OBJECTIVETo analyze the relationship between normal serum uric acid (SUA) levels and nonalcoholic fatty liver disease (NAFLD) among postmenopausal women, and determine the possible risk factors of NAFLD in this patient population.

METHODSChinese postmenopausal women who participated in the annual health check-up program from March 2009 to February 2010 were retrospectively assessed to identify individuals with SUA within normal range for study inclusion. For the total 1425 study participants, the recorded data of anthropometric parameters, metabolic factors, and serum biochemical parameters were collected. Results from abdominal ultrasonography examination were used to group participants according to presence of fatty liver. Women with fatty liver were divided into NAFLD and non-NAFLD groups. Further sub-grouping was performed according to SUA quartiles, as follows: Q1 group: less than 226.1 mumol/L); Q2 group: 226.1 mumol/L less than or equal to SUA less than 267.8 mumol/L; Q3 group: 267.8 mumol/Lless than or equal to SUA less than 303.5 mumol/L); Q4 group: 303.5 mumol/Lless than or equal toSUAless than or equal to357.0 mumol/L. The independent-sample t-test was used to compare normally distributed variables between groups, and the Mann-Whitney U test was used to analyze variables with skewed distribution. Categorical variables were examined by the R * C x2 test. Binary logistic analysis was used to determine the risk factors for fatty liver and to adjust for possible confounders. The multiple non-parameter independent-sample test (Kruskal-Wallis test) was used to compare the differences of SUA levels among NAFLD groups with different disease severity.

RESULTSThe prevalence of NAFLD among Chinese postmenopausal women with normal SUA was 32.8%, with NAFLD prevalences of 20.4% (70/343) in women with Q1 SUA, 26.3% (104/395) with Q2 SUA, 35.2% (128/364) with Q3 SUA, and 51.4% (166/323) with Q4 SUA. The prevalence of fatty liver showed a significant increasing trend according to the SUA quartile (x2 = 76.470, P-trend less than 0.01). Women in the SUA Q3 and Q4 groups had significantly higher risk of fatty liver presence than women in the Q1 group (P less than 0.01 for both, with or without adjustment of confounders). Disease severity did not appear to be related to disease severity, as the SUA levels in women with mild, moderate or severe fatty liver were not significantly different (286.8+/-48.2 mumol/L vs. 277.9+/-53.0 mumol/L vs. 281.4+/-48.2 mumol/L, respectively; x2 = 3.025, P more than 0.05).

CONCLUSIONSUA levels were independently correlated with NAFLD in Chinese postmenopausal women. SUA levels in the higher quartiles of the normal range may be an independent risk factor of NAFLD.