A cross-sectional study of alcohol consumption and alcoholic liver disease in Beijing: based on 74,998 community residents | BMC Public Health

Subjects and sampling

Our work was part of an epidemiological study of the liver health of community residents in Beijing. It was based on two-stage stratified cluster sampling carried out in 16 districts and 331 townships between 2017 and 2020. First, 11 out of 16 districts were randomly sampled. Then, 2 townships from each district were randomly sampled. All residents of the sampled townships were required to participate in the survey. Each participant was asked to sign an informed consent agreement before the survey. All participants were asked to answer a questionnaire, undergo a physical examination and a blood sample. Each subject was then confirmed to ensure that the questionnaire, blood sample and physical examination were completed at the survey site. If an item was not completed, it was completed immediately. Inclusion criteria were: (1) adults, aged 25 years and older; (2) residents who lived in Beijing for more than 6 months and had medical insurance. Exclusion criteria were: (1) residents younger than 25; (2) residents with pacemakers; (3) pregnant women; (4) residents with a large amount of ascites; (5) residents with an unhealed wound on the right upper abdomen required by the Fibrotouch test.

The sample size is estimated at:

$${displaystyle begin{array}{c}N=frac{1.96^2times Ptimes left(1-Pright)}{sigma^2}times Deff {} Deff =1+left(M-1right)times ICC {} ICC=frac{K^2times P}{1-P}end{array}}$$

1.96 is the bilateral Zα value where α is 0.05. P is the expected true proportion of ALD in Beijing, which is 5% for men and 3% for women [15]. σ is the relative precision, which is fixed at 0.02. K is the coefficient of variation between clusters, which is fixed at 0.6. ICC is the intraclass correlation coefficient which is estimated at 0.019 in men and 0.011 in women. M is the cluster size (number of individuals targeted), and it is approximately constant from cluster to cluster. M’s estimate is 5,000 inhabitants in each township. The deff corresponds to the design effect which is estimated at 95.7 for men and 56.6 for women. Given the need to draw blood, the responder rate is estimated at 80%. The sample size for males is estimated at 54,582. The sample size for females is estimated at 19,794. The total sample size is estimated at 74,376.

Questionnaire and physical examination

All interviewers were trained prior to the questionnaire and physical examination. Once the participants signed the informed consent, a face-to-face questionnaire began. The questionnaire included: (1) demographic variables, including age, gender, region, education, occupation, nationality, marital and living status, and annual household income. (2) Assessment of alcohol consumption, including detailed questions on consumption of alcoholic beverages, types of alcoholic beverages consumed, amount of alcohol consumed at each shot, duration of consumption, etc. (3) Medical history included previous diagnosis of chronic liver disease and other chronic illnesses. The physical examination included the following: (1) height, weight, waist circumference, hip circumference, and blood pressure. (2) Fibrotouch test using the FibroTouch FT100 (WuXi Hisky Medical Technologies Co.Ltd), a new technology that indirectly assesses the degree of liver fibrosis, similar to FibroScan. A successful measurement of liver fibrosis requires three conditions: (1) at least 10 valid measurements (2) a success rate of 60% or more (3) an interquartile/median range of less than 33%. Those whose Fibrotouch DBM was ≥ 240 db/m were diagnosed with fatty liver disease. Those whose Fibrotouch LSM was ≥ 12.96 Kpa were diagnosed with liver fibrosis.

Blood collection and evaluation

A 10ml blood sample was taken from each participant to examine liver function, routine blood, HBsAg, anti-HBsAg, anti-HBc and anti-HCV. Anti-HCV positive participants were then tested for HCV RNA. All liver function tests (ALT, AST, GGT) were performed on the Hitachi 7600–110 automatic analyzer (Hitachi High-Technologies, Tokyo, Japan), using reagents from Wako (Pure Chemical Industry, Japan) . Routine blood tests were analyzed with Cell-DYN Ruby (Abbott Laboratories, Diagnostic Division, Abbott Park, IL, USA) within 2 h of collection. HBV serological markers were tested by Architect i2000 (Chemiluminescence MicroparticleImunoassay, Abbott, Chicago, USA). Serological markers of HCV were first tested using the colloidal gold method (YingkeXinChuang, China), and then the confirmation of anti-HCV positive samples was confirmed by an enzyme immune test (ARCHITECT Anti- HCV; Abbott Laboratories, USA). Anti-HCV positive samples were tested for HCV RNA using the Abbott Real Time HCV (Abbott Laboratories), carrying a sensitivity of 15 IU/ml for viral load determination.

Assessment of alcohol consumption

Participants who consumed alcoholic beverages in the past 12 months were classified as current drinkers. Current drinkers have been subdivided into non-weekly and weekly drinkers. Current drinkers who consumed alcohol occasionally (less than once a week) were classified as non-weekly drinkers. Current drinkers who drank alcohol at least once a week were classified as weekly drinkers. Those who never drank alcohol were classified as lifelong abstainers. Those who ever drank alcohol but did not drink in the past 12 months were classified as former drinkers. The above alcohol consumption categories were consistent with the WHO Global Status Report on Alcohol and Health 2018 [3]and WHO guidelines for monitoring alcohol consumption [20].

Current drinkers who drank weekly in the past 12 months were further asked about beverage types (beer, grape wine, rice wine, light spirits

Diagnostic criteria

The diagnosis of ALD was confirmed according to the Guidelines for the Prevention and Treatment of Alcoholic Liver Disease: A 2018 Updated Version by the National Workshop on Fatty Liver Disease and Alcoholic Liver Disease, China Society of Hepatology, Chinese Medical Association and Fatty Liver Disease Expert Committee, and Chinese Medicine Physicians Association [21]. The diagnosis of ALD met all of the following criteria: (1) men consuming more than 40 g of ethanol per day or women consuming more than 20 g of ethanol per day; (2) those who have consumed alcohol for more than 5 years; (3) [(ALT> 40 U/L or AST > 40 U/L) and AST/ALT> 2] or GGT > 55 U/L or MCV > 96 fl; (4) people with fatty liver disease (Fibrotouch DBM ≥ 240 db/m) or liver fibrosis (Fibrotouch LSM ≥ 12.96 Kpa); (5) persons infected with HBV or HCV were excluded (positive for HBsAg or HCV RNA).

statistical analyzes

Epidata (3.1) was used to establish databases. All participant information was entered separately by two groups from Beijing XunChiFeiLong Data Technology Co.Ltd. Data verification was performed independently by two investigators from the same company. Data were analyzed using SPSS statistical analysis package (SPSS Inc., Chicago IL, version 19.0). Differences in categorical variables were tested using the χ2 or Fisher’s exact test. Continuous variables, with a normal distribution, are presented as means ± standard deviation (SD), and differences were tested by Student’s t-test or Anova test. A p– value P– the value of the univariate analysis was p– value