DOI : 10.4046/trd.2009.66.1.1 ISSN : 1738-3536(Print)/2005-6184(Online) Tuberc Respir Dis 2009;66:1-5 CopyrightC2009. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved. 수면호흡장애의유병률과정의 고려대학교의과대학안산병원호흡기내과학교실수면호흡장애센터 신 철 Epidemiology and Definition of Sleep Disordered Breathing Chol Shin, M.D., Ph.D., F.C.C.P. Sleep Breathing Disorder Center, Department of Pulmonary and Critical Care, College of Medicine, Korea University, Ansan Hospital, Ansan, Korea 서 수면호흡장애 (sleep disordered breathing, SDB) 란, 수면중상기도의저항증가로일어나는호흡이상으로단순코골이, 상기도저항증후군, 폐쇄성수면무호흡증, 중추성무호흡을포함하는질환군이다 1. 특히폐쇄성수면무호흡은상대적으로흔한질환으로반복적인수면중의호흡기류의감소로인해가스교환의장애가발생하고, 수면중각성을유발하게된다. 폐쇄성수면무호흡증후군이건강에미치는영향은다양하게알려져있으며치료를하지않으면지나친주간졸림이나, 인지장애, 직업수행능력의감소, 삶의질이하락하게되며, 최근연구들에의해고혈압, 심혈관계질환, 당대사의이상을유발함이밝혀지고있다 2-4. 조기발견과적절한치료로신경행동학적합병증과심혈관계의손상을예방할수있음이알려진후수면호흡장애에대한중요성이더욱강조되고있다 5. 본문헌에서는수면호흡장애의유병률과각질환의정의에대하여최근연구결과를바탕으로기술하고자한다. Address for correspondence: Chol Shin, M.D., Ph.D. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, 516, Gojan-1-dong, Danwon-gu, Ansan 425-707, Korea Phone: 82-31-412-5603, Fax: 82-31-412-5604 E-mail: chol-shin@korea.ac.kr 론 수면호흡질환의유병률 수면호흡질환특히폐쇄성수면무호흡증에대한관 심이높아지면서유병률에대한연구결과가많이보고되었다 1,6. 그러나각질환의정의, 진단방법, 표본선택의편향에따라많은차이를보인다는방법적론적한계가있다. 코골이의유병률은남성은 10.8 64%, 여성의경우는 3.2 52% 로다양하게보고되었다 (Table 1) 7. 무호흡-저호흡지수가 5 이상인폐쇄성수면무호흡증의유병률은연구지역에따라다양하게보고되었으나남성은 1.5 27.1%, 여성은 0.8 28% 이다 (Table 2). 최근비만인구가증가함에따라유병률은점차증가할것으로예상된다. Table 1. Prevalence of regular or frequent snoring Prevalence (%) Study location n Age (years) Men Women United Kingdom 4,972 15 or over 47.7 33.6 United State 602 30 60 64 52 Korea 4,164 40 65 15.6 8.4 Chinese 805 20 74 10.8 3.2 Indian 719 20 74 16 6.3 Adapted from the reference 9. 수면호흡장애의분류 수면호흡장애질환은수면중에일어나는다양한호흡장애를총칭하는것으로국제수면질환분류 (The International Classification of Sleep Disorders-2nd edition, ICSD-2) 에서는수면호흡장애질환을크게중추성수면무호흡 (central sleep apnea syndrome, CSAS) 과폐쇄성 1
C Shin: Epidemiology and definition of sleep disordered breathing Table 2. Prevalence of obstructive sleep apnea in Asia and elsewhere AHI 5 (%) Country Year Age n* Men Women Wisconsin 1993 30 60 602 24 9 Pennsylvania 1998 20 99 741 17 Spain 2001 30 70 555 26 28 Australia 1995 40 65 294 26 Korea 2004 40 69 457 27.1 16.8 Hong Kong 2001, 2004 30 60 258 8.8 3.7 India 2004 35 65 250 19.5 Singapore 1998 20 74 2,298 1.5 0.8 Adapted from the Reference 2,6,9. *Numbers of subjects who underwent PSG or home monitoring, Interviewer-administered survey in multi-ethnic sample. Table 3. Classification of sleep-related breathing disorders Central sleep apnea syndromes Primary central sleep apnea Other central sleep apnea due to a medical condition Cheyne-Stokes breathing pattern High attitude periodic breathing Central sleep apnea due to a medical condition Not Cheyne-Stokes or high attitude Central sleep apnea due to a drug or substance Other sleep-related breathing disorder due to a drug or substance Primary sleep apnea in infancy (formally primary sleep apnea of the new born) Obstructive sleep apnea syndromes Obstructive sleep apnea, adult Obstructive sleep apnea, pediatric Adapted from the International Classification of Sleep Disorders, 2nd edition: Diagnostic and coding manual 8. 수면무호흡 (obstructive sleep apnea syndrome, OSAS) 으로분류한다 8. 중추성수면무호흡증은각각의원인에따라서소분류로나누며폐쇄성수면무호흡증후군은나이에따라임상적인양상과수면이상호흡에대한진단기준이다르기때문에성인형과소아형으로나눈다 (Table 3). 수면무호흡의중추성과폐쇄성의근본적인차이는수면장애를유발하는병리적기전이다. 중추성수면무호흡증은중추신경계의호흡조절능력의장애에의한것인반면, 폐쇄성수면무호흡증은해부학적이상혹은상기도의 개방성을유지하는근육운동의이상조절등에의한상기도의폐쇄가주된기전이된다. 수면호흡장애의정의 1. 폐쇄성수면무호흡증 (obstructive sleep apnea syndrome) 폐쇄성수면무호흡증의특징은수면시반복적인부분적또는완전한상기도의폐쇄이며상기도의완전한폐쇄는무호흡을, 부분적인폐쇄는저호흡을유발한다. 무호흡과저호흡에의한반복적인폐환기의저하는저산소혈증과동맥혈이산화탄소분압의증가를야기하며 9 무호흡을중지시키기위해수면중각성이요구되고, 이런반복적인수면중의각성에의해주간졸림, 집중력저하등의주간증상이초래된다. ICSD-2 에의하면성인의폐쇄성수면무호흡증의진단기준은환자가 1 주간졸림, 개운하지않은수면혹은불면증, 2 수면중의숨정지, 질식감, 헐떡거림, 3 배우자가시끄러운코골이및호흡장애를호소하는경우중한가지이상을호소하는경우이며, 수면다원검사상으로는시간당 5회이상의무호흡, 저호흡, RERA (respiratory effort-related arousals) 가있으면서호흡장애기간중호흡노력이있어야한다. 부가적으로는수면다원검사상으로시간당 15회이상의무호흡, 저호흡, RERA가있으면서호흡장애기간중호흡노력이있으면환자의증상이없어도폐쇄성수면무호흡으로진단할수있다 8. 2
Table 4. Definitions of parameters of abnormal breathing Tuberculosis and Respiratory Diseases Vol. 66. No. 1, Jan. 2009 Apnea (1) There is a drop in the peak thermal sensor excursion by 90% of baseline. (2) The duration of the event lasts at least 10 seconds. (3) At least 90% of the event's duration meets the amplitude reduction criteria for apnea. Hypopnea (1) The nasal pressure signal excursion drop by 30% of baseline. (2) The duration of this drop occurs for a period lasting at least 10 seconds. (3) There is a 3% desaturation from pre-event baseline or the event is associated with arousal. (4) At least 90% of the event's duration meets the amplitude reduction criteria for Hypopnea. Apnea-hypopnea index (AHI) Total number of apneas and hypopneas divided by the hours of sleep. Respiratory disturbance index (RDI) Total number of apneas, hypopneas, and RERAs divided by the hours of sleep. Respiratory effort-related arousal (RERA) If there is a sequence of breaths lasting at least 10 seconds characterized by increasing respiratory effort or flattening of the nasal pressure waveform leading to an arousal from sleep when the sequence of breaths does not meet criteria for an apnea or hypopnea. Adapted from the Reference 10. 가넓어지고, 작아질수록상기도는폐쇄된다. 상기도를확장하려는힘은상기도확장근이중요한요소이며상기도를함몰시키는힘에는기도주변의연부조직, 골격의이상, 근긴장도의감소, 이산화탄소조절등의생리학적장애등이관여한다. 특히수면시에는상기도확장근의활성도가낮아져상기도의내경과인두벽의폐쇄정도가증가된다 12. 2. 중추성수면무호흡증후군 (central sleep apnea, CSA) Figure 1. Common site of anatomical obstruction in obstructive sleep apnea. A: nasal cavity; B: retropalatal area; C: retrolingual area; D: epiglottic area. 폐쇄성호흡장애에는무호흡, 저호흡, RERA가포함이되는데이들의정의는 Table 4와같다 10. 1) 수면무호흡에서상기도의해부학적폐쇄부위 : 폐쇄성수면무호흡은수면중상기도의폐쇄에의해발생한다. 상기도의어디든지폐쇄가일어날수있으며, 일반적으로비강, 구개후부, 설근부, 후두개부, 인두측면부로나누고있다 (Figure 1) 11. 2) 수면무호흡의기도폐쇄의병태생리 : 수면무호흡에서상기도의폐쇄는상기도를확장하는힘과함몰시키는힘의차이에의해생기며이를상기도의경벽압 (transmural pressure) 이라고한다. 경벽압이커질수록상기도 중추성수면무호흡증은상기도폐쇄소견없이수면중무호흡이반복되는것이특징으로환기조절시스템 (ventilatory control system) 의이상이주된기전이다. 중추성수면무호흡증은저산소증과반복되는각성을야기하여불면증이나주간졸림과같은주간증상을동반한다. 중추성수면무호흡의진단은주간졸림이나수면중각성증상이있으면서 5회이상의중추성무호흡이동반되고동맥혈가스분압이 45 torr 이하로감소하는경우이다. 중추성무호흡이란무호흡의조건을만족시키면서호흡기류가없는동안호흡노력이없는경우를말한다 10. 3. Cheyne-Stokes Respiration (CSR) Cheyne-Stokes 호흡은호흡운동의주기적인증감을특징으로하는중추성수면무호흡증의한형태로호흡의진폭이주기적인크레센도-데크레센도 (crescendo and decrescendo) 변화를보이며주로심부전이나뇌신경질환에서동반된다. 심부전환자에서 Cheyne-Stokes 호흡은흔하게동반되며나쁜예후와연관성이있고 13 불면증 3
C Shin: Epidemiology and definition of sleep disordered breathing 과발작적인야간호흡곤란을야기하지만, 심장기능개선시호전될수있다. 수면호흡장애의다양한스펙트럼 1. 코골이 (snoring) 코골이란, 수면중상기도에서발생하는음으로, 주로관찰자에의해서보고되며환자는코골이나호흡기류감소에의한불편감을호소하지않고불면증이나주간졸림은없는것이일반적이다. 진단을위해서수면다원검사는필요하지않으며, 가능하다면마이크로폰을통해코골이소리를측정할수있다. 코골이는호흡기류장애나수면중각성, 산소포화도의감소, 심부정맥과는연관성이없다. 2. 상기도저항증후군 (upper airway resistance syndrome) 상기도저항증후군은상기도의저항이증가하여수면중각성이동반되고주간졸림이있는경우로, 수면다원검사상의특징은 (1) 폐쇄성수면무호흡이없고, (2) 무호흡 -저호흡지수가 5 이하이면서, (3) 의미있는산소포화도감소가없는것이다. 상기도압력증가는식도압을측정하여진단하는것이추천되지만, 정규적으로사용하지는않는다. 진단은앞서언급한수면다원검사결과와주간졸림이있는경우내릴수있다. 상기도저항증후군을독립적인증후군으로분류하는것에대해서는논란이있는상태로일반적으로는폐쇄성수면무호흡의경증상태정도로파악한다 9. 3. 비만성저환기증후군 (obesity hypoventilation syndrome, OHS) 비만은많은경우에폐쇄성수면무호흡증에영향을주며비만이심한환자는수면중뿐만아니라깨어있는상태에서도저환기상태가유지되기도한다. 비만과저환기상태가공존하는경우비만성-저환기증후군이나 Pickwickian 중후군이라는명칭을사용하고있으며최근에는수면저환기증후군이라고도한다. 진단기준은 BMI 가 30 이상인비만환자중저환기로인해혈중이산화탄소분압이 45 torr 이상인경우로동반된심폐질환이없는경우이다 14. 폐쇄성수면무호흡증과비만성-저환기증후군은모두주간졸림을특징으로하지만중요한차이가있다. 폐쇄 성수면무호흡환자의경우호흡조절시스템은정상이며, 비만이진단에반드시필요한것은아닌반면에비만성-저환기증후군의경우에는비만정도가진단에필요조건이며, 저환기상태가수면중뿐만아니라깨어있는상태에도지속된다는특징이있다. 결 수면무호흡질환은다양한표적장기의합병증을유발하는흔한질환으로심혈관계와신경인지장애와의연관성은잘알려져있으며전세계적으로비만인구가증가하면서조기진단의중요성이더욱커지고있다. 수면호흡질환은다양한스펙트럼을가지고있으며상호독립적이면서도서로연관되어있기때문에정확한진단기준과임상양상을숙지함은이제필수적이라할수있다. 론 참고문헌 1. Young T, Palta M, Dempsey J, Skatrud J, Weber S, Badr S. The occurrence of sleep-disordered breathing among middle-aged adults. N Engl J Med 1993;328: 1230-5. 2. Peppard PE, Young T, Palta M, Skatrud J. Prospective study of the association between sleep-disordered breathing and hypertension. N Engl J Med 2000;342: 1378-84. 3. Peker Y, Carlson J, Hedner J. Increased incidence of coronary artery disease in sleep apnoea: a long-term follow-up. Eur Respir J 2006;28:596-602. 4. Punjabi NM, Polotsky VY. Disorders of glucose metabolism in sleep apnea. J Appl Physiol 2005;99:1998-2007. 5. Marin JM, Carrizo SJ, Vicente E, Agusti AG. Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure: an observational study. Lancet 2005;365:1046-53. 6. Bearpark H, Elliott L, Grunstein R, Cullen S, Schneider H, Althaus W, et al. Snoring and sleep apnea: a population study in Australian men. Am J Respir Crit Care Med 1995;151:1459-65. 7. Ohayon MM, Guilleminault C, Priest RG, Caulet M. Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample. BMJ 1997;314:860-3. 4
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