# Body mass index mediates the association between serum fibroblast growth factor-19 and diabetes

## TL;DR

Higher levels of a protein called FGF19 are linked to lower diabetes risk, partly because it's associated with lower body mass index.

## Contribution

This study identifies BMI as a partial mediator in the relationship between serum FGF19 and diabetes risk in a Chinese population.

## Key findings

- FGF19 levels were inversely associated with BMI and diabetes risk after adjusting for multiple factors.
- BMI reduction explained 10.1% of the association between FGF19 and diabetes.
- No significant interactions were found between FGF19 and age, sex, or obesity in relation to diabetes.

## Abstract

This study aimed to investigate the relationship between serum fibroblast growth factor-19 (FGF19) levels and diabetes, as well as the potential mediating role of body mass index (BMI).

Data from 1,018 participants with valid serum FGF19 measurements from the Shenzhen–Hong Kong United Network on Cardiovascular Disease study were analyzed. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for diabetes risk. Mediation analysis was conducted to assess the extent to which BMI mediated the association between serum FGF19 levels and diabetes.

The mean age of participants was 45.1 years, with 77 individuals (7.6%) diagnosed with diabetes. Natural logarithm (ln)-transformed FGF19 levels were inversely associated with BMI [age- and sex-adjusted β (95% CI): -0.30 (-0.58, -0.03)]. Ln-transformed FGF19 levels were also negatively associated with diabetes after adjusting for covariates, including age, sex, smoking status, alcohol consumption, blood pressure, BMI, waist circumference, and lipid profile [OR (95% CI): 0.66 (0.47–0.95)]. No significant interactions were observed between ln-transformed FGF19 levels and age, sex, obesity, or abdominal obesity in relation to diabetes. Mediation analysis revealed that BMI reduction accounted for 10.1% of the association between ln-transformed FGF19 levels and diabetes.

Serum FGF19 levels are inversely associated with diabetes risk in the Chinese population, with BMI serving as a partial mediator of this relationship.

The online version contains supplementary material available at 10.1007/s40200-025-01850-y.