title: C-Peptide Levels Predict the Effectiveness of Dipeptidyl Peptidase-4 Inhibitor Therapy.
abstract: Background. Our aim was to define the conditions that affect therapeutic success when dipeptidyl peptidase-4 (DPP-4) inhibitor is added to metformin monotherapy.Materials and Methods. We reviewed the medical records of 56 patients who had received DPP-4 inhibitor as an add-on to metformin monotherapy and evaluated their response in the first year of therapy. Fasting blood glucose (FBG), HbA1c, C-peptide, and weight of the patients were recorded at 3-month intervals during the first year of treatment.Results. Patients who added DPP-4 inhibitor to metformin monotherapy had significant weight loss (P= 0.004) and FBG and HbA1c levels were significantly lowered during the first 6 months (bothP< 0.001). Baseline levels of C-peptide were predictive for success of the treatment (P= 0.02), even after correction for confounding factors, for example, age, gender, or BMI (P= 0.03). Duration of diabetes was not a predictor of response to treatment (P= 0.60).Conclusion. Our study demonstrates that in patients having inadequate glycemic control, the addition of a DPP-4 inhibitor as a second oral agent to metformin monotherapy provides better glycemic control, protectsβ-cell reserves, and does not cause weight gain. These effects depend on baseline C-peptide levels.
authors.affiliation: Department of Family Medicine, Eleskirt Public Hospital, 04600 Agri, Turkey.
authors.forename: Sevin
authors.initials: S
authors.lastname: Demir
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Kartal Dr. Lutfi Kirdar Training and Research Hospital, 34890 Istanbul, Turkey.
authors.forename: Sule
authors.identifier: 0000-0002-0450-755X
authors.initials: S
authors.lastname: Temizkan
authors.affiliation: Department of Family Medicine, Medeniyet University Goztepe Training and Research Hospital, 34722 Istanbul, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Sargin
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D000068900:Sitagliptin Phosphate / Q000627:therapeutic use*; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin; D000068900:Sitagliptin Phosphate; C517652:hemoglobin A1c protein, human