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1 대한내과학회지 : 제 77 권제 6 호 2009 특집 (Special Review) - 당뇨병성신부전의관리와최신치료 당뇨병성신증에대한진단및검사 고려대학교의과대학내과학교실 강영선 차대룡 Diagnosis and test for diabetic kidney disease Young Sun Kang, M.D., and Dae Ryong Cha, M.D. Department of Internal Medicine, Korea University College of Medicine, Ansan, Korea Diabetic kidney disease, as one of the important diabetic complication, developed in 20% to 40% of patients with diabetes and is now the most common cause of end-stage renal disease. Although it has been recommended that annual screening of renal function including microalbuminuria in diabetic patients, many patients are currently under-diagnosed state. Early recognition of diabetic renal complication has a pivotal role in the management of diabetic patients for improvement of patient's prognosis. The detection of microalbuminuria is particularly important as a marker of early diabetic kidney disease, and is related with an elevated cardiovascular complications. Like other chronic renal disease, diabetic kidney disease has characteristic to show a progressive decline in renal function, but significantly increased cardiovascular mortality even in the early stage of diabetic kidney disease. Therefore, more aggressive trials for detection of the presence of diabetic kidney disease and comorbid cardiovascular disease and management for cardiovascular risk factor reduction and adequate therapeutic intervention for slowing the progression of renal disease is essential to proper management for patients with diabetic kidney disease. (Korean J Med 77: , 2009) Key Words: Diabetic kidney disease; Diabetic nephropathy; Microalbuminuria; Diabetic retinopathy; Cardiovascular disease 서론당뇨병은평균수명의연장, 의료기술의발달, 식습관및생활습관의변화로인해지속적으로증가하는추세로이에따른당뇨병의합병증인당뇨병성신증은꾸준히증가하여현재전세계적으로말기신부전의가장흔한원인질환이다 1,2). 현재국내에서가장많은제2형당뇨환자의경우제1 형당뇨환자와다르게이미초기진단시에약 50% 환자에서당뇨병성혈관합병증이동반되어있어환자의사망률은더욱높은것으로알려져있다. 당뇨병성신장질환 (Diabetic kidney disease) 의정의는다른신장질환이없이당뇨에의해신장이손상된것으로소변내단백의증가를확인함으로써진단한다 1). 최근미국신장협회 (KDOQI) 권고에의하 면당뇨병성신증 (Diabetic nephropathy) 이라는용어는신장조직검사를통해당뇨병에서관찰되는사구체기저막의비후및혈관사이질의증식등과같은특징적인병리변화가확인되고하루요단백이 500 mg 이상의 macroalbuminuria 가동반된경우사용할것을권장하고있다 1). 미국당뇨병학회 (ADA) 및신장협회에서는당뇨진단후에매년정기적으로알부민뇨 (albuminuria) 와신기능지표인혈청크레아티닌을측정할것을권장하지만아직도많은당뇨환자들이신장합병증에대한검사가제대로이루어지지않고있는실정이다 3,4). 당뇨병의형태에따른차이를살펴보면 1형당뇨환자의경우유럽의연구결과에서는약 7년이상경과할경우미세단백뇨 (microalbuminuria) 는약 12.6%, 18 년후에약 33% 에서발생한다고보고되었다 5,6). 제2형당뇨

2 - Young Sun Kang, et al. Diagnosis and test for diabetic kidney disease - 환자의경우는영국의연구결과진단후 10년에약 25% 환자에서미세단백뇨소견을보이고매 10년마다약 2% 정도의발생률이증가함이보고되었다 7). Macroalbuminuria는 1형당뇨환자에서 15~40% 가진단후약 15~20 년후에발생하고 2형당뇨환자의경우는다양하여 5~20% 의발생빈도가보고되었다 8,9). 당뇨환자에서미세단백뇨의측정은당뇨로인한신장합병증의진단에가장중요한검사로서이는일반소변검사에서측정되지않는미세단백뇨의검출은신장합병증의초기에나타나는것으로향후신장합병증의진행을예견하는인자이기때문이다. 미세단백뇨의임상적인의의는당뇨환자의치료에서대단히중요한의미를지니는데이는미세단백뇨가검출되는환자의경우순환기계합병증의빈도가증가하기때문에보다철저한신기능예방치료와함께순환기계합병증에대한예방적인치료가필요하기때문이다 10-12). 미세단백뇨의위험인자로는고혈당과고혈압을들수있는데일부의연구에서는고혈압은미세단백뇨가발생하기이전혹은미세단백뇨의출현과동시에유발된다고보고되었다 13,14). 1형당뇨환자를대상으로한연구에의하면미세단백뇨를동반한당뇨환자들의평균혈압은고혈압전단계인 120~139/80~89 mmhg 수준을보이다가단백뇨의진행에비례하여혈압은지속적으로증가하며, 고혈압의발생은향후미세단백뇨의발생과도밀접한연관이있다 15,16). 미세단백뇨와밀접한연관이있는임상증세로는표 1에기술한것과같이다양한심혈관계합병증과연관된질환들이알려져있다. 따라서기타신장질환과달리당뇨병성신증환자의사망률은동반되는순환기계합병증에의해월등히증가하는데, 특히신장기능이감소되기시작하면사망률은급증한 Table 1. Commonly associated diseases with microalbuminuria Elevated blood pressure Dyslipidemia Elevated fibrinogen and plasminogen activator inhibitor 1 Increased insulin resistance Increased sodium disorders and related disorders Increased transcapillary escape rate of albumin Impaired basal endothelium-dependent vasorelaxation Increased left ventricular volume Diabetic retinopathy Diabetic neuropathy Peripheral vascular disease Silent ischemic heart disease 다 12,17-19). 즉신장기능이만성신장질환 3기 (stage 3 CKD) 가넘어서는단계 ( 사구체여과율이 60 ml/min 이하 ) 에서는일반인에비해사망률은약 3.5배증가하고, 5기인말기신부전상태에서는사망률은약 6배이상증가함으로써 12) 당뇨환자에서신장기능의진행의평가는대단히중요한의미를지닌다. 미세단백뇨의측정미세단백뇨의측정은일정기간수집한소변 (24시간소변혹은 overnight collected urine) 및일회성소변 (spot urine) 을통해평가가가능하다. 당뇨환자에서단백뇨의평가에서일반적인소변검사인 dipstick test는권장되지않는데, 미세단백뇨는 dipstick test로검출되지않고단백뇨의정량에도환자의수분상태및여러인자에의해결과가달라지므로정확한단백뇨측정이정확하지않기때문이다 20). 일반적으로 24시간소변을통한단백뇨의정량분석이가장보편화된방법이기는하지만소변수집의번거로움과소변수집의정확성에문제가있다. 이러한단점을보완하는대체방법으로 overnight timed urine collection을사용할수있으나소변의수집기간이짧은단점으로인해단백뇨정량의민감도는낮은단점이있다 21). 이러한여러가지문제점으로인해미국당뇨병학회및신장협회에서는 spot urine을이용한소변내 albumin/creatinine ratio (spot urine ACR) 를사용할것을권장하고있다 20). 이미많은연구에서 24시간소변검사를통한단백뇨의정량분석과 spot urine ACR 이상당히연관성이높다는연구결과들이있는데이는소변내 albumin과 creatinine 모두수용성이고환자의체액상태와무관하게 albumin 및 creatinine이유사하게변하기때문이다 22-24). 그러나 spot urine ACR 을평가할때주의사항으로는일시적으로요단백의배설이증가되는상황인소변검사 24시간이전에심한운동, 고열, 요로감염, 울혈성심부전, 심한고혈당, 조절되지않는고혈압및다량의단백질섭취시에거짓양성결과를얻을수있으므로주의를요한다 25). 또다른단점으로는동일환자에서도 spot urine ACR 은개체내변이 (variation) 가약 40% 에육박하므로 26) first morning voided urine을이용한 ACR 측정이권장되고 3~6개월에서로다른시기에측정한 spot urine ACR 이최소한 2회이상상승되어있을때진단적의의를지닌다 1,20). 또한최근에는 spot urine의 microalbumin 값만을이용하여도미세단백뇨의진단에는문제가없어 spot urine micro

3 - 대한내과학회지 : 제 77 권제 6 호통권제 592 호 Table 2. Stage of diabetic nephropathy: cutoff value of urine albumin and clinical characteristics in each stage Stages Urine sample Albuminuria cutoff values Clinical characteristics Microalbuminuria Timed urine 20~199 µg/min Abnormal nocturnal decrease of blood pressure and increased blood pressure levels 24 hr urine 20~299 mg/24 h Increased triglycerides, total and LDL cholesterol, and saturated fatty acids Spot urine 30~299 mg/g Increased frequency of metabolic syndrome components Endothelial dysfunction Association with diabetic retinopathy, amputation, and cardiovascular disease Increased cardiovascular mortality Stable GFR Macroalbuminuria Timed urine 200 µg/min Hypertension 24 hr urine 300 mg/24 h Increased triglycerides and total and LDL cholesterol Spot urine >300 mg/g Asymptomatic myocardial ischemia Progressive GFR decline albumin값이 17 mg/l 이상일경우미세단백뇨진단의 sensitivity는 100%, specificity 는 80% 로보고되었고, 유럽당뇨학회에서는 20 mg/l 이상을사용할것을권장하고있다 27). 미세단백뇨의측정은현재 immunoassay 기법을많이사용하지만 immunoassay 기법은 sensitivity가낮고 HPLC 기법이우월한것으로알려져있다 28). 표 2는서로다른소변검체를이용하여측정한결과에따른단백뇨의정의및각시기별임상적특징을요약한것이다. 주의사항은환자의미세단백뇨값이정상범위 (normoalbuminuria) 에있더라도비교적높은범위의정상치 (high normal) 값을보일경우추후당뇨병성신증으로진행할위험성이있으며, 순환기계합병증의경우 normoalbuminuria 범위에서도상대적으로높은값을지닐경우수치에비례하여위험성은증가하므로지속적으로세심한추적관찰이요구된다 29-31). 실제로진단초기에미세단백뇨값이 10 μg/min 이상인환자의경우 10년후에당뇨병성신증으로진행할위험도는약 30배정도높으며 30), 따라서최근에는미세단백뇨의기준치설정을바꾸어야한다는의견들이꾸준히제시되고있다. 또한당뇨병성신증이진단된경우라하더라도매년정기적인추적관찰을함으로써당뇨병성신증의진행정도및치료에대한반응을평가하는데중요하므로모든당뇨환자는주기적인소변내미세단백뇨의배설량에대한추적관찰이요구된다. 당뇨환자에서당뇨병성신증에대한검사는 2형당뇨환자의경우이미약 7% 의환자에서미세단백뇨를보여진단과동시에이에대한검사가필요하다 7). 반면 1형당뇨환자에서는초기진단후 5년이경과할경우당뇨병성신증에대한검사를시행할것을권장하나 20), 일반적으로진단후혈당및혈압관리가잘되지않는환자들의경우 5년이내에약 18% 환자에서미세단백뇨가발생하고 32) 사춘기연령에서발생빈도가급증하므로 33) 1형당뇨환자의경우도진단후 1년이내에당뇨병성신증에대한검사가필요하다 20). 환자의예후와관련된당뇨환자에서의미세단백뇨의임상적의의는제1형당뇨환자의경우 macroalbuminuria는신장의조직소견과연관성이높아만성신기능장애로진행될위험성이높으며 34), microalbuminuria의경우는신장의조직학적변화는심하지않으나고혈압이동반될경우역시만성으로진행할위험도는증가한다 35). 그러나제2형당뇨환자의경우에서는 microalbuminuria는신장의조직학적변화와연관성이낮으며미세단백뇨를지닌 2형당뇨환자의경우실제신장의조직학적변화는 30% 환자에서만관찰된다 36). 그러나 2형당뇨환자가당뇨병성망막변증 (diabetic retinopathy) 소견을동반하는경우에는미세단백뇨를보이는경우만성으로진행할위험도는높은것으로알려져있으므로제2형당뇨환자의경우망막병증의확인을위한안저검사 (ophthalmoscopic examination) 가반드시필요하다 1). 그러나 2형당뇨환자의경우상당한신기능저하가동반되어있는경우에도약 30% 의환자에서는당뇨병성망막변증및단백뇨가동반되어있지않을수있으므로진단시주의를요한다 37)

4 - 강영선외 1 인. 당뇨병성신증에대한진단및검사 - 미국당뇨학회에서는제2형당뇨환자의경우신장기능의평가를위해매년미세단백뇨와사구체여과율 (GFR) 의변화를측정할것을권장한다 1). 그러나당뇨환자의경우대부분이다량의단백뇨를동반할것으로추측되지만, 많은환자에서는미세단백뇨가없이신기능만저하된다는조사결과가최근발표된바있다 38,39). 단백뇨가없이신기능이저하된환자의유병률에대한최근의대규모연구결과에의하면제2형당뇨환자중에서 GFR이 60 ml/min/1.73 m 2 미만인환자의빈도는 23.1% 로서일반국민에비해약 1.3배이상의높은빈도를보였고, 신기능이저하된당뇨환자의 55% 환자에서미세단백뇨가없는특징을보였다 40). 그러나미세단백뇨를동반하지않는신기능저하환자는환자의성별, 인종및당뇨의유병기간에상관없이당뇨환자에비해일반인에서더욱높은빈도를보였다. 미세단백뇨가없이신기능이저하된당뇨환자의원인으로는몇가지가설이제시되고있다. 첫째로대부분의환자에서사용중인레닌- 안지오텐신 (RAS) 차단제의효과와혈압약제의사용에의한혈압조절및고지혈증약제의효과등에의해단백뇨가소실되었을가능성이있다. 또다른가능성으로는당뇨의합병증이세뇨관간질조직에서주로발생하는경우와당뇨와같이수반될수있는비당뇨병성신장질환이동반되었을가능성, 수입소동맥을침범하는신장혈관의질환및신장의노화과정의급속한진행등이서로복합적으로작용하여나타난다고추정된다. 그러나현재이러한환자들에대한병태생리학적기전에대한연구가전무하여단백뇨를수반하지않는당뇨병성만성신장질환의병태생리및치료에대해보다적극적인연구가필요하며당뇨로진단된환자에서는미세단백뇨가없더라도신기능이감소할수있으며주기적인 GFR의측정이반드시같이시행되어야한다. 당뇨환자에서당뇨병성신장합병증의정확한진단은환자의치료에서대단히중요한데, 단백뇨를평가함과동시에다음과같은임상소견을보이는경우에는당뇨병성신장합병증이외의다른질환이숨겨있을확률이높으므로반드시감별진단에대한검사를시행해야한다. 즉당뇨병성망막증이없거나 GFR의감소속도가매월 1 ml/min/1.73 m 2 이상으로빠르게진행하는경우, 갑작스럽게다량의단백뇨가관찰되는경우, 혈압약제에잘조절되지않는악성고혈압이발생하는경우및 RAS 차단제사용후 6개월이내에신장기능이 30% 이상으로감소하는경우에는당뇨병성신장합병증이외의동반가능한다른질환에대한검사가필요하다. 신장기능의평가및추적관찰이미전술한바와같이미국당뇨병학회에서는당뇨병이진단되면 1형당뇨환자의경우진단후 5년에미세단백뇨와크레아티닌의매년주기적인추적관찰을권장하고, 2형당뇨환자의경우는진단과동시에검사를진행할것을권장하고있다 1). 일단당뇨병성신장질환이진단되면신기능진행을평가하기위해 GFR을매년정기적으로추적관찰하는것이중요하며이와동시에미세단백뇨의변화에대한추적을같이시행하여야한다. 주의할점은미세단백뇨의변화보다는 GFR이보다정확한신기능을반영하므로 GFR의변화추이는환자의예후를결정짓는중요한인자라는사실이다. 제1형및 2형당뇨환자모두에서여러임상결과에의하면특히신장의기능이 3기이상인환자들의경우초기치료후에감소되는요단백량은향후신장의예후를반영하는좋은지표로되어있으나, 신장질환초기인만성신장질환 1, 2기의환자들의경우는치료후초기요단백감소가신장의장기적인예후인자는아님이알려져있다. 따라서초기당뇨병성신장질환환자의치료시에는반드시 GFR 에대한평가가같이이루어져야한다. 당뇨환자에서신장의기능에대한평가는일반적인크레아티닌수치만으로평가하는것이크레아티닌의특성상여러가지변수에의해변화될수있어정확도가많이떨어지므로추천되지않는다 10,21). 보다정확한신장기능의평가는 GFR을측정함으로써평가가가능한데 GFR을측정하는방법은여러가지가있어각각의장단점을언급할필요가있다. 가장간단한방법으로 24시간소변내크레아티닌제거율을측정하는방법이있는데, 이는신기능초기에는 GFR을저평가하고 3기이상의만성신장질환환자에서는 GFR을과대평가하는단점과 24시간소변의수집과정의문제점으로인해정확도가떨어지는방법이다. 가장정확한 GFR의측정은신장의사구체에서 100% 여과되고세뇨관에서재흡수및분비가일어나지않는 inulin 혹은 fructose 의제거율을측정하는것이좋으나검사과정이번거롭고비용이비싼단점이있어임상에적용하기어려운문제점이있다. 이를대체하는방법으로동위원소인 DTPA 혹은 iothalamate의여과율을측정하는방법이지만비용이들고정상인에서 GFR을과대평가하는문제가있어임상적으로널리사용되지는않는다 21,41). 미국당뇨병학회및신장협회에서는혈청크레아티닌을이용한단순화한 GFR 산출공식을이용한 MDRD 공식혹

5 - The Korean Journal of Medicine: Vol. 77, No. 6, 은 Cockcroft-Gault 공식을이용한 GFR의측정을권장하고있다 1). 두가지방법에의한 GFR의측정은환자의연령, 성별및인종의차이를고려하여산출한공식으로현재가장보편적으로사용되고있다. MDRD 공식에의한 GFR의평가는 Cockcroft-Gault 공식에의한 GFR의평가보다신장질환초기에보다정확한 GFR을반영하는것으로알려져있으나두방법모두신장질환초기에는진정한 GFR을저평가하는단점이있으며 42), 두가지방법모두당뇨병성신증환자를대상으로 GFR의정확도를비교한대규모연구가없는실정이다 10). 최근의연구결과에의하면두공식모두미세단백뇨를수반한당뇨환자에서 GFR을저평가하고신장질환의진행에서도두가지방법을사용할경우진정한신장질환의진행을저평가한다는단점이있다 42). 한편다양한단백뇨를보이는 2형당뇨환자를대상으로한추적관찰연구에서는두공식모두진정한 GFR을저평가하는단점이있다고보고되었으나, 신기능이저하된 3기이상의환자에서는 MDRD 공식이비교적진정한 GFR의변화를반영한다고보고되었다 43). 당뇨환자에서두가지공식이진정한 GFR을저평가하는이유는아직정확하지않으나환자의연령, 성별, 인종, 체중, 근육량및식이단백섭취정도등이복합적으로작용한다고추정된다. 따라서미국신장협회에서는신기능이비교적정상인신기능초기당뇨환자중에서고도의비만환자에서는동위원소를이용한보다정확한 GFR의측정을권장하고있다. GFR을반영하는또다른검사방법으로는혈청 cystatin C 농도를측정하는방법이있는데 cystatin C는사구체에서 100% 여과되고세뇨관에서재흡수되어대사되는혈액단백질로, 여러임상연구에서는신장질환초기의 GFR을기타방법보다는비교적정확하게반영한다고보고되었으나현재널리임상에서사용되지는않고있다. 그러나최근연구결과에서는혈청 cystatin C는제2형당뇨환자에서기타방법에비해우수하게진정한 GFR의변화를반영한다고보고되어 44,45) 보다많은수의환자를대상으로한임상연구가필요한실정이다. 당뇨병성신증환자의평가당뇨환자에서미세단백뇨이상의다량의단백뇨가관찰되면다른기저신장질환의유무, 신장의기능및기타동반되는당뇨합병질환의유무에대한검사가시행되어야한다. 다른기저신장질환에대한평가는환자의병력, 진찰 소견, 방사선검사및혈청학적검사등을통해진단할수있다. 병력에서 1형당뇨환자의경우 10년이상의당뇨의경력이있고특히당뇨병성망막합병증이동반되는경우쉽게당뇨병성신증을진단할수있다. 2형당뇨환자의경우유병기간을모르더라도다량의단백뇨소견을보이고특히당뇨병성망막병증소견을보이는경우쉽게당뇨병성신증이진단된다. 그러나다수의 2형당뇨환자의경우는당뇨의유병기간을모르는경우가많고약 30% 의환자에서는당뇨병성망막병증이없기때문에당뇨병성신증의진단에어려움이있다 46). 환자가빈뇨및다뇨등의요로감염의증세, 요로결석시동반되는육안적혈뇨소견을보이거나피부반점혹은관절통등의전신질환을암시하는임상증세를보이는경우기타동반질환에대한검사가필요하다. 과거 B 혹은 C형간염의병력, 성병의기왕력, 임신시발생한고혈압및단백뇨, 신장질환의가족력이있을경우역시다른기저사구체질환및다낭신등과도감별이필요하다. 특히환자가요로감염, 요로폐색, 요로결석및다낭신의가족력이있는경우방사선검사중복부초음파검사를통한감별이중요하다. 현재당뇨환자에서신장조직검사의적응증은아직확립된것은없으나 1형당뇨환자가당뇨의유병기간이짧은상태에서다량의단백뇨가있거나신장질환의진행속도가비정상적으로빠르면서당뇨병성망막병증이없을경우신장조직검사가필요하다 47). 2형당뇨환자의경우신장조직검사의적응증은더욱복잡하여임상의사의종합적인판단이중요하지만일반적으로 2형당뇨환자에서당뇨병성망막병증을수반하지않는환자에서신장조직검사를시행할경우비당뇨병성신장질환의빈도는백인의경우 12% 정도로낮은빈도를보여당뇨병성망막병증의유무가신장조직검사를결정하는데중요한지표로사용될수있다. 그러나동양인의경우에서는백인과달리 2형당뇨환자에서신장조직검사를시행할경우기타신장질환은 46%, 당뇨병성신증과기타신장질환이동반되는경우는 19% 로보고되어동양인의경우약 60% 의환자에서는다른신장질환이동반될확률이높다고보고되었다 48). 따라서동양인의경우 2형당뇨환자에서하루단백뇨량이 1 g을넘고당뇨병성망막병증이없으며설명할수없는혈뇨소견을보이는경우에는신장조직검사를통한확진이필요하다. 모든당뇨환자에서평가해야할다른검사로는당뇨병성망막병증의유무에대한검사로서이는당뇨병성신증의진단에중요하기때문이다. 2형당뇨환자를대상으로시행한

6 - Young Sun Kang, et al. Diagnosis and test for diabetic kidney disease - 전향적연구에의하면당뇨병성망막병증소견을보이는환자들은추후당뇨병성신증의예측인자로서이러한결과는두질환모두당뇨환자에서관찰되는미세혈관합병증으로공통적인병태생리학적기전에기인하기때문으로추정된다 49). 또한모든당뇨환자는자율신경병증 (autonomic neuropathy) 및말초신경병증 (peripheral neuropathy) 에대한검사가필요한데이는당뇨병성신경합병증의빈도도당뇨병성신증환자에서빈도가높고, 신경합병증을지닌환자들은추후사망률이높기때문이다 50,51). 또한당뇨병성신증을지닌당뇨환자들은환자의증상유무와상관없이관상동맥질환의유무에대한평가가필요하다. 이와함께당뇨병의대형혈관합병증인경동맥, 말초동맥및신장동맥혈관상태에대한검사등도같이추천되는검사항목이다. 그러나검사과정에서사용되는조영제의신독성을반드시고려하여예방조치를충분히한상태에서검사를진행할필요가있으며, 다수의신기능저하가동반된경우에는환자의임상증상이동맥허혈증세에합당할경우에는신독성이없는기타검사로대체하여평가할필요가있다. 실제로고혈압이있는당뇨환자에서유의한신동맥의협착 (>70% stenosis) 은약 17% 환자에서관찰되고 52) 이러한허혈성신장질환 (ischemic nephropathy) 환자의경우고혈압이더욱악화되어신기능저하속도가빨라진다는문제점과 RAS 차단제등의혈압약제를사용할경우신장의급속한악화를유발한다는사실을고려하면임상적으로이에대한평가는대단히중요하다. 임상적으로신동맥협착의존재를암시하는소견으로는 RAS 차단제사용후에기존의혈청크레아티닌의 6개월이내에 30% 이상상승하거나, 다른대형혈관질환 ( 관상동맥, 경동맥및말초동맥 ) 이동반되어있으면서단백뇨가경미하고당뇨병성망막병증이없으며양측신장의크기에차이가심하게있는경우의심할수있다 53). 당뇨환자에서신동맥협착의진단에가장좋은검사로는 MR (magnetic resonance) angiography로알려져있으나 captopril renal scintigraphy, duplex doppler ultrasonography 등도진단에사용되는검사기법이다. 결론당뇨병성신장합병증은당뇨환자의 20~40% 에서발생하는중대합병증으로만성신부전의가장중요한원인질환이다. 당뇨환자에서매년주기적인신장기능의평가가권장되지만아직도많은당뇨환자에서신장기능의평가가제대 로시행되지않고있는실정이다. 당뇨병성신장합병증은특히초기진단이중요하며조기에적극적인치료를함으로써환자의예후를향상시킬수있다. 당뇨환자에서미세단백뇨는신장합병증의초기에관찰되는중요한검사소견으로미세단백뇨의발생은순환기계합병증의발생빈도를증가시킨다. 다른기타신장질환과마찬가지로당뇨병성신장합병증은대부분지속적으로진행하며다른신장질환과달리신장합병증의초기단계부터순환기계사망률은증가되어있다. 따라서초기에보다적극적인순환기계합병증의존재유무를확인하고위험인자에대한보다적극적인대처가필요하고, 신장의기능이감소될경우사망률은급격한증가를보인다는점을고려할때보다초기에당뇨병성신장합병증의진단과신장기능의진행에대한적극적인평가가요망된다. 중심단어 : 당뇨병성신장질환 ; 당뇨병성신증 ; 미세단백뇨 ; 당뇨병성망막병증 ; 순환기계질환 REFERENCES 1) KDOQI. KDOQI Clinical practice guidelines and clinical practice recommendations for diabetes and chronic kidney disease. Am J Kidney Dis 49(Suppl 2):S12-S154, ) Coresh J, Selvin E, Stevens LA, Manzi J, Kusek JW, Eggers P, van Lente F, Levey AS. Prevalence of chronic kidney disease in the United States. JAMA 298: , ) Middleton RJ, Foley RN, Hegarty J, Cheung CM, McEluff P, Gibson JM, Kalra PA, O'Donoghue DJ, New JP. The unrecognized prevalence of chronic kidney disease in diabetes. Nephrol Dial Transplant 21:88-92, ) McClellan WM, Knight DF, Karp H, Brown WW. Early detection and treatment of renal disease in hospitalized diabetic and hypertensive patients: important differences between practice and published guidelines. Am J Kidney Dis 29: , ) Chaturvedi N, Bandinelli S, Mangili R, Penno G, Rottiers RE, Fuller JH. Microalbuminuria in type 1 diabetes: rates, risk factors and glycemic threshold. Kidney Int 60: , ) Hovind P, Tarnow L, Rossing P, Jensen BR, Graae M, Torp I, Binder C, Parving HH. Predictors of the development of microalbuminuria and macroalbuminuria in patients with type 1 diabetes: inception cohort study. BMJ 328:1105, ) Adler AI, Stevens RJ, Manley SE, Bilous RW, Cull CA, Holman RR. Development and progression of nephropathy in type 2 diabetes: the United Kingdom Prospective Diabetes Study (UKPDS 64). Kidney Int 63: , ) Andersen AR, Christiansen JS, Andersen JK, Kreiner S, Deckert

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A 617 Special Issue Diabetic Retinopathy Won Ki Lee, M.D. Department of Ophthalmology The Catholic University of Korea College of Medicine Kangnam St. Mary s Hospital E mail : wklee@catholic.ac.kr Abstract R