初诊2型糖尿病患者血清25-羟维生素D3水平与胰岛β细胞功能和胰岛素抵抗的相关性

Association of serum 25-hydroxyvitamin D3 with islet β cell function and insulin resistance in new onset type 2 diabetics

目的 评估初诊2型糖尿病患者低维生素D血症发生率,探讨血清25-羟维生素D3与胰岛β细胞功能和胰岛素抵抗的关系.方法 入选2008年4至7月在四川省人民医院就诊的初诊2型糖尿病患者97例（糖尿病组）,其中男57例,女40例,年龄（52±10）岁.以同期健康体检者69名为对照组,其中男40名,女29名,年龄（50±11）岁.采用高压液相色谱法测定2组参试者空腹血清25-羟维生素D3水平.根据25-羟维生素D3是否＜37.5 nmol/L将糖尿病组分为低25-羟维生素D3亚组（n=61）和非低25-羟维生素D3亚组（n=36）,比较糖化血红蛋白、稳态模型胰岛素抵抗指数、胰岛β细胞功能指数、早期相胰岛素分泌指数、葡萄糖曲线下面积、胰岛素曲线下面积.采用多元逐步回归分析评价血清25-羟维生素D3与性别、年龄、体质指数、腰臀比、血压、血脂、糖化血红蛋白、胰岛素抵抗及胰岛β细胞功能的相关性.结果 糖尿病组血清25-羟维生素D3水平显著低于对照组[（36±19）nmol/L vs（80±26）nmol/L,t=-13.00,P＜0.01].糖尿病组低25-羟维生素D3的发生率为62.9%（61/97）.与非低25-羟维生素D3亚组比较,低25-羟维生素D3亚组糖化血红蛋白、葡萄糖曲线下面积较高[（10.1±3.0）% vs （7.7±2.6）%,（32±7）h·mmol-1·L-1 vs （25±7）h·mmol-1·L-1,t值分别为4.44、4.45,均P＜0.01],胰岛β细胞功能指数、早期相胰岛素分泌指数、胰岛素曲线下面积较低[21±16 vs 75±64,1.9±1.9 vs 8.3±7.7,（30±21）h·mU-1·L-1vs（104±80）h·mU-1·L-1,t值分别为-5.68、-6.81、-7.69,均P＜0.01].多元逐步回归分析显示,2型糖尿病患者早期相胰岛素分泌指数、胰岛素曲线下面积与25-羟维生素D3独立正相关（t值分别为2.21、4.67,均P＜0.01）.结论部分初诊2型糖尿病患者存在25-羟维生素D3缺乏,缺乏程度与血糖升高程度有关;25-羟维生素D3缺乏与早期相胰岛素分泌和总体胰岛素分泌下降有关.

Objective To study the change of vitamin D in newly diagnosed type 2 diabetes mellitus （T2DM）, and to explore the relationship between the level of serum vitamin D and islet β cell dysfunction as well as insulin resistance.Methods Fasting serum 25-hydroxyvitamin D3 （ 25-（ OH ） D3 ） concentration was measured by high pressure liquid chromatography （HPLC） in 97 newly diagnosed T2DM patients （men 57, women 40, aged （52 ± 10）years） and 69 healthy controls （men 40, women 29, aged （50 ± 11） years）.Oral-glucose-tolerance test was performed, and area under the curve of glucose （ AUCG）, area under the curve of insulin （AUCI）, early-phase insulin secretion index （△I30/△G30）, β cell function index （ HOMA-B）, insulin resistance index （HOMA-IR） were compared between T2DM with low 25-（ OH ） D3 （ （ 25-（ OH ） D3 〈 37.5 nmol/L, n = 61 ） and those without （ n = 36）.The correlation of serum 25-（OH） D3 with sex, age, body mass index （BMI）, waist-hip rate （WHR）, blood pressure, lipids, HbA1c, insulin resistance and β cell function was analysed by using Pearson correlation and multiple stepwise regression analysis.Results The level of serum 25-（OH） D3 was much lower in T2DM patients than in controls （ （36 ± 19） nmol/L vs （ 80 ± 26 ） nmoL/L, t = - 13.00, P 〈 0.01 ）.The prevelence of hypovitaminosis 25-（OH） D3 in T2DM was 62.9% （61/97）.Among T2DM, when compared with those without hypovitaminosis 25-（OH） D3, patients with hypovitaminosis 25-（OH） D3 showed higher HbA1 c and AUCG were 4.44 or 4.45, both P 〈 0.01 ）, although HOMA-B, △I30/△G30, and AUCI were significantly lower values were -5.68, -6.81, and -7.69; all P 〈0.01 ）.In multiple stepwise regression analysis, △I30/△G30 and AUCI had independent positive correlation with 25-（OH）D3（t values were 2.21 and 4.67, all P 〈0.01 ）.Conclusion 25-（ OH ）D3 is lower in newly diagnosed T2DM, and associated with severity of blood glucose disorders.The shortage of vitamin D in T2DM may be correlated with decreased early-phase insulin secretion and whole insulin secretion.