Normal secretion and action of the gut incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide in young men with low birth weight

Abstract

Context: Low birth weight (LBW) is associated with increased risk of type 2 diabetes mellitus. An impaired incretin effect was reported previously in type 2 diabetic patients. Objective: We studied the secretion and action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in young LBW men (n = 24) and matched normal birth weight controls (NBW) (n = 25). Results: LBW subjects were 5 cm shorter but had a body mass index similar to NBW. LBW subjects had significantly elevated fasting and postprandial plasma glucose, as well as postprandial (standard meal test) plasma insulin and C-peptide concentrations, suggestive of insulin resistance. Insulin secretion in response to changes in glucose concentration ("β-cell responsiveness") during the meal test was similar in LBW and NBW but inappropriate in LBW relative to insulin sensitivity. Fasting and postprandial plasma GLP-1 and GIP levels were similar in the groups. First- and second-phase insulin responses were similar in LBW and NBW during a hyperglycemic clamp (7 mM) with infusion of GLP-1 or GIP, respectively, demonstrating normal action of these hormones on insulin secretion. Conclusion: Reduced secretion or action of GLP-1 or GIP does not explain a relative reduced β-cell responsiveness to glucose or the slightly elevated plasma glucose concentrations observed in young LBW men. Copyright © 2005 by The Endocrine Society.