Korean J Gastroenterol Vol. 61 No. 4, 186-190 http://dx.doi.org/10.4166/kjg.2013.61.4.186 pissn 1598-9992 eissn 2233-6869 REVIEW ARTICLE 위암환자의영양평가와수술전후의영양지원 서경원, 윤기영 고신대학교의과대학외과학교실 Nutritional Assessment and Perioperative Nutritional Support in Gastric Cancer Patients Kyung Won Seo and Ki Young Yoon Department of Surgery, Kosin University College of Medicine, Busan, Korea Weight loss and malnutrition are common in cancer patients. Although weight loss is predominantly due to loss of fat mass, the morbidity risk is given by the decrease in muscle mass. The assessment of nutritional status is essential for a diagnosis of nutritional compromise and required for the multidisciplinary approach. Subjective global assessment (SGA) is made by the patients nutritional symptoms and weight loss. The objective assessment, a significant weight loss (>10%) for 6 months is considered an indicator of nutritional deficiency. The mean body index, body fat mass and body protein mass are decreased as cancer stage increases. The biochemical data of albumin, cholesterol, triglyceride, Zn, transferrin, total lymphocyte count are decreased in advanced cancer stage. Daily energy intake, cabohyderate and Vit B1 intake is decreased according to cancer stage. The patients are divided into three groups according to SGA. The three groups showed a significant difference in body weight, 1 month weight loss%, 6 month weight loss%, body mass index, mid arm circumference, albumin, energy intake, as well as carbohyderate intake protein and energy malnutrition. Nutritional assessment is of great importance because undernutrition has been shown to be associated with increase in stomach cancer associated morbidity and mortality. The authors concluded that nutritional assessment should be done in cancer patients preoperatively, and with adequate nutritional support, the morbidity and mortality would be decreased. (Korean J Gastroenterol 2013;61:186-190) Key Words: Nutritional assessment; Stomach neoplasms; Perioperative nutritional support 서론 환자가입원할당시의영양상태가나쁜경우입원기간동안영양상태는더욱악화되고, 특히암환자의경우질병의경과와치료과정으로타질환에비해영양불량의위험이크다. 1,2 또한입원환자는질환자체뿐아니라수술이나검사로금식기간이늘어나면서영양부족에빠지기쉽고, 이러한영양부족은합병증비율과재원기간을증가시킨다. 3,4 영양결핍이있는암환자에서합병증을감소시키기위하여수술전후에영양공급을시행하면좋은효과를나타내는것으로보고된다. 5 그러므로, 영양결핍이있는환자는정확하고객관적인영양상 태를평가하여이상이있는경우사전에영양공급을충분히시행함으로써이환율과사망률을감소시킬수있을것으로기대된다. 따라서영양상태의측정이영양치료의시작이라할수있다. 환자각자의영양상태를평가할확실한단독검사법은없지만생화학검사, 인체계측법등을이용한객관적인평가방법과병력및신체검사를이용한임상적인평가방법이이용되고있다. 4 이글에서는위암환자의영양불량상태와영양평가방법에관하여살펴보고실제임상에서의영양지원요법의적용에관하여고찰해보고자한다. CC This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 교신저자 : 윤기영, 602-702, 부산시서구감천로 262, 고신대학교의과대학외과학교실 Correspondence to: Ki Young Yoon, Department of Surgery, Kosin University College of Medicine, 262 Gamcheon-ro, Seo-gu, Busan 602-702, Korea. Tel: +82-51- 990-6462, Fax: +82-51-246-6093, E-mail: yoonkiyoung@naver.com Financial support: None. Conflict of interest: None. Korean J Gastroenterol, Vol. 61 No. 4, April 2013 www.kjg.or.kr
Seo KW and Yoon KY. Nutritional Support in Gastric Cancer Patients 187 본론 1. 위암환자에서의영양불량상태위암은한국인에게가장많이발생하는암종이며, 암사망률은 3번째로높은빈도를차지한다. 6 최근조기위암의빈도가늘면서장기생존환자의수가증가함에따라위절제술후의영양결핍에대한관리는위암환자의추적에있어서아주중요한부분을차지하고있다. 위암으로인해위를부분, 혹은전체절제하면위의용적이감소하여, 음식섭취량부족과흡수불량으로인한체중감소, 저장기능상실에의한덤핑증후군, 미주신경절단에의한위산부족및흡수불량으로인한설사, 철섭취량부족및출혈로인한철결핍성빈혈, 위전절제술후내인성인자부족에의한비타민 B12결핍증, 칼슘섭취량부족및흡수불량으로인한골질환등의영양문제를일으킬수있다. 7 위부분절제후에는잔위의저장용적이절제범위에따라차이가있을수는있으나전절제에비하여상당한양의음식을저장할수있다. 그리하여수술후일시적으로체중감소나영양부족상태가오지만대부분빠른시일내에정상적인식이과정으로복귀함을볼수있다. Yu 등 8 의후향연구에서위부분절제와위전절제에서두그룹모두헤모글로빈수치의감소를보였으나전절제그룹에서철분수치가더심하게감소되었고, 또한혈중비타민 B12의농도가전절제그룹에서더낮았다. 또한위전절제후에부분절제에비해체중감소가크고, 신체지방량이적었음을보고하였다. 위전절제술후에나타나는가장큰영양학적문제는체중감소이다. 위전절제술후에체중감소의정도는수술전체중의 10-15% 정도로나타나며이러한원인으로는불충분한경구섭취, 췌장효소와의불완전혼합으로인한상대적췌장효소결핍, 소장통과시간단축, 소장내세균증식등이거론되고있다. 위전절제술후에는탄수화물이나단백질량의흡수장애나결핍보다는지방량의감소가현저하고체중감소의원인으로지목되고있다. 7 또한위전절제술후에나타나는특징적인영양학적문제로비타민 B12 결핍과그로인한거대적혈수성빈혈이있다. 빠르면 6개월에서 1-2년후에증상이나타난다. 위암환자는타질환에비해영양불량의위험이큰편이며 9 특히말기암환자는 80% 정도가영양불량상태이다. 이러한영양불량상태는암의치료를제한하고합병증발생을증가시키는결과를가져와암환자사망의주원인으로작용하게되고, 암환자의 22% 정도가영양불량으로사망한다. 10 Ottery 11 는암으로인한전체사망의 20% 정도는종양치료의실패보다영양악화때문에사망한다고보고하였다. 2. 영양상태평가방법 1) 섭취도조사질병으로입원하는외과환자에서는약 50% 에서영양결핍이있는것으로보고되며이러한환자들이외과적처치를받을경우이로인해정상인보다더높은합병증과사망률을나타내게된다. 12,13 대상환자들의식사섭취도조사는영양사의면담을통하여입원전평균식품군별섭취빈도 (food frequency) 조사, 섭취횟수, 일회섭취량, 활동량등에대한설문조사를실시한다. 14 정확한식품섭취분량의측정을위하여실물크기의식품모형을제시하여비교조사하는것을권장하며, 이와같이기록된영양소섭취량은전산화된영양평가프로그램을이용하여분석하여대상자들이섭취한영양소들을나이및성별에따른각영양소들의한국인영양권장량에대한비율로계산할수있다. 15 한국인영양섭취기준이란질병이없는대다수의한국사람들이건강을최적상태로유지하고질병을예방하는데도움이되는영양소섭취수준을제시하는기준이다. 종전의영양권장량에서는각영양소별로단일값으로제시하였으나만성질환이나영양소과다섭취에관한우려와예방의필요성을고려하여여러수준으로의영양섭취기준을 2005년도에새로이설정하였고 2010년도에 1차개정이이루어지게되었다. 영양섭취기준 (dietary reference intakes) 은평균필요량 (estimated average requirement), 권장섭취량 (recommended nutrient intake), 충분섭취량 (adequate intake) 및상한섭취량 (tolerable upper intake level, UL) 의 4가지로구성되어있다. 2) 주관적영양상태평가 (subjective global assessment, SGA) 1987년 Detsky 등 16 은외과적수술을받을 202명의환자를대상으로 5명의관찰자 ( 의사, 간호사 ) 가임상적영양상태평가 ( 몸무게변화, 식이습관, 소화관증상, 피하지방및근육정도, 부종및복수유무 ) 를조사하여 A, B, C 세군으로분류한결과개개관찰자의일치율은 0.78 (95% CI 0.62-0.94) 로재현성이좋은것으로보고하면서, 환자개개인의병력과신체검사에기초를둔영양상태평가를주관적영양상태평가 (SGA) 라고하였다. 최근의체중감소, 평상시식사섭취변화, 위장증상, 신체기능력, 신제검사시의증상, 질병상태등을점수로표시하여정상영양상태의환자를 group A, 경증에서중등도의영양불량환자를 group B, 그리고중증영양실조상태의환자를 group C로구분하였다. 이들은또한위장관수술을겪은환자에서경증혹은중증영양불량을보이는환자가각각 48%, 31% 였으며, 체중감소율은 percent weight loss class C를예상할수있는중요한지표임을나타내었고, Vol. 61 No. 4, April 2013
188 서경원, 윤기영. 위암환자의영양평가와수술전후의영양지원 주관적영양상태평가는병원에입원한환자의영양상태를평가하는데유용한방법이라고보고하였다. 3) 신체계측신체계측조사방법은신체의체조직구성상태를측정함으로써영양상태를판정하는방법으로비교적장기간의영양상태판정에유용하게이용된다. 또한신체계측은간편하고재현성이좋으며비용이적게들고단기간의훈련을통하여수행될수있으므로개인이나집단의영양상태판정에널리사용되고있다. 신체계측은표준체중대비백분율, 체지방량측정을위한체질량지수 (body mass index: 체중 [kg]/ 신장 [m 2 ]), 상완삼두근피하지방두께 (triceps skin fold thickness) 가있다. 상완삼두근피하지방두께는환자의오른팔을복부를가로질러직각으로구부린후견봉돌기와주두돌기중간부위의지방조직과피부를잡고 skin fold caliper를사용하여 3회반복측정한다. 또중간근위 (mid arm muscle circumference, MAMC) 는상완위근육둘레 (mid-arm circumference) 를줄자를이용하여 3회반복측정하고다음공식에의해계산한다. [ 중간근위 = 상완위근육둘레 (cm)-(0.314 상완삼두근피하지방두께 (mm)] 상완삼두근피하지방두께는체내지방조직보유량을의미하며, 이는에너지원으로사용된다. 약 50% 의지방조직이피하에위치하며신체의여러부분에균등하게분포되어있으나편의상환자의우상완에서측정한다. 상완위근육둘레를보면근육단백저장량, 즉 lean body mass를측정하는것이며측정방법은전술한바와같고특히하지의정형외과적수술을받은환자에서유병률의중요한지표로이용되고있다. 4) 생화학검사실험실검사법으로내장단백질의표지자인알부민, 트랜스페린 (tranferrin) 과프리알부민 (prealbumin) 이있다. 영양불량의표지자로서알부민혈청농도는 3.5 g/dl 이하를기준으로하며특히향후질환의예후를반영한다. 트랜스페린은반감기가 9일이며, 철분, 신증후군, 만성감염등에의하여영향을받는다. 프리알부민은 thyroxine binding protein으로도불리며, 반감기가 48시간이어서반감기가 3주정도인알부민에비하여영양불량상태의변화를반영하는데유리하다. 프리알부민은간질환이나심한스트레스로혈청농도가떨어지며, 스테로이드투여시올라간다. 콜레스테롤치가 160 mg/dl 이하이면사망률을증가시키는위험인자이다. 크레아티닌은근육대사산물로소변으로배출되며근육대사의정도를추정할수있다. 영양불량으로인한면역력의감소변화는총림프구수와지연과민피부검사로측정한다. 질소평형유무로단백질이화상태에대한공급균형을추정할수있으며 retinol binding protein, fibronectin, insulin-like growth factor I (IGF-I, somatomedin C), C-reactive protein과 tumor necrosis factor 등이활용가능한영양지표이다. Lowrie 와 Lew 17 는알부민농도가 4.0-4.5 g/dl인환자를기준으로하였을때알부민농도가 3.5-4.0 g/dl인환자는사망률이 2 배, 3.0-3.5 g/dl인환자는약 5배로증가하여알부민농도와사망률사이에는밀접한상관관계가있으며낮은알부민농도는사망률을예측하는데가장강력한검사자료이고사망에독립적인위험요인이된다고보고하였다. 암환자의영양검색지표 (cancer screening parameters) 로는체질량지수, 혈청알부민, 콜레스테롤, 총림프구수가사용되었고, 18 관상동맥질환의위험인자의하나인콜레스테롤에대한연구가활발히이루어지던중암환자에서혈청콜레스테롤치가낮다는첫보고를한후이에관한실험적, 역학적연구가계속적으로이루어져왔다. 19 이중암환자에서혈청콜레스테롤치가낮을수록사망률이높을수있다는연구내용이제기되어왔으나, 낮은혈청콜레스테롤치와암발생률의역학관계는아직도논란이많으며암종류에따라서도다양한연구결과보고가있다. 19,20 암조직내콜레스테롤치가정상세포에비해높은데, 이런경우악성세포에서분비되는여러가지사이토카인에의해체내콜레스테롤이변하고혈중고밀도지단백농도감소등이나타난다. 이는낮은혈청콜레스테롤치가암발생의원인이기보다는암그자체, 즉암발생후생기는암대사의결과이기때문으로해석되고있다. 또한병기진행정도에따라서도유의한연관성을보여종양의크기, 침범과전이정도에따라서도콜레스테롤치의감소를보이고있다. 21,22 체중감소는모든암환자에게있을수있지만특히소화기암환자에서심하며그원인으로는식욕부진에의한영양섭취부족과자라나는암세포에의한대사증가등을꼽을수있다. 23 Christensen과 Gstundtner 24 는혈청알부민이 3.5 g/dl 이하이거나총림프구수가 1,500 cells/mm 3 이하를기준으로영양불량을나누었을때, 정상군의재원일수는 5.4일, 영양불량환자의재원일수는 10.8일로 5.4일의차이가있다고보고하였다. 또한사망률에있어서정상보다낮은환자군의사망률은정상군보다 8배가량높았다고보고하였다. Harvey 등 25 은혈청트랜스페린, 혈청알부민, 지연성과민성피부반응과사망률과의관계를조사하였으며정상군에서의사망률 8% 에비해영양결핍군에서의사망률이 31% 로훨씬높았음을보고하였다. 1985년 Christensen과 Gstundtner 24 는혈중알부민과총임파구수가정상보다낮은환자군의사망률이정상군보다 8배가량높다고보고하였다. 1991년 Velanovich 26 도영양불량환자군의사망률은정상군에비해 10배가량높은것으로보고하였다. The Korean Journal of Gastroenterology
Seo KW and Yoon KY. Nutritional Support in Gastric Cancer Patients 189 3. 수술전후영양공급이수술에미치는영향 영양상태평가법에는식이력, 인체계측, 그리고각종생화학적지표등이사용되어왔으나어느것이가장정확하게환자의영양상태를반영하는지표인가에대해서는논란의여지가있는상태이다. 1936년 Studely 27 가소화성궤양으로수술받은환자중평소체중의 20% 이상체중감소가있는환자의사망률이 33.9% 로, 20% 이하의체중감소를보인환자보다 (3.5%) 무려 10배나높은사망률을보였음을보고하며체중감소를술후사망률에영향을미치는중요한지표라고보고한이래구미에서는 1970년대초부터여러가지지표들을이용하여환자들의영양상태를객관적으로측정및평가하기시작하였다. Smale 등 28 은 1981년암환자를대상으로이들의영양상태를 prognostic nutritional index에의해분류하여수술전경정맥영양요법 (preoperative total parenteral nutrition [TPN]) 의효과를비교하였다. 그결과영양불량군을대상으로수술전에경정맥영양요법을시행하였을때호흡부전 (respiratory insufficiency), 쇼크 (shock), 장관루 (intestinal fistula), 폐동맥색전 (pulmonary embolism), 심근경색증 (myocardial infarction), 장폐쇄 (bowel obstruction) 등의발생률이 66% 에서 31% 로 1/2로감소하였고, 패혈증, 농양, 폐렴등의발생률은 43% 에서 15% 로 1/3로감소하였으며, 사망률도 40% 에서 15% 로감소하였다고하였다. Müller 등 29 은소화기암환자를대상으로영양불량여부와상관없이 TPN을실시하여수술후합병증발생을비교하였다. 그결과상처감염, 폐렴, 사망률에는차이가없었지만농양, 복막염 (peritonitis), 문합부누출 (anastomotic leakage) 등주요합병증의발생률이 32.2% 에서 16.7% 로감소하였다. 영양불량여부와상관없이경정맥영양요법을실시했을때는합병증발생감소효과는부분적인것으로나타났다. 암환자에있어서영양관련문제들을조기에진단하고적극적으로대처함으로써 50-90% 정도에서체중감소를예방할수있다는보고가있다. 결 론 암환자의치료를위해조기에환자의영양상태를평가하고이에적절한영양중재 (nutrition intervention) 를하는것은암치료에핵심적부분이다. 또한적절한영양관리가질병회복, 재원기간의감소로인한경제적이익을가져오므로치료효율을높일수있을것이다. REFERENCES 1. Sheean PM, Peterson SJ, Chen Y, Liu D, Lateef O, Braunschweig CA. Utilizing multiple methods to classify malnutrition among elderly patients admitted to the medical and surgical intensive care units (ICU). Clin Nutr 2013. [Epub ahead of print] 2. Middleton MH, Nazarenko G, Nivison-Smith I, Smerdely P. Prevalence of malnutrition and 12-month incidence of mortality in two Sydney teaching hospitals. Intern Med J 2001;31: 455-461. 3. Chima CS, Barco K, Dewitt ML, Maeda M, Teran JC, Mullen KD. Relationship of nutritional status to length of stay, hospital costs, and discharge status of patients hospitalized in the medicine service. J Am Diet Assoc 1997;97:975-978. 4. Thorsdóttir I, Eriksen B, Eysteinsdóttir S. Nutritional status at submission for dietetic services and screening for malnutrition at admission to hospital. Clin Nutr 1999;18:15-21. 5. Bozzetti F, Gianotti L, Braga M, Di Carlo V, Mariani L. Postoperative complications in gastrointestinal cancer patients: the joint role of the nutritional status and the nutritional support. Clin Nutr 2007;26:698-709. 6. Jung KW, Park S, Kong HJ, et al. Cancer statistics in Korea: incidence, mortality, survival, and prevalence in 2008. Cancer Res Treat 2011;43:1-11. 7. Bae JM, Park JW, Yang HK, Kim JP. Nutritional status of gastric cancer patients after total gastrectomy. World J Surg 1998;22: 254-260. 8. Yu W, Chung HY. Nutritional status after curative surgery in patients with gastric cancer: comparison of total versus subtotal gastrectomy. J Korean Surg Soc 2001;60:297-301. 9. Li QD, Li H, Li FJ, et al. Nutrition deficiency increases the risk of stomach cancer mortality. BMC Cancer 2012;12:315. 10. Nitenberg G, Raynard B. Nutritional support of the cancer patient: issues and dilemmas. Crit Rev Oncol Hematol 2000;34: 137-168. 11. Ottery FD. Definition of standardized nutritional assessment and interventional pathways in oncology. Nutrition 1996;12(1 Suppl):S15-S19. 12. Bistrian BR, Blackburn GL, Hallowell E, Heddle R. Protein status of general surgical patients. JAMA 1974;230:858-860. 13. Rey-Ferro M, Castaño R, Orozco O, Serna A, Moreno A. Nutritional and immunologic evaluation of patients with gastric cancer before and after surgery. Nutrition 1997;13:878-881. 14. Song DY, Park JE, Shim JE, Lee JE. Trends in the major dish groups and food groups contributing to sodium intake in the Korea National Health and Nutrition Examination Survey 1998-2010. Korean J Nutr 2013;46:72-85. 15. Son SH, Lee HJ, Park K, Ha TY, Seo JS. Nutritional evaluation and its relation to the risk of metabolic syndrome according to the consumption of cooked rice and cooked rice with multi-grains in korean adults: based on 2007-2008 Korean National Health and Nutrition Examination Survey. Korean J Community Nutr 2013;18:77-87. 16. Detsky AS, McLaughlin JR, Baker JP, et al. What is subjective global assessment of nutritional status? JPEN J Parenter Enteral Nutr 1987;11:8-13. 17. Lowrie EG, Lew NL. Death risk in hemodialysis patients: the predictive value of commonly measured variables and an evaluation of death rate differences between facilities. Am J Kidney Dis 1990;15:458-482. Vol. 61 No. 4, April 2013
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