title: Preserved Insulin Secretory Capacity and Weight Loss Are the Predominant Predictors of Glycemic Control in Patients With Type 2 Diabetes Randomized to Roux-en-Y Gastric Bypass.
abstract: Improvement in type 2 diabetes after Roux-en-Y gastric bypass (RYGB) has been attributed partly to weight loss, but mechanisms beyond weight loss remain unclear. We performed an ancillary study to the Diabetes Surgery Study to assess changes in incretins, insulin sensitivity, and secretion 1 year after randomization to lifestyle modification and intensive medical management (LS/IMM) alone (n = 34) or in conjunction with RYGB (n = 34). The RYGB group lost more weight and had greater improvement in HbA1c. Fasting glucose was lower after RYGB than after LS/IMM, although the glucose area under the curve decreased comparably for both groups. Insulin sensitivity increased in both groups. Insulin secretion was unchanged after LS/IMM but decreased after RYGB, except for a rapid increase during the first 30 min after meal ingestion. Glucagon-like peptide 1 (GLP-1) was substantially increased after RYGB, while gastric inhibitory polypeptide and glucagon decreased. Lower HbA1c was most strongly correlated with the percentage of weight loss for both groups. At baseline, a greater C-peptide index and 90-min postprandial C-peptide level were predictive of lower HbA1c at 1 year after RYGB. β-Cell glucose sensitivity, which improved only after RYGB, and improved disposition index were associated with lower HbA1c in both groups, independent of weight loss. Weight loss and preserved β-cell function both predominantly determine the greatest glycemic benefit after RYGB.
authors.affiliation: Division of Endocrinology, Department of Medicine, Columbia University Medical Center, New York, NY.
authors.forename: Kim T
authors.initials: KT
authors.lastname: Nguyen
authors.affiliation: Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Billington
authors.affiliation: Division of Endocrinology and Diabetes, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Adrian
authors.initials: A
authors.lastname: Vella
authors.affiliation: Division of Biostatistics, University of Minnesota, Minneapolis, MN.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Surgery, Columbia University Medical Center, New York, NY.
authors.forename: Leaque
authors.initials: L
authors.lastname: Ahmed
authors.affiliation: Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN.
authors.forename: John P
authors.initials: JP
authors.lastname: Bantle
authors.affiliation: Department of Surgery, Columbia University Medical Center, New York, NY.
authors.forename: Marc
authors.initials: M
authors.lastname: Bessler
authors.affiliation: Division of Biostatistics, University of Minnesota, Minneapolis, MN.
authors.forename: John E
authors.initials: JE
authors.lastname: Connett
authors.affiliation: Department of Surgery, Mount Sinai Medical Center, New York, NY.
authors.forename: William B
authors.initials: WB
authors.lastname: Inabnet
authors.affiliation: Division of Biostatistics, University of Minnesota, Minneapolis, MN.
authors.forename: Avis
authors.initials: A
authors.lastname: Thomas
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, MN.
authors.forename: Sayeed
authors.initials: S
authors.lastname: Ikramuddin
authors.affiliation: Division of Endocrinology, Department of Medicine, Columbia University Medical Center, New York, NY jk181@cumc.columbia.edu.
authors.forename: Judith
authors.initials: J
authors.lastname: Korner
mesh_terms: D052242:Adiponectin / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D002096:C-Peptide / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D015390:Gastric Bypass; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D053767:Glucagon-Like Peptide 2 / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000378:metabolism / Q000601:surgery*; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D002096:C-Peptide; D005749:Gastric Inhibitory Polypeptide; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D053767:Glucagon-Like Peptide 2; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human