Associations between adiposity indices and liver steatosis and stiffness assessed by two-dimensional shear wave elastography in patients with type 2 diabetes mellitus: a cross-sectional study.

OBJECTIVE

This study investigated associations between adiposity indices and non-invasive markers of liver fibrosis and steatosis in adults with type 2 diabetes mellitus (T2DM).

METHODS

We assessed adiposity using body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and visceral adiposity index (VAI), along with body composition and fat distribution measured by bioimpedance analysis and abdominal ultrasonography, respectively. Liver steatosis and fibrosis were evaluated using non-invasive imaging methods, including two-dimensional shear wave elastography (2D-SWE). Multivariable regression was used to examine independent associations between adiposity indices and liver outcomes after adjustment for confounders, and receiver operating characteristic (ROC) curve analysis with area under the curve (AUC) values was performed to assess discriminative ability.

RESULTS

Among 164 adults with T2DM (86 men, 78 women), 27 (16.5%) had hepatic steatosis (≥ S2; attenuation coefficient > 0.6 dB/cm/MHz), and 19 (11.6%) had fibrosis (≥ F1; liver stiffness > 7.1 kPa). In fully adjusted for relevant confounders, central adiposity indices including visceral fat thickness (VFT) (B = 0.023; p = 0.012), WC (B = 0.049; p < 0.001), WHtR (B = 6.532; p = 0.005), and WHR (B = 5.155; p = 0.037) were independently associated with increased liver stiffness. Hepatic steatosis showed associations with BMI (B = 0.012; p < 0.001), total fat mass (TFM) (B = 0.007; p < 0.001), WHtR (B = 0.642; p < 0.001), WC (B = 0.005; p < 0.001), and VFT (B = 0.002; p = 0.014). None were associated with the Fibrosis-4 (FIB-4) score, and ROC analyses revealed sex-specific differences in association-based discrimination. For liver fibrosis (≥ F1), among females, VFT (AUC = 0.902; 95% CI: 0.787-1.000), WC (AUC = 0.891; 95% CI: 0.789-0.999), WHtR (AUC = 0.853; 95% CI: 0.732-0.973), and WHR (AUC = 0.839; 95% CI: 0.701-0.978) showed strong discrimination. In males, only WC demonstrated statistically significant discrimination (AUC = 0.718; 95% CI: 0.519-0.918). For moderate or greater steatosis (≥ S2), WC performed best in males (AUC = 0.818; 95% CI: 0.695-0.941), while TFM was most accurate in females (AUC = 0.751; 95% CI: 0.622-0.880).

CONCLUSIONS

Central adiposity indices were independently associated with increased liver stiffness, while both general and central adiposity measures were significantly related to hepatic steatosis, independent of confounders. Their discriminative performance showed distinct sex-specific patterns: for both fibrosis and steatosis, WC was the best-performing index in men, whereas VFT performed best for fibrosis in women and TFM was the best discriminator for steatosis in women.

CLINICAL TRIAL NUMBER: Not applicable.