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)%. 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 three 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.