脂质运载蛋白2和老年2型糖尿病患者骨密度和骨转换标志物的相关性研究

The association of serum lipocalin 2 with bone mineral density and bone turnover marker in elderly patients with type 2 diabetes mellitus

目的探讨脂质运载蛋白2(lipocalin 2,LCN2)对老年2型糖尿病(type 2 diabetes mellitus,T2DM)患者骨代谢的影响。方法研究对象共119例,其中84例为老年T2DM患者,35例为非T2DM对照。采取静脉血检测空腹血糖(fasting plasma glucose,FPG)、糖化血红蛋白(glycosylated hemoglobin,Hb Alc)、25-羟维生素D[25(OH)D]、I型胶原交联羧基末端肽(collagen type 1 cross-linked C-telopeptide,CTX)、Ⅰ型前胶原氨基端延长肽(type 1 N-terminal procollagen,P1NP)、全段甲状旁腺素以及肌酐、血钙(Ca)、血磷(P)等指标,用ELISA法检测血清LCN2。用双能X线骨密度仪检测股骨颈和腰椎1~4(L1~4)的骨密度(bone mineral density,BMD)。结果老年T2DM患者血清LCN2水平高于非T2DM对照组(197.13±42.15 ng/m L vs172.29±54.71 ng/m L,P=0.01)。按照血清LCN2水平三分位数将T2DM患者分为3组。其中腰椎BMD、股骨颈BMD、P1NP和CTX伴随LCN2水平增高而增高,而FPG和Hb A1c伴随LCN2水平增高而降低(所有趋势P<0.05)。Pearson相关性分析显示,LCN2和T2DM患者BMD呈正相关(股骨颈:r=0.350,P=0.001;腰椎:r=0.355,P=0.001),和骨转换标志物呈正相关(P1NP:r=0.354,P=0.001;CTX:r=0.438,P<0.001),和糖代谢指标呈负相关(FPG:r=-0.321,P=0.003;Hb A1c:r=-0.342,P=0.002)。进一步回归分析显示,LCN2是T2DM患者腰椎BMD的影响因素(P<0.05)。结论血清LCN2水平和老年T2DM患者骨代谢相关,LCN2水平增高可能有助于BMD的增加。

Objective This study was aimed to explore the relationship between lipocalin 2 （LCN2） and bone mineral density （BMD） as well as bone turnover marker （BTM） in elderly patients with type 2 diabetes mellitus （T2DM）.Methods A total of 119 subjects were included in this study, including 84 elderly patients with T2DM and 35 non-T2DM subjects as control.The BMDs of the lumbar spine 1 -4 and femoral neck were measured using dual energy X-ray absorptiometry.Venous blood samples were collected and serum 25-hydroxyvitamin D（25-OH-D）, fasting plasma glucose （FPG）, type 1 N-terminal procollagen （P1NP）, collagen type 1 cross-linked C-telopeptide （CTX） and other biochemical parameters were assayed.Results Serum LCN2 levels were significantly higher in T2DM subjects than those without T2DM （197.13 ±42.15 ng/mL vs.172.29 ±54.71 ng/mL, P=0.01）.The subjects were divided into three groups according to tertiles of serum LCN2 level.With the increase in LCN2 levels, both BMDs and BTMs increased significantly （all P〈0.05）.LCN2 positively correlated to BMDs （femoral neck： r=0.350, P=0.001; lumbar spine： r=0.355, P=0.001）, and BTMs （P1NP, r=0.354, P=0.001; CTX, r=0.438, P〈0.001）, and negatively correlated to the indexes of glucose metabolism （FPG, r=-0.321; P=0.003; HbA1c, r=-0.342, P=0.002）. Regression analysis showed that LCN2 was a predictor for lumbar spine BMD （P〈0.05）.Conclusion LCN2 was related to bone metabolism in elderly patients with T2DM and increased LCN2 may confribute to BMD.