Noninvasive assessment of hepatic lipid composition: Advancing understanding and management of fatty liver disorders
Noninvasive assessment of hepatic lipid composition: Advancing understanding and management of fatty liver disorders
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DOI：
10.1002/hep.22220
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发表时间：
2008-05-01
期刊：
影响因子：
13.5
通讯作者：
George, Jacob
中科院分区：
文献类型：
--
作者：
Johnson, Nathan A.;Walton, David W.;George, Jacob
非酒精性脂肪肝在肥胖个体中经常被观察到，然而预测其发展以及向肝脏疾病进展的因素却知之甚少。我们提出质子磁共振波谱（H - 1 - MRS）可能允许对肝脏脂质成分进行无创评估。通过H - 1 - MRS测量的脂质饱和度（SI）和多不饱和指数（PUI）与已知成分的油脂中预期的数值相符。然后在健康的瘦体型男性（LEAN）、肝脏甘油三酯浓度正常的肥胖男性（013）以及患有肝脂肪变性的肥胖男性（OB + HS）中测量肝脏甘油三酯浓度（HTGC）和成分。在瘦体型男性中，还比较了正常混合饮食（NM）和低碳水化合物、高饱和脂肪饮食（LCHF）67小时后饮食脂肪摄入的显著变化对肝脏脂质的影响。OB + HS组（0.970 ± 0.004）和OB组（0.944 ± 0.008）的SI显著高于LEAN组（0.818 ± 0.025）（两者P < 0.01）。OB + HS组（0.003 ± 0.001）和OB组（0.022 ± 0.005）的PUI显著低于LEAN组（0.120 ± 0.021）（P < 0.01），并且OB + HS组显著低于OB组（P < 0.05）。LCHF饮食没有改变HTGC、SI或PUI（P > 0.05）。H - 1 - MRS方法可对脂质成分进行快速的定性评估。该技术在肝脏中的应用所产生的结果与基于活检的方法一致，表明随着肥胖，肝脏脂质相对饱和度增加，多不饱和程度降低。与肥胖相关的肝脂肪变性的特征是肝脏多不饱和脂质进一步减少。结论：这种易于获取且无创的方法应促进对肝脏和全身脂质代谢之间相互作用的进一步研究，并有助于阐明以肝脏内脂质蓄积为特征的疾病的发病机制。
Nonalcoholic fatty liver is frequently observed in obese individuals, yet the factors that predict its development and progression to liver disease are poorly understood. We proposed that proton magnetic resonance spectroscopy (H-1-MRS) might allow noninvasive assessment of hepatic lipid composition. Lipid saturation (SI) and polyunsaturation (PUI) indices measured by H-1-MRS were in agreement with those expected in oils of known composition. Hepatic triglyceride concentration (HTGC) and composition were then measured in healthy lean (LEAN) men, obese men with normal HTGC (013), and obese men with hepatic steatosis (OB+HS). The effect of marked changes in dietary fat consumption on hepatic lipids were also compared in lean men after 67 hours of a normal mixed (NM) diet versus a low-carbohydrate, high-saturated-fat (LCHF) diet. SI was significantly higher in OB+HS (0.970 +/- 0.004) and OB (0.944 +/- 0.008) versus LEAN (0.818 +/- 0.025) (P < 0.01 for both). PUI was significantly lower in OB+HS (0.003 +/- 0.001) and OB (0.022 +/- 0.005) versus LEAN (0.120 +/- 0.021) (P < 0.01), and significantly lower in OB+HS versus OB (P < 0.05). LCHF diet did not alter HTGC, SI, or PUI (P > 0.05). The H-1-MRS method provides for rapid, qualitative assessment of lipid composition. Application of this technique in the liver produces results that are consistent with biopsy-based approaches demonstrating that relative hepatic lipid saturation increases and polyunsaturation decreases with obesity. Obesity-related hepatic steatosis is characterized by further depletion of polyunsaturated hepatic lipids. Conclusion: This readily available and noninvasive approach should promote further study into interactions between hepatic and whole-body lipid metabolism and help to elucidate the pathogenesis of disorders characterized by lipid accumulation within the liver.