Prevalence and factors associated with nonalcoholic fatty liver disease in Shanghai work-units

Abstract

Backgrounds: Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in Asians. However, data on prevalence and factors associated with NAFLD in Asians are lacking. The aim of this study is to investigate the prevalence of NAFLD in Shanghai employees to assess the relationship between NAFLD and age, gender, metabolic risk factors in this studied population.

Methods: We selected 7152 employees of Shanghai work-units. Each of them underwent detailed medical history-taking, physical examination, laboratory assessments and abdominal ultrasonography. The diagnosis of NAFLD was done according to established criteria. Receiver operating characteristics (ROC) curves were applied to detect areas under the ROC curves for each index. Nominal logistic regression analysis was used to estimate the odds ratio for risk factors of NAFLD.

Results: About 38.17% employees had NAFLD, more in men than in women. The prevalence of NAFLD increased with increasing age. In both genders, the prevalence of metabolic factors was higher in the NAFLD group. Body max index, waist circumference, weight-to-height ratio, blood pressure, blood glucose, total cholesterol, triglyceride, low density lipoprotein, high density lipoprotein and uric acid were found to have a diagnostic value for NAFLD. Body max index is a better index for diagnosing NAFLD. Uric acid is a new diagnosing index not inferior to lipid metabolic factors. Metabolic factors can increase the risk of NAFLD up to 1.5 ~ 3.8 times.

Conclusions: Older age, male gender, metabolic factors such as obesity, abdominal obesity, dyslipidemia, hypertension or type 2 diabetes are risk factors for NAFLD. Prevalence of NAFLD in Shanghai employees is high. Prevention is extremely important. Those achieve the critical point should have early intervention.

Figure 1

Age-specific prevalence of NAFLD. The prevalence of NAFLD increased according to age(trend chi-square value = 23.7292, p < 0.0001in total; chi-square value = 15.4859, p < 0.0001in male; trend chi-square value = 19.0515, p < 0.0001in female). The peak prevalence was in the 50-65 age group, up to 54% persons had NAFLD in total. The prevalence of NAFLD in males was significantly higher than females within the same age group (25% vs 3.89% in younger than 30- year old age group, 50% vs 13.29% in 30-39 age group, 56.06% vs 24.27% in 40-49 age group, and 57.35% vs 45.79% in 50-64 age group). In female, the prevalence increased dramatically after 50 years old. *The contraction between male and female in the same age group, p < 0.0001.