Glomerular filtration rate in patients with type 2 diabetes mellitus: is serum isthmin-1 level a possible link?

INTRODUCTION: Isthmin-1 (Ism-1) is a novel adipokine. However, little is known regarding the association between Ism-1 and type 2 diabetes mellitus (T2DM). This study aimed to investigate the relationship between serum Ism-1 levels and glomerular filtration rate (GFR) in patients with T2DM. RESEARCH DESIGN AND METHODS: A total of 209 patients with T2DM were recruited into this retrospective study. Clinical data were collected. Fasting blood samples were collected for serum Ism-1 testing using ELISA kits. Based on the estimated glomerular filtration rate (eGFR), participants were divided into the normal eGFR group (n=167) and the decreased eGFR group (n=42). The relationship between Ism-1 and eGFR was assessed using linear and binary logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was employed to examine the predictive efficacy of Ism-1 for distinguishing patients with eGFR <60 mL/min/1.73 m(2). RESULTS: Compared with patients with normal eGFR, serum Ism-1 levels were increased in patients with decreased eGFR (p<0.001). Serum Ism-1 levels were negatively correlated with eGFR in patients with T2DM even after multiple adjustments (p<0.001). For each 0.1 ng/mL increment of Ism-1, the odds of having an eGFR <60 mL/min/1.73 m(2) increased by 54.5% (OR=1.545; p<0.001) in patients with T2DM. ROC analysis showed that higher serum Ism-1 levels (>1.297 ng/mL) had predictive efficacy in patients with eGFR <60 mL/min/1.73 m(2), with an area under the curve of 0.908. CONCLUSIONS: Serum Ism-1 levels were inversely associated with eGFR, and high Ism-1 levels may be used as a potential biomarker for predicting kidney function impairment in patients with T2DM.