Department of Community and Preventive Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA.
Neurotoxicology. 2010 Jan;31(1):126-33. doi: 10.1016/j.neuro.2009.10.005. Epub 2009 Oct 22.
Previous studies have demonstrated increased levels of serum markers of systemic inflammation and immune system function among individuals with depressive symptoms. Despite these observations, the biological mechanisms behind this association remain elusive. The objective of the present analysis was to examine the individual and joint associations of white blood cell counts, platelet counts, and C-reactive protein with depression severity and to determine whether oxidative stress might mediate these associations. We conducted an analysis of 3867 subjects from the 2005-2006 National Health and Nutritional Examination Survey. Ordinal logistic regression was used to assess associations between three levels of depression symptom severity (as measured by the nine-item Patient Health Questionnaire) and serum C-reactive protein, white blood cell counts, platelet counts, and four surrogate markers of oxidative stress. Covariates included sex, age, smoking status, physical activity, education, poverty to income ratio, as well as medication use and medical conditions influencing inflammation levels. In separate models, the risk of moderate to severe depression was significantly greater in the highest quartiles of CRP (OR=1.84. 95 percent confidence interval (CI)=1.35-2.52), WBC (OR=1.70, CI=1.31-2.19), and platelet counts (OR=1.41, CI=1.13-1.76) after adjusting for basic sociodemographic and behavioral factors. After additional adjustment for medication use and oxidative stress surrogate measures, the highest quartile of WBC counts remained associated with depression (OR=1.60, CI=1.23-2.09). Adjustment for oxidative stress measures did not substantially affect estimated associations of inflammation/immunologic markers. In summary, we observed significantly elevated white blood cell counts among subjects with moderate and severe depression, and oxidative stress and a medical history of inflammatory diseases do not appear to mediate this association. Although limited through its use of cross-sectional data, this is the first analysis to simultaneously consider immunologic and oxidative stress markers. Further research is needed to identify the biological basis for this persistent association.
先前的研究表明，患有抑郁症状的个体的血清系统炎症和免疫系统功能的标志物水平升高。尽管有这些观察结果，但这种关联背后的生物学机制仍难以捉摸。本分析的目的是检查白细胞计数、血小板计数和 C 反应蛋白与抑郁严重程度的个体和联合关联，并确定氧化应激是否可能介导这些关联。我们对 2005-2006 年全国健康和营养检查调查中的 3867 名受试者进行了分析。有序逻辑回归用于评估三种抑郁症状严重程度（由九项患者健康问卷测量）与血清 C 反应蛋白、白细胞计数、血小板计数和四种氧化应激替代标志物之间的关联。协变量包括性别、年龄、吸烟状况、身体活动、教育、贫困收入比，以及影响炎症水平的药物使用和医疗状况。在单独的模型中，在 CRP（比值比 [OR]=1.84，95%置信区间 [CI]=1.35-2.52）、WBC（OR=1.70，CI=1.31-2.19）和血小板计数（OR=1.41，CI=1.13-1.76）的最高四分位数的情况下，调整基本社会人口统计学和行为因素后，中度至重度抑郁的风险显著更高。在进一步调整药物使用和氧化应激替代指标后，白细胞计数的最高四分位数仍与抑郁相关（OR=1.60，CI=1.23-2.09）。调整氧化应激指标并没有实质性地影响炎症/免疫标志物的估计关联。总之，我们观察到中度和重度抑郁患者的白细胞计数显著升高，而氧化应激和炎症性疾病的病史似乎并没有介导这种关联。尽管由于使用了横断面数据而受到限制，但这是首次同时考虑免疫和氧化应激标志物的分析。需要进一步研究以确定这种持续关联的生物学基础。
