title: A two year observational study of nicotinamide and intensive insulin therapy in patients with recent onset type 1 diabetes mellitus.
abstract: OBJECTIVE
  A number of trials have evaluated residual beta-cell function in patients with recent onset type 1 diabetes mellitus (DM1) treated with nicotinamide in addition to intensive insulin therapy (IIT). In most studies, only a slight decline of C-peptide secretion was observed 12 months after diagnosis; however, no data is available on C-peptide secretion and metabolic control in patients continuing nicotinamide and IIT for up to 2 years after diagnosis.
  
  
  METHODS
  We retrospectively analysed data from 25 patients (mean age 14.7 years +/- 5 SD) with DM1 in whom nicotinamide at a dose of 25 mg/kg b. wt. was added from diagnosis (< 4 weeks) to IIT (three injections of regular insulin at meals + one NPH at bed time) and continued for up to 2 years after diagnosis. Data were also analysed from patients (n = 27) in whom IIT was introduced at diagnosis and who were similarly followed for 2 years. Baseline C-peptide as well as insulin dose and HbA1c levels were evaluated at 12 and 24 months after diagnosis.
  
  
  RESULTS
  In the course of the follow-up, patients on nicotinamide + IIT or IIT alone did not significantly differ in terms of C-peptide secretion (values at 24 months in the two groups were 0.19 +/- 0.24 nM vs 0.19 +/- 0.13 nM, respectively). Insulin requirement (0.6 +/- 0.3 U/kg/day vs 0.7 +/- 0.2 U/kg/day at 24 months, respectively) did not differ between the two groups. However, HbA1c was significantly lower 2 years after diagnosis in patients treated with nicotinamide + IIT (6.09 +/- 0.9% vs 6.98 +/- 0.9%, respectively, p < 0.01). No adverse effects were observed in patients receiving nicotinamide for 2 years.
  
  
  CONCLUSIONS
  Implementation of IIT with the addition of nicotinamide at diagnosis continued for 2 years improves metabolic control as assessed by HbA1c. In both nicotinamide and control patients, no decline in C-peptide was detected 2 years after diagnosis, indicating that IIT preserves C-peptide secretion. We conclude that nicotinamide + IIT at diagnosis of DM1 prolonged for up to 2 years can be recommended, but longer follow-up is required to determine whether nicotinamide should be continued beyond this period.
authors.affiliation: Department of Endocrinology and Diabetes, Clinica Medica, Universitá Catholica Sacro Cuore and Ospedale Pediatrico Bambino Gesu, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Crinó
authors.forename: R
authors.initials: R
authors.lastname: Schiaffini
authors.forename: P
authors.initials: P
authors.lastname: Ciampalini
authors.forename: M C
authors.initials: MC
authors.lastname: Suraci
authors.forename: S
authors.initials: S
authors.lastname: Manfrini
authors.forename: N
authors.initials: N
authors.lastname: Visalli
authors.forename: M C
authors.initials: MC
authors.lastname: Matteoli
authors.forename: P
authors.initials: P
authors.lastname: Patera
authors.forename: R
authors.initials: R
authors.lastname: Buzzetti
authors.forename: C
authors.initials: C
authors.lastname: Guglielmi
authors.forename: S
authors.initials: S
authors.lastname: Spera
authors.forename: F
authors.initials: F
authors.lastname: Costanza
authors.forename: E
authors.initials: E
authors.lastname: Fioriti
authors.forename: D
authors.initials: D
authors.lastname: Pitocco
authors.forename: P
authors.initials: P
authors.lastname: Pozzilli
mesh_terms: D000293:Adolescent; D000328:Adult; D002096:C-Peptide / Q000378:metabolism; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D009536:Niacinamide / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: D002096:C-Peptide; D007004:Hypoglycemic Agents; D007328:Insulin; D009536:Niacinamide