楊曉瑜 楊伍灸
[摘要] 目的 探討2型糖尿病老年患者血清維生素D水平與代謝的相關性。方法 將全部149例2型糖尿病患者按照血清25-(OH)-D含量及肥胖程度分組,對比分析各組糖脂代謝指標及炎癥因子。結果 25-(OH)-D缺乏組BMI、HbA1c、C-RP及HOMA-IR含量顯著高于不足組,而25-(OH)-D及HDL-C含量顯著低于不足組(P<0.05或P<0.01)。肥胖組25-(OH)-D水平與BMI、WC、FPG等指標呈負相關,與HOMA-β及HDL-C呈正相關;而非肥胖組的25-(OH)-D水平與WC、FPG、HbA1c等指標呈負相關,與BMI、FINS、HOMA-β等呈正相關。HbA1c與C-RP是與缺乏25-(OH)-D密切相關的獨立危險因素(P均<0.05)。 結論 2型糖尿病老年患者發(fā)生25-(OH)-D含量低下較普遍,25-(OH)-D水平低下與多種代謝障礙相關。
[關鍵詞] 2型糖尿??;維生素D;糖脂代謝;炎癥因子
[中圖分類號] R587.1 [文獻標識碼] A [文章編號] 1673-9701(2014)20-0005-04
維生素D為脂溶性維生素,在結構上屬于類固醇的衍生物。血清25羥維生素D3 [25-hydroxyvitamin D3, 25-(OH)-D3]是維生素D的主要活性形式,在調(diào)節(jié)機體鈣磷代謝方面發(fā)揮重要作用[1-3]。有文獻[4]報道顯示,維生素D缺乏與2型糖尿病密切相關。本文采取橫斷面研究方法評價2型糖尿病老年患者血清維生素D的缺乏狀況,旨在觀察維生素D缺乏與糖脂代謝指標及炎癥因子的相關性。
1 資料與方法
1.1 一般資料
選擇我院2011年8月~2013年8月間收治的149例2型糖尿病患者,所有患者均滿足1999年世界衛(wèi)生組織(WHO)對糖尿病的臨床診斷標準,其中男65例,女84例,平均年齡為(66.01±8.71)歲。對全部患者血清中25羥維生素D [25-(OH)-D]含量進行測定,按照患者血清25-(OH)-D含量分成三組:25-(OH)-D<25 nmol/L為缺乏組,共79例;25 nmol/L≤25-(OH)-D≤74 nmol/L為不足組,共62例;25-(OH)-D>74 nmol/L為足夠組,共8例。按照肥胖程度(BMI)將全部患者分成兩組:BMI≥25 kg/m2者為肥胖組,共83例;BMI<25 kg/m2者為非肥胖組,共66例。兩組在性別、年齡方面比較差異不具有統(tǒng)計學意義。全部患者均經(jīng)門診治療后入院,納入研究前使用磺脲類促泌劑單藥實施治療,低密度膽固醇(LDL-C)水平均在2.6 mmol/L以上,患者均常規(guī)給予他汀類藥物,均無維生素D類藥物及鈣劑服用史。將肝、腎功能異常者、高滲性昏迷者、糖尿病酮癥或DKA者以及存在骨代謝異常病史者予以排除。全部患者均自愿簽訂知情同意書,本研究經(jīng)醫(yī)院倫理委員會審批通過。
1.2 研究方法
患者入院后對其身高、體重進行準確測定并計算身體質量指數(shù)(Body Mass Index,BMI)、腰圍(WC)。入院次日晨抽取靜脈血,測定空腹血糖(FPG)、高脂血癥(TG)、總膽固醇(TC)、低密度脂蛋白膽固醇(LDL-C)、高密度脂蛋白膽固醇(HDL-C)、糖化血紅蛋白(HbA1c)、空腹胰島素(FINS)、C-反應蛋白(C-RP)及25-(OH)-D。采用德國西門子公司制造的全自動生化儀對血糖及血脂進行測定;采用美國安捷倫1200高效液相色譜儀測定HbA1c;采用美國貝克曼庫爾特化學發(fā)光免疫分析儀測定FINS;采用美國貝克曼IMMAGE特定蛋白儀測定C-RP;采用意大利BIOBASE2000全自動酶聯(lián)免疫分析儀通過酶聯(lián)免疫吸附法(ELISA)測定25-(OH)-D。通過穩(wěn)態(tài)模式對胰島素抵抗指數(shù)(HOMA-IR)進行評估,公式為:HOMA-IR=FPG×FINS/22.5;通過穩(wěn)態(tài)模式對胰島β細胞分泌功能(HOMA-β)進行評估,公式為:HOMA-β=20×FINS/(FPG-3.5)[5]。
1.3 觀察指標
觀察缺乏組、不足組患者及肥胖組與非肥胖組糖脂代謝指標及炎癥因子結果,分析2型糖尿病患者25-(OH)-D水平同各指標的相關性。
1.4統(tǒng)計學分析
應用SPSS 17.5統(tǒng)計學軟件進行數(shù)據(jù)處理。計量資料用(x±s)形式表示,兩組間比較進行t檢驗或t檢驗,計量數(shù)據(jù)其是否服從正態(tài)分布分別采用單因素方差分析及非參數(shù)檢驗。并采取Pearson相關分析及Logistic回歸分析,將所得偏態(tài)分布資料轉換為對數(shù)數(shù)據(jù)后再進行統(tǒng)計學分析。
2 結果
2.1 缺乏組與不足組患者糖脂代謝指標及炎癥因子對比結果
缺乏組與不足組在性別及年齡方面相比差異不具有統(tǒng)計學意義。兩組間WC、TC、TG、FPG、FINS、HDL-C、HOMA-β水平相比差異無統(tǒng)計學意義(P>0.05)。但缺乏組BMI、HbA1c、C-RP及HOMA-IR含量顯著高于不足組,而25-(OH)-D及HDL-C含量顯著低于不足組,差異均具有統(tǒng)計學意義(P<0.05或P<0.01)。見表1。
2.2 肥胖組與非肥胖組糖脂代謝指標及炎癥因子對比分析
肥胖組受試者的25-(OH)-D含量顯著低于非肥胖組(P<0.05),但肥胖組的BMI、WC、HOMA-IR以及FINS水平均顯著高于非肥胖組(P<0.01或P<0.05)。見表2。
2.3 2型糖尿病患者25-(OH)-D水平同其他各指標的相關性
將25-(OH)-D作為因變量,其他各指標作為自變量,采取Pearson相關性分析顯示,肥胖組25-(OH)-D水平與BMI、WC、FPG等指標呈負相關,與HOMA-β及HDL-C呈正相關;非肥胖組25-(OH)-D水平與WC、FPG、HbA1c等指標呈負相關,而與BMI、FINS、HOMA-β等呈正相關。見表3。endprint
表3 2型糖尿病患者25-(OH)-D水平同其他各指標的相關性[r(P)]
2.4 25-(OH)-D水平與其他各指標的Logistic回歸分析
將25-(OH)-D水平作為因變量,將性別、年齡、BMI及WC等作為自變量,采取多因素Logistic回歸分析后顯示,與缺乏25-(OH)-D密切相關的獨立危險因素為HbA1c與C-RP(P均<0.05)。見表4。
表4 25-(OH)-D水平與其他各指標的Logistic回歸分析
3 討論
維生素D屬于脂溶性維生素,可通過食物獲取,主要通過皮膚中的7脫氫膽固醇(7-dehydrocholesterol)在290~315 nm波長的紫外線照射下進行合成[6]。由外界吸收或自身合成的維生素D,在肝臟組織內(nèi)可轉化為25-(OH)-D3,在腎臟組織中羥化為維生素D的活性形式1,25-(OH)-D3[7]?;钚跃S生素D與細胞內(nèi)的維生素D受體發(fā)生特異性結合而發(fā)揮其生物效應[10]。由于25-(OH)-D3在血液中有較高的含量,且半衰期較長,一般3周左右,而1,25-(OH)-D3的半衰期在5h左右,因此25-(OH)-D3更加穩(wěn)定,所以近年來臨床上大多采用測定血液中25-(OH)-D3含量來評估機體維生素D的含量[8]。老年人群的維生素D缺乏現(xiàn)象十分普遍,且與多種慢性疾病的高發(fā)病風險密切相關[9,10]。中國人飲食中富含維生素D的食物匱乏,而且加上戶外活動以及曬太陽的機會不多等因素均使維生素D缺乏的風險加大。本文結果顯示,僅5.4%(8/149)的老年2型糖尿病患者的25-(OH)-D含量處于正常范圍內(nèi),與國內(nèi)文獻報道的我國老年人群的大規(guī)模流行病學研究結果相符[11]。國外文獻[12]報道顯示,糖尿病患者維生素D含量顯著低于非糖尿病患者,血清維生素D含量與2型糖尿病發(fā)病密切相關,與維生素D含量低的人群相比,血清維生素D含量高的人群患2型糖尿病的風險下降。本文結果未研究非糖尿病的健康老年人群樣本,未對比正常健康人群及糖尿病患者人群維生素D含量的差異。但本文結果顯示,在2型糖尿病老年患者中,25-(OH)-D缺乏與血糖控制、肥胖、IR以及患者的炎癥狀態(tài)關系密切,HbA1c與C-RP均是與缺乏25-(OH)-D密切相關的獨立危險因素(P均<0.05),這一結果表明在我國2型糖尿病老年患者中,維生素D發(fā)揮著關鍵作用。胰島β細胞功能異常及胰島素抵抗是2型糖尿病發(fā)病的關鍵環(huán)節(jié),而維生素D對胰島β細胞的功能及外周器官產(chǎn)生的胰島素均有作用[13]。文獻報道[14]顯示,給成人隱匿性自身免疫糖尿病患者提供α-D3能夠提高C肽水平,表明維生素D可增強胰島β細胞的分泌作用。國外文獻[15-17]報道顯示,維生素D缺乏與胰島素水平下降有關,但維生素D水平與糖尿病的確切關系尚需大量的高質量研究予以證實。本文結果顯示,25-(OH)-D在肥胖與非肥胖2型糖尿病患者中的意義是不同的。在非肥胖2型糖尿病患者中,未見25-(OH)-D與胰島素抵抗或分泌有關;但在肥胖糖尿病患者中,25-(OH)-D水平下降與FPG、胰島β細胞分泌功能以及外周胰島素抵抗密切相關。
總之,25-(OH)-D含量降低在我國2型糖尿病老年患者中非常普遍,維生素D可通過多種途徑參與2型糖尿病的病理生理反應,與患者的BMI、糖脂代謝、胰島β細胞功能以及胰島素抵抗等關密切相關。因此,我們認為改善維生素D缺乏將使2型糖尿病患者受益,但該結論仍需更大樣本的深入研究加以支持。
[參考文獻]
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[9] Kane L,Moore K,Lütjohann D,et al. Vitamin D3 effects on lipids differ in statin and non-statin-treated humans: Superiority of free 25-OH-D levels in detecting relationships[J]. J Clin Endocrinol Metab,2013,98(11):4400-4409.
[10] Kim TH,Lee B,Kwon E,et al. Regulation of TREM-1 expression by 1,25-dihydroxyvitamin D3 in human mo nocytes/macrophages[J]. Immunol Lett,2013,154(1-2):80-85.
[11] Lu L,Pan A,Lin X,et al. Plasma 25-hydroxyvitamin D concentration and metabolic syndrome among middle-aged and elderly Chinese[J].Diabetes Care,2009,32(2):1278-1283.
[12] Eraslan S,Kizilgul M,Uzunlulu M,et al. Frequency of metabolic syndrome and 25-hydroxyvitamin D3 levels in patients with non-alcoholic fatty liver disease[J]. Minerva Med,2013,104(4):447-453.
[13] Lehmann U,Hirche F,Stangl GI,et al. Bioavailability of vitamin d2 and d3 in healthy volunteers,a randomized placebo-controlled trial[J]. J Clin Endocrinol Metab,2013, 98(11):4339-4345.
[14] Nakayama J,Imafuku S,Mori T,et al. Narrowband ultraviolet B irradiation increases the serum level of vitamin D3 in patients with neurofibromatosis 1[J]. J Dermatol,2013,40(10):829-831.
[15] Shab-Bidar S,Bours SP,Geusens PP,et al. Suboptimal effect of different vitamin D3 supplementations and doses adapted to baseline serum 25-(OH)-D on achieved 25-(OH)-D levels in patients with a recent fracture: A prospective observational study[J]. Eur J Endocrinol,2013, 169(5):597-604.
[16] Nurbazlin M,Chee WS,Rokiah P,et al. Effects of sun exposure on 25(OH)vitamin D concentration in urban and rural women in Malaysia[J]. Asia Pac J Clin Nutr,2013,22(3):391-399.
[17] Chow EC,Durk MR,Maeng HJ,et al. Comparative effects of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on transporters and enzymes in fxr(+/+)and fxr(-/-)mice[J]. Biopharm Drug Dispos,2013,34(7):402-416.
(收稿日期:2013-11-25)endprint
[6] Moghtaderi A,Tamadon GH,Haghighi F. 25-hydroxyvitamin D3 concentration in serum and cerebrospinal Fluid of patients with remitting-relapse multiple sclerosis[J]. Prague Med Rep,2013,114(3):162-171.
[7] Agarwal N,Mithal A,Dhingra V,et al. Effect of two different doses of oral cholecalciferol supplementation on serum 25-hydroxy-vitamin D levels in healthy Indian postmenopausal women: A randomized controlled trial[J]. Indian J Endocrinol Metab,2013,17(5):883-889.
[8] Piccolo BD,Dolnikowski G,Seyoum E,et al. Association between subcutaneous white adipose tissue and serum 25-hydroxyvitamin D in overweight and obese adults[J]. Nutrients,2013,5(9):3352-3366.
[9] Kane L,Moore K,Lütjohann D,et al. Vitamin D3 effects on lipids differ in statin and non-statin-treated humans: Superiority of free 25-OH-D levels in detecting relationships[J]. J Clin Endocrinol Metab,2013,98(11):4400-4409.
[10] Kim TH,Lee B,Kwon E,et al. Regulation of TREM-1 expression by 1,25-dihydroxyvitamin D3 in human mo nocytes/macrophages[J]. Immunol Lett,2013,154(1-2):80-85.
[11] Lu L,Pan A,Lin X,et al. Plasma 25-hydroxyvitamin D concentration and metabolic syndrome among middle-aged and elderly Chinese[J].Diabetes Care,2009,32(2):1278-1283.
[12] Eraslan S,Kizilgul M,Uzunlulu M,et al. Frequency of metabolic syndrome and 25-hydroxyvitamin D3 levels in patients with non-alcoholic fatty liver disease[J]. Minerva Med,2013,104(4):447-453.
[13] Lehmann U,Hirche F,Stangl GI,et al. Bioavailability of vitamin d2 and d3 in healthy volunteers,a randomized placebo-controlled trial[J]. J Clin Endocrinol Metab,2013, 98(11):4339-4345.
[14] Nakayama J,Imafuku S,Mori T,et al. Narrowband ultraviolet B irradiation increases the serum level of vitamin D3 in patients with neurofibromatosis 1[J]. J Dermatol,2013,40(10):829-831.
[15] Shab-Bidar S,Bours SP,Geusens PP,et al. Suboptimal effect of different vitamin D3 supplementations and doses adapted to baseline serum 25-(OH)-D on achieved 25-(OH)-D levels in patients with a recent fracture: A prospective observational study[J]. Eur J Endocrinol,2013, 169(5):597-604.
[16] Nurbazlin M,Chee WS,Rokiah P,et al. Effects of sun exposure on 25(OH)vitamin D concentration in urban and rural women in Malaysia[J]. Asia Pac J Clin Nutr,2013,22(3):391-399.
[17] Chow EC,Durk MR,Maeng HJ,et al. Comparative effects of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on transporters and enzymes in fxr(+/+)and fxr(-/-)mice[J]. Biopharm Drug Dispos,2013,34(7):402-416.
(收稿日期:2013-11-25)endprint
[6] Moghtaderi A,Tamadon GH,Haghighi F. 25-hydroxyvitamin D3 concentration in serum and cerebrospinal Fluid of patients with remitting-relapse multiple sclerosis[J]. Prague Med Rep,2013,114(3):162-171.
[7] Agarwal N,Mithal A,Dhingra V,et al. Effect of two different doses of oral cholecalciferol supplementation on serum 25-hydroxy-vitamin D levels in healthy Indian postmenopausal women: A randomized controlled trial[J]. Indian J Endocrinol Metab,2013,17(5):883-889.
[8] Piccolo BD,Dolnikowski G,Seyoum E,et al. Association between subcutaneous white adipose tissue and serum 25-hydroxyvitamin D in overweight and obese adults[J]. Nutrients,2013,5(9):3352-3366.
[9] Kane L,Moore K,Lütjohann D,et al. Vitamin D3 effects on lipids differ in statin and non-statin-treated humans: Superiority of free 25-OH-D levels in detecting relationships[J]. J Clin Endocrinol Metab,2013,98(11):4400-4409.
[10] Kim TH,Lee B,Kwon E,et al. Regulation of TREM-1 expression by 1,25-dihydroxyvitamin D3 in human mo nocytes/macrophages[J]. Immunol Lett,2013,154(1-2):80-85.
[11] Lu L,Pan A,Lin X,et al. Plasma 25-hydroxyvitamin D concentration and metabolic syndrome among middle-aged and elderly Chinese[J].Diabetes Care,2009,32(2):1278-1283.
[12] Eraslan S,Kizilgul M,Uzunlulu M,et al. Frequency of metabolic syndrome and 25-hydroxyvitamin D3 levels in patients with non-alcoholic fatty liver disease[J]. Minerva Med,2013,104(4):447-453.
[13] Lehmann U,Hirche F,Stangl GI,et al. Bioavailability of vitamin d2 and d3 in healthy volunteers,a randomized placebo-controlled trial[J]. J Clin Endocrinol Metab,2013, 98(11):4339-4345.
[14] Nakayama J,Imafuku S,Mori T,et al. Narrowband ultraviolet B irradiation increases the serum level of vitamin D3 in patients with neurofibromatosis 1[J]. J Dermatol,2013,40(10):829-831.
[15] Shab-Bidar S,Bours SP,Geusens PP,et al. Suboptimal effect of different vitamin D3 supplementations and doses adapted to baseline serum 25-(OH)-D on achieved 25-(OH)-D levels in patients with a recent fracture: A prospective observational study[J]. Eur J Endocrinol,2013, 169(5):597-604.
[16] Nurbazlin M,Chee WS,Rokiah P,et al. Effects of sun exposure on 25(OH)vitamin D concentration in urban and rural women in Malaysia[J]. Asia Pac J Clin Nutr,2013,22(3):391-399.
[17] Chow EC,Durk MR,Maeng HJ,et al. Comparative effects of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on transporters and enzymes in fxr(+/+)and fxr(-/-)mice[J]. Biopharm Drug Dispos,2013,34(7):402-416.
(收稿日期:2013-11-25)endprint