title: Clinical Characteristics and Metabolic Predictors of Rapid Responders to Dipeptidyl Peptidase-4 Inhibitor as an Add-on Therapy to Sulfonylurea and Metformin.
abstract: BACKGROUND
  Dipeptidyl peptidase-4 (DPP-4) inhibitor add-on therapy is a new option for patients with inadequately controlled type 2 diabetes who are taking combined metformin and sulfonylurea (SU). We evaluated the efficacy and safety of this triple therapy and the characteristics of rapid responders and hypoglycemia-prone patients.
  
  
  METHODS
  We included 807 patients with type 2 diabetes who were prescribed a newly added DPP-4 inhibitor to ongoing metformin and SU in 2009 to 2011. Glycemia and other metabolic parameters at baseline, 12, 24, and 52 weeks, as well as episodes of hypoglycemia were analyzed. Rapid responders were defined as patients with ≥25% reduction in glycosylated hemoglobin (HbA1c) within 12 weeks.
  
  
  RESULTS
  At baseline, while on the submaximal metformin and SU combination, the mean HbA1c level was 8.4%. Twelve weeks after initiation of DPP-4 inhibitor add-on, 269 patients (34.4%) achieved an HbA1c level ≤7%. Sixty-six patients (8.2%, 47 men) were rapid responders. The duration of diabetes was shorter in rapid responders, and their baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and homeostasis model assessment of insulin resistance were significantly higher. Patients who experienced hypoglycemia after taking DPP-4 inhibitor add-on were more likely to be female, to have a lower body weight and lower triglyceride and FPG levels, and to have higher homeostasis model assessment of β-cells.
  
  
  CONCLUSIONS
  An oral hypoglycemic triple agent combination including a DPP-4 inhibitor was effective in patients with uncontrolled diabetes. Proactive dose reduction of SU should be considered when a DPP-4 inhibitor is added for rapid responders and hypoglycemia-prone patients.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea.
authors.forename: Ye An
authors.initials: YA
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
authors.forename: Won Sang
authors.initials: WS
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Konkuk University Chungju Hospital, Konkuk University School of Medicine, Chungju, Korea.
authors.forename: Eun Shil
authors.initials: ES
authors.lastname: Hong
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju, Korea.
authors.forename: Eu Jeong
authors.initials: EJ
authors.lastname: Ku
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Kyeong Seon
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Soo
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyong Soo
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Hak Chul
authors.initials: HC
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.|Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea. drshchoi@snu.ac.kr.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
keywords: Combination; Diabetes mellitus, type 2; Dipeptidyl-peptidase IV inhibitors; Hypoglycemia; Response; Sulfonylurea compounds