Universidade da Coruña, DICOMOSA Group, Department of Psychology, Area of Psychobiology, A Coruña, Spain; ISPUP-EPIUnit, Universidade do Porto, Porto, Portugal.
Universidade da Coruña, DICOMOSA Group, Department of Psychology, Area of Psychobiology, A Coruña, Spain; Universidade da Coruña, Department of Cell and Molecular Biology, A Coruña, Spain.
Exp Gerontol. 2018 Oct 2;112:119-126. doi: 10.1016/j.exger.2018.09.010. Epub 2018 Sep 18.
Frailty is a progressive physiologic decline in multiple body systems, characterized by loss of function, loss of physiologic reserve, and increased vulnerability to disease and death. This condition is induced by a complex and multifactorial interaction between genetic, biological, physical, psychological and environmental factors. To understand the interplay between the age-related decline of the immune response, and the upregulation of the inflammatory response, the so called inflammaging, we investigated the role of different inflammatory mediators on frailty status in the elderly. The study was performed in a population of 180 older adults (≥65 years), who were classified according to Fried's frailty phenotype. Plasma concentrations of neopterin, tryptophan, kynurenine, phenylalanine, tyrosine as well as kynurenine/tryptophan (Kyn/Trp) and phenylalanine/tyrosine (Phe/Tyr) ratios were analyzed as immune stimulation biomarkers. In addition, nitrite and C-reactive protein levels were measured as indicators of nitric oxide production and acute inflammation, respectively. Significant increases in neopterin, C-reactive protein and Kyn/Trp ratio, and decreases in tryptophan and nitrite concentrations in frail individuals compared with non-frail group were found. Both Kyn/Trp and Phe/Tyr ratios were significantly and positively correlated with neopterin. A positive correlation between kynurenine and tryptophan was also observed. Four parameters, i.e., neopterin, tryptophan, nitrite and C-reactive protein, were found to be strongly related to frailty status, although only nitrite confirmed its role of predictor after multiple regression analysis, supporting its use as a potential biomarker of frailty. Further investigation is required to strengthen the consistence and reproducibility of these findings, and to establish this parameter as a clinical biomarker of frailty.
衰弱是一种多系统生理衰退的进行性疾病，其特征是功能丧失、生理储备减少以及对疾病和死亡的易感性增加。这种情况是由遗传、生物、物理、心理和环境因素之间复杂的多因素相互作用引起的。为了了解免疫反应随年龄的衰退与炎症反应的上调（所谓的炎症衰老）之间的相互作用，我们研究了不同炎症介质在老年人衰弱状态中的作用。该研究在 180 名老年人（≥65 岁）中进行，根据 Fried 的衰弱表型进行分类。分析了血浆中新蝶呤、色氨酸、犬尿氨酸、苯丙氨酸、酪氨酸以及犬尿氨酸/色氨酸（Kyn/Trp）和苯丙氨酸/酪氨酸（Phe/Tyr）比值作为免疫刺激生物标志物的浓度。此外，还测量了亚硝酸盐和 C-反应蛋白水平，作为一氧化氮产生和急性炎症的指标。与非衰弱组相比，衰弱个体的新蝶呤、C-反应蛋白和 Kyn/Trp 比值显著增加，色氨酸和亚硝酸盐浓度显著降低。Kyn/Trp 和 Phe/Tyr 比值与新蝶呤呈显著正相关。还观察到犬尿氨酸和色氨酸之间存在正相关。新蝶呤、色氨酸、亚硝酸盐和 C-反应蛋白 4 个参数与衰弱状态密切相关，尽管只有亚硝酸盐在多元回归分析后证实了其作为预测因子的作用，支持其作为衰弱的潜在生物标志物。需要进一步研究以增强这些发现的一致性和可重复性，并将该参数确立为衰弱的临床生物标志物。
