NIH Chromium, Antioxidant Diabetes Program Announcements Issued

The National Institutes of Health has established two new programs to fund studies on the benefits of chromium and antioxidants in diabetic subjects.

The first program announcement - issued June 27 by the Office of Dietary Supplements, National Institute of Diabetes & Digestive & Kidney Diseases, National Eye Institute, National Heart, Lung & Blood Institute, National Institute on Aging and National Institute of Neurological Disorders & Stroke - is for research into the role of antioxidants, and vitamin E in particular, in the prevention of diabetic complications.

The PA requests applications for research to "determine the efficacy of vitamin E or other antioxidants in preventing, delaying or ameliorating the micro- or macrovascular complications of diabetes and...provide insight into the mechanism(s) by which antioxidants might prevent or influence the development of diabetic vascular disease."

However, applications may not be submitted for "epidemiological or descriptive studies which assess diet or nutritional supplementation, or which simply measure blood levels of oxidants/antioxidants in patients with diabetes," NIH cautions.

The program will provide R01 and R21 grants and will accept applications through Oct. 1, 2004. Projects suggested under an R01 application may not exceed five years, while R21 proposals may not exceed two years at $125,000 per year.

Addressing the impetus for the program, the NIH document notes in vitro and in vivo research has indicated "hyperglycemia leads to increased oxidative stress and endothelial dysfunction."

The PA adds, "numerous studies have suggested that patients with diabetes appear to have decreased antioxidant defense capability," such as low levels of vitamins C and E.

Further data are needed, though, because published studies have looked at "widely variable" preparations and doses of vitamin E. Moreover, "little data [are] available regarding potential toxicity of high doses... [or] potential interactions of vitamin E with other nutrients or other antioxidants," the PA says.

The announcement notes the negative results of recent randomized, prospective trials on vitamin E's preventive effects with regard to cardiovascular disease and cancer have "tempered" NIH's interest in the antioxidant. However, it maintains "the enormous public health cost of diabetes" outweighs such concerns.

The chromium program, announced July 2, is intended, in part, to fund research on the use of chromium as adjuvant therapy for type 2 diabetes and impaired glucose tolerance. As with the antioxidant program, NIH will provide R01 and R21 grants with the same funding parameters through Oct. 1, 2004.

ODS, NIDDK and the National Center for Complementary & Alternative Medicine are sponsoring the program; funding for chromium research was approved by NCCAM's advisory panel last May (¹ (Also see "Botanical/Drug Interactions To Be Studied By NCCAM" - Pink Sheet, 15 May, 2000.)).

Specific areas of inquiry suggested in the announcement include physiological dose-response studies, Phase I/II trials to determine safe and effective dosing and research to determine biomarkers of efficacy.

"It is not the intent of this PA to support Phase III clinical trials," the NIH document notes, adding it also "does not have as its primary focus case-control studies, health services studies, surveys or epidemiological studies."

Research funded by the program will help bolster the current body of data on chromium. ODS has looked at the nutrient's therapeutic effects before, hosting a workshop in November 1999.

Although an ODS meta-analysis cited in the PA states there is "'strong evidence that chromium has no effect on glucose control in healthy subjects,'" the data for diabetic patients "were found to be equivocal and pointed to the need for small, focused clinical trials in glucose-intolerant and diabetic subjects."

Therefore, "more rigorous, blinded and well-controlled studies are needed to fully assess the efficacy and mechanism of action of chromium supplementation," NIH explains.

Additional research also could lead to Dietary Reference Intakes. The Institute of Medicine's Food & Nutrition Board reported in January it would not establish a recommended dietary allowance for the nutrient until more is known about its benefits (² (Also see "More Chromium Research Needed To Set RDA, FNB Report Concludes" - Pink Sheet, 15 Jan, 2001.)).