Ranganath L, Sedgwick I, Morgan L, Wright J, Marks V
Epsom General Hospital, Surrey, UK.
Diabetologia. 1998 Nov;41(11):1309-13. doi: 10.1007/s001250051070.
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.
衰老是非胰岛素依赖型糖尿病（NIDDM）和糖耐量受损（IGT）等糖耐量异常的主要危险因素之一。尽管目前尚无关于主要促胰岛素激素——葡萄糖依赖性促胰岛素多肽（GIP）和胰高血糖素样肽（7-36酰胺）（GLP-1）分泌的年龄相关性变化的信息，但胰岛素分泌减少已被描述为正常衰老的一部分。我们评估了6名年轻绝经前女性和6名老年绝经后女性口服碳水化合物后的肠-胰岛轴。年轻组和老年组的胰岛素和葡萄糖综合反应相似。老年受试者中GIP和GLP-1的总综合反应显著更大。年龄与葡萄糖（r = 0.65；p < 0.02）以及GLP-1（r = 0.85；p < 0.001）的总综合反应之间呈正相关。我们推测，年龄相关的对促胰岛素激素GIP和GLP-1的胰岛素分泌受损，导致了该年龄组糖耐量的降低。餐后GIP和GLP-1分泌的显著代偿性增加不仅为肠促胰岛素与胰岛素分泌之间的负反馈关系提供了进一步证据，也为肠-胰岛轴在胰岛素分泌调节中的重要性提供了进一步证据。
