Association between Insulin Resistance and Sudomotor Dysfunction in Adults with Type 1 Diabetes

Aims Insulin resistance is increasingly recognized in type 1 diabetes as a risk factor for chronic complications and cardiovascular disease. Sudomotor dysfunction, reflecting small fiber neuropathy, can be assessed non-invasively by electrochemical skin conductance (ESC). This study evaluated the association between sudomotor function and insulin resistance in adults with type 1 diabetes. Methods The study included 476 adults with type 1 diabetes (247 men), aged 42 (IQR: 33-53) years, with a disease duration of 24 (IQR: 19-32) years, and HbA1c level of 7.9 (IQR: 7.2-8.9)%. The sudomotor function was evaluated using the SUDOSCAN device. Insulin resistance was assessed using the estimated glucose disposal rate formula (eGDR), which is based on HbA1c, waist-to-hip ratio, and the presence of hypertension. The study group was subdivided into 3 groups based on tertiles of eGDR (<5.5, 5.5–9.5, >9.5 mg/kg/min). Results Participants with lower eGDR (lower insulin sensitivity) had lower Feet ESC [71 (IQR:50-81) vs 79 (IQR:63-85) vs 83 (IQR:74-86) μS; p<0.0001. We found a positive correlation between Feet ESC and eGDR (Rs=0.28, p<0.001). In a multiple linear regression model, Feet ESC was independently associated with eGDR (β=0.16, p=0.001). Conclusion Insulin resistance is associated with impaired sudomotor function in adults with type 1 diabetes.