Type 1 Diabetes, Endothelin, and Skeletal Muscle Mitochondrial Dysfunction: The Role of Sirtuin-1

Preliminary data from the investigators' laboratory demonstrate a negative relationship between hemoglobin A1c (HbA1c) and ETBR function, supporting ETBR may be dysfunctional in the presence of T1D. Using near infrared spectroscopy (NIRS) to non-invasively assess muscle function, the investigators have also observed reduced skeletal muscle mitochondrial function in people with T1D compared to healthy controls. In addition, reduced circulating Sirt1 is associated with both ETBR and skeletal muscle mitochondrial dysfunction in the general population. For the current application, the investigators propose to utilize intradermal microdialysis and NIRS as unique, novel, and minimally invasive methods to investigate ETBR and skeletal muscle mitochondrial function, respectively, in people with T1D. Accordingly, the central hypothesis is that increasing circulating Sirt1 with oral supplementation of resveratrol will improve both ETBR function and mitochondrial skeletal muscle function, reducing overall CVD risk (Figure 1). The investigators will test this hypothesis with the following specific aims:

Aim 1: To test the hypothesis that an increase in Sirt1 will improve ETBR function in people with T1D. The investigators will evaluate ETBR function and circulating Sirt1 at baseline and after a 12-week treatment of resveratrol or placebo. Based on preliminary data, the investigators predict that people with T1D will have ETBR dysfunction compared to controls. In addition, the investigators predict that increasing Sirt1 following resveratrol treatment will improve ETBR function, whereas no change will occur with placebo.

Aim 2: To test the hypothesis that an increase in Sirt1 will improve skeletal muscle mitochondrial function and lower HbA1c in people with T1D. A non-invasive assessment of skeletal muscle function will be performed on people with T1D before and after 12-weeks of treatment with resveratrol or placebo. Compared to controls, the investigators predict that people with T1D will have skeletal muscle dysfunction. Following 12 weeks of resveratrol, the investigators predict that the increase in circulating Sirt1 will improve skeletal muscle function. Additionally, the investigators predict the improved skeletal muscle function will contribute to a subsequent decrease in HbA1c in people with T1D.

• Change in Percentage Flow-Mediated Dilation (FMD) [Time frame: Measure taken at Baseline and post 12 weeks]
• Change in Pulse Wave Velocity (PWV) [Time frame: Measure taken at Baseline and post 12 weeks]
• Change in Post Occlusive Reactive Hyperemia (PORH) [Time frame: Baseline and post 12 weeks]