Radmard Amir Reza, Poustchi Hossein, Dadgostar Mehrdad, Yoonessi Ali, Kooraki Soheil, Jafari Elham, Hashemi Taheri Amir Pejman, Malekzadeh Reza, Merat Shahin
Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran; Digestive Tract Image Processing Research Group, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Liver and Pancreatobiliary Diseases Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Shariati Hospital, North Kargar Avenue, Tehran 14117-13135, Iran.
Acad Radiol. 2015 Jun;22(6):714-21. doi: 10.1016/j.acra.2015.01.011. Epub 2015 Mar 7.
Existing evidence suggests potential contribution of iron in pathogenesis of nonalcoholic fatty liver disease (NAFLD). We aimed to investigate whether hepatic iron content correlates with liver enzyme levels in NAFLD using a noninvasive magnetic resonance imaging (MRI) technique.
Subjects from Golestan Cohort Study were randomly selected. Diagnosis of NAFLD was made by combination of ultrasound and MRI. Subjects with NAFLD were divided into two groups with high (H-NAFLD) and low (L-NAFLD) enzyme level according to 95th percentile of alanine aminotransferase (ALT) value in normal population. Quantitative T2* maps of entire cross-sectional area of liver were calculated on pixel-by-pixel basis using a semiautomated software.
A total of 207 subjects were enrolled. Mean T2* values were significantly lower in NAFLD group than controls (P < .001) indicating higher iron content. Male subjects with H-NAFLD had statistically lower T2* values than those with L-NAFLD in multivariate analysis (odds ratio, 0.74; 95% confidence interval [CI], 0.58-0.95), whereas this was not observed in women. Unlike women, there was significant negative correlation between ALT levels and T2* values in men with H-NAFLD (r = -0.66, P = .01). Every 1-millisecond decrement in T2* value was associated with 6.37 IU/L increase in ALT level (95% CI, 1.8-10.9, P = .01) in men with H-NAFLD.
Higher hepatic iron in men with H-NAFLD, estimated by T2* mapping, may support the role of iron in possible progression of simple steatosis to nonalcoholic steatohepatitis. Lack of such correlation in women could be attributed to relatively lower iron storage or other mechanisms rather than iron.
现有证据表明铁在非酒精性脂肪性肝病（NAFLD）发病机制中具有潜在作用。我们旨在使用非侵入性磁共振成像（MRI）技术研究NAFLD患者肝脏铁含量与肝酶水平是否相关。
从戈勒斯坦队列研究中随机选取受试者。通过超声和MRI联合诊断NAFLD。根据正常人群丙氨酸氨基转移酶（ALT）值的第95百分位数，将NAFLD患者分为酶水平高（H-NAFLD）和低（L-NAFLD）两组。使用半自动软件逐像素计算肝脏整个横截面积的定量T2*图。
共纳入207名受试者。NAFLD组的平均T2值显著低于对照组（P <.001），表明铁含量更高。在多变量分析中，H-NAFLD男性受试者的T2值在统计学上低于L-NAFLD男性受试者（优势比，0.74；95%置信区间[CI]，0.58 - 0.95），而在女性中未观察到这种情况。与女性不同，H-NAFLD男性的ALT水平与T2值之间存在显著负相关（r = -0.66，P =.01）。在H-NAFLD男性中，T2值每降低1毫秒，ALT水平升高6.37 IU/L（95% CI，1.8 - 10.9，P =.01）。
通过T2*成像估计，H-NAFLD男性肝脏铁含量较高，这可能支持铁在单纯性脂肪变性向非酒精性脂肪性肝炎可能进展过程中的作用。女性缺乏这种相关性可能归因于铁储存相对较低或其他机制而非铁。
