邱媛+沈莉+戎紅輝+李永祥+姚明
[摘要] 目的 評(píng)估糖化清蛋白檢測(cè)反映血糖水平的臨床意義。方法 采用糖化清蛋白(GA)快速檢測(cè)法與糖化血紅蛋白(HbA1c)檢測(cè)法分別檢測(cè)糖尿病與非糖尿患者血糖水平,分析二者的相關(guān)性以及糖化清蛋白快速檢測(cè)法的精確性與靈敏度。結(jié)果 糖化清蛋白快速檢測(cè)法精密度良好,且抗干擾能力較好,均符合臨床檢測(cè)的要求。GA與HbA1c、空腹血糖(FPG)、餐后2h血糖(2hBG)均呈良好的正相關(guān)性, 其回歸方程分別為Y=0.89X+0.21,Y=0.84X+0.11,Y=0.92X+0.15; r值分別為0.94、0.92、0.96(P<0.01)。 結(jié)論 GA快速檢測(cè)法可反映糖尿病患者近期整體血糖水平,具有重要臨床價(jià)值。
[關(guān)鍵詞] 糖尿??;糖基化血紅蛋白;糖化血清白蛋白
[中圖分類號(hào)] R587.1 [文獻(xiàn)標(biāo)識(shí)碼] B [文章編號(hào)] 1673-9701(2014)17-0086-03
Clinical comparison of the enzymatic measurement of glycated albumin and the detection of glycated hemoglobin
QIU Yuan1 SHEN Li1 RONG Honghui1 LI Yongxiang1 YAO Ming2
1.Department of Clinical Laboratory, Maternity and Children Health Care Hospital of Jiaxing City in Zhejiang Province, Jiaxing 314015, China; 2.Department of Anesthesiology, the First Hospital of Jiaxing City in Zhejiang Province, Jiaxing 314002, China
[Abstract] Objective To investigate the clinical significance of enzymatic measurement of glycated albumin (GA). Methods A total of 72 cases of patients with diabetes mellitus and 110 cases of healthy controls were enrolled. The levels of GA were detected by using enzymatic measurement, and the precision and linear rage of the detection kits were analyzed by the detection of samples with high and low levels of GA, and the correlation between GA and other indexes was evaluated. Results The enzymatic measurement of GA was with good precision and better anti-interference ability, and met the requirements of clinical testing. In patients group,there was fine correlation between GA and glycosylated hemoglobin A (HbAlc),fasting plasma glucose (FPG) and 2h postprandial blood glucose (2hBG) (equation of linear regression: Y=0.89X+0.21,Y=0.84X+0.11,Y=0.92X+0.15; r=0.94,0.92,0.96; P< 0.01). Conclusion The enzymatic measurement of GA is with fine precision and anti-interference ability, could be well correlated with HbAlc.
[Key words] Diabetes mellitus;Glycosylated hemoglobin A; Glycated albumin
糖化血紅蛋白(HbA1c)是紅細(xì)胞內(nèi)的血紅蛋白與血糖不可逆結(jié)合的產(chǎn)物,其濃度與血糖水平成正比,且其含量不受血糖短暫波動(dòng)的影響。HbA1c的檢測(cè)反映了患者近8~12周的血糖控制情況,是目前臨床糖尿病療效判定和調(diào)整治療方案的金標(biāo)準(zhǔn)[1]。但是,由于血紅蛋白半衰期較長(zhǎng),HbA1c反映的是血糖的平均值,因此對(duì)于紅細(xì)胞更新率增加和/或血糖波動(dòng)幅度較大的患者,HbA1c不能準(zhǔn)確反映血糖的控制情況,亦不能靈敏反映血糖的波動(dòng)情況[2]。與糖化血紅蛋白相比,血清清蛋白(GA)代謝半衰期為21d,因此GA反映了患者近2~3周內(nèi)的平均血糖水平,對(duì)短期內(nèi)血糖變化更為敏感[3]。本研究擬采用酶法快速檢測(cè)糖尿病患者GA,分析GA與常用血糖指標(biāo)的相關(guān)性,評(píng)估GA酶法快速檢測(cè)在糖尿病患者中應(yīng)用的臨床意義。
1 資料與方法
1.1 臨床資料
2012年1~12月我院體檢中心體檢者血樣182例,其中正常健康者110例(對(duì)照組),年齡21~65歲;確診為糖尿病患者72例(糖尿病組),均符合1999年世界衛(wèi)生組織的糖尿病診斷標(biāo)準(zhǔn):空腹血糖(FPG)≥7.0mmol/L和/或餐后2h血糖(2hBG)≥11.1mmol/L,年齡33~65歲。所有患者肝、腎、心臟、呼吸功能正常,排除其他代謝性疾病。endprint
1.2 檢測(cè)方法
采用雅培C16000全自動(dòng)生化分析儀。采用己糖激酶法檢測(cè)血糖濃度(試劑由日本積水醫(yī)療株式會(huì)社提供),采用液態(tài)酶法檢測(cè)GA濃度(試劑由日本旭化成公司提供),采用果糖基肽氧化酶法檢測(cè)HbAlc濃度(試劑由北京九強(qiáng)公司提供)。由全自動(dòng)生化分析儀自動(dòng)完成檢測(cè)過(guò)程,每次測(cè)定時(shí)均進(jìn)行質(zhì)控,確定試劑的精密度、線性等性能。
1.3 統(tǒng)計(jì)學(xué)分析
計(jì)量資料采用均數(shù)±標(biāo)準(zhǔn)差(x±s)表示,使用SPSS 13.0軟件進(jìn)行統(tǒng)計(jì)學(xué)分析,組間比較采用t檢驗(yàn),采用person相關(guān)性分析參數(shù)間相關(guān)性,P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
2 結(jié)果
2.1 精密度檢測(cè)
按照美國(guó)臨床實(shí)驗(yàn)標(biāo)準(zhǔn)委員會(huì)(NCCLS)的標(biāo)準(zhǔn),分別進(jìn)行批內(nèi)與批間精密度檢測(cè)。采用GA含量為4.2%、11.0% 、20.2%標(biāo)準(zhǔn)品血清3份,其中一份連續(xù)測(cè)定20次以確定批內(nèi)精密度;另兩份每日分上下午各測(cè)1次,連續(xù)20 d,得到批間精密。結(jié)果批內(nèi)與批間CV%值分別為1.28、2.71,符合要求。
2.2 線性測(cè)定
取GA高值標(biāo)本,用稀釋液稀釋成4%、8%、12%、16%、20% 5個(gè)濃度梯度,測(cè)定GA含量,進(jìn)行線性回歸分析。其回歸方程為Y=0.92X+0.23,r=0.96(X為測(cè)定值,Y為理論值),符合要求。
2.3干擾試驗(yàn)
取GA濃度為11.0%的標(biāo)本4份,分別加入40μL蒸餾水或等量的含8.7 mmol/L甘油三酯或8.4 mmol/L膽固醇,或824 μmol/L膽紅素的標(biāo)準(zhǔn)血清,測(cè)定GA含量以確定以上因素對(duì)GA測(cè)定結(jié)果的影響,結(jié)果顯示上述干擾因素對(duì)GA酶法快速測(cè)定結(jié)果無(wú)干擾。
2.4 糖尿病檢測(cè)指標(biāo)分析
與健康對(duì)照組相比,糖尿病組患者HbA1c、GA、FPG、2hBG均明顯增高(P<0.01),見(jiàn)表1。
表1 兩組血糖指標(biāo)對(duì)比(x±s)
注:與對(duì)照組相比具有統(tǒng)計(jì)學(xué)意義(*P <0.05)
2.5 相關(guān)性分析
對(duì)147例患者的相關(guān)性分析顯示,GA與HbA1c、FPG、2hBG均具有良好的正相關(guān)性,其回歸方程分別為Y=0.89X+0.21,Y=0.84X+0.11,Y=0.92X+0.15;r值分別為0.94、0.92、0.96(P均< 0.01)。
3討論
糖尿病的診斷與療效的檢測(cè)主要依賴于對(duì)血糖濃度的監(jiān)測(cè),其中糖基化蛋白質(zhì)的測(cè)定是重要手段。與非糖尿病患者相比,糖尿病患者體內(nèi)存在多種糖基化蛋白質(zhì)。這些糖基化蛋白質(zhì)中,HbA1c作為判定糖尿病患者血糖控制水平的金標(biāo)準(zhǔn),其含量與血糖水平、并發(fā)癥的發(fā)生率密切相關(guān)[1]。而全血HbAlc水平控制在7.0 以下可有效降低糖尿病慢性并發(fā)癥如腎病、白內(nèi)障、動(dòng)脈硬化的發(fā)生率,表明HbAlc與糖尿病并發(fā)癥間同樣存在緊密聯(lián)系[4]。
與先前的研究結(jié)果一致,我們的結(jié)果表明,糖尿病患者HbAlc較非糖尿病患者明顯增高。但是,HbAlc是血紅蛋白與血糖間緩慢的不可逆結(jié)合的產(chǎn)物,其濃度主要受一段時(shí)期內(nèi)血糖平均水平與紅細(xì)胞平均壽命的影響[5]。體內(nèi)紅細(xì)胞的平均壽命約120 d,因此HbAlc僅反映抽血前2~3個(gè)月內(nèi)血糖的平均水平[6]。但是血糖波動(dòng)、進(jìn)食以及運(yùn)動(dòng)HbAlc影響不大,因此其不能反映患者短期內(nèi)血糖波動(dòng)的程度。此外紅細(xì)胞的更新率增加,如貧血、溶血等情況下,其準(zhǔn)確性亦受到影響[7]。
GA由血清清蛋白和葡萄糖以非酶促的氧化反應(yīng)結(jié)合生成。與血紅蛋白不同,清蛋白的半衰期不受血紅蛋白代謝率的影響,因此檢測(cè)GA反映血糖控制水平時(shí)可以避免上述血紅細(xì)胞代謝紊亂的影響[8]。與血紅蛋白相比,血清清蛋白的半衰期較短,約為21d,因此當(dāng)出現(xiàn)短期血糖控制水平波動(dòng)時(shí),GA的反應(yīng)更為靈敏[9]。2型糖尿病患者接受胰島素治療2周后,HbAlc從10.9%降至10.0%,而GA 水平從35.6%降至25.0%[10]。提示GA 比HbAlc更能反映DM 藥物和其他因素導(dǎo)致的短期內(nèi)血糖水平的波動(dòng)情況,能迅速、靈敏、特異地評(píng)價(jià)和監(jiān)控降糖藥物的療效。此外,GA 比HbA1c能更好地反映糖尿病慢性并發(fā)癥,出現(xiàn)此現(xiàn)象的原因除了與GA能更好地反映短期內(nèi)血糖波動(dòng)幅度外, GA本身的細(xì)胞毒性也是重要原因。研究發(fā)現(xiàn)血GA濃度升高使視網(wǎng)膜感光細(xì)胞的凋亡增加,表明高GA血癥對(duì)視網(wǎng)膜神經(jīng)元存在直接毒性,與DM引起的視網(wǎng)膜病變密切相關(guān)[11];高GA血癥導(dǎo)致腎小球系膜細(xì)胞增生與Ⅳ型膠原分泌增加,促進(jìn)腎小球硬化,加重糖尿病性腎病的病理改變[12]。
早期GA的測(cè)定依靠高效液相色譜法,成本高、效率低不適于臨床應(yīng)用。固體與液態(tài)酶法GA測(cè)定技術(shù)的開(kāi)發(fā)成功,大大降低了檢測(cè)成本,提高了檢測(cè)效率,簡(jiǎn)化了操作過(guò)程[13,14]。GA酶法快速檢測(cè)是采用糖化氨基酸氧化酶將內(nèi)源性糖化氨基酸分解為葡萄糖酮醛、氨基酸、雙氧水而去除,在處理液中加入對(duì)白蛋白特異的蛋白酶將GA水解為糖化氨基酸,再次使用糖化氨基酸氧化酶將GA水解生成的糖化氨基酸水解為葡萄糖酮醛、氨基酸、過(guò)氧化氫。生成的過(guò)氧化氫與N, N-雙(4-磺丁基)-3-甲基苯胺二鈉鹽在過(guò)氧化物酶的作用下定量生成藍(lán)紫色色素,通過(guò)測(cè)定此紫藍(lán)色色素的吸光度,計(jì)算GA濃度。我們的研究結(jié)果顯示,液態(tài)酶法快速檢測(cè)GA的精密度良好,且抗干擾能力較好,能準(zhǔn)確地區(qū)別糖尿病與非糖尿病患者。GA與HbA1c、FPG、2hBG均呈良好的正相關(guān)性[14,15],表明酶法檢測(cè)GA簡(jiǎn)便快速,且準(zhǔn)確可靠。
因此,GA快速檢測(cè)法可反映糖尿病患者近期整體血糖水平,具有重要臨床價(jià)值。
[參考文獻(xiàn)]
[1] Schleicher ED, Gerbitz KD, Dolhofer R, et al. Clinical utility of non enzymatic glycosylated blood proteins as an index of glucose control[J]. Diabetes Care, 1984, 7(6):548-556.endprint
[2] Lee SY, Chen YC, Tsai IC, et al. Glycosylated hemoglobin and albumin-corrected fructosamine are good indicators for glycemic control in peritoneal dialysis patients[J]. PLoS One, 2013, 8(3):57762.
[3] Yang C, Li H, Wang Z, et al. Glycated albumin is a potential diagnostic tool for diabetes mellitus[J]. Clin Med, 2012, 12(6):568-571.
[4] Cozma AI, Sievenpiper JL, de Souza RJ, et al. Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials[J]. Diabetes Care, 2012, 35(7): 1611-1620.
[5] Kouzuma T, Uemastu Y, Usami T, et al. Study of glycated aminoacid elimination reaction for an improved enzymatic glycated albumin measurement method[J]. Clin Chim Acta, 2004, 346(2):135-143.
[6] Sany D, Elshahawy Y, Anwar W. Glycated albumin versus glycated hemoglobin as glycemic indicator in hemodialysis patients with diabetes mellitus: Variables that influence[J]. Saudi J Kidney Dis Transpl, 2013, 24(2): 260-273.
[7] Shen Y, Pu LJ, Lu L, et al. Glycated albumin is superior to hemoglobin A1c for evaluating the presence and severity of coronary artery disease in type 2 diabetic patients[J]. Cardiology, 2012, 123(2): 84-90.
[8] Tessari P, Kiwanuka E, Millioni R, et al. Albumin and fibrinogen synthesis and insulin effect in type 2 diabetic patients with normal albuminuria[J]. Diabetes Care, 2006, 29(2):323-328.
[9] Yang C, Li H, Wang Z, et al. Glycated albumin is a potential diagnostic tool for diabetes mellitus[J]. Clin Med, 2012, 12(6):568-571.
[10] Kim C, Bullard KM, Herman WH, et al. Association between iron deficiency and AIc levels among adults without diabetes in the national health and nutrition examination survey,1999-2006[J]. Diabetes Care,2010,33(4):780-785.
[11] Song SO, Kim KJ, Lee BW, et al. Predicts the progression of carotid arterial atherosclerosis[J]. Atherosclerosis, 2012, 225(2):450-455.
[12] Cohen MP, Iautenslager GT, Hud E, et a1. Inhibiting albumin glycation at tenuates dysregulation of VEGFR2 1 and collagenⅣ subchain production and the development of renal insufficiency[J]. Ann Physiol Renal Physiol, 2007, 292(2):789-795.
[13] 賈珂珂,李國(guó)權(quán),張捷. 酮胺氧化酶法測(cè)定糖化白蛋白的評(píng)價(jià)[J]. 中國(guó)實(shí)驗(yàn)診斷學(xué),2010,14(10):1620-1623.
[14] 呂冰,王立. 2型糖尿病患者平均血糖值與糖化白蛋白相關(guān)性研究[J]. 疑難病雜志,2013,(2):28-30.
[15] 湯世博,曹利民. 糖化血紅蛋白檢測(cè)方法研究進(jìn)展[J]. 北京生物醫(yī)學(xué)工程,2013,32(3):325-329.
(收稿日期:2014-01-07)endprint
[2] Lee SY, Chen YC, Tsai IC, et al. Glycosylated hemoglobin and albumin-corrected fructosamine are good indicators for glycemic control in peritoneal dialysis patients[J]. PLoS One, 2013, 8(3):57762.
[3] Yang C, Li H, Wang Z, et al. Glycated albumin is a potential diagnostic tool for diabetes mellitus[J]. Clin Med, 2012, 12(6):568-571.
[4] Cozma AI, Sievenpiper JL, de Souza RJ, et al. Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials[J]. Diabetes Care, 2012, 35(7): 1611-1620.
[5] Kouzuma T, Uemastu Y, Usami T, et al. Study of glycated aminoacid elimination reaction for an improved enzymatic glycated albumin measurement method[J]. Clin Chim Acta, 2004, 346(2):135-143.
[6] Sany D, Elshahawy Y, Anwar W. Glycated albumin versus glycated hemoglobin as glycemic indicator in hemodialysis patients with diabetes mellitus: Variables that influence[J]. Saudi J Kidney Dis Transpl, 2013, 24(2): 260-273.
[7] Shen Y, Pu LJ, Lu L, et al. Glycated albumin is superior to hemoglobin A1c for evaluating the presence and severity of coronary artery disease in type 2 diabetic patients[J]. Cardiology, 2012, 123(2): 84-90.
[8] Tessari P, Kiwanuka E, Millioni R, et al. Albumin and fibrinogen synthesis and insulin effect in type 2 diabetic patients with normal albuminuria[J]. Diabetes Care, 2006, 29(2):323-328.
[9] Yang C, Li H, Wang Z, et al. Glycated albumin is a potential diagnostic tool for diabetes mellitus[J]. Clin Med, 2012, 12(6):568-571.
[10] Kim C, Bullard KM, Herman WH, et al. Association between iron deficiency and AIc levels among adults without diabetes in the national health and nutrition examination survey,1999-2006[J]. Diabetes Care,2010,33(4):780-785.
[11] Song SO, Kim KJ, Lee BW, et al. Predicts the progression of carotid arterial atherosclerosis[J]. Atherosclerosis, 2012, 225(2):450-455.
[12] Cohen MP, Iautenslager GT, Hud E, et a1. Inhibiting albumin glycation at tenuates dysregulation of VEGFR2 1 and collagenⅣ subchain production and the development of renal insufficiency[J]. Ann Physiol Renal Physiol, 2007, 292(2):789-795.
[13] 賈珂珂,李國(guó)權(quán),張捷. 酮胺氧化酶法測(cè)定糖化白蛋白的評(píng)價(jià)[J]. 中國(guó)實(shí)驗(yàn)診斷學(xué),2010,14(10):1620-1623.
[14] 呂冰,王立. 2型糖尿病患者平均血糖值與糖化白蛋白相關(guān)性研究[J]. 疑難病雜志,2013,(2):28-30.
[15] 湯世博,曹利民. 糖化血紅蛋白檢測(cè)方法研究進(jìn)展[J]. 北京生物醫(yī)學(xué)工程,2013,32(3):325-329.
(收稿日期:2014-01-07)endprint
[2] Lee SY, Chen YC, Tsai IC, et al. Glycosylated hemoglobin and albumin-corrected fructosamine are good indicators for glycemic control in peritoneal dialysis patients[J]. PLoS One, 2013, 8(3):57762.
[3] Yang C, Li H, Wang Z, et al. Glycated albumin is a potential diagnostic tool for diabetes mellitus[J]. Clin Med, 2012, 12(6):568-571.
[4] Cozma AI, Sievenpiper JL, de Souza RJ, et al. Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials[J]. Diabetes Care, 2012, 35(7): 1611-1620.
[5] Kouzuma T, Uemastu Y, Usami T, et al. Study of glycated aminoacid elimination reaction for an improved enzymatic glycated albumin measurement method[J]. Clin Chim Acta, 2004, 346(2):135-143.
[6] Sany D, Elshahawy Y, Anwar W. Glycated albumin versus glycated hemoglobin as glycemic indicator in hemodialysis patients with diabetes mellitus: Variables that influence[J]. Saudi J Kidney Dis Transpl, 2013, 24(2): 260-273.
[7] Shen Y, Pu LJ, Lu L, et al. Glycated albumin is superior to hemoglobin A1c for evaluating the presence and severity of coronary artery disease in type 2 diabetic patients[J]. Cardiology, 2012, 123(2): 84-90.
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(收稿日期:2014-01-07)endprint