| OBJECTIVE: Nicotinamide, a vitamin of the B group, has in vitro
actions capable of interfering with the pathogenetic process leading
to IDDM. Since 1987, several studies have evaluated nicotinamide as a
means of protecting beta-cells from end-stage destruction in insulin-
treated patients with newly diagnosed IDDM. The aim of the study was
to determine whether nicotinamide protects residual beta-cell
function when given at IDDM diagnosis. RESEARCH DESIGN AND METHODS:
We performed a meta-analysis of the integrated parameters of
metabolic control (C-peptide, glycosylated hemoglobin, insulin dose)
in 10 randomized (5 of which were placebo) controlled trials
conducted in recent-onset IDDM patients for a total of 211
nicotinamide-treated patients. Data on the adverse effects of
nicotinamide were also collected from an additional four trials to
yield a grand total of 291 nicotinamide-receiving patients. RESULTS:
One year after diagnosis, baseline C-peptide was significantly higher
in nicotinamide-treated patients, compared with control patients
(0.73 +/- 0.65 vs. 0.32 +/- 0.56 ng/ml, P < 0.005). This statistical
difference remained also when the five placebo-controlled trials only
were considered (P < 0.05). No differences were observed in the
insulin dose required or glycosylated hemoglobin values between
nicotinamide and control patients. Adverse effects were reported in
few patients (transient elevation of transaminase, n = 2; skin rash,
n = 2; recurrent hypoglycemia, n = 2). CONCLUSIONS: This combined
analysis demonstrates a therapeutic effect of nicotinamide in
preserving residual beta-cell function when given at IDDM diagnosis
in addition to insulin. Since adverse effects were negligible, we
suggest that prolonged use of nicotinamide after IDDM diagnosis
should be tested to see whether residual beta-cell function can be
preserved for longer periods.
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