Nicotinamide fails to impress in major diabetes trial
For the second time in two years, a major study designed to prevent the development of type 1 diabetes has ended in disappointment. A twice daily dose of the B vitamin, nicotinamide, has failed to protect relatives of type 1 diabetes patients from developing the disease.
In the European nicotinamide diabetes intervention trial (ENDIT), 552
relatives with islet cell antibodies were randomised to oral modified
release nicotinamide (1.2g/m2) or placebo for five years (Lancet 2004;363:925).
Of 159 participants who developed diabetes during the trial, 92 were
taking nicotinamide and 77 were on placebo. The difference was not significant.
Nicotinamide had been chosen for the study because it prevents autoimmune
diabetes in animal models, possibly by protecting pancreatic beta cells
from destructive by-products of cellular repair mechanisms. Promising
results had also been obtained in small studies in humans.
The ENDIT researchers suggest that the dose of nicotinamide used in the
study may have been too low. They also point out that the drug was given
at a later stage of the disease process than in the animal studies.
In 2002, insulin injections were found not to prevent the onset of type
1 diabetes in relatives of patients with the disease (New England Journal of Medicine 2002;346:1685). The diabetes prevention trial – type
1 (DPT-1) failed to show that, by allowing beta cells to rest, insulin
treatment could ease their
autoimmune-mediated destruction. |
The
Pharmaceutical Journal