The relationship between visceral obesity and hepatic steatosis measured by controlled attenuation parameter

BackgroundNonalcoholic fatty liver disease (NAFLD) is closely related with obesity. However, obese subjects, generally represented by high BMI, do not always develop NAFLD. A number of possible causes of NAFLD have been studied, but the exact mechanism has not yet been elucidated.MethodsA total of 304 consecutive subjects who underwent general health examinations including abdominal ultrasonography, transient elastography and abdominal fat computed tomography were prospectively enrolled. Significant steatosis was diagnosed by ultrasonography and controlled attenuation parameter (CAP) assessed by transient elastography.ResultsVisceral fat area (VFA) was significantly related to hepatic steatosis assessed by CAP, whereas body mass index (BMI) was related to CAP only in univariate analysis. In multiple logistic regression analysis, VFA (odds ratio [OR], 1.010; 95% confidence interval [CI], 1.001–1.019; P = 0.028) and triglycerides (TG) (OR, 1.006; 95% CI, 1.001–1.011; P = 0.022) were independent risk factors for significant hepatic steatosis. The risk of significant hepatic steatosis was higher in patients with higher VFA: the OR was 4.838 (PP200 cm2, compared to patients with a VFA ≤100 cm2.ConclusionsOur data demonstrated that VFA and TG is significantly related to hepatic steatosis assessed by CAP not BMI. This finding suggests that surveillance for subjects with NAFLD should incorporate an indicator of visceral obesity, and not simply rely on BMI.研究背景：非酒精性脂肪性肝病（Nonalcoholic fatty liver disease, NAFLD）与肥胖密切相关。然而，以高体质量指数（body mass index, BMI）为代表的肥胖人群并非均会罹患非酒精性脂肪性肝病。目前已针对非酒精性脂肪性肝病的多种潜在致病因素开展了研究，但其确切发病机制尚未阐明。 研究方法：本研究前瞻性纳入了304名接受常规健康体检的连续受试者，所有受试者均接受了腹部超声（abdominal ultrasonography）、瞬时弹性成像（transient elastography）以及腹部脂肪计算机断层扫描检查。通过腹部超声及瞬时弹性成像检测的受控衰减参数（controlled attenuation parameter, CAP）诊断为显著肝脏脂肪变。 研究结果：内脏脂肪面积（visceral fat area, VFA）与通过受控衰减参数评估的肝脏脂肪变显著相关，而体质量指数仅在单变量分析中与受控衰减参数存在相关性。多因素logistic回归分析显示，内脏脂肪面积（比值比（odds ratio, OR）, 1.010; 95%置信区间（confidence interval, CI）, 1.001–1.019; P = 0.028）与甘油三酯（triglycerides, TG）（OR, 1.006; 95%CI, 1.001–1.011; P = 0.022）是显著肝脏脂肪变的独立危险因素。内脏脂肪面积更高的受试者罹患显著肝脏脂肪变的风险更高：与内脏脂肪面积≤100 cm²的受试者相比，内脏脂肪面积≥200 cm²者的OR值为4.838。 研究结论：本研究数据表明，通过受控衰减参数评估的肝脏脂肪变与内脏脂肪面积及甘油三酯显著相关，而与体质量指数无关。该研究结果提示，针对非酒精性脂肪性肝病高危人群的监测应纳入内脏肥胖相关指标，而非单纯依赖体质量指数。