Baseline and change in serum lipid and uric acid level over time and incident of nonalcoholic fatty liver disease (NAFLD) in Chinese adults

Observational studies have shown that non-alcoholic fatty liver disease (NAFLD) is strongly associated with metabolic dysfunction. However, there is a paucity of research on whether changes in indicators of serum metabolism contribute to the development of NAFLD. This study was conducted with 4084 participants who underwent healthy physical examinations at Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China, in 2022 and 2023. Baseline and follow-up measurements, including anthropometric data, abdominal ultrasound and blood samples were collected. The diagnosis of NAFLD was based on the 2010 Chinese Guidelines on Diagnosis and Treatment of NAFLD. Multiple logistic regression was utilized to analyze the odds ratios (ORs) for the 1-year risk of NAFLD in connection with both baseline metabolic indicators and changes in metabolic indicators observed over the course of 1 year. A total of 3425 study participants who were free of NAFLD at baseline, including 1146 men and 2279 women, were included in the final analysis. The mean age was 34.43 ± 7.20 years. Participants who developed NAFLD were older, male and had higher levels of body mass index (BMI), blood pressure, fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), free triiodothyronine (fT3), uric acid (UA), alanine aminotransferase (ALT) and aspartate aminotransferase (AST); and lower levels of high-density lipoprotein cholesterol (HDL-C) and free thyroxine (fT4) (all P values < 0.05). The multivariable model showed that baseline BMI, diastolic blood pressure (DBP), TG, TC, HDL-C, LDL-C, UA, fT4, fT3, ALT and changes in TG, HDL-C, and UA were associated with the 1-year risk of developing NAFLD. The risk of NAFLD increased by 56% [OR 1.56, 95% Confidence Interval (CI) 1.32-1.87] and 40% (OR 1.40, 95% CI 1.19-1.64) for each standard deviation (SD) increase in altered TG values (1.01 mmol/L) and altered UA values (55 µmol/L) respectively. Conversely, for each SD (0.27 mmol/L) increase in HDL-C change, the 1-year risk of incident NAFLD was reduced by 50% (OR 0.50, 95% CI 0.40-0.62). The present study suggested that increases in TG and UA, and decreases in HDL-C, significantly increase the risk of developing NAFLD. Therefore, more attention should be paid to these factors in the management and prevention of NAFLD.