中华流行病学杂志  2015, Vol. 36 Issue (9): 958-961   PDF    
http://dx.doi.org/10.3760/cma.j.issn.0254-6450.2015.09.011
中华医学会主办。
0

文章信息

曹意, 王澄, 师雯琦, 朱影影, 陈耿东, 陈裕明.
Cao Yi, Wang Cheng, Shi Wenqi, Zhu Yingying, Chen Gengdong, Chen Yuming.
广州市中老年人非酒精性脂肪肝患病率及代谢相关因素分析
Prevalence and metabolic risk factors of nonalcoholic fatty liver disease in a middle-aged and elderly population in Guangzhou
中华流行病学杂志, 2015, 36(9): 958-961
Chinese Journal of Epidemiology, 2015, 36(9): 958-961
http://dx.doi.org/10.3760/cma.j.issn.0254-6450.2015.09.011

文章历史

投稿日期: 2015-01-30
广州市中老年人非酒精性脂肪肝患病率及代谢相关因素分析
曹意1,2, 王澄1, 师雯琦1, 朱影影1, 陈耿东1, 陈裕明1     
1. 510080 广州, 中山大学公共卫生学院医学统计与流行病学系;
2. 广州中山大学第一附属医院病案管理科
摘要: 目的 探讨非酒精性脂肪性肝病(NAFLD)在中老年人群中的患病情况及其代谢相关因素。方法 采用横断面调查的方法,通过问卷调查和实验室检测对2 935名广州市中老年人进行资料收集、整理。探讨NAFLD在中老年人群中的患病情况,并采用协方差和logistic回归分析代谢因素与NAFLD患病情况之间的关系。NAFLD的诊断标准采用中华医学会肝脏病学分会脂肪肝和酒精性肝病学组的影像学诊断标准,并且按照其严重程度分为轻、中、重三个等级。结果 广州市中老年人群中NAFLD的患病率为50.6%。NAFLD患者组中WC、BMI、FPG、TG、SBP、DBP以及MS患病率均明显高于对照组,而体力活动水平和HDL-C明显降低(P< 0.001)。logistic回归分析显示,WC、SBP、DBP、TG、FPG和HDL-C每升高一个标准差其对应NAFLD患病的OR值(95%CI)分别为2.70(2.45~2.98)、1.47(1.35~1.59)、1.48(1.37~1.60)、1.88(1.66~2.12)、1.25(1.15~1.36)和0.51(0.47~0.56)。随着NAFLD严重程度不断增加,WC、BMI、TG、SBP、DBP和FPG水平均呈现上升趋势,而HDL-C呈现减少的趋势(P< 0.001)。结论 中老年人NAFLD患病率较高,MS及相关组分与NAFLD关系密切,其中WC增加对NAFLD患病影响最大。
关键词: 非酒精性脂肪性肝病     患病率     代谢相关因素    
Prevalence and metabolic risk factors of nonalcoholic fatty liver disease in a middle-aged and elderly population in Guangzhou
Cao Yi1,2, Wang Cheng1, Shi Wenqi1, Zhu Yingying1, Chen Gengdong1, Chen Yuming1     
1. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China;
2. Department of Medical Records Statistics, the First Affiliated Hospital of Sun Yat-sen University
Abstract: Objective To investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and understand the relationship between NAFLD and metabolic risk factors in middle-aged and elderly adults. Methods This cross-sectional study recruited 2 935 subjects in Guangzhou,Guangdong province. Face-to-face interviews and laboratory analyses were conducted to collect general information and other covariates. Analysis of covariance and logistic regression analysis were performed to investigate the relationship between metabolic factors and the prevalence of NAFLD. NAFLD was diagnosed based on standard criteria recommend by the Fatty Liver Disease and Alcoholic Liver Disease Branch of Chinese Hepatology Society,and the degree of steatosis was assessed (mild,moderate or severe). Results Compared with normal subjects,those with NAFLD had higher levels of WC,BMI,FPG,TG,SBP,DBP and greater prevalence of metabolic syndrome,but lower levels of physical activity and HDL-C. After adjusted for covariates,the OR for each standard deviation change was 2.70(95%CI:2.45-2.98) for WC,1.47(95%CI:1.35-1.59) for SBP,1.48(95%CI:1.37-1.60) for DBP,1.88(95%CI:1.66-2.12) for TG,1.25(95%CI:1.15-1.36) for FPG and 0.51(95%CI:0.47-0.56) for HDL-C (all P< 0.001). Higher levels of WC,BMI,TG,SBP,DBP and FPG were significantly related with the increase in degree of NAFLD (P-trend< 0.001). Conclusion There is a relatively high prevalence of NAFLD in middle-aged and elderly adults in China. NAFLD is closely related with the different forms of metabolic syndrome,and WC is the leading risk factor for NAFLD.
Key words: Nonalcoholic fatty liver disease     Prevalence     Metabolic factor    

非酒精性脂肪性肝病(NAFLD)是常见慢性肝病[1, 2]。代谢相关因素尤其是胰岛素抵抗、肥胖以及糖尿病在NAFLD的发病机制中起着重要的作用[3, 4]。国内针对中老年人群的NAFLD患病情况与代谢相关因素关系的研究较少。本研究旨在分析广州市中老年人群NAFLD患病率,探究代谢相关因素与NAFLD患病及其严重程度分级的关系。

对象与方法

1.研究对象:基于一项探索环境因素和基因对心血管事件和骨质疏松症影响队列研究的一次横断面调查[5],该研究在2011年4月至2013年1月共调查3 336名符合条件的中老年人,排除不符合条件者后共纳入2 935人进行研究。本研究对这部分人群进行横断面调查。

2.研究方法:采用面对面方式通过问卷调查收集研究对象基本人口学资料(年龄、性别、家庭收入等)和生活行为因素(吸烟、饮酒和体力活动情况等),按照统一标准测定受试者身高、体重和WC,计算BMI。测定血压时,要求研究对象静息5 min之后重复测定,两次重复测定的误差>4 mmHg (1 mmHg=0.133 kPa)时,需进行第三次测定,取测量均数纳入分析。在受试者空腹12 h后,采集静脉血。血样经分离和分装后送中山大学附属第一医院测定血中TG、HDL-C和FPG水平。

3.MS定义:参照文献[6],腹型肥胖定义为男性WC ≥ 90 cm、女性WC ≥ 80 cm或BMI ≥ 25 kg/m2;高TG血症定义为血中TG ≥ 1.7 mmol/L;HDL-C减少定义为男性血清HDL-C<1.03 mmol/L、女性血清HDL-C<1.29 mmol/L;血压(mmHg)升高定义为SBP/DBP ≥ 130/85或者既往诊断患有高血压;血糖升高定义为FPG ≥ 5.6 mmol/L或者既往诊断患有糖尿病。

4.NAFLD诊断:B超检查由固定的专业超声医师进行,采用深圳开立公司SSI-5500多普勒超声诊断仪,探头频率3.5 MHz。NAFLD诊断标准采用中华医学会肝脏病学分会脂肪肝和酒精性肝病学组的影像学诊断标准,按严重程度分为轻、中、重3个等级[1]

5.统计学分析:连续性变量采用x±s,分类变量采用频数(频率)进行描述。分别采用Student's t检验、χ2检验比较NAFLD患者和非患者之间均数、频率之间的差异。将WC、SBP、DBP、TG、HDL-C及FPG标准化,校正年龄、性别、吸烟、体力活动以及家庭收入情况后,采用logistic回归分析NAFLD发病相关的代谢因素,计算相应的回归系数、OR值及其95% CI。对于NAFLD的不同分级之间,采用协方差分析在校正了年龄、性别、吸烟、体力活动以及家庭收入情况的影响之后,观察代谢相关因素在NAFLD不同分级之间的组间差异和线性趋势。分析均采用SPSS 20.0软件进行,统计学检验水准α=0.05,采用双侧检验。

结果

1.基本情况:纳入2 935名研究对象,其中女性2 006名,男性929名。诊断出NAFLD患者1 486例(女性:49.6%,男性:52.9%)。NAFLD患者与非患者相比,其WC、BMI、FPG、血清TG、SBP、DBP均较高,体力活动水平和HDL-C较低,见表 1

表 1 NAFLD患者与非患者的基本情况

2.不同年龄人群NAFLD患病情况:男性和女性NAFLD患病率在50岁前随着年龄增加而升高,且男性患病率高于女性。50~55岁组NAFLD的患病率在女性中继续上升、男性中出现下降,二者在数值上逐渐接近。55岁之后NAFLD的患病率在男性和女性中相似,趋于稳定,见图 1

图 1 不同年龄人群 NAFLD患病率

3.代谢相关因素与NAFLD患病风险:多因素logistic回归分析显示,校正年龄、性别、吸烟、体力活动和家庭收入情况等因素后,总人群的WC、SBP、DBP、TG、FPG和HDL-C每升高一个标准差(s),其对应NAFLD患病的OR值(95% CI)分别为2.70(2.45~2.98)、1.47(1.35~1.59)、1.48(1.37~1.60)、1.88(1.66~2.12)、1.25(1.15~1.36)和0.51(0.47~0.56)。在各项代谢性因素中,WC改变与NAFLD患病关系最为密切。按性别分层后,结果无明显变化,见表 2。进一步采用协方差分析,在校正上述协变量之后观察代谢相关因素在不同严重程度NAFLD患者中的总体水平。结果显示,随着NAFLD严重程度不断增加,WC、糖尿病和高TG血症患病率、BMI、TG、SBP、DBP和FPG水平均呈上升趋势,而HDL-C的浓度呈减少趋势(线性趋势P<0.001),见表 3

表 2 代谢相关因素与 NAFLD logistic回归分析
表 3 脂肪肝不同分级下代谢相关因素水平
讨论

本研究显示,在广州市区中老年人群中,NAFLD患病风险与WC、BMI、血清TG、SBP、DBP和FPG水平呈正相关,与HDL-C水平呈负相关。随着NAFLD严重程度的增加,WC、BMI、血清TG、SBP、DBP和FPG水平均呈现上升趋势,而血清HDL-C浓度呈减少趋势。

NAFLD患病率因检测手段不同略有差异。目前,超声诊断因其无创性和费用少且灵敏度及特异度较好而常用于脂肪肝的筛查[7]。从世界范围内来看,NAFLD患病率同时也显示出人种的差异,一项来自美国的队列研究显示,经超声诊断的NAFLD患病率在总人群中为46%,其中拉丁裔最高(58.3%),其次是高加索人(44.4%)和非裔美国人(35.1%)[8]。与西方人群相比,亚洲人虽BMI较低但内脏脂肪含量较高[9],因而NAFLD在亚洲人群中同样易感。本研究显示,NAFLD在广州市中老年人群中的患病率为50.6%,且NAFLD患者大部分为轻度(79.2%),中度和重度较少,分别为17.2%和3.6%。这种现象与研究对象招募时,排除了现患糖尿病和心脑血管病患者有关;也可能是NAFLD在中国人群中流行时间较短,而其病程需要一段时间才进展为中重度。

NAFLD患病率的快速增长与社会经济水平发展,人们饮食习惯生活方式的改变密切相关[10]。国外研究显示,NAFLD与MS共同的致病机制为胰岛素抵抗,NAFLD也被认为是MS在肝脏中的表现[11]。既往研究显示,NAFLD与多元代谢紊乱密切相关,腹型肥胖、高血压及血脂和血糖代谢异常相关因素单独或者联合存在[12, 13, 14]。本研究显示,WC每增加一个s将会使中老年人群中NAFLD的患病风险增加1.7倍,在所有的代谢相关因素中作用最强。WC可以较好的指示向心性肥胖,反映内脏脂肪的含量,过多的内脏脂肪容易引起胰岛素抵抗,进而引起肝脏的脂肪积累,形成NAFLD[6]。日本的一项研究表明,人群中因向心性肥胖而引起的脂肪肝患病率增加的效应最为明显[15]。在国内,有研究对810例体检者的调查显示,向心性肥胖导致NAFLD患病风险增加2.65倍,高于由TG、血糖代谢紊乱和高血压而导致的NAFLD患病风险增加[16]。本研究还显示,伴随着NAFLD严重程度增加,各类代谢相关因素水平也进一步升高,而HDL-C的水平进一步下降。提示NAFLD可以加剧代谢紊乱,NAFLD与MS之间可能互为因果,存在恶性循环[17]

本研究存在局限性。首先,本研究为横断面研究,不能确定因果关系。其次,超声诊断NAFLD与肝组织活检相比虽然有较好的灵敏度和特异度,但是其对于NAFLD组织形态学的分型能力较差[7]。此外,研究对象的招募采用社区宣传方式而非完全随机,样本代表性不好,影响结果外延。

[本研究得到中山大学"临床医学研究5010计划"(2007032)资助,感谢本组其他工作人员在资料收集方面作出的贡献]

参考文献
[1] Fatty Liver and Alcoholic Liver Disease Study Group of the Chinese Liver Disease Association. Guidelines for diagnosis and treatment of nonalcoholic fatty liver diseases[J]. Chin J Hepatol, 2006, 14 (3):161-163.(in Chinese)中华医学会肝脏病学分会脂肪肝和酒精性肝病学组.非酒精性脂肪性肝病诊疗指南[J].中华肝脏病杂志, 2006, 14(3):161-163.
[2] Bellentani S, Scaglioni F, Marino M, et al. Epidemiology of nonalcoholic fatty liver disease[J]. Dig Dis, 2010, 28 (1):155-161.
[3] Angulo P. Nonalcoholic fatty liver disease[J]. N Engl J Med, 2002, 346 (16):1221-1231.
[4] Li ZZ, Xue J, Chen P, et al. Prevalence of nonalcoholic fatty liver disease in mainland of China:a meta-analysis of published studies[J]. J Gastroenterol Hepatol, 2014, 29 (1):42-51.
[5] Li ZX, Li XR, Zhang Y, et al. Erythrocyte membrane fatty acid composition is related to overloaded plasma ferritin in Chinese males with angiographic coronary artery disease[J]. Food Funct, 2013, 4 (10):1535-1542.
[6] Fan JG,Saibara T, Chitturi S, et al. What are the risk factors and settings for non-alcoholic fatty liver disease in Asia-Pacific?[J]. J Gastroenterol Hepatol, 2007, 22 (6):794-800.
[7] Schwenzer NF,Springer F,Schraml C,et al. Non-invasive assessment and quantification of liver steatosis by ultrasound, computed tomography and magnetic resonance[J]. J Hepatol, 2009, 51 (3):433-445.
[8] Williams CD, Stengel J, Asike MI, et al. Prevalence of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis among a largely middle-aged population utilizing ultrasound and liver biopsy:a prospective study[J]. Gastroenterology, 2011, 140 (1):124-131.
[9] Lyon CJ, Law RE, Hsueh WA. Minireview:adiposity, inflammation, and atherogenesis[J]. Endocrinology, 2003, 144 (6):2195-2200.
[10] Popkin BM, Horton S, Kim S, et al. Trends in diet,nutritional status, and diet-related noncommunicable diseases in China and India:the economic costs of the nutrition transition[J]. Nutr Rev, 2001, 59 (12):379-390.
[11] Levene AP,Goldin RD. The epidemiology,pathogenesis and histopathology of fatty liver disease[J]. Histopathology, 2012, 61 (2):141-152.
[12] Chen YY,Fan ZP,Mao YM, et al. Study of the prevalence and correlation between non-alcoholic fatty liver disease and metabolic syndrome[J]. Chin Hepatol, 2008, 13(6):456-458. (in Chinese)陈一奕,范竹萍,茅益民,等.非酒精性脂肪性肝病与代谢综合征的流行现状及相关性研究[J].肝脏, 2008, 13 (6):456-458.
[13] Liu HX, Liu Y, Leng S. Correlation between non-alcoholic fatty liver disease and metabolic syndrome[J]. Chin J Diabet, 2011, 19 (7):535-538.(in Chinese)刘海霞,刘颖,冷松.非酒精性脂肪性肝病与代谢综合征的相关性研究[J].中国糖尿病杂志, 2011, 19 (7):535-538.
[14] Guan XH, Fan BH, Li SG. Relationship between nonalcoholic fatty liver disease and metabolic syndrome in adults[J]. Chin J Public Health, 2009, 25 (7):829-830.(in Chinese)观晓辉,范碧惠,李韶光.成人非酒精性脂肪性肝病与代谢综合征关系[J].中国公共卫生, 2009, 25 (7):829-830.
[15] Hsieh SD, Yoshinaga H, Muto T, et al. Health risks among Japanese men with moderate body mass index[J]. Int J Obes, 2000, 24 (3):358-362.
[16] Lin MX, Li ZK, Luo MQ, et al. Association between nonalcoholic fatty liver disease and metabolic syndrome[J]. Chin J Pathophysiol, 2010, 26 (12):2465-2466.(in Chinese)林妙霞,李泽楷,罗敏琪,等.非酒精性脂肪性肝病与代谢综合征的关系研究[J].中国病理生理杂志, 2010, 26(12):2465- 2466.
[17] Angulo P. GI Epidemiology:nonalcoholic fatty liver disease[J]. Aliment Pharmacol Ther, 2007, 25 (8):883-889.