title: Efficacy and safety of nateglinide plus vildagliptin combination therapy compared with switching to vildagliptin in type 2 diabetes patients inadequately controlled with nateglinide.
abstract: OBJECTIVE
  To investigate the efficacy and safety of vildagliptin, a potent dipeptidyl peptidase-4 inhibitor, as add-on to nateglinide, compared with switching to vildagliptin in Japanese type 2 diabetes patients poorly controlled with nateglinide.
  
  
  METHODS
  A total of 40 patients inadequately controlled with nateglinide were randomized to the switching group (n = 20, switching from nateglinide to vildagliptin) or combination group (n = 20, nateglinide plus vildagliptin). A meal tolerance test was carried out at weeks 0 and 24.
  
  
  RESULTS
  The mean changes in glycated hemoglobin from baseline to week 24 were -1.2 ± 0.3% and -0.3 ± 0.5% in patients of the combination and switching groups, respectively, and the difference between the groups was statistically significant (P < 0.001). The mean changes in area under the curve of glucose from 0 to 180 min (AUC0-180 min) from baseline to week 24 was -361 ± 271.3 mmol·min/L in patients of the combination group compared with 141 ± 241.9 mmol·min/L in those of the switching group (P < 0.001). The incidence of hypoglycemic events was low (three in the combination group), and none of the patients developed severe hypoglycemia. Although the addition of vildagliptin to nateglinide did not significantly increase insulin secretion relative to glucose elevation (ISG) after meal load (ISG0-180 min: AUC0-180 min insulin / AUC0-180 min glucose) in comparison with that in baseline, the mean ISG0-30 min 24 weeks after addition of vildagliptin to nateglinide was significantly higher than that at baseline. In contrast, switching from nateglinide to vildagliptin reduced the mean ISG0-180 min, relative to baseline.
  
  
  CONCLUSIONS
  The combination therapy of vildagliptin and nateglinide is effective and safe in Japanese type 2 diabetes, and the improved glycemic control is as a result of augmentation of nateglinide-induced early phase insulin secretion. This trial was registered with UMIN (no. ID000004010).
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kudo-Fujimaki
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan ; Division of Diabetes, Metabolism and Endocrinology Department of Medicine Toho University School of Medicine Tokyo Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Hirose
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yoshihara
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Sato
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Someya
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Ohmura
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kanazawa
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan ; Center for Therapeutic Innovations in Diabetes Toho University School of Medicine Tokyo Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Fujitani
authors.affiliation: Department of Metabolism and Endocrinology Toho University School of Medicine Tokyo Japan ; Center for Beta-Cell Biology and Regeneration Toho University School of Medicine Tokyo Japan ; Center for Therapeutic Innovations in Diabetes Toho University School of Medicine Tokyo Japan ; Center for Molecular Diabetology Toho University School of Medicine Tokyo Japan ; Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Watada
keywords: Dipeptidyl peptidase‐IV inhibitors; Glinides; Insulin secretion