~1H MRS对初诊2型糖尿病患者胰腺脂肪沉积的量化及与胰岛β细胞功能的关系研究

~1H MRS quantification of ectopic fat accumulation in pancreas and its relationship with islet beta-cell function in patients with newly diagnosed type 2 diabetes mellitus

目的分析胰腺脂肪含量与肝脏脂肪含量、血清甘油三酯(TG)及胰岛β细胞功能的关系。材料与方法在3.0 T磁共振系统应用单体素点分辨波谱序列(PRESS)对58例初诊2型糖尿病患者和32名无糖尿病志愿者的胰腺和肝脏进行1H MRS扫描,应用SAGE软件测量其脂肪和水的峰下面积,计算胰腺和肝脏脂肪分数。分析胰腺脂肪含量与肝脏脂肪含量、身高体重指数(BMI)、TG、空腹血糖、空腹胰岛素(FINS)、稳态模型胰岛素分泌指数(HOMA-β)、胰岛素抵抗指数(HOMA-IR)以及李-Bennett胰岛β细胞功能指数(MBCI)的相关性。结果58例初诊2型糖尿病患者和32名无糖尿病志愿者的平均胰腺脂肪分数分别为(16.09±6.27)%和(14.56±7.97)%,差异无统计学差异(P>0.05)。其中,32例初诊2型糖尿病患者和全部无糖尿病志愿者成功测量肝脏脂肪分数,平均数值分别为(21.13±14.44)%和(12.43±12.19)%,差异有统计学差异(P=0.006)。相关性分析表明,初诊2型糖尿病患者的胰腺脂肪含量与肝脏脂肪含量、BMI、TG、空腹血糖、FINS、MBCI、HOMA-β及HOMA-IR均无明确相关性(r<0.15,P>0.05),而无糖尿病志愿者的胰腺脂肪含量与肝脏脂肪含量(r=0.502,P=0.003)、TG(r=0.467,P=0.007)及BMI(r=0.362,P=0.042)有中度至低度的相关性。结论初诊2型糖尿病患者的胰腺脂肪含量与肝脏脂肪含量、TG及胰岛β细胞功能不相关。

Objective： To in vivo quantify the pancreatic fat content in newly diagnosed type 2 diabetes mellitus （T2DM） by applying1H MRS, and investigate its relationships with liver fat content, serum triglyceride （TG） and islet beta-cell function. Materials and Methods： Fifty-eight T2DM subjects and thirty-two volunteers without T2DM were included in this study. All T2DM subjects were newly diagnosed according to the clinical criteria without any therapy. The pancreatic spectroscopy of at least one location （head, body, and tail） and liver spectroscopy at right lobe were acquired by single-voxel PRESS sequence on 3.0 T MR scanner. The pancreas fat content （PFC） and liver fat content （LFC） were calculated in each case.Spearman correlations between PFC and LFC, TG, the body mass index （BMI）, the fasting blood-glucose （FBG）, the fasting serum insulin （FINS）, the homeostasis model assessment of insulin resistance （HOMA-IR）, the homeostasis model assessment-β （HOMA-β）and the Lee-Bennett islet beta cell function index （MBCI） were performed in order to visualize their relationships.Results：The mean values of PFC in 58 T2DM subjects and 32 volunteers without T2DM were （16.09±6.27）% and （14.56±7.97）%, respectively, there is no statistically difference （P〉0.05）. The LFC in 32 T2DM subjects and all volunteers without T2DM was successfully measured, the mean values were （21.13±14.44）% and （12.43±12.19）%, respectively, there was statistically signiifcant differences （P=0.006）. Moderate to low correlations were found between PFC and LFC （r=0.502,P=0.003）, TG （r=0.467,P=0.007）, and BMI （r=0.362,P=0.042） in volunteers without T2DM, but no statistical correlation was found between PFC and LFC, TG, BMI, FBG, FINS, HOMA-IR, HOMA-β, and MBCI （r〈0.15,P〉0.05） in T2DM subjects.Conclusions：No correlation was found between PFC and LPF, TG, and islet beta-cell function in patients with newly diagnosed T2DM.