Insulin autoantibodies, D-dimer and microalbuminuria: A cross-sectional, case-control study of type 2 diabetes

Type 2 diabetes mellitus (T2DM) often leads to vascular complications, such as albuminuria. The role of insulin autoantibodies (IAA) and their interaction with D-dimer in this context remains unclear.

To investigate the characteristics of IAA and its effect on albuminuria in T2DM patients.

We retrospectively analyzed clinical data from 115 T2DM patients with positive IAA induced by exogenous insulin, and 115 age- and sex-matched IAA-negative T2DM patients as controls. Propensity scores were calculated using multivariate logistic regression. Key variables were selected using the least absolute shrinkage and selection operator (LASSO) algorithm. We constructed a prediction model and analyzed the association between IAA and albuminuria based on demographic and laboratory parameters.

The IAA-positive group had significantly higher D-dimer levels [0.30 (0.19-0.55) mg/L vs 0.21 (0.19-0.33) mg/L, P = 0.008] and plasma insulin levels [39.1 (12.0-102.7) μU/mL vs 9.8 (5.5-17.6) μU/mL, P < 0.001] compared to the IAA-negative group. Increases in the insulin dose per weight ratio, diabetes duration, and urinary albumin-to-creatinine ratio (UACR) were observed but did not reach statistical significance. The LASSO model identified plasma insulin and D-dimer as key factors with larger coefficients. D-dimer was significantly associated with UACR in the total and IAA-positive groups but not in the IAA-negative group. The odds ratio for D-dimer elevation (> 0.5 g/L) was 2.88 (95% confidence interval: 1.17-7.07) in the IAA-positive group (P interaction < 0.05).

D-dimer elevation is an independent risk factor for abnormal albuminuria and interacts with IAA in the development of abnormal albuminuria in T2DM patients.