Charlotte Vaurs1, Jean-Frédéric Brun2, Emilie Bérard3, Mael Chalret du Rieu4, Hélène Hanaire1, Patrick Ritz5. 1. Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France. 2. INSERM U1046, Heart and Muscle Pathophysiology and Experimental Medicine, Metabolic Exploration Unit (CERAMM), Service Central de Physiologie Clinique, Hôpital Lapeyronie, CHU de Montpellier, France. 3. Department of Epidemiology, Health Economics and Public Health, UMR1027 INSERM-University of Toulouse 3, CHU de Toulouse, Toulouse, France. 4. Bariatric Surgery Department, CHU de Toulouse, Toulouse, France. 5. Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France; Department of Epidemiology, Health Economics and Public Health, UMR1027 INSERM-University of Toulouse 3, CHU de Toulouse, Toulouse, France. Electronic address: patrick.ritz@wanadoo.fr.
Abstract
BACKGROUND: Early and intense hyperglycemic peaks are observed after Roux-en-Y gastric bypass (RYGB). OBJECTIVES: The aim of this observational study was to compare the ß-cell pancreatic function of patients with (PEAK) and without hyperglycemic peaks (NOPEAK). SETTING: Referral bariatric surgery center. METHODS: Insulin secretion rate, clearance, and sensitivity and ß-cell and rate sensitivities were computed after a 75-g oral glucose tolerance test in 42 patients who underwent RYGB. RESULTS: PEAK patients (n = 18; 30-min glycemia>10.4 mmol/L) did not differ from NOPEAK patients (n = 24) in their presurgery or weight loss characteristics. PEAK patients had significantly higher plasma concentrations of glucose and C-peptide than did NOPEAK patients, whereas insulin and glucagon-like peptide-1 concentrations did not differ. The insulin secretion rate and whole-body insulin clearance (208%) were significantly greater, but insulin sensitivity was significantly less (48%) in PEAK patients. Insulin secretion normalized to plasma glucose was significantly lower in PEAK patients, and the disposition index was reduced (35% to 41% of the values in NOPEAK patients). CONCLUSION: We conclude that RYGB reveals a series of dysfunctions leading to hyperglycemia in a subset of patients. In PEAK patients, an insufficient adaptation of ß-cell function to glycemia, an increased insulin clearance, and a decreased insulin sensitivity cumulated to contribute to hyperglycemic peaks.
BACKGROUND: Early and intense hyperglycemic peaks are observed after Roux-en-Y gastric bypass (RYGB). OBJECTIVES: The aim of this observational study was to compare the ß-cell pancreatic function of patients with (PEAK) and without hyperglycemic peaks (NOPEAK). SETTING: Referral bariatric surgery center. METHODS:Insulin secretion rate, clearance, and sensitivity and ß-cell and rate sensitivities were computed after a 75-g oral glucose tolerance test in 42 patients who underwent RYGB. RESULTS: PEAK patients (n = 18; 30-min glycemia>10.4 mmol/L) did not differ from NOPEAK patients (n = 24) in their presurgery or weight loss characteristics. PEAK patients had significantly higher plasma concentrations of glucose and C-peptide than did NOPEAK patients, whereas insulin and glucagon-like peptide-1 concentrations did not differ. The insulin secretion rate and whole-body insulin clearance (208%) were significantly greater, but insulin sensitivity was significantly less (48%) in PEAK patients. Insulin secretion normalized to plasma glucose was significantly lower in PEAK patients, and the disposition index was reduced (35% to 41% of the values in NOPEAK patients). CONCLUSION: We conclude that RYGB reveals a series of dysfunctions leading to hyperglycemia in a subset of patients. In PEAK patients, an insufficient adaptation of ß-cell function to glycemia, an increased insulin clearance, and a decreased insulin sensitivity cumulated to contribute to hyperglycemic peaks.