The ageing entero-insular axis.
Ageing is one of the major risk factors for glucose intolerance including impaired glucose tolerance and Type II (non-insulin-dependent) diabetes mellitus. Reduced insulin secretion has been described as part of normal ageing although there is no information on age-related changes in the secretion of the major insulinotropic hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (7-36 amide) (GLP-1). We assessed the entero-insular axis in 6 young premenopausal and 6 older postmenopausal women following treatment with oral carbohydrate. Insulin and glucose integrated responses were similar in the younger and older groups. Total integrated responses for GIP and GLP-1 were considerably greater in the older subjects. A positive correlation between age and total integrated responses for glucose (r = 0.65; p < 0.02) as well as GLP-1 (r = 0.85; p < 0.001) was seen. We hypothesise that an age-related impairment of insulin secretion to insulinotropic hormones, GIP and GLP-1, contributes to a reduction in glucose tolerance in this age group. The pronounced compensatory increase in postprandial secretion of GIP and GLP-1 provides further evidence not only for the negative feedback relation between incretin and insulin secretion but also for the importance of the entero-insular axis in the regulation of insulin secretion.
Ranganath
L
L
Epsom General Hospital, Surrey, UK.
Sedgwick
I
I
Morgan
L
L
Wright
J
J
Marks
V
V
D000082:Acetaminophen / Q000097:blood / Q000493:pharmacokinetics; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001835:Body Weight; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000503:physiopathology; D004040:Dietary Carbohydrates; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood / Q000378:metabolism*; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D018149:Glucose Intolerance / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D010446:Peptide Fragments / Q000097:blood / Q000378:metabolism*; D017698:Postmenopause / Q000097:blood / Q000502:physiology; D017697:Premenopause / Q000097:blood / Q000502:physiology; D012307:Risk Factors
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D010446:Peptide Fragments; C055453:glucagon-like peptide 1 (7-36)amide; D000082:Acetaminophen; D005749:Gastric Inhibitory Polypeptide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon