Study of the Effects of Vitamin C on Patients With Type 2 Diabetes

Launched by NATIONAL CENTER FOR COMPLEMENTARY AND INTEGRATIVE HEALTH (NCCIH) · Nov 3, 1999

Keywords

ClinConnect Summary

Diabetes is characterized by decreased sensitivity to the actions of insulin to promote both glucose utilization and vasodilation in skeletal muscle beds. Insulin's vasodilator action is mediated, in part, by endothelial-derived nitric oxide (NO). Increased blood flow accounts for approximately 25% of the increase in skeletal muscle glucose disposal mediated by insulin. Therefore, endothelial dysfunction may contribute to insulin resistance. Intraarterial administration of vitamin C improves NO-dependent vascular reactivity in diabetic subjects (but not normal subjects). This may be due to ...

Gender

ALL

Eligibility criteria

• INCLUSION CRITERIA:
• DIABETIC SUBJECTS:
• • Males and non-pregnant females between the ages of 18 and 65 in good general health except for type 2 diabetes controlled with diet and/or oral hypoglycemic agents.
• • Patients found to have plasma vitamin C levels less than 40 microliter M, will be enrolled into the protocol and taken off hypoglycemic agents approximately one week prior to each study.
• VITAMIN C-DEFICIENT CLINICAL RESEARCH VOLUNTEERS:
• • Adults between the ages of 18 and 35 in good general health and on no drugs or medications.
• EXCLUSION CRITERIA:
• ALL SUBJECTS:
• • Pregnancy, liver disease, pulmonary disease, renal insufficiency, coronary heart disease, heart failure, peripheral vascular disease, coagulopathy, disease predisposing to vasculitis or Raynaud's phenomenon, bleeding disorders, kidney stones, glucose-6-phosphate dehydrogenase deficiency, family history of hemochromatosis/iron overload, platelet count less than 150,000/ml blood, prothrombin time/partial thromboplastin time (PT/PTT) greater than 1 second above the normal range, inability to give informed consent for all procedures, and positive tests for HIV, or hepatitis B or C.
• DIABETIC SUBJECTS:
• • In addition, to the above exclusion criteria, the presence of proteinuria greater than 500 mg/24 hrs, proliferative retinipathy, or diabetic neuropathy
• VITAMIN C-DEFICIENT CLINICAL RESEARCH VOLUNTEERS:
• • All the above exclusion criteria.