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

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

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.

(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.

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.