【摘要】 目的：探讨代谢综合征(MS)的非酒精性脂肪肝病(non-alcoholic fatty liver disease， NAFLD)和血管性勃起功能障碍(Erectile dysfunction， ED)的危险因素。方法：从2008～2009年北方城市健康体检人群中随机整群抽样资料完整者18 096例为研究对象，并分析探讨NAFLD和ED的危险因素。结果：本次研究对象为18 096例，年龄18～76岁，平均(46.8±10.1)岁。男 10 096例(55.79%)，女 8 000例(44.21%)。MS知晓率为8.33%;成年健康体检者MS的患病率为21.18%。MS最常见的成分依次是高尿酸血症(27%， 4838/18096)、肥胖和超重(21%)、高血压(20%)和血脂异常(17%)。MS各亚组的人体质量指数(BMI， kg/m2)和腰臀比(WHR)从高到低分别依次为ED[(28.9±1.1)、(1.26±0.03)]、超重或肥胖[(27.5±2.3)、(1.31±0.03)]、糖尿病前期[(26.8±2.6)、(1.03±0.03)]和高血压[(26.1±1.3)、(0.90±0.04)]。MS伴发NAFLD 3721例，患病率为20.56%;以MS伴发的NAFLD为因变量， Logistic回归分析显示： ALT升高、腰围、年龄、DM家族史、LDL-C、BMI(依次β=1.004～0.479，P=0.000～0.016)等为NAFLD的危险因素，体育锻炼和职业性体力劳动为其保护因素。ED106例，患病率为1.04%; Logistic回归分析显示： 年龄、腰围、LDL-C、DM家族史、BMI(依次β=0.681～0.238，P=0.000～0.018)等为ED的危险因素，文化程度、体育锻炼和职业性体力劳动为其保护因素。结论：MS合并的NAFLD和ED的危险因素与MS关系密切， 针对 MS危险因素的矫正是预防和治疗NAFLD，ED的新途径。
Abstract：Objective：To study risk factors for non-alcoholic fatty liver disease (NAFLD) and vascular erectile dysfunction (ED) in patients with metabolic syndrome (MS). Methods：A total of 18 096 subjects were selected from people undergoing physical examination from 2008 to 2009 in northern cities of China by random cluster sampling method， and analyzed the risk factors for NAFLD and ED.Results： The 18 096 cases with age 18～76 (46.8±10.1) years old，containng 10 096 (55.79%) males and 8 000 (44.21%) females. Awareness rate of MS was 8.33% and prevalence rate of MS in healthy adults was 21.18%. Most common components of MS were hyperuricemia (27%)， obesity and overweight (21%)， hypertension (20%) and dyslipidemia (17%) in turn. Body mass index (BMI， kg/m2) and waist/hip ratio (WHR) of all MS subgroups from high to low were ED group [(28.9±1.1)， (1.26±0.03)]， overweight or obesity group [(27.5±2.3)， (1.31±0.03)]， prediabetes group [(26.8±2.6)， (1.03±0.03)] and hypertension group [(26.1±1.3)， (0.90±0.04)] in turn. A total of 3 721 MS patients (20.56%)complicated with NAFLD; By means of NAFLD complicated by MS as dependent variable， Logistic regression analysis indicated that increased ALT， waist circumference(WC)， age， DM family history， LDL-C and BMI (β=1.004～0.479， P=0.000～0.016 in turn) were risk factors for NAFLD， and physical exercise and occupational physical work were protective factors for NAFLD. There were 106 ED males and its prevalence rate was 1.04%; Logistic regression analysis indicated that age， WC， LDL-C， DM family history and BMI (β=0.681～0.238， P=0.000～0.018 in turn) were risk factors for ED， and educational degree， physical exercise and occupational physical work were protective factors for ED.Conclusion：Risk factors for NAFLD and ED in MS were closely correlated with MS. It's a new path to prevent and treat NAFLD and ED through correcting risk factors of MS.
Key words： Metabolic syndrome; Fatty liver; Impotence
Metabolic syndrome (MS) can be regard as a large independent syndrome related with considerable diseases， such as non-alcoholic fatty liver disease， (NAFLD) and vascular erectile dysfunction (ED). More and more studies proved that NAFLD and vascular ED are closely correlated with MS， even some authors thought that NAFLD and vascular ED were an aspect of MS and were included into clinical disease spectrum of MS [1-4]. The present study explores risk factors of NAFLD and vascular ED in MS patients， intending to provide new methods for their prevention and cure.
1 Subjects and methods
A total of 18 096 subjects were selected from 2008 to 2009 undergoing physical examination person in department of cadres medical work and physical examination center of the first affiliated hospital of China medical university by random cluster sampling method. The age was 18～76 years old， including 10 096 males with age (49.1±10.8) years old and 8 000 females with age (43.1±12.1) years old.
Cross-sectional study of prevalence rate of MS Questionnaire was designed by ourselves， including over 200 factors that may be related with MS. The survey was constituted of three parts： questionnaire survey， physical measurements and laboratory detections. (1) Questionnaire： unified directions of questionnaire were made. Investigators(10 postgraduates and undergraduates)underwent unified training， practice and examination，and took part in present study only after taking certificate. MP3 record was used in the whole process of questionnaire survey; (2) Quality control： Physical examination was unified and all instruments had been checked based on above questionnaire survey plan.
1.3 Diagnostic standards
MS was diagnosed according to diagnostic standard of MS formulated by international diabetes federation (IDF) and Chinese diabetes society (CDS) in 2004. Prediabetes： Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were diagnosed according to diagnostic standards formulated by American diabetes association (ADA) in 1997 and WHO in 1999. TFG and IGT together were called impaired glucose regulation (IGR) and it can also be called prediabetes. Type 2 diabetes was diagnosed according to Chinese guidelines for prevention and treatment of type 2 diabetes (2007). Hypertension was diagnosed according to Chinese guideline for prevention and treatment of hypertension (revised in 2005). Dyslipidemia was diagnosed according to Chinese guidelines for prevention and treatment of dyslipidemia in adults (2007); obesity was diagnosed according to Chinese guidelines for prevention and control of overweight and obesity in adults (trial) revised in 2003. Smoking was diagnosed according to Chinese guidelines for clinical smoking cessation (2008). Alcohol drinking was diagnosed according to Guidelines for diagnosis and treatment of alcoholic fatty liver formulated by liver disease branch of Chinese medical association in 2006.NAFLD was diagnosed according to diagnostic standard of fatty liver by type B ultrasonography in Guidelines for diagnosis and treatment of non-alcoholic fatty liver disease formulated by liver disease branch of Chinese medical association in 2006. ED was diagnosed according to International index of erectile function questionnaire (IIEF).
1.4 Statistical methods
SPSS 13.0 software was used to perform statistical analysis. Measurement data were presented as mean ± standard deviation (x-±s). U test was used to compare between two samples. Risk factors were analyzed using Logistic regression analysis; prevalence rates were standardized according to constitution of age and gender in whole China in 2000.
2.1 Awareness rate and prevalence rate of MS
Awareness rate of MS was 8.33%(318/3833). Prevalence rate of MS was 21.18% in adult， and there was significant difference between males and females (P<0.05); as age increased， prevalence rate of MS gradually increased， but it significantly decreased after 60 years old (P<0.01). Most common components of MS were hyperuricemia， obesity， hypertension and dyslipidemia. They were shown in table 1. Table 1 The prevalence rate of MS in a large sample of physical examination with different ages and sexes
2.2 BMI and WHR of MS group and its subgroups
There were significant difference in body mass index(BMI， kg/m2)and waist/hip ratio (WHR)between males and females and among all MS subgroups (P<0.01 all); as age increased， BMI and WHR gradually increased and significantly decreased after 60 years old in MS patients (P<0.01). BMI and WHR of all MS subgroups from high to low were ED group [(28.9±1.1)， (1.26±0.03)]， overweight or obesity group [(27.5±2.3)， (1.31±0.03)]， prediabetes group [(26.8±2.6)， (1.03±0.03)] and hypertension group [(26.1±1.3)， (0.90±0.04)] in turn， were shown in table 1.
2.3 MS and NAFLD
There were 3 721 MS patients complicated with NAFLD (20.56%,3721/18096). By means of NAFLD complicated by MS as dependent variable， Logistic regression analysis indicated that increased ALT， WC， age， DM family history， LDL-C and BMI (β=1.004～0.479， P=0.000～0.016 in turn) were risk factors for NAFLD， and physical exercise and occupational physical work were protective factors for NAFLD，were shown in table 2. Table 2 Single factor non-conditional Logistic regression analysis of MS complicated with NAFLD
2.4 MS and vascular ED
There were 106 MS patients complicated with vascular ED (1.04%,106/10096); Logistic regression analysis indicated that age， WC， LDL-C， DM family history and BMI (β=0.681～0.238， P=0.000～0.018 in turn) were risk factors for ED， and educational degree， physical exercise and occupational manual labor were protective factors for ED，were shown in table 3.
Incidence rate of MS had been sharply increase in recent 20 years. There was report indicated that prevalence rate of MS had reached 25% in the USA. Prevalence of MS in 35～74 years old adults reached 16.5% in China. Main clinical consequence of MS are cardiovascular diseases (including coronary heart disease and stroke) and type 2 DM. The west of Scotland coronary prevention study (WOSCOPS) and coronary artery risk development in young adults study (CARDIA) in America indicated that more components of MS complicated， higher incidence rate of coronary heart disease and type 2 DM have. Prevalence rate in present study was lower than that of Chen SJ etc ， may be related with age and large sample of population.Table 3 Single factor non-conditional Logistic regression analysis of MS complicated with ED
Incidence rate of NAFLD is high in patients with type 2 DM， common basis of them is IR. NAFLD is considered as the manifest of MS in liver. Though pathogenesis of NAFLD is not very clear， but many past studies and present study proved that NAFLD is closely correlated with abnormal glucose and lipid metabolism and other risk factors for cardiovascular diseases. In patients with central obesity， their abdominal fat mainly composed from large fat cells. Sensitivity to insulin of these fat cells significantly decreases， activity of lipolytic enzyme is high， velocity of lipoclasis is faster than fat cells of other sites， fatty acid can even directly enter liver via portal vein and increases free fatty acid in liver. When synthesis of fat in liver exceeds oxidation， utilization， and output of fat， they accumulate in liver and fatty liver is formed. Meanwhile， liver cells with cumulated fat produce resistance to insulin， leads to vicious cycle between IR and fatty liver. The present study indicated that increased ALT， WC， age， DM family history， LDL-C and BMI were risk factors for NAFLD， and physical exercise and occupational physical work were protective factors for NAFLD.
Recently， more and more studies indicated that MS was closely related with ED. Several surveys of large scale population from Europe indicated that nearly 70% ED was caused by the underlying causes， in which MS was a prominent problem. Survey about 28 000 males from eight countries by British investigators indicated that ED patients usually complicated with hypertension， coronary heart disease and hypercholesterolemia. Most ED males possessed one complication at least; the more severe ED was， the higher risk for IR， elevated blood glucose level and more serious MS were. The present study indicated that age， WC， LDL-C， DM family history and BMI were risk factors for ED， and educational degree， physical exercise and occupational physical work were protective factors for ED
In short， the present study suggested that NAFLD and ED complicated in MS were closely related with components of MS， providing a new way for prevention and treatment of NAFLD and ED.
陈思娇，张 浩，时景璞，等.沈阳市部分地区老年代谢综合征患病率横断面调查[J]. 中国医师杂志 2008,10(7)：991-992.