S1 Data set -

Purpose
To investigate the relationship between estimated glomerular filtration rate (eGFR) and para-perirenal fat thickness in comparison with other indices of adiposity in type 2 diabetes mellitus (T2DM).
Methods
This single-center, retrospective and cross-sectional study evaluated 337 patients with T2DM. The obesity-related indicators including height, weight, body surface area (BSA), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), para-perirenal fat thickness (PRFT), total abdominal fat (TAF), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT). eGFR was calculated by CKD-EPI equation. The correlation between eGFR and obesity-related indicators was performed by pearson or spearman correlation analysis and multivariate linear regression.
Results
337 subjects (mean age, 60.2 ± 11.6 years; 195 males, 57.9%) were evaluated. eGFR was negatively correlated with height, weight, BMI, PRFT, TAF, SAT, and VAT, among which the correlation between eGFR and PRFT was the strongest (r = -0.294, p< 0.001). eGFR remained the strongest correlation with PRFT in the subgroup separated by sex (r = -0.319 in the male subgroup, and -0.432 in the female subgroup, respectively, p < 0.001). Age and PRFT were the independent predictive factors for eGFR. PRFT was the best predictor of chronic kidney disease (CKD) in T2DM (AUC = 0.686, p = 0.001, 95% CI: 0.582–0.791). CKD in T2DM can be predicted well by linking age with PRFT (AUC = 0.708, p<0.001, 95% CI = 0.605–0.812).
Conclusions
PRFT is more closely related to glomerular filtration rate than other obesity-related indicators in T2DM. The model combining age with PRFT could predict CKD in T2DM well.