The GLP-1 response to glucose does not mediate beta and alpha cell dysfunction in Hispanics with abnormal glucose metabolism.

Abstract

AIMS:

Glucagon-like peptide-1 (GLP-1) contributes to insulin secretion after meals. Though Hispanics have increased risk for type 2 diabetes mellitus, it is unknown if impaired GLP-1 secretion contributes to this risk. We therefore studied plasma GLP-1 secretion and action in Hispanic adults.

METHODS:

Hispanic (H; n = 31) and non-Hispanic (nH; n = 15) participants underwent an oral glucose tolerance test (OGTT). All participants were categorized by glucose tolerance into four groups: normal glucose tolerant non-Hispanic (NGT-nH; n = 15), normal glucose tolerant Hispanic (NGT-H; n = 12), impaired glucose tolerant Hispanic (IGT-H; n = 11), or newly diagnosed type 2 diabetes mellitus, Hispanic (T2D-H; n = 8).

RESULTS:

Glucose-induced increments in plasma GLP-1 (Δ-GLP-1) were not different in NGT-H and NGT-nH (p = .38), nor amongst Hispanic subgroups with varying degrees of glucose homeostasis (p = .6). In contrast, the insulinogenic index in T2D-H group was lower than the other groups (p = .016). Subjects with abnormal glucose homeostasis (AGH), i.e., T2D-H plus IGT-H, had a diminished glucagon suppression index compared to patients with normal glucose homeostasis (NGT-H plus NGT-nH) (p = .035).

CONCLUSIONS:

GLP-1 responses to glucose were similar in Hispanic and Non-Hispanic NGT. Despite similar glucose-induced Δ-GLP-1, insulin and glucagon responses were abnormal in T2D-H and AGH, respectively. Thus, impaired GLP-1 secretion is unlikely to play a role in islet dysfunction in T2D. Although GLP-1 therapeutics enhance insulin secretion and glucagon suppression, it is likely due to pharmacological amplification of the GLP-1 pathways rather than treatment of hormonal deficiency.

• Authors: Elizabeth Adams, Pauline Genter, Emma Keefe, Kevin Sandow, Virginia Gray, Jerome I Rotter, Yii-Der Ida Chen, Eli Ipp
• Journal: Diabetes research and clinical practice (Diabetes Res Clin Pract) Vol. 135 Pg. 185-191 (Jan 2018) ISSN: 1872-8227 [Electronic] Ireland
• PMID: 29155153 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• Blood Glucose
• Glucagon-Like Peptide 1

Topics

• Adult
• Blood Glucose (metabolism)
• Diabetes Mellitus, Type 2 (blood)
• Female
• Glucagon-Like Peptide 1 (blood)
• Glucose Intolerance (blood)
• Hispanic or Latino
• Humans
• Male
• Middle Aged