Insulin resistance is a major contributor to complications in type 1 diabetes, especially when kidney function is impaired. Data from the European Association for the Study of Diabetes 2025 demonstrate this using gold-standard metabolic measurements. 

Euglycaemic hyperinsulinaemic clamp data from 189 adults with type 1 diabetes (34 with diabetic kidney disease) across four international centres in Finland, Poland, and Australia were analyzed. Kidney disease was defined using centre-specific criteria incorporating albuminuria and glomerular filtration rate. 

Glucose disposal rate during the last 30 minutes of the clamp was 4.9 mg/kg/min in those with diabetic kidney disease versus 6.4 mg/kg/min in those without (p=0.004). After adjustment for age, sex, glycated haemoglobin, and lipid concentrations, the difference remained notable. Daily insulin requirements were higher in those with kidney disease (0.60 vs. 0.48 IU/kg, p=0.0005). Most calculated formulae for estimated glucose disposal rate confirmed lower insulin sensitivity in affected individuals.

These findings highlight that insulin resistance is a core metabolic defect in type 1 diabetes with kidney involvement, reinforcing the importance of early detection and therapeutic strategies targeting insulin sensitivity.