Korean J Fam Med. 2010;31:679-687 doi:10.4082/kjfm.2010.31.9.679 이차미분맥파를이용한흡연에의한혈관의급성변화 Original Article 이인희, 최창진 *, 김철민, 윤상아, 홍지영, 김자연 가톨릭대학교의과대학서울성모병원가정의학교실 The Examination of the Acute Vascular Changes Due to Smoking Using Second Derivative of Photoplethysmogram In Hui Lee, Chang Jin Choi*, Chul Min Kim, Sang Ah Yoon, Ji Young Hong, Ja Yeon Kim Department of Family Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea School of Medicine, Seoul, Korea Background: Although smoking is the major risk factor for atherosclerosis under the age of 40, the smoking rate of adolescent and young adult has been is increasing. In case of young adults, there is no available clinical indices reflecting harmful effects of smoking. The aim of this study was to investigate whether any second derivative of photoplethysmogram (SDPTG) index can be used as a clinical index of acute effects of smoking. Methods: Twenty smoking and eighteen never-smoking males ages between 20-39 without medical history of atherosclerotic disease nor peripheral vascular diseases were selected for this study. We investigated the life styles and risk factors of atherosclerosis through a questionnaire, laboratory test and physical examination. We measured SDPTG at baseline, 3, 5, 10, 15, and 20 minutes for smokers after smoking and walking and for never-smokers after walking. Repeated measures ANOVA and ANCOVA were used for analysing the changes of SDPTG according to time. Results: The heart rate and blood vessel tension (BVT) were different between the smokers and never-smokers after adjusting age, fasting blood sugar, body mass index, depression, and exercise (P < 0.05, P < 0.05, respectively). In contrast to never-smokers, heart rate of smokers at 3 minutes after smoking was increased for 10.1 per minute (P < 0.001) and higher than never-smokers until 15 minutes (P < 0.05). BVT in smokers was decreased at 3 minutes (P < 0.05) from baseline and lower than never-smokers at 3 minutes (P < 0.05). Differential pulse wave index, stress power, remained blood volume, and the changes of these indices according to time were not significantly different between the two groups. Conclusion: BVT and heart rate reflected the acute effect of smoking on blood vessels and could be used to provide motivation to quit smoking and make people more concerned about their own health especially to the young smokers who has no symptoms yet. Keywords: Smoking; Photoplethysmography; Atherosclerosis 서론 Received: August 31, 2009, Accepted: August 20, 2010 *Corresponding Author: Chang Jin Choi Tel: 02-2258-2894, Fax: 02-2258-2907 E-mail: fmchcj@catholic.ac.kr Korean Journal of Family Medicine Copyright 2010 by The Korean Academy of Family Medicine 최근 10년간의국민영양조사결과에의하면우리나라 40 세미만남성에서동맥경화의위험인자인비만, 당뇨병, 고지질혈증의유병률이증가추세에있으며 1) 남자청소년의흡연율또한증가추세에있다. 2) 이러한보고는향후동맥경화관련질환이증가할가능성을시사한다. 사고사한사람의부검 Vol. 31, No. 9 Sep 2010 679
In Hui Lee, et al: The Examination of the Acute Vascular Changes Due to Smoking Using Second Derivative of Photoplethysmogram 을통한연구결과 40세미만의젊은성인에서도동맥경화가발견되는경우가있으며, 동맥경화의위험인자가있는경우젊은연령부터동맥경화가진행될수있고이와관련된주된요인이흡연임이보고된바있다. 3) 흡연은조기동맥경화의강력한주위험인자인동시에조절가능한위험인자이다. 금연시흡연으로인한혈관내피세포의손상은 12개월내에가역적으로회복가능하여 4) 심장병으로발전하는관상동맥질환발생위험이 50% 줄어들고, 15년이경과시서서히뇌졸중위험도감소한다. 5) 젊은성인은전반적인신체건강이양호하여흡연으로인한신체의이상소견을가시적으로제시할수있는임상지표가거의없다. 신체에대한흡연의급성영향은혈압과맥박을상승시키고혈관을수축시키며동맥내피세포의기능을저해하여혈관의탄력성을감소시키는것이다. 6,7) 이러한흡연의급성영향을확인할수있는지표가있다면무증상의젊은성인에서금연의동기를유도하는한가지방법으로사용할수있을것으로생각된다. 동맥혈관의탄력성을평가하는방법중에서맥파를통해얻은 photoplethysmogram 의이차미분파 (second derivative of photoplethysmogram, SDPTG) 는상행대동맥의수축기압력파를반영하며동맥경화의위험요소와좋은상관관계를보인다고보고되었다. 8) SDPTG 는손가락끝에탐지자를위치하여검사하는간편하면서도비침습적이며, 검사시간이짧으며쉽게사용할수있고결과를바로확인할수있는장점이있다. 본연구는 SDPTG 지표들이흡연의급성효과를반영하는가시적인임상지표로사용될수있는지확인하기위해, 흡연군과비흡연군에서흡연과보행후 SDPTG 지표의시간에따른변화를조사하였다. 방법 1. 연구대상 2009년 3월 23일부터 2009년 8월 21일까지서울소재의일개대학병원가정의학과를방문한 20-39세사이의남성중에서현재담배를피우고있는흡연군 ( 실험군 ) 20명과전혀담배를피운적이없는비흡연군 ( 대조군 ) 18명을대상자로하였다. 설문지와인체계측, 신체진찰을통하여고혈압, 심장질환 ( 좌심실비대, 부정맥, 심근경색, 심부전, 협심증등 ), 당뇨, 신장질환, 뇌졸중, 암, 급성또는만성염증질환의병력이있는경우는제외하였다. 레이노증후군등의말초혈관질환을진단받은경우와진동기구를많이사용하는직업을가진사람 도대상에서제외하였다. 연구프로토콜은동일대학병원의임상시험심사위원회의승인을받았으며이에대한정보를연구참여자들에게제공하였고설문내용과계측내용만이연구자료로사용될것임을설명한후서면동의서를작성하도록하였다. 2. 설문조사대상자의사회인구학적특성, 음주력, 흡연력, 규칙적인운동여부, 불안-우울성향, 스트레스정도, 니코틴의존도정도를자가기입식으로설문조사하였다. 불안-우울성향은 Hospital Anxiety Scale 검사를이용하여 8점이상의점수일때각각우울군, 불안군으로정의하였다. 9) 스트레스수준은 Modified Brief Encounter Psycho-social Instrument (BEPSI) 설문지를이용하여점수가 1.8 이상인경우를스트레스군으로판정하였다. 10,11) 흡연군은 Fagerstrom Test for Nicotine Dependence (FTND) 12) 를이용하여니코틴의존도를평가하여 6점이상을니코틴의존그룹으로분류하였고운동군은주 3회이상, 회당 30분이상, 최소 3개월이상운동을지속한경우로정의하였다. 그리고하루알콜섭취량 ( 알콜농도 마신술의양 0.789/100) 이 30 mg을넘는경우음주군으로분류하였다. 3. 신체계측, 생화학적검사모든종류의신체계측과혈액샘플을이용한생화학적검사는오전 7-11시사이에시행하였다. 체질량지수 [ 몸무게 (kg)/ 키 (m 2 )] 가 25 이상인경우비만으로정의하였다. 혈압은수은혈압계를사용하여앉은자세로최소 5분이상의휴식을취한후왼쪽팔오금부위에서측정하였다. 최소 8시간의금식후에혈액을채취하여공복혈당, 혈중총콜레스테롤, 중성지방, 고밀도지단백콜레스테롤, 저밀도지단백콜레스테롤, 혈색소를검사하였다. 총콜레스테롤 / 고밀도지단백 (TC/HDL) 콜레스테롤비가 5 이상, 13) 혹은고밀도지단백콜레스테롤이 40 mg/dl 미만인경우를이상지혈증으로판정하였다. 호기내일산화탄소농도는 MICRO CO (Micro Medical, Basingstoke, UK) 기계를이용하여측정하였으며숨을최대한깊게들이마신후 20초동안참았다가내쉴때의호기내일산화탄소농도를측정하였다. 4. Finger photoplethysmogram 의 SDPTG 검사 SDPTG 란맥파 (photoplethysmograph, PTG) 의이차미분맥파로서맥파라는것은심장의박동에따른흉벽및대혈관의박동을파형으로기록한것으로심장주기에따라혈관벽압 680 Vol. 31, No. 9 Sep 2010 Korean J Fam Med
이인희외 : 이차미분맥파를이용한흡연에의한혈관의급성변화 및혈관직경이변동됨에따라말초쪽으로전파되는동맥계파동의변화를말하는것이다. Finger photoplethysmogram 은맥파측정기계의변환기가말초순환의혈류량의변화의신호를기계로보내는데 Figure 1처럼손가락끝의상부에서파장을발광다이오드 (light emitting diode, LED) 로발광시켜손가락을통과하게하며이빛을하부의수광다이오드 (photo diode) 로받아서헤모글로빈에의한투과광량의변화를 Lambert- Beer law를따라파형으로기록한다. 14) 이후기계에서자동으로맥압의이중미분이이루어져서가속도맥파가그려진다. 맥파는대동맥과말초혈관모두의특성이나혈류량을반영하는것으로, 지첨용적맥파의변곡점을보다잘인식할수있는방법으로고려된것이맥파의이차미분파인가속도맥파의 Figure 1. The light from light emitting diode (LED) will reach photo diode through finger, and the changes in light transmission are expressed as pulse wave. 14) 파형모양이다. 헤모글로빈의흡광량변화는혈관내헤모글로빈량의변화, 즉기본혈액량에서의변동된양에따라변화하며, 혈액변동량이많을수록맥파의진폭이커진다. 1) SDPTG 지표 SA-3000P (Cardio-Peri, Medicore, Seoul, Korea) 를이용해맥파를측정하였으며기계에서자동으로계산되는 SDPTG 지표들을실험에사용하였다. SDPTG 지표는아래와같다 (Figure 2). 맥박수 (heart rate, HR) 혈관탄성도 (blood vessel tension, BVT): c/a, 혈관의탄성을의미하며기본값에서양의값을가지고동맥경화가진행될수록음의값의방향으로이동한다. 박출강도 (stress power, SP): b/a, 혈관상태가양호할수록절대값이크며혈관의확장성을반영한다. 15,16) 미분맥파지수 (differential pulse wave index, DPI): [-b+c+d] /a, 혈관노화정도를나타내는지표로서절대값이작을수록노화정도가심하다. 잔혈량 (remained blood volume, RBV): -d/a, 절대값이작을수록혈관상태가좋으며동맥경화와같은경우에절대값이증가한다. 16,17) 혈관상태 : 7단계로나누어지며 1단계가가장양호한상태이고, 2단계는현재상태는양호하나나빠질가능성이있는단계, 3단계부터는혈관노화가시작되기시작하여 7단계로갈수록동맥경화가진행된상태로판정한다. Figure 2. A schema of the finger photoplethysmogram (PTG; A) and the second derivative of the finger photoplethysmogram (SDPTG; C). The results obtained by pulse wave measuring machine are presented as A. B is first derivative of A. And C is the results of the second derivative of A. The SDPTG consists of 5 different kinds of waves and the slope of basis points to each peaks of waves. Each wave is consecutively named as a, b, c, d, and e wave, respectively. The a and b waves are in the early systolic phase, the c and d waves are in the late systolic phase, and the 'e' wave is in the early diastolic phase of the PTG. 14) 2) SDPTG 측정방법검사실은조용하고편안한환경으로실내온도는 22-25 o C 사이로유지하였다. 대상자는최소검사 2시간전부터금식및금연하도록하였으며검사시피험자는팔을편안하게놓고똑바로누워서 5분이상안정을취하도록한후검사를시행하였다. 기계의센서를왼손검지손가락의손톱에부착하여광선을균일하게비출수있도록편평한곳에위치시키고알코올이나아세톤등으로손톱의매니큐어등의이물질을제거하였다. 팔이나손에검사기기외의압력은가해지지않도록하였다. 흡연군은흡연전에 SDPTG 를측정한후, 검사실에서 70 m 떨어진실외에서담배 1개피를흡연하고스톱워치로시간을측정하여흡연후 3분, 5분, 10분, 15분, 20분에 SDPTG 를반복측정하였다. 비흡연군은안정상태에서 SDPTG 를측정한후, 흡연자의이동으로인한혈류변화를보정하기위해흡연자가이동한거리와동일한장소를평상시의걸음으로왕복시킨 Vol. 31, No. 9 Sep 2010 681
In Hui Lee, et al: The Examination of the Acute Vascular Changes Due to Smoking Using Second Derivative of Photoplethysmogram 후, 보행후 3분, 5분, 10분, 15분, 20분에 SDPTG 를반복측정하 였다. 5. 통계분석 흡연군과비흡연군의특성중, 범주형항목은 chi-squire test로분석하고, 연속형항목은 independent t-test로분석하 였다. 보행과흡연후시간에따라, 흡연자와비흡연자에 서 SDPTG 지표들의시간에따른차이는 repeated measures Table 1. General characteristics between the smokers and the never-smokers. Variables Smokers Never-smokers (N = 20) (N = 18) P-value Age (years) 32.0 ± 4.1 29.8 ± 4.8 0.132 CO (ppm) 19.5 ± 11.5 4.9 ± 2.9 0.000* SBP (mmhg) 120.7 ± 11.4 119.0 ± 7.1 0.589 DBP (mmhg) 79.6 ± 6.0 75.9 ± 7.5 0.100 FBS (mg/dl) 93.0 ± 6.0 87.4 ± 6.4 0.008* TC (mg/dl) 190.1 ± 36.4 173.7 ± 29.3 0.138 TG (mg/dl) 195.4 ± 182.5 112.1 ± 71.3 0.095 LDL (mg/dl) 111.8 ± 32.8 106.3 ± 25.6 0.571 HDL (mg/dl) 44.9 ± 10.7 45.0 ± 7.9 0.985 Hb (g/dl) 16.01 ± 0.7 14.9 ± 0.7 0.000* TC/HDL 5 6 (30.0) 2 (11.1) 0.154 HDL < 40 (mg/dl) 7 (35.0) 5 (27.8) 0.632 Obesity 15 (75.0) 7 (38.9) 0.024 Depression 5 (25.0) 0 (0) 0.023 Anxiety 6 (30.0) 3 (16.7) 0.334 Stress 9 (45.0) 8 (44.4) 0.973 Alcohol 3 (15.0) 0 (0) 0.087 Exercise** 4 (20.0) 10 (55.6) 0.023 Values are presented as mean ± SD or number of events (rate, %). CO: carbon monoxide, SBP: systolic blood pressure, DBP: diastolic blood pressure, FBS: fasting blood sugar, TG: trygiyceride, LDL: low-density lipoprotein, HDL: high-density lipoprotein, TC: total cholesterol. *P < 0.05 by independent t-test. P < 0.05 by chi-square test. Obesity: body mass index 25 kg/m 2. Depression & anxiety: hospital-anxiety scale scores 8. Stress: modified Brief Encounter Psycho-Social (BEPS) score 1.8. Alcohol: daily alcohol intake (alcohol concentration amount of drinking 0.789/100) > 30 mg. **Exercise: frequency 3 times/wk, duration 30 min, at least for 3 months. ANOVA 로, 흡연군과비흡연군간의각시점에서의차이는 ANCOVA 로분석하였다. SPSS ver. 15.0 (SPSS Inc., Chicago, IL, USA) 프로그램을사용하였으며유의수준은 P<0.05 로하였 다. 결과 1. 실험대상자의일반적인특성 흡연군에서비흡연군에비해공복혈당, 혈중헤모글로 빈수치, 호기내일산화탄소농도가높았다 ( 각각 P=0.008, P<0.001, P<0.001). 우울군에속하는대상자는전원이흡연자 였으며, 불안군과고스트레스군에속하는대상자의수는두 그룹에서유의한차이가없었다. 흡연자는비운동군이많았 고 (P=0.01) 비만에해당하는경우가많았다 (P=0.024). 그외나 이, 혈압, 이상지혈증, 음주군은두그룹에서유의한차이가없 었다 (Table 1). 흡연군에서니코틴중독정도가높은사람이 7 명 (35%) 이었으며, 흡연력이 10 갑년미만인사람이 5 명 (25%), 10 에서 20 갑년미만인사람이 11 명 (55%), 20 갑년이상인사람이 4 명 (20%) 이었다. 2. 흡연군과비흡연군에서안정시에측정한 SDPTG 지표들의비교 흡연군과비흡연군에서흡연이나보행전안정단계에서 측정한 SDPTG 지표들중에서 1 단계혈관상태가흡연군에서 Table 2. The baseline SDPTG indices for smokers and neversmokers. Variables Smokers (N = 20) Never-smokers P-value (N = 18) HR (beats/min) 69.3 ± 2.3 65.4 ± 2.4 0.29 BVT -1.7 ± 1.7 2.3 ± 1.8 0.14 SP -76.5 ± 1.7-75.4 ± 1.8 0.68 DPI -80.5 ± 3.5-80.5 ± 3.7 0.15 RBV -17.1 ± 1.9-15.1 ± 2.0 0.71 Values are presented as mean ± SE. P-value by ANCOVA adjusted for age, fasting blood sugar, body mass index, depression, and exercise. SDPTG: second derivative of photoplethysmogram, HR: heart rate, BVT: blood vessel tension, SP: stress power, DPI: differential pulse wave index, RBV: remained blood volume. 682 Vol. 31, No. 9 Sep 2010 Korean J Fam Med
이인희외 : 이차미분맥파를이용한흡연에의한혈관의급성변화 5명 (25%), 비흡연군에서 11명 (61.1%) 이었고, 2단계혈관상태는흡연군은 15명 (75%), 비흡연군 7명 (38.9%) 의분포를보였다 (P<0.05). 그외의지표들은흡연군과비흡연군간의유의한차이가있거나동맥경화와관련되는요인들 ( 연령, 혈당, 체질량지수, 우울과운동유무 ) 을보정한후유의한차이를보이지않았다 (Table 2). 3. 흡연또는보행후의흡연군과비흡연군에서의 SDPTG 지표들의시간에따른변화 1) 심박동수 흡연군과비흡연군은시간에따라심박동수의유의한차 이를보였으며 (P<0.001), 안정시를제외한모든시점에서흡 연군은비흡연군에비해심박동수가증가된소견을보였다 Figure 3. The changes of second derivative of photoplethysmogram (SDPTG) parameters after smoking and walking according to time. The open circle and closed circle represent never-smokers and smokers, respectively. These figures show the changes of heart rate (HR; A), blood vessel tension (BVT; B), stress power (SP; C), differential pulse wave index (DPI; D), remained blood volume (RBV; E) of smokers (after smoking) and never-smokers (after walking) according to time after adjusting for age, fasting blood sugar, body mass index, depression, and exercise. Only in BVT and HR showed the significant differences between smokers and neversmokers. *P < 0.05, P < 0.01, by ANCOVA. Vol. 31, No. 9 Sep 2010 683
In Hui Lee, et al: The Examination of the Acute Vascular Changes Due to Smoking Using Second Derivative of Photoplethysmogram Table 3. Mean change in SDPTG parameters from each time to baseline. Variables Difference from each time to baseline (Mean ± SE) 3 min 5 min 10 min 15 min 20 min Smoker (N = 20) HR (beats/min) 10.1 ± 1.4 8.0 ± 1.2 4.5 ± 1.1* 3.2 ± 1.1* 2.2 ± 1.4 BVT -3.4 ± 1.2* -0.8 ± 1.4 1.0 ± 1.6 1.6 ± 1.8 1.6 ± 1.8 SP -2.7 ± 1.8-3.8 ± 1.8-3.9 ± 1.8-4.0 ± 1.8-4.3 ± 1.9 Never-smokers (N = 18) HR (beats/min) -0.4 ± 0.6-1.5 ± 0.7-2.6 ± 1.2-2.7 ± 1.0-1.7 ± 1.0 BVT 0.6 ± 1.4 2.2 ± 1.4 3.3 ± 1.1 4.0 ± 1.3* 2.1 ± 2.2 SP -2.8 ± 1.9 5.7 ± 9.5-3.8 ± 1.7-5.7 ± 1.4* -5.8 ± 1.7* SDPTG: second derivative of photoplethysmogram, HR: heart rate, BVT: blood vessel tension, SP: stress power. *P < 0.05, P < 0.01, by one-sample repeated measures ANOVA adjusted for age, fasting blood sugar, body mass index, depression, and exercise. (P<0.05)(Figure 3A). 흡연군에서심박동수는흡연후증가하였다가시간에따라감소하는소견을보였다. 흡연 3분후에심박동수가흡연전에비해평균 10.1회증가하였고 (P<0.001), 흡연 15분후에도흡연전에비해평균 3.2회증가되었다 (P<0.05). 비흡연군에서보행후의심박동수는시간이지남에따라점차감소하는양상이었으나유의하지는않았다 (Table 3). 5) 잔혈량 (RBV) 흡연군과비흡연군의시간에따른변화에는유의한차이가없었다. 흡연군이비흡연군에비해 RBV 절대값이전반적으로큰경향을보이나이차이는유의성이없었다 (Figure 3E). 고찰 2) 혈관탄성도 (BVT) BVT는혈관의탄성도를반영하는지표로서흡연군과비흡연군은유의한차이가있었다 (P<0.05). 흡연후 3분시점에서흡연군이비흡연군보다 BVT가유의하게작았다 (P<0.01) (Figure 3B). 흡연군에서흡연 3분후에흡연전과비교시 BVT 가평균 3.4 감소하였으며 (P<0.05), 비흡연군은점차로증가하는양상이나유의하지않았다 (Table 3). 3) 박출강도 (SP) SP는흡연군에서는시간에따른유의한차이가없었으며비흡연군에서는보행 20분후에측정한값이안정시에비해절대값이평균 5.8 증가하였다 (P<0.05). 흡연군과비흡연군간의 SP에유의한차이는없었다 (Figure 3C). 4) 미분맥파지수 (DPI) 혈관의동맥경화정도의지표인 DPI는흡연군과비흡연군에서시간에따라절대값이증가하는양상을보였으나유의성은없었다. 흡연군에서비흡연군보다절대값이작아서혈관의경화정도가더진행된경향을보이나유의한차이는없었다 (Figure 3D). SDPTG 의임상적유용성에대한이전의연구들에서여러지표들이혈관벽의긴장도나탄력성을반영하며동맥경화의평가방법이될수있다고제시하고있다. 15,17,18) 이러한연구결과들은어느한시점에서 SDPTG 지표들과동맥경화의위험인자들간의관련성을확인하여제시한것으로동맥경화가진행되어혈관의탄력성이떨어질수록 RBV가증가하고 SP, DPI가감소한다고보고하고있으며, 15-17) BVT는나이가듦에따라감소한다고확인되었으나그외의다른임상적의미는확인되지않았다. 16) 현재까지혈류변화를일으킬수있는물질에노출전후의 SDPTG 지표의변화를보고한환자대조군연구는보고된바가없다. 흡연으로니코틴이체내에흡수되면카테콜아민을유리시키며이것은혈관평활근에있는알파 1-아드레날린성수용체와결합하여근수축과혈관수축 19) 을일으키는데, 건강한사람의경우이러한혈관수축은즉각적으로혈관내피세포에서유리되는혈관이완물질에의해회복된다. 20) 그러나반복적인흡연은혈관내피세포에손상을입혀혈관내피세포의특징적인혈관이완물질인산화질소와프로스타사이클린의생성을감소시켜혈관의긴장도를증가시키고 20) 동맥의탄력성을떨어뜨리게된다. 7) 흡연의동맥수축효과는주로대동 684 Vol. 31, No. 9 Sep 2010 Korean J Fam Med
이인희외 : 이차미분맥파를이용한흡연에의한혈관의급성변화 맥에비해말초세동맥에서현저하게나타나므로 21) 본연구에서는흡연에대한즉각적이고가역적인변화를평가하는도구로써말초혈류의변화를측정하는도구인 SDPTG를이용하였고동맥경화가상당히진행된대상자를제외하고자 40대미만이고과거력에서동맥경화성질환을가진대상자를제외하고시행하였다. 연구결과, 흡연자와비흡연자간에흡연후시간에따른유의한차이를보여준지표는혈관의탄력성을반영하는지표인 BVT와심박동수였다. 기저및모든시점에서혈관상태 2단계 ( 현재양호하나나빠질수있다고판정하는단계 ) 의비율이흡연군에서비흡연군에비해유의하게많게나타났으나, 흡연후일부흡연자의혈관상태의단계는호전되었고일부비흡연자의혈관상태단계는나빠지는등일률적인양상을나타내지못하였다. BVT는흡연군에서흡연 3분후에최대로감소되었고점차회복되었고, 비흡연군에서는시간이지남에따라 BVT가증가하여보행 15분후에초기값에비해증가된경향을보였다. 흡연 3분후에측정한 BVT 값이감소한것은 5명의흡연자를대상으로손가락혈관에서 photoplethysmogram 으로혈관의탄력성을측정한 Marc 등 22) 의연구에서흡연후즉각적으로혈관의탄력성이저하되었으며최소 4분이상저하된상태가유지되었다가회복된다고보고한결과와일치하는소견이다. 이는흡연전과흡연후 3분이내에재측정한 BVT의변화가말초혈류의감소를가시적으로제시하는임상적인지표가될있음을암시한다. SDPTG 지표중에서동맥벽의신전성을나타내고신전성이저하될경우절대값이감소하는 SP가흡연후감소한결과가나타나지않은것은흡연의급성혈류변화효과가대동맥보다는말초동맥의변화로나타나기때문이라고추정된다. 동맥경화나혈관내압의상승과같이반사파가커지는상황에서이를반영하는 RBV가증가 16) 할것으로예상하였는데흡연군에서흡연 3분후 RBV가증가하는양상을보이나흡연군과비흡연군에서통계적인차이는없었다. 혈관의동맥경화도와가장관련이높다고보고된 DPI는비흡연자에비해흡연자에서절대값이낮아동맥경화도가높은경향은있었으나통계적인차이는없었고흡연후의특정변화를반영하지못했다. 이는본연구대상자에서진행된동맥경화가있는사람이제외되었을가능성이높고, DPI가흡연으로인한급성혈관변화를반영하는지표로는사용할수없음을시사한다. 흡연자들이흡연장소에서흡연후검사실로이동하는신체활동으로인한심박동변화를감안하기위하여대조군도같은거리를보행하도록하여검사를하였다. 개인의보행속 도에따라차이가있을수있지만너무빠르거나너무느리지않게평소의속도대로걷게하였으며보행에걸린시간은모두 3분미만이었다. 흡연자의평균심박동수가 10.1회증가한데비해, 비흡연자는평균심박동수가별다른변화가없었으며, 이후시간에따른변화도대조군에서는계속적으로침대에누워안정을취하면서심박동수가감소하는양상이었다. 담배가심장박동을증가시키는효과역시니코틴에의한것으로말초신경계통에서는니코틴이카테콜라민, 아드레날린, 노르아드레날린을분비하게만들어혈압을상승시키고심박동수를증가시킨다. 20) 이러한심혈관계의급성변화는흡연후최소 30분정도지속되는것으로보이며다시담배를피우는경우에재현되었다. 22) 이실험에서도흡연후 15분까지안정시의박동수로회복되지못했음을확인할수있었다. 본연구의제한점은첫째, 연구대상자의동맥경화의정도를경동맥초음파, 상완-발목맥파속도검사등기존의동맥경화검사로확인하지못한것, 둘째, 운동등의말초혈류에영향을줄수있는생활습관이동등한대상자를선정하지못하였다는것이다. 그러나흡연자에서바람직하지못한생활습관 ( 운동, 음주등 ) 과동맥경화의다른위험인자들이비흡연자에비해군집하여나타나는경우는실제진료현장에서흔히볼수있으며, 흡연군과비흡연군에서차이가나는변수등을보정하여확인한결과가보정전과유사한패턴으로나타남을확인하였다. 이연구의의의는동맥경화의가장큰변수인연령을 40대이전으로제한하였고다른만성질환이없는자를대상으로하여, 비흡연자를대조군으로비교함으로써흡연에의한급성말초혈관변화를반영한최초의연구라는것이다. 추후흡연자그룹자체에서동맥경화의위험정도가높음을고려하여동맥경화정도와흡연에의한말초혈류변화의관계에대한연구와, 흡연이외의다른동맥경화위험인자들과 SDPTG 지표들간의관련성에대한연구가더진행되어야할것이다. 요약하면흡연자는심박동수는흡연 3분후최대증가후흡연 15분후까지상승되었고, BVT는흡연 3분후최대로감소하여, SDPTG 표지자중흡연후급성혈관변화를표시하는임상적인지표는심박동수와 BVT인것으로나타났다. SDPTG 검사는비침습적이고검사시간이 1분으로짧으며즉각적인피드백이가능한장점이있어흡연전후의 BVT 감소와심박동수의증가가호기내일산화탄소검사와더불어흡연자에게가시적인흡연의급성영향을제시하는지표로사용될수있음을제안한다. Vol. 31, No. 9 Sep 2010 685
In Hui Lee, et al: The Examination of the Acute Vascular Changes Due to Smoking Using Second Derivative of Photoplethysmogram 요약 연구배경 : 흡연은 40세미만의동맥경화의주된위험인자이나최근청소년이나젊은성인에서의흡연율이증가하고있다. 젊은성인의경우, 전반적인신체건강이양호하여흡연으로인한신체의이상소견을가시적으로제시할수있는임상적인지표가거의없다. 본연구는이차미분파 (second derivative of photoplethysmogram, SDPTG) 지표들이흡연의급성효과를반영하는가시적인임상지표로사용될수있는지확인하고자하였다. 방법 : 동맥경화성질환과말초혈류질환의과거력이없는 20-39세사이의남성중현재흡연자 20명과이전에전혀담배를피운적이없는비흡연자 18명을대상자로하여설문조사, 생화학검사, 신체계측을통해생활습관과동맥경화의위험인자를조사하였다. 흡연군은흡연전과흡연후 3분, 5분, 10 분, 15분, 20분에, 대조군은흡연자와같은거리를보행한후흡연군과같은시간간격으로 SDPTG를반복측정하였다. 흡연군과비흡연군간의시간에따른 SDPTG의차이를 reapeated measures ANOVA 로, 각시점의차이를 ANCOVA 로분석하였다. 결과 : 연령, 공복혈당, 체질량지수, 우울및운동유무를보정한후흡연군과비흡연군을비교시심박동수와잔혈량 (RBV) 에서시간에따른차이가있었다 ( 각각 P<0.05, P<0.05). 흡연군에서심박동수는흡연 3분후에평균 10.1회증가하였고 (P<0.001) 흡연후 15분까지비흡연군보다상승되어있었다 (P<0.05). 흡연군에서탄성도 (blood vessel tension, BVT) 는흡연 3분후에감소하였으며 (P<0.05) 흡연 3분에서비흡연군보다감소되어있었다 (P<0.05). 미분파지수, 박출강도, RBV는시간에따른변화와두군에서나타난반응의차이모두유의하지않았다. 결론 : BVT와심박동수는혈관에대한흡연의급성영향을반영하므로, 이들지표들은젊은무증상의흡연자에게건강에대한관심을유발하고금연에대해동기를부여하는방법으로사용할수있을것이다. 중심단어 : 흡연 ; 이차미분파 ; 동맥경화 REFERENCES 1. Korean National Health &Nutrition Examination Survey: chronic disease status [Internet]. Seoul: Korea Center for Disease Control and Prevention; [cited 2009 Aug 26]. Available from: http://knhanes.cdc.go.kr. 2. Smoking statistics [Internet]. Daejeon: Korea National Statistical Office; [cited 2009 Aug 26]. Available from: http://kostat.go.kr. 3. Berenson GS, Srinivasan SR, Bao W, Newman WP 3rd, Tracy RE, Wattigney WA. Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults. The Bogalusa Heart Study. N Engl J Med 1998;338:1650-6. 4. Higman DJ, Strachan AM, Powell JT. Reversibility of smokinginduced endothelial dysfunction. Br J Surg 1994;81:977-8. 5. The reality of smoking [Internet]. Stop smoking; [cited 2009 Aug 26]. Available from: http://www.nosmokingnara.org/ zbxe/?mid=nosmok_info01. 6. Rozanski A, Qureshi E, Bauman M, Reed G, Pillar G, Diamond GA. Peripheral arterial responses to treadmill exercise among healthy subjects and atherosclerotic patients. Circulation 2001; 103:2084-9. 7. Giannattasio C, Mangoni AA, Stella ML, Carugo S, Grassi G, Mancia G. Acute effects of smoking on radial artery compliance in humans. J Hypertens1994;12:691-6. 8. Fitchett DH. Forearm arterial compliance: a new measure of arterial compliance? Cardiovasc Res 1984;18:651-6. 9. Oh SM, Min KJ, Park DB. A study on the standardization of the hospital anxiety and depression scale for Koreans: a comparison of normal, depressed and anxious groups. J Korean Neuropsychiatr Assoc 1999;38:289-96. 10. Bae JM, Jeong EK, Yoo TW, Huh BY, Kim CH. A quick measurement of stress in outpatient clinic setting. J Korean Acad Fam Med 1992;13:809-20. 11. Lee KH, Chung WJ, Lee SM. Association of stress level with smoking. J Korean Acad Fam Med 2006;27:42-8. 12. Fagerstrom KO. Measuring degree of physical dependence to tobacco smoking with reference to individualization of treatment. Addict Behav 1978;3:235-41. 13. AHA: cholestreol ratio [Internet]. Dallas (TX): American Heart Association; [cited 2009 Aug 26]. Available from: http://www. americanheart.org/presenter.jhtml?identifier=4503. 14. Medi-Core. Clinical manual (machine guide book). Seoul: Medi-Core; 2010. 15. Takazawa K, Tanaka N, Fujita M, Matsuoka O, Saiki T, Aikawa M, et al. Assessment of vasoactive agents and vascular aging 686 Vol. 31, No. 9 Sep 2010 Korean J Fam Med
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