Department of Nursing B, Faculty of Health and Caring Professions, Technological Educational Institute of Athens, Greece.
Neuropeptides. 2013 Feb;47(1):25-36. doi: 10.1016/j.npep.2012.07.007. Epub 2012 Sep 12.
Potential physiological correlates of stress and the role of stress neuropeptides, other than those of the hypothalamic-pituitary-adrenal axis, in critical illness have not been addressed. We investigated: (a) serum levels of stress neuropeptides (ACTH, substance P (SP), neuropeptide Y (NPY), cortisol, prolactin) in critically ill individuals compared to matched controls, (b) associations with lymphocyte counts, (c) associations among stress neuropeptide levels, and (d) associations with perceived intensity of stress, critical illness severity and survival.
Correlational design with repeated measures. Thirty-six critically ill patients were followed up for 14 days compared to 36 healthy matched controls. Stress was assessed by the ICUESS scale. Correlations, cross-sectional comparisons and multiple regression models were pursued.
For the first time, we report lower SP (Difference of means (DM) = 2928-3286 ng/ml, p < 0.001) and NPY (DM = 0.77-0.83 ng/ml, p < 0.0001) levels in critically ill individuals compared to controls. Cortisol levels were higher (DM = 140-173 ng/ml, p<0.0001) and lymphocyte population counts (p < 0.002) were lower in patients throughout the study. NPY levels associated with lymphocyte (r = 0.411-0.664, p < 0.04), T-lymphocyte (r = 0.403-0.781, p< 0.05), T-helper (r = 0.492-0.690, p < 0.03) and T-cytotoxic cell populations (r = 0.39-0.740, p < 0.03). On day 1, cortisol levels exhibited associations with lymphocyte (r = -0.452, p = 0.01), T-cell (r = -0.446, p = 0.02), T-helper (r = -0.428, p = 0.026) and T-cytotoxic cells ( r = -0.426, p = 0.027). ACTH levels associated with NK cell counts (r = 0.326-0.441, p < 0.05). Associations among stress neuropeptides levels were observed throughout (p < 0.05). ACTH levels associated with disease severity (r = 0.340-0.387, p < 0.005). A trend for an association between ACTH levels and intensity of stress was noted (r = 0.340, p = 0.057).
The significantly lowered NPY and SP levels and the associations with cortisol, ACTH and lymphocytes suggest that the role of these peptides in critical illness merit further investigation. Future studies need to address associations between these neuropeptides and functional immune cell responses and inflammatory markers in critical illness.
尚未探讨压力的潜在生理相关性以及除下丘脑-垂体-肾上腺轴以外的应激神经肽在危重病中的作用。我们研究了：（a）与匹配的对照组相比，危重病患者的应激神经肽（ACTH、P 物质（SP）、神经肽 Y（NPY）、皮质醇、催乳素）血清水平，（b）与淋巴细胞计数的相关性，（c）应激神经肽水平之间的相关性，以及（d）与感知到的压力强度、危重病严重程度和存活率的相关性。
采用具有重复测量的相关性设计。与 36 名健康匹配的对照组相比，对 36 名危重病患者进行了为期 14 天的随访。通过 ICUESS 量表评估应激。进行了相关性、横断面比较和多元回归模型分析。
我们首次报告了与对照组相比，危重病患者的 SP（差异均值（DM）=2928-3286ng/ml，p<0.001）和 NPY（DM=0.77-0.83ng/ml，p<0.0001）水平降低。在整个研究过程中，患者的皮质醇水平更高（DM=140-173ng/ml，p<0.0001），淋巴细胞群体计数更低（p<0.002）。NPY 水平与淋巴细胞（r=0.411-0.664，p<0.04）、T 淋巴细胞（r=0.403-0.781，p<0.05）、T 辅助细胞（r=0.492-0.690，p<0.03）和 T 细胞毒性细胞群体（r=0.39-0.740，p<0.03）呈正相关。在第 1 天，皮质醇水平与淋巴细胞（r=-0.452，p=0.01）、T 细胞（r=-0.446，p=0.02）、T 辅助细胞（r=-0.428，p=0.026）和 T 细胞毒性细胞（r=-0.426，p=0.027）呈负相关。ACTH 水平与 NK 细胞计数呈正相关（r=0.326-0.441，p<0.05）。应激神经肽水平之间的相关性贯穿始终（p<0.05）。ACTH 水平与疾病严重程度相关（r=0.340-0.387，p<0.005）。注意到 ACTH 水平与应激强度之间存在关联的趋势（r=0.340，p=0.057）。
NPY 和 SP 水平显著降低，以及与皮质醇、ACTH 和淋巴细胞的相关性提示这些肽类在危重病中的作用值得进一步研究。未来的研究需要解决这些神经肽与危重病中功能性免疫细胞反应和炎症标志物之间的关联。
