Vitamin C Supplementation as a Preventive Treatment of Diabetic Peripheral Neuropathy

Phase 1

Completed

• Conditions: Diabetic Neuropathies
• Interventions: Dietary Supplement: Vitamin C; Dietary Supplement: Placebo

• Registration Number: NCT00634998
• Lead Sponsor: Washington State University

Brief Summary

The purpose of this pilot study is to determine whether vitamin C supplementation is beneficial in treating and/or preventing diabetic peripheral neuropathy in people with type 2 diabetes.

Detailed Description

Painful diabetic peripheral neuropathy (DPN), a condition characterized by pain affecting the feet, legs and hands that is often characterized as burning or a "pins and needles" sensation, is estimated to affect up to 66% of the U.S. diabetic population. This pilot study will examine the effect of a daily dose of ascorbic acid, a known aldose reductase inhibitor, versus placebo, and the effect that it can have on intracellular erythrocyte (red blood cell) sorbitol levels, aldose reductase activity and aldose reductase enzyme levels utilizing benchtop methods, and effects on clinical DPN-associated pain reporting and changes in quantitative sensory testing in the lower extremities via touch discrimination and vibratory sensory testing in patients with Type 2 Diabetes Mellitus (T2DM) over the course of 90 days of treatment.

Study Timeline

• Study Start: 2007-11
• Study First Submitted: 2008-03-05
• Study First Submitted QC: 2008-03-05
• Study First Posted: 2008-03-13
• Primary Completion: 2008-08
• Study Completion: 2008-08
• Status Verified: 2023-04
• Last Update Submitted: 2023-04-25
• Last Update Posted: 2023-04-27

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 10

Inclusion Criteria

• type 2 diabetes mellitus
• diabetic peripheral neuropathy
• A1C of 6.0-10.0%

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Exclusion Criteria

• Terminal diagnosis
• Dementia
• Anemia
• Significant renal dysfunction
• History of B-12 deficiency
• Peripheral vascular disease
• Current smoker
• History of kidney stones
• Current ascorbic acid use
• Presence or foot infection and/or ulcer

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
1	Vitamin C	1000mg Vitamin C capsules orally twice daily for 90 days
2	Placebo	1000mg Placebo capsules orally twice daily for 90 days

Primary Outcome Measures

Name	Time	Method
Changes in aldose reductase enzyme levels	Levels at 90 days compared to baseline
Changes in intracellular erythrocyte sorbitol levels	Changes at 90 days compared to baseline
Changes in aldose reductase enzyme activity	Activity at 90 days compared to baseline

Secondary Outcome Measures

Name	Time	Method
Changes in Neuropathic Pain Scale (NPS) measurement and quantitative sensory testing in the lower extremities via touch discrimination with Semmes-Weinstein monofilaments and vibratory sensation testing	Changes at 90 days compared to baseline

Trial Locations

Locations (1)

Washington State University, College of Pharmacy, Department of Pharmacotherapy; 🇺🇸 Spokane, Washington, United States