title: Retrospective analysis on the efficacy, safety and treatment failure group of sitagliptin for mean 10-month duration.
abstract: BACKGROUND
  To investigate the clinical results of sitagliptin (SITA) and the characteristics of the treatment failure group or of low responders to SITA.
  
  
  METHODS
  A retrospective study of type 2 diabetic patients reviewed 99 cases, including 12 treatment failure cases, who stopped SITA because of worsening patients' condition, and 87 cases, who continued treatment over five visits (total 9.9±10.1 months) after receiving the prescription of SITA from December 2008 to June 2009. Subjects were classified as five groups administered SITA as an initial combination with metformin (MET), add-on to metformin or sulfonylurea, and switching from sulfonylurea or thiazolidinedione. The changes in HbA1c level from the first to last visit (ΔHbA1c) in treatment maintenance group were subanalyzed.
  
  
  RESULTS
  The HbA1c level was significantly reduced in four groups, including initial coadministration of SITA with metformin (ΔHbA1c=-1.1%, P<0.001), add-on to MET (ΔHbA1c=-0.6%, P=0.017), add-on to sulfonylurea (ΔHbA1c=-0.5%, P<0.001), and switching from thiazolidinedione (ΔHbA1c=-0.3%, P=0.013). SITA was noninferior to sulfonlyurea (ΔHbA1c=-0.2%, P=0.63). There was no significant adverse effect. The treatment failure group had a longer diabeties duration (P=0.008), higher HbA1c (P=0.001) and fasting plasma glucose (P=0.003) compared to the maintenance group. Subanalysis on the tertiles of ΔHbA1c showed that low-response to SITA (tertile 1) was associated with a longer diabetes duration (P=0.009) and lower HbA1c (P<0.001).
  
  
  CONCLUSIONS
  SITA was effective and safe for use in Korean type 2 diabetic patients. However, its clinical responses and long-term benefit-harm profile is yet to be established.
authors.affiliation: Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Kim
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
authors.forename: Eun Haeng
authors.initials: EH
authors.lastname: Jeong
authors.forename: Jeong Youn
authors.initials: JY
authors.lastname: Seo
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Seol
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Rhee
authors.forename: Won Young
authors.initials: WY
authors.lastname: Lee
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Oh
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Sun Woo
authors.initials: SW
authors.lastname: Kim