Sturm Kerstin, MacIntosh Caroline G, Parker Barbara A, Wishart Judith, Horowitz Michael, Chapman Ian M
Department of Medicine, University of Adelaide, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000, Australia.
J Clin Endocrinol Metab. 2003 Aug;88(8):3747-55. doi: 10.1210/jc.2002-021656.
Aging is associated with a reduction in appetite and food intake, predisposing to protein-energy malnutrition. The causes of this "anorexia of aging" are largely unknown. To investigate possible contributions of enhanced satiating effects of cholecystokinin (CCK) and reduced stimulation of food intake by ghrelin, eight undernourished older women [age, 80.4 +/- 2.6 yr; body mass index (BMI), 16.9 +/- 0.57 kg/m(2)], eight well-nourished older women (age, 77 +/- 0.9 yr; BMI, 23.7 +/- 0.8 kg/m(2)), and eight well-nourished young women (age, 22 +/- 1.3 yr; BMI, 20.5 +/- 0.4 kg/m(2)), in randomized order, ate on 1 d a 280-kCal preload and on the other no preload, 90 min before an ad libitum meal. At baseline the undernourished, but not the well-nourished, older subjects were less hungry (P < 0.05) than young subjects. Before and after the preload, plasma CCK levels were higher (P < 0.05) in the older than young subjects, with no difference between the older groups. Plasma ghrelin concentrations were higher in the undernourished than both well-nourished groups and decreased similarly after the preload in all groups. The preload suppressed food intake in the well-nourished older and young subjects (P < 0.05), but was without effect in the undernourished old. These observations suggest that reduced basal hunger, rather than increased meal-induced satiety, contributes to the anorexia of aging and that changes in CCK and ghrelin are unlikely to be responsible.
衰老与食欲和食物摄入量的减少有关，易导致蛋白质 - 能量营养不良。这种“衰老性厌食”的原因在很大程度上尚不清楚。为了研究胆囊收缩素（CCK）饱腹感增强和胃饥饿素对食物摄入刺激减少可能产生的影响，8名营养不良的老年女性[年龄，80.4±2.6岁；体重指数（BMI），16.9±0.57kg/m²]、8名营养良好的老年女性（年龄，77±0.9岁；BMI，23.7±0.8kg/m²）和8名营养良好的年轻女性（年龄，22±1.3岁；BMI，20.5±0.4kg/m²），按随机顺序，在随意进餐前90分钟，一天进食280千卡的预负荷食物，另一天不进食预负荷食物。在基线时，营养不良的老年受试者（而非营养良好的老年受试者）比年轻受试者饥饿感更低（P<0.05）。预负荷前后，老年受试者的血浆CCK水平高于年轻受试者（P<0.05），老年组之间无差异。营养不良组的血浆胃饥饿素浓度高于两个营养良好组，且所有组在预负荷后均有类似程度的下降。预负荷抑制了营养良好的老年和年轻受试者的食物摄入量（P<0.05），但对营养不良的老年人无效。这些观察结果表明，基础饥饿感降低而非进餐诱导的饱腹感增加导致了衰老性厌食，并且CCK和胃饥饿素的变化不太可能是其原因。
