저치의 50 % 이상감소된상태가 10초이상지속되고이로인해동맥혈산소포화도가 4% 이상감소하는경우로하였으며, 무호흡지수 (apnea index) 는전체수면시간동안의전체무호흡횟수를전체수면시간으로나누어산출하고, 저호흡지수 (hyponea index) 는전체수면시간동안의전체저호흡횟수를전체수면시간으로나누어계산하였다. 무호흡-저호흡지수 (apnea-hypopnea index) 는무호흡지수와저호흡지수를합한값으로하였다 7. 수면다원검사에서무호흡-저호흡지수가 5 이상이고주간졸음증이동반된경우를수면무호흡증후군 (sleep apnea syndrome) 으로진단하였고, 5이상 20미만은경증, 20 이상 40미만은중등증, 40 이상은중증으로분류하였다. 3. 통계분석 (Statistical analysis) 전체대상의일반적인특성을분석하였고, 코골이의정도, 수면후각성상태및주간졸음증의정도와무호흡-저호흡지수의평균치는 ANOVA를이용하여 77
JH Kang et al : Analysis of sleep questionnaires of patients who performed overnight polysomnography 비교하였으며, 평소에낮잠을자는군과자지않는군간의무호흡-저호흡지수의비교는 t-test를이용하였다. 수면무호흡의중증도에따른각군간의 ESS의평균은 ANOVA를이용하여비교하였다. 모든통계분석에는 SPSS 10.0 window를사용하였다. 1. 일반적특성 Table 1. Clinical and baseline characteristics of study subjects M : F 849 : 232 Age, years 44.2±12.8 (15-82) BMI, kg/m 2 26.1±3.8 (12.5-41.8) Neck circumference, cm 37.7±3.7 (22.0-55.0) Lowest O2 saturation, % 84.9±9.9 (40.0-98.0) Mean O2 saturation, % 94.9±3.8 (65.1-99.5) AI 14.0±20.7 (0-124.6) AHI 20.8±25.6 (0-148.3) AHI<5 422 [39.0] 5 AHI<20 300 [27.8] 20 AHI<40 142 [13.1] 40 AHI 217 [20.1] ESS* 10.0±4.2 (0-23) Abbreviations: BMI; body mass index, AI; apnea index, AHI; apnea-hypopnea index, ESS; Epworth Sleepiness Scale * Number of study subjects are 509 persons Values are mean (range) Values are mean [%] Table 2. Main problems of visiting clinic Problems N % Snoring 991 91.7 Sleep Apnea 805 74.5 Excessive Daytime Sleepiness 87 8.0 Insomnia 47 4.3 Bruxism 12 1.1 Attention Deficit 5 0.5 Total 1,081 100.0 N; number of subjects 결 과 전체연구대상자 1081명 ( 남자 849명, 여자 232명 ) 의평균연령은 44.2±12.8세, 평균비만도 (body mass index, BMI) 는 26.1±3.8kg/m 2, 목둘레는 37.7±3.7cm 이었다. 전체대상자의최저동맥혈산소포화도는 84.9± 9.9%, 평균동맥혈산소포화도는 94.9±3.8% 이었다. 무호흡지수는 14.0±20.7, 무호흡-저호흡지수는 20.8± 25.6 이었다. 무호흡-저호흡지수가 5 미만인경우는 422명 (39.0%) 이었으며, 5 이상 20 미만의경증수면무호흡증후군환자는 300명 (27.8%), 20 이상 40 미만의중등증은 142명 (13.1%), 40 이상의중증은 217명 (20.1%) 이었다. 전체대상자중 509명이작성한 ESS 의평균은 10.0±4.2 이었다 (Table 1). 동반하고있는질환은고혈압 23.3%, 심장질환 8.5%, 폐질환 8.1%, 당뇨 5.9%, 관절염 1.1% 로고혈압이가장많았다. 2. 수면설문조사결과분석 수면다원검사를시행하게된주된동기로는코골이가 991명 (91.7%), 수면무호흡이 805명 (74.5%), 주간졸음증이 87명 (8.0%), 불면증이 47명 (4.3%), 이갈이가 12명 (1.1%), 집중력장애가 5명 (0.5%) 이었다 (Table 2). 수면중깨는횟수는 1.6±1.8회였으며그이유로는 소변을보기위해서 가 44.3% 로가장많았고 무호흡 이 3.4%, 코골이 가 0.3% 이었다 (Figure 1). ESS는무호흡-저호흡지수와약한상관관계를보였다 (r=0.209, p<0.01)(figure 2). 그러나수면무호흡의중증도에따라 ESS의평균치를비교한결과 ESS 는각군간에서통계적으로유의한차이를보였다 (p<0.001)(figure 3). 평소수면중에코를고는사람 50 45 40 35 30 25 20 15 10 5 0 % Urination Unknown Apnea Thirst Sleeptalking Snoring Figure 1. Distribution for the causes of awakening during sleep 78
Tuberculosis and Respiratory Diseases Vol. 60. No. 1, Jan. 2006 AHI 160 140 r=0.209, p<0.01 ESS 16 p<0.001 p<0.001 120 14 100 12 80 60 40 20 0 0 5 10 15 20 25 ESS 10 8 6 4 AHI<5 5 AHI<20 20 AHI<40 40 AHI Figure 3. Comparison of ESS between categorized apnea-hypopnea index Figure 2. Correlation between ESS and apnea-hypopnea index 은 1,012명으로전체대상자중 93.6% 이었으며, 코골이가있다고답한대상자중에서그정도에따라 심하다, 보통이다, 약하다 로구분하여질문했을때 심하다 라고답한군은 853명 (84.3%), 보통이다 는 126명 (12.4%), 약하다 는 33명 (3.3%) 이었다. 이들의무호흡-저호흡지수는각각 24.4±27.0, 8.2±12.7, 7.9± 12.9 이었으며코골이정도에따라무호흡-저호흡지수는통계적으로유의한차이를보였다 (p<0.001) (Table 3). 평상시수면후각성상태에대하여질문했을때 명료하다 라고답한군은 198명 (18.4%), 조금몽롱하다 라고답한군은 686명 (63.7%), 극도로몽롱하다 라고답한군은 193명 (17.9%) 이었고, 무호흡-저호흡지수는각각17.2±21.4, 20.8±25.6, 23.7±28.9 이었으며, 수면후각성상태와무호흡-저호흡지수는유의한관련성을보였다 (p<0.05)(table 3). TV를시청하거나, 회의중혹은공공장소에서자신도모르게깜박졸거나졸지않으려고애쓴적이있느냐는질문에 항상 은 208명 (19.3%), 자주 는 408명 (37.9%), 드물게 는 255명 (23.7%), 전혀 는 206명 (19.1%) 이었고, 이들의무호흡-저호흡지수는각각 29.0±31.3, 22.5±26.3, 16.2±20.4, 14.0±20.3 이었으며, 주간졸음증의정도와무호흡-저호흡지수는통계적으로유의한차이를보였다 (p<0.001)(table 3). 평소에운전을하는대상자중에서운전중에졸거나졸지않으려고애쓴적이있느냐는질문에 항상 은 50명 (6.9%), 자 주 는 204명 (28.1%), 드물게 는 173명 (23.8%), 전혀 는 294명 (41.2%) 이었고, 각군의무호흡-저호흡지수는각각 47.4±38.8, 29.9±29.7, 19.6±22.4, 18.8± 23.2 이었으며, 운전중졸음의정도와무호흡-저호흡지수는통계적으로유의한차이를보였다 (p<0.001) (Table 3). 평소에낮잠을규칙적으로자는군은 470 명 (43.6%), 그렇지않는군은 607명 (56.4%) 으로이들의평균무호흡-저호흡지수는각각 22.8±26.6, 19.0± 24.7로두군간에유의한차이를보였다 (p<0.05) (Table 3). 고찰수면무호흡증후군환자의중요한문제점으로는심혈관계및정신신경학적합병증이외에도환자의자각증상과삶의질저하를들수있으며 8-10, 수면무호흡은업무수행능력의저하, 병가나이혼율증가와같은정신-사회학적결과들을예측할수있는독립적인자가될수있다는지적이있다 11. 또한이들환자는졸음운전사고나산업재해발생률이상대적으로높고 12, 기억력감소, 인지능력장애, 우울증등으로고통을받는다 13,14. 따라서수면장애가있는환자들은수면다원검사의실시와더불어주관적임상증상의정도를반드시확인해야한다. 환자나보호자특히같이잠을자는사람이가장불편하게느끼는증상은코골이와무호흡이며, 같이잠을자는사람에게심각한스트레스를주고환자를 79
JH Kang et al : Analysis of sleep questionnaires of patients who performed overnight polysomnography Table 3. Comparison of apnea-hypopnea index according to the level of sleep-related events Degree of snoring Mild Moderate Severe N 33 126 853 AHI 7.9±12.9 8.2±12.7 24.4±27.0 p <0.001* T a a b State of arousal in the morning Alert Mild drowsy Severe drowsy N 198 686 193 AHI 17.2±21.4 20.8±25.6 23.7±28.9 p <0.05* T a a,b b Chance of dozing in public place Never Sometimes Often Always N 206 255 408 208 AHI 14.0±20.3 16.2±20.4 22.5±26.3 29.0±31.3 p <0.001* T a a,b b c Chance of drowsy driving Never Sometimes Often Always N 294 173 204 50 AHI 18.8±23.2 19.6±22.4 29.9±29.7 47.4±38.8 p <0.001* T a a b c Taking a nap Yes No N 470 607 AHI 22.8±26.6 19.0±24.7 p <0.05 * Statistical significance were tested by ANOVA The same letters indicates non-significant difference between groups based on Tukey s multiple comparison test Statistical significance was evaluated by paired t-test AHI : apnea-hypopnea index N : number of subjects 병원에데리고오게되는중요한이유이기도하다. 본클리닉에내원하게된주된동기로는코골이가 91.7 %, 수면무호흡이 74.5% 이었고, 수면무호흡증후군으로진단된환자는 61.0% 이었다. 수면중에깨는이유로소변을보기위해일어난다는대답이 44.3% 로가장많은것처럼야뇨증은이들환자에게흔한증상이다. 야뇨증은심방나트륨이뇨펩티드 (atrial natriuretic peptide) 분비증가와복압 (intra-abdominal pressure) 상승에의해발생하는것 으로알려져있으며 15-17, 야뇨증은수면무호흡의치료에의해효과적으로개선될수있다 18,19. 주간졸음증의정도를나타내는주관적방법으로 Epworth Sleepiness Scale(ESS) 이있다. 본연구에서 ESS가전체무호흡-저호흡지수와는약한상관관계를보였고, 수면무호흡증후군의중증도에따른각군간에는유의한차이를보였다. 특히무호흡-저호흡지수가 5미만인경우와중증환자, 경증환자와중증환자간에만유의한차이를보인점을감안할때 ESS 80
Tuberculosis and Respiratory Diseases Vol. 60. No. 1, Jan. 2006 는주간졸음증의정도를주관적으로표현하는편리한방법이지만민감도는낮은것으로생각되었다. 대규모역학조사에서무호흡-저호흡지수가 5이상인사람들중소수만이수면장애를호소하고임상증상과무호흡-저호흡지수는상관관계는있지만미약하다는연구결과가있었으며 20, 또한이들환자에서주관적임상증상의중증도와수면다원검사결과가일치하지않는다는보고도있었다 10,21. 그러나본연구에서는환자들이평소에느끼는주관적증상들이무호흡-저호흡지수와유의한관련성이있다는것을관찰할수있었다. 또한 2004년 Weaver 등 21 은수면설문조사를기초로한임상적중증도가무호흡-저호흡지수와일치하지않는다고보고하였으나, 이들이사용한수면설문지는주로정신건강과관련된내용으로구성되어있으며, 본연구는수면장애를환자의주관적측면에서체계적으로평가할수있도록만들어진수면설문지를사용하였다는점에서차이가있다. 수면장애를평가할수있도록만들어진수면설문지를사용한다른연구자역시수면다원검사의지표와상관관계가있다고보고한바있다 22,23. 결론적으로수면다원검사에서나타나는수면무호흡의중증도는주간졸음증이나수면후각성상태등임상증상의주관적중증도와유의한상관관계가있음을관찰할수있었으며, 수면설문지조사는환자의수면장애특히수면과관련된호흡장애의정도를예측하는데유용한자료가될수있다는것을알수있었다. 요약연구배경 : 수면설문조사가환자의수면과관련된문제점을파악하고수면다원검사의시행을필요로하는환자를선별하는검사로써임상적유용성이있는지여부를알아보고자하였다방법 : 가톨릭대학교성바오로병원수면장애클리닉에의뢰되어수면다원검사와수면설문조사를시행한환자를대상으로, 수면설문조사에포함되어있는환자의일반적특성, 병력, 수면-각성주기동안의행동, 코골 이, 수면과관련된호흡장애및주간졸음증과관계된증상등각각의항목과수면다원검사의각지표를비교분석하였다. 결과 : 전체환자수는 1081명으로남자 849명, 여자 232명이었고나이는 44.2±12.8세였다. AHI<5인군은 38.9 %, 5 AHI<20는 27.9%, 20 AHI<40는 13.2% 그리고AHI 40는 20.0% 였다. 검사를시행하게된주된동기는코골이 (91.7%), 무호흡 (74.5%), 주간졸음증 (8.0%), 불면증 (4.3%), 이갈이 (1.1%), 집중력장애 (0.5%) 였다. 수면중깨는횟수는평균 1.6회였으며그이유는소변을보기위함이 46.3% 로가장많았다. Epworth Sleepiness Scale과무호흡-저호흡지수 (A HI) 는상관관계가있었다 (r=0.209, p<0.01). 수면설문조사항목중코골이, 주간졸음증, 수면후각성상태의중증도에따른각군간의평균 AHI는통계적으로유의한차이를보였다. 결론 : 수면설문조사에서나타나는 ESS, 코골이, 주간졸음증이나수면후각성상태등주관적임상증상의중증도는수면다원검사결과의수면무호흡의중증도와유의한상관관계가있음을관찰할수있었다. 따라서수면설문조사는환자의수면장애특히수면과관련된호흡장애의정도를예측하는데유용하게이용될수있을것으로생각한다. 참고문헌 1. Henk B, Robert VW, Rene MK, Jan MB, Paul IM, Frans GA. Long-term results of uvulopalatopharyngoplasty for obstructive sleep apnea syndrome. Laryngoscope 2000;110:469 75. 2. Wittles ES. Obesity and hormonal factors in sleep and sleep apnea. Med Clin North Am 1985;69:1265-80. 3. Brown IB, McClean PA, Boucher R, Zamel N, Hoffstein V. Changes in pharyngeal cross-sectional area with posture and application of continuous positive airway pressure in patients with obstructive sleep apnea. Am Rev Respir Dis 1987;136:628-32. 4. Ronald DC, Christian G. Obstructive sleep apnea and related disorders. Neurol Clin 1996;14:583-609. 5. Medelson WB. Use of the sleep laboratory in suspected sleep apnea syndrome: is one night enough? Cleve 81
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