Diabetes Care, Vol 23, Issue 3 360-364, Copyright © 2000 by American Diabetes Association
Effects of nicotinamide and intravenous insulin therapy in newly diagnosed type 1 diabetes
J Vidal, M Fernandez-Balsells, G Sesmilo, E Aguilera, R Casamitjana, R Gomis and I Conget
Endocrinology and Diabetes Unit, Institut d'Investigacions Biomedicas August Pi i Sunyer, Hospital Clinic i Universitari, Barcelona, Spain.
OBJECTIVE: To investigate the effect of intravenous insulin therapy
combined with nicotinamide in the metabolic control and beta-cell function
of newly diagnosed type 1 diabetic subjects in comparison with intensive
insulin therapy and nicotinamide alone. RESEARCH DESIGN AND METHODS: A
total of 34 newly diagnosed type 1 diabetic patients were included. After
the correction of initial metabolic disturbances, subjects were randomly
assigned to the following three groups within 72 h after admission: 1)
intensive insulin therapy + placebo (C) (n = 12); 2) intensive insulin
therapy + nicotinamide, 700 mg three times a day (NIC) (n = 11); and 3)
72-h intravenous insulin followed by intensive insulin therapy +
nicotinamide, 700 mg three times a day (NIV) (n = 11). The subjects were
monitored for 12 months. GAD, tyrosine phosphatase antibodies, and insulin
autoantibodies were measured. C-peptide was measured basally and after 2,
4, 6, 8, and 10 min of 1 mg intravenous glucagon. HbA1c, glucagon, and
antibody measurements were determined initially and at 1, 3, 6, 9, and 12
months. RESULTS: HbA1c values declined to normal after treatment was
initiated in all groups and remained not significantly different during the
follow-up period. We did not find differences between experimental (NIC and
NIV) and placebo (C) groups in terms of beta-cell function, considering
basal or glucagon-stimulated C-peptide (maximal stimulated C-peptide and
area under the curve [AUC] of C-peptide) values during the follow-up
period. After pooling data from the NIC and NIV groups (both including
nicotinamide) and comparing it with data from the C group, the results
remained unchanged. At diagnosis, GAD positivity was observed in 10 of 12,
8 of 11, and 10 of 11 subjects (NS) in the C, NIC, and NIV groups,
respectively, and IA2 positivity was observed in 3 of 12, 4 of 11, and 4 of
11 subjects (NS) in the C, NIC, and NIV groups, respectively. Antibody
titers displayed a similar behavior in all groups during the follow-up
period. CONCLUSIONS: Our pilot study failed to demonstrate that the
addition of 72-h intravenous insulin and nicotinamide to conventional
intensive insulin therapy produces any beneficial effect in newly diagnosed
type 1 diabetic subjects in terms of beta-cell function and metabolic
control.