Page 79 - 南京医科大学自然版

第46卷第5期 周 洁，乔瑞洁，章忆惠，等. 糖尿病胰岛素抵抗分级与基于磁共振IDEAL⁃IQ技术的肾皮质脂肪浸润分
2026年5月 数的定量关联及肾小管损伤的中介作用［J］. 南京医科大学学报（自然科学版），2026，46（5）：700-707·701 ·

Nanjing University，Nanjing 210023；Departnent of Radiology，the Affiliated Kizilsu Kirghiz Autonomous Prefecture
4
People’s Hospital of Nanjing Medical University，Artux 845350，China

［Abstract］ Objective：To quantitatively evaluate the degree of renal cortical fat infiltration in patients with type 2 diabetes mellitus
（T2DM）using magnetic resonance iterative decomposition of water and fat with echo asymmetry and least⁃squares estimation⁃iron
quantification（IDEAL⁃IQ）technology，analyze its quantitative correlation with different grades of insulin resistance（IR），and explore
the mediating effect of renal tubular injury between them. Methods：A total of 124 patients diagnosed with T2DM from July 2022 to
October 2025 were prospectively enrolled. According to the homeostasis model assessment of insulin resistance（HOMA ⁃ IR），the
patients were divided into the mild IR group（HOMA⁃IR 2.5⁃5.0，n=42），moderate IR group（HOMA⁃IR 5.1~10.0，n=40）and severe IR
group（HOMA⁃IR>10.0，n=42）. All subjects underwent renal 3.0T MRI⁃IDEAL⁃IQ examination to quantitatively measure the renal
cortical fat fraction（FF）. Glycometabolic indicators including fasting plasma glucose（FPG）and glycosylated hemoglobin（HbA1c），
renal function indicators including serum creatinine（Scr）and estimated glomerular filtration rate（eGFR），and renal tubular injury
markers including urine neutrophil gelatinase⁃associated lipocalin（NGAL），kidney injury molecule⁃1（KIM⁃1）and urine albumin/
creatinine ratio（UACR）were detected，and HOMA ⁃ IR was calculated. The differences in renal cortical FF，renal tubular injury
markers and renal function indicators among different IR grade groups were compared. Pearson correlation analysis was used to explore
the correlation between renal cortical FF and various indicators. Multiple linear regression analysis was performed to verify the
independent effect of IR on renal cortical FF. Mediation effect analysis was adopted to investigate the mediating role of renal tubular
injury between IR and renal cortical fat infiltration. Results：With the aggravation of IR grading，renal cortical FF，NGAL，KIM⁃1，
UACR and Scr in patients showed a gradual increasing trend，while eGFR showed a gradual decreasing trend，with statistically
significant differences among all grade groups（P < 0.05）. Pearson correlation analysis revealed that renal cortical FF was highly
positively correlated with HOMA⁃IR，KIM⁃1，UACR，and the comprehensive score of renal tubular injury（r=0.834，P < 0.001；r=0.810，
P < 0.001；r=0.834，P < 0.001；r=0.831，P < 0.001），moderately positively correlated with NGAL，Scr，and BUN（r=0.673 ⁃ 0.772，all
P < 0.001），and highly negatively correlated with eGFR（r=-0.817，P < 0.001）. Multiple linear regression analysis indicated that after
adjusting for age，gender，body mass index（BMI），and HbA1c，HOMA⁃IR was still an independent risk factor for the increase of renal
cortical FF in T2DM patients（β=0.682，P < 0.001）. Mediation effect analysis showed that renal tubular injury（comprehensive score of
NGAL+KIM⁃1+UACR）had a partial mediation effect between IR and cortical fat infiltration，accounting for 45.98% of the total effect.
Conclusion：The degree of renal cortical fat infiltration in T2DM patients has a significant dose⁃effect relationship with IR grade. IR
directly promotes renal cortical fat deposition，and also indirectly mediates the occurrence and development of renal cortical fat
infiltration by inducing renal tubular injury. Renal cortical FF quantitatively detected by IDEAL⁃IQ technology can be used as a non⁃
invasive imaging indicator to reflect the degree of IR and early renal tubular injury in T2DM patients，providing a new perspective for
the early assessment of diabetic renal complications.
［Key words］ type 2 diabetes mellitus；insulin resistance；renal cortical fat infiltration；IDEAL⁃IQ；renal tubular injury；mediation
effect
［J Nanjing Med Univ，2026，46（05）：700⁃707］

2 型糖尿病（type 2 diabetes mellitus，T2DM）是 还可通过激活氧化应激、炎症反应、脂质代谢异常
［6］
全球高发的慢性代谢性疾病，糖尿病肾病（diabetic 等途径，介导肾脏微血管及肾小管间质损伤 。近
kidney disease，DKD）作为其严重的微血管并发症之 年研究发现，脂肪代谢紊乱导致的肾实质脂肪异常
一，是终末期肾病的首要病因，严重威胁患者生命 沉积是 DKD 早期重要病理特征，与肾间质纤维化、
［1］
健康 。目前临床对 DKD 的诊断多依赖尿白蛋白/ 肾小球硬化密切相关，但 IR 与肾皮质脂肪浸润的
肌酐比值（urine albumin⁃to⁃creatinine ratio，UACR） 定量关联及二者相互作用的病理机制尚未明确，

及估算肾小球滤过率（estimated glomerular filtration 尤其是肾小管损伤在其中的介导作用仍缺乏系统
rate，eGFR），但此类指标在疾病早期缺乏特异性，且 研究。
一旦出现明显白蛋白尿，肾实质损伤已进入不可逆阶 磁共振最小二乘法估计和不对称回波迭代分
段 ［2-5］ 。胰岛素抵抗（insulin resistance，IR）是T2DM的 解水和脂肪的脂肪成像（iterative decomposition of
核心病理生理机制，不仅参与糖代谢紊乱的发生， water and fat with echo asymmetry and least squares