Correlation between income and non-alcoholic fatty liver disease in a Chinese population.

Objective: The aim of the study was to analyze the correlation between income and non-alcoholic fatty liver disease (NAFLD) in a Chinese population.

Method: subjects were divided into three groups according to liver fat content (LFC). (1) normal: LFC < 9.15%, 197 cases; (2) low LFC: LFC 9.15-20%, 532 cases; and (3) high LFC: LFC > 20%, 201 cases. Participants' clinical and social background were collected, including a routine fasting test to assess the relevant indices. Intergroup differences were compared on 1-way ANOVA, to analyze the relation between income and each index on Pearson correlation, and independent factors for LFC were identified on binary logistic regression.

Results: (1) In retired persons, prevalence of NAFLD was greater in females (81.2%) than males (75%), but fell with age: the highest prevalence was between 40 and 49 years of age (87.5%), and the lowest above 70 years (68%). (2) Income correlated positively with triglyceride and serum uric acid levels and LFC (P < 0.05) and negatively with alanine aminotransferase (P = 0.01). (3) As income increased from level I to V, prevalence of NAFLD increased progressively (P < 0.05). In the study, LFC was taken as the dependent variable, and the traditional NAFLD risk factors and income level (I-V) were taken as independent variables. Income emerged as an independent risk factor for NAFLD. Risk in group V was 1.964-fold higher than in group I.

Conclusion: Prevalence of NAFLD was closely related to socio-economic level. Demographic risk factors include female gender, age 40-49 years, and monthly income > 5,000 RMB. Thus, if income is increased without improving educational level and health awareness, NAFLD prevalence will rise.