老龄对下丘脑-垂体前叶功能的影响

Aging-related changes of hypothalamic-anterior pituitary function

老年人下丘脑-垂体前叶的功能变化主要包括两方面,一是与正常老龄过程相关的下丘脑-垂体功能变化,如生长激素（GH）-胰岛素样生长因子Ⅰ（IGF-Ⅰ）轴活性降低以及CRH-ACTH轴功能活跃等;二是老年人垂体前叶本身亦可因疾病而出现激素分泌功能低下,如鞍区肿瘤、缺血、纤维化等所致垂体前叶功能受损.对于下丘脑-垂体前叶功能改变的老年患者,临床上需仔细分析判断系老龄伴随的生理现象,还是疾病所致的病理过程.国内外学术界对于正常老龄过程中出现的垂体前叶功能变化是否需要干预存在诸多争议,而老年人垂体前叶功能低下的临床表现缺乏特异性,极易与正常老龄的生理功能变化混淆而漏诊.本文将简述老龄相关的GH-IGF-Ⅰ轴以及CRH-ACTH轴功能变化及其临床意义,并讨论老年人垂体前叶功能减退临床诊治中需注意的问题.

The changes in hypothalamic-pituitary function in older people include the effects of aging per se on hypothalamic-pituitary physiology,such as age-related declines in GH-IFG-1 system and increased activity in CRH-ACTH axis,and the hormone hyposecretion due to anterior pituitary diseases in elderly,including fibrosis and vascular alterations.In considering changes in hypothalamic-pituitary function in older people,it is important to distinguish between what is age-related and what is disease-related.Symptoms associated with hypopituitarism are nonspecific and may be often attributed to normal aging and can be challenging in clinical practice.Furthermore,the benefits and safety of selective pituitary hormonal replacement,including growth hormone replacement,remain controversial in the elderly.The evidence for age-related changes in GH-IGF-1 system and CRH-ACTH axis and their clinical consequences are reviewed.The characteristics in the clinical approach to disease-related hypopituitarism in older person are also briefly discussed.