Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
J Gastroenterol. 2010 Jun;45(6):666-72. doi: 10.1007/s00535-009-0198-4. Epub 2010 Jan 19.
Despite the increase in nonalcoholic fatty liver disease (NAFLD) in Japanese adults, its prevalence in adolescents remains unclear. This prompted us to evaluate the incidence and clinical characteristics of NAFLD among junior high school students.
A population-based cross-sectional study was conducted among students in a single junior high school in Nagano prefecture. Serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (gammaGT) measurements and abdominal ultrasonography were performed in 249 and 288 students in 2004 and 2007, respectively. In the latter survey, student lifestyle habits were also assessed, using questionnaires.
The prevalence of NAFLD was 4.4% and 4.5% in 2004 and 2007, respectively, which was lower than that of obesity (10.0% and 5.9%). Body mass index and ALT and gammaGT levels increased significantly with hepatic steatosis severity. Multivariate logistic regression analysis demonstrated that the presence of obesity and an ALT level of 30 U/L or more were independent predictors of NAFLD (odds ratio 16.9, P<0.001 and odds ratio 16.6, P=0.001, respectively). The ratios of students commuting to and from school by car and not doing sports outside of school were higher in NAFLD students compared with non-NAFLD ones. Such tendencies were observed independently of the presence of obesity. Additionally, one obese student with severe steatosis and liver dysfunction was diagnosed as having nonalcoholic steatohepatitis (NASH).
Approximately 4% of junior high school students had NAFLD that was primarily associated with obesity and reduced daily physical activity. Serum ALT measurement during school check-ups is recommended for the early detection of young adolescent NAFLD/NASH.
尽管日本成年人中非酒精性脂肪性肝病（NAFLD）的发病率有所增加，但青少年中的流行情况尚不清楚。这促使我们评估初中生中 NAFLD 的发病率和临床特征。
在长野县的一所初中进行了一项基于人群的横断面研究。在 2004 年和 2007 年，分别对 249 名和 288 名学生进行了血清丙氨酸氨基转移酶（ALT）和γ-谷氨酰转移酶（γGT）测量和腹部超声检查。在后一项调查中，还使用问卷评估了学生的生活方式习惯。
2004 年和 2007 年，NAFLD 的患病率分别为 4.4%和 4.5%，低于肥胖症（10.0%和 5.9%）。体重指数、ALT 和γGT 水平随着肝脂肪变性严重程度的增加而显著升高。多变量逻辑回归分析表明，肥胖和 ALT 水平为 30 U/L 或更高是 NAFLD 的独立预测因素（比值比 16.9，P<0.001 和比值比 16.6，P=0.001）。与非 NAFLD 学生相比，NAFLD 学生上下学乘坐汽车和不进行校外体育活动的比例较高。这些趋势独立于肥胖的存在。此外，一名肥胖且肝脂肪变性和肝功能障碍严重的学生被诊断为非酒精性脂肪性肝炎（NASH）。
大约 4%的初中生患有 NAFLD，主要与肥胖和日常体力活动减少有关。建议在校内体检期间测量血清 ALT，以早期发现青少年 NAFLD/NASH。
