Association of serum vitamin C with liver fibrosis in adults with nonalcoholic fatty liver disease

Abstract

Objective

This study aimed to investigate the association between serum vitamin C and liver fibrosis in patients with NAFLD in the US adults.

Methods

We conducted a cross-sectional analysis of data from the 2017 to 2018 cycle of National Health and Nutrition Examination Survey (NHANES). Serum vitamin C and transient elastography (TE)-accessed liver stiffness was taken as independent and dependent variables, respectively. Liver steatosis and fibrosis were detected by controlling attenuation parameter (CAP) and TE. NAFLD was defined by a CAP score of ≥248 dB/m without any indication of other causes of chronic liver disease. The median liver stiffness of ≥8.2 kPa was used to identify significant fibrosis (≥F2) among NAFLD patients. We calculated the adjusted odds ratio (OR) and 95% confidential intervals (CIs) for associations with significant NAFLD fibrosis using multivariable logistic regression models.

Results

Overall, 1926 individuals with NAFLD were included in the analysis and 267 subjects met the definition of significant fibrosis. Serum vitamin C was associated with lower odds of liver fibrosis in NAFLD after adjusting for potential confounders (OR = 0.60, 95% CI, 0.43–0.84), while in the subgroup analysis stratified by gender and body mass index (BMI), this association showed a difference after adjusting for confounders (males: OR = 0.43, 95% CI, 0.26–0.71; females: OR = 0.78, 95% CI, 0.49–1.24). There were no significant associations of serum vitamin C with liver fibrosis in NAFLD with underweight or normal (OR = 1.34, 95% CI, 0.19–9.34).

Conclusions

This cross-sectional study indicated an association of serum vitamin C with significant fibrosis in men and overweight or obese patients with NAFLD.

Keywords:

• Vitamin C
• NAFLD
• liver fibrosis
• controlled attenuation parameter
• NHANES

Acknowledgements

The authors appreciate the efforts given by participants in the NHANES project.

Ethics approval

The NHANES was approved by the NCHS Research Ethics Review Board. This study uses publically available secondary data.

Authors contributions

Yipu Zhao contributed to the study concept and design, analysis and interpretation of data, revision of the manuscript and study supervision. Hailu Li contributed to data analysis and writing of the manuscript. Both authors approved the final version of the manuscript.

Disclosure statement

The authors report no conflict of interest.

Data availability statement

All data are freely available in the NHANES: https://www.cdc.gov/nchs/nhanes/.