OBJECTIVE The aim of this study was to compare the effect of nicotinamide (NCT) alone or in combination with a cortisone-like substance, deflazacort (DFL), on the integrated parameters of metabolic control in patients with the recent-onset of insulin-dependent diabetes mellitus (IDDM).

RESEARCH DESIGN AND METHODS Thirty-six patients who were diagnosed with diabetes between 5 and 35 years of age entered a randomized, double-blind, 1-year prospective study. Group A (n = 18) received NCT for 1 year (25 mg· kg^–1 · day^–1) plus DFL for 3 months (0.6 mg · kg^–1 · day^–1 in the first month, 0.3 mg · kg^–1 · day^–1 in the other 2 months). Group B (n = 18) received NCT for 1 year (25 mg · kg^–1 · day^–1) plus placebo forthe first 3 months. All patients were treated with intensified insulin therapy.

RESULTS At 3 months after diagnosis, the insulin dose was significantly higher in group A compared with group B (P < 0.03) with similar HbA₁ levels. Basal and stimulated C-peptide levels in group A of both adults and children were significantly higher compared with patients of group B (P < 0.05 and P <0.03, respectively). At the end of a 1-year follow-up, basal C-peptide did not differ between the two groups, although stimulated C-peptide was still significantly higher in patients of group A compared with group B (P < 0.05). Finally, insulin requirement did not differ between the two groups.

CONCLUSIONS A short-term course of DFL therapy at diagnosis in addition to NCT slightly increases glucagon-stimulated but not basal β-cell function after 1 year.