The ageing entero-insular axis

Area of Science:

• Endocrinology
• Gerontology
• Metabolic Health

Background:

• Aging is a significant risk factor for glucose intolerance and Type II diabetes.
• While reduced insulin secretion is noted in aging, age-related changes in key insulinotropic hormones like GIP and GLP-1 remain unclear.

Purpose of the Study:

• To investigate the entero-insular axis in young versus older women.
• To assess age-related differences in the secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) after oral carbohydrate intake.

Main Methods:

• Comparative analysis of oral carbohydrate challenge in 6 young premenopausal and 6 older postmenopausal women.
• Measurement of integrated insulin, glucose, GIP, and GLP-1 responses.

Main Results:

• Similar integrated insulin and glucose responses were observed between the younger and older groups.
• Older subjects exhibited significantly greater total integrated responses for both GIP and GLP-1.
• Positive correlations were found between age and integrated glucose response (r=0.65) and GLP-1 response (r=0.85).

Conclusions:

• Age-related impairment in insulin secretion in response to GIP and GLP-1 may contribute to reduced glucose tolerance in older adults.
• The heightened compensatory increase in GIP and GLP-1 secretion underscores the importance of the entero-insular axis in regulating insulin secretion and highlights feedback mechanisms.