a Division of Weight Management and Wellness, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, USA.
b Graduate School of Physical Education, Kyung Hee University, Yongin-si Gyeonggi-do, 446701, Republic of Korea.
Appl Physiol Nutr Metab. 2017 Aug;42(8):829-833. doi: 10.1139/apnm-2016-0410. Epub 2017 Mar 23.
We examined whether waist circumference (WC) is associated with liver fat in black and white adolescents. Liver fat was measured using a 3T proton magnetic resonance spectroscopy (H-MRS) in 152 overweight/obese adolescents (94 black and 58 white, body mass index (BMI) ≥85th percentile, aged 12-18 years) without liver diseases or diabetes. WC was measured at the last rib. Total and visceral adipose tissue (VAT) were measured by dual-energy X-ray absorptiometry and magnetic resonance imaging, respectively. The proportion of fatty liver (defined as liver fat ≥5.0% by H-MRS) was lower (P < 0.01) in black adolescents (5.3%) compared with their white peers (24.1%). Despite similar age, BMI, WC, and total adiposity (%), black adolescents had lower (P < 0.01) VAT (59.0% vs. 81.3 cm), liver fat (1.6% vs. 3.5%), and alanine aminotransferase (17.2 vs. 22.0 IU/L) compared with their white peers. Independent of race, WC was associated with liver fat (black, r = 0.43; white, r = 0.64) in a similar magnitude to the association between VAT and liver fat (black, r = 0.44; white, r = 0.51) and these findings remained significant after controlling for age, sex, Tanner stage, and total adiposity. In blacks, WC and sex (male) were independent (P < 0.01) predictors of liver fat, explaining 17.1% and 5.6% of the variance, respectively, while in whites WC was the single best predictor, explaining 40.8% of the variance in liver fat. These findings suggest that enlarged WC is a marker of increased liver fat in overweight/obese white and black adolescents.
我们研究了腰围（WC）与黑人和白人青少年肝脏脂肪之间的关系。在 152 名超重/肥胖青少年（94 名黑人，58 名白人，BMI≥第 85 百分位，年龄 12-18 岁）中，使用 3T 质子磁共振波谱（H-MRS）测量肝脏脂肪，这些青少年没有肝脏疾病或糖尿病。WC 在最后一根肋骨处测量。通过双能 X 射线吸收法和磁共振成像分别测量总脂肪和内脏脂肪组织（VAT）。通过 H-MRS 定义的脂肪肝比例（定义为肝脏脂肪≥5.0%）黑人青少年（5.3%）低于白人同龄人（24.1%）（P<0.01）。尽管年龄、BMI、WC 和总脂肪量（%）相似，黑人青少年的 VAT（59.0%比 81.3cm）、肝脏脂肪（1.6%比 3.5%）和丙氨酸氨基转移酶（17.2 比 22.0IU/L）均较低（P<0.01）与白人同龄人相比。与 VAT 与肝脏脂肪之间的关联相似（黑人 r=0.44；白人 r=0.51），独立于种族，WC 与肝脏脂肪之间存在关联（黑人 r=0.43；白人 r=0.64），并且这些关联在控制年龄、性别、Tanner 阶段和总脂肪量后仍然显著。在黑人中，WC 和性别（男性）是肝脏脂肪的独立（P<0.01）预测因子，分别解释 17.1%和 5.6%的方差，而在白人中，WC 是唯一最好的预测因子，解释 40.8%的肝脏脂肪方差。这些发现表明，在超重/肥胖的黑人和白人青少年中，增大的 WC 是肝脏脂肪增加的标志物。
