Diabetic neuropathy (DN) is the most common chronic complication of diabetes, affecting up to 50% of individuals with type 1 diabetes (T1DM). DN is a progressive disease, leading to severe morbidity and staggering health care costs ($22 billion/year www.diabetes.org). Patients experience poor quality of life due to pain, loss of sensation leading to poor balance, falls and eventual foot deformities with high rates of ulcerations and amputations. While not as commonly diagnosed as DN, cardiovascular autonomic neuropathy (CAN) carries equal morbidity with patients experiencing orthostasis, arrhythmias and premature death. Evidence for an important role of low-grade inflammation in the pathogenesis of DN and CAN is emerging from both experimental and clinical studies. We recently completed a series of microarray analyses of sural nerve biopsies from subjects with stable versus progressive DN and discovered a highly significant increase in the expression of inflammatory response genes in subjects with progressive DN. Salsalate is highly effective anti- inflammatory therapy, with a large margin of safety and low cost. In a prior proof of concept pilot study (R03 DK 094499), we obtained the IND (IND 113650) for the use of salsalate and completed clinical and safety assessments in 8 subjects with T1DM and DN, treated with 3 gram/day salsalate for 3 months, with evidence of early clinical efficacy and drug safety. Our long-term goal is to identify mechanism based therapies for the treatment of DN and CAN. The objective here is to determine if salsalate is an effective and safe therapy for DN and CAN. Our central hypothesis is that inflammation has a role in the development and progression of DN and CAN and that blocking inflammation with salsalate can positively affect disease progression. The rationale for the proposed research is that a pilot clinical trial of salsalate therapy will: 1) test the role of inflammation in DN and CAN, 2) allow for biomarker development for both disorders, and 3) provide the justification for a large scale clinical trial of salsalate n the treatment of DN and CAN. We plan to test our central hypothesis, and thereby accomplish the objective of this application, by pursuing two specific aims:
Aim 1 : Examine the therapeutic efficacy of 3 gram/day salsalate for 12 months on measures of DN and CAN in subjects with T1DM and mild DN Aim 2: Determine the safety profile of 3 gram/day salsalate in patients with T1DM and mild DN.

Public Health Relevance

This study is relevant to public health because diabetic neuropathy (DN) is the most common chronic complication of diabetes, ultimately affecting half of patients with diabetes and leading to severe morbidity, high mortality, major physical disability, and poor quality of life. This is relevant to the NIH mission because to date there is still no specific treatment for DN. We propose to use a FDA-approved drug commonly used to treat osteoarthritis, to address inflammation - a critical mediator in the development and progression of peripheral nerve damage and pain in diabetes, which has recently been shown to have potential clinical benefit in DN.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
1R01DK107956-01
Application #
9008753
Study Section
Clinical Neuroplasticity and Neurotransmitters Study Section (CNNT)
Program Officer
Jones, Teresa L Z
Project Start
2016-03-01
Project End
2021-02-28
Budget Start
2016-03-01
Budget End
2017-02-28
Support Year
1
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Neurology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
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Callaghan, Brian C; Xia, Rong; Reynolds, Evan et al. (2018) Better diagnostic accuracy of neuropathy in obesity: A new challenge for neurologists. Clin Neurophysiol 129:654-662
Rumora, Amy E; Lentz, Stephen I; Hinder, Lucy M et al. (2018) Dyslipidemia impairs mitochondrial trafficking and function in sensory neurons. FASEB J 32:195-207
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Pop-Busui, Rodica; Ang, Lynn; Holmes, Crystal et al. (2016) Inflammation as a Therapeutic Target for Diabetic Neuropathies. Curr Diab Rep 16:29