Aim: To demonstrate the prevalence of sonographic fatty liver, overweight and ischemic heart disease (IHD) among the male workers in Taiwan, and to investigate the possible association of these three factors.
Methods: From July to September 2003, a total of 2 088 male aircraft-maintenance workers aged from 22 to 65 years (mean 40.5) underwent an annual health examination, including anthropometrical evaluation, blood pressure measurement, personal medical history assessment, biochemical blood analysis, abdominal ultrasonographic examination and digital electrocardiography (ECG). The Student's t-test, chi(2) test and multivariate logistic regression analysis were utilized to evaluate the relationship between IHD and salient risk factors.
Results: The all-over prevalence of overweight was 41.4%, and that of fatty liver was 29.5% (mild, moderate and severe fatty liver being 14.5%, 11.3%, and 3.7%, respectively); while the prevalence of ischemic changes on ECG was 17.1% in this study. The abnormal rates for conventional IHD risk factors including hypertension, dyslipidemia, hyperglycemia and overweight increased in accordance with the severity of fatty liver. Overweight and severity of fatty liver were independently associated with increased risks for developing IHD. Overweight subjects had a 1.32-fold (95%CI: 1.01-1.73) increased IHD risk. Participants with mild, moderate, and severe fatty liver had a 1.88-fold (95%CI: 1.37-2.6), 2.37-fold (95%CI: 1.66-3.37) and 2.76-fold (95%CI: 1.62-4.72) increased risk for developing IHD. The prevalence of ischemic ECG for the fatty liver-affected subjects with or without overweight was 30.1% and 19.1%, while that of overweight subjects free from fatty liver was 14.4%. Compared to the subjects without fatty liver nor overweight, IHD risk for the three subgroups above was as follows: OR: 2.95 (95%CI: 2.31-4.09), OR: 1.60 (95%CI: 1.07-2.39) and OR: 1.11 (95%CI: 0.78-1.56), respectively.
Conclusion: The presence of fatty liver and its severity should be carefully considered as independent risk factors for IHD. Results of the study suggest the synergistic effect between fatty liver and overweight for developing IHD. Abdominal sonographic examination may provide valuable information for IHD risk assessment in addition to limited report about liver status, especially for overweight males.