Sørensen Cecilie J, Pedersen Ole B, Petersen Mikkel S, Sørensen Erik, Kotzé Sebastian, Thørner Lise W, Hjalgrim Henrik, Rigas Andreas S, Møller Bjarne, Rostgaard Klaus, Riiskjær Mads, Ullum Henrik, Erikstrup Christian
Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark.
Department of Clinical Immunology, Næstved Sygehus, Næstved, Denmark.
PLoS One. 2014 Feb 6;9(2):e88196. doi: 10.1371/journal.pone.0088196. eCollection 2014.
C-reactive protein (CRP) is a well-established marker of inflammation. The level of CRP is affected by several lifestyle factors. A slightly increased CRP level, also known as low-grade inflammation (LGI), is associated with increased risk of several diseases, especially cardiovascular disease. The aim of this study was to identify predictors of increased CRP levels in healthy individuals. We therefore assessed CRP in a large cohort of blood donors.
We measured plasma CRP levels in 15,684 participants from the Danish Blood Donor Study. CRP was measured by a commercial assay. Furthermore, all participants completed a standard questionnaire on smoking status, alcohol consumption, physical activity, diet, and various body measurements. Female participants also reported the use of contraception, childbirth, and menopausal status. The relationship between LGI (defined here as a plasma CRP level between 3 mg/L and 10 mg/L) and predictors was explored by multivariable logistic regression analysis. Results were presented as odds ratios (OR) with 95% confidence intervals (CI).
We found LGI in a total of 1,561 (10.0%) participants. LGI was more frequent in women using combined oral contraception (OC) (29.9%) than in men (6.1%) and women not using OC (7.9%). Among premenopausal women, OC was the strongest predictor of LGI (odds ratio = 8.98, p<0.001). Additionally, body mass index (BMI) and waist circumference were positively associated with LGI.
High BMI and abdominal obesity strongly predicted LGI among healthy individuals. However, the most striking finding was the high prevalence of LGI among premenopausal women who used combined oral contraception. Although the significance of CRP as a marker of inflammation is well known, the role of CRP in pathogenesis is still uncertain. The impact of oral contraception on CRP levels should nevertheless be considered when CRP is used in risk assessment.
C反应蛋白（CRP）是一种公认的炎症标志物。CRP水平受多种生活方式因素影响。CRP水平轻度升高，也称为低度炎症（LGI），与多种疾病风险增加相关，尤其是心血管疾病。本研究旨在确定健康个体中CRP水平升高的预测因素。因此，我们在一大群献血者中评估了CRP。
我们在丹麦献血者研究的15684名参与者中测量了血浆CRP水平。CRP通过商业检测方法进行测量。此外，所有参与者都完成了一份关于吸烟状况、饮酒、体育活动、饮食和各种身体测量的标准问卷。女性参与者还报告了避孕措施的使用、生育情况和绝经状态。通过多变量逻辑回归分析探讨LGI（此处定义为血浆CRP水平在3mg/L至10mg/L之间）与预测因素之间的关系。结果以比值比（OR）和95%置信区间（CI）表示。
我们共在1561名（10.0%）参与者中发现了LGI。使用复方口服避孕药（OC）的女性中LGI更为常见（29.9%），高于男性（6.1%）和未使用OC的女性（7.9%）。在绝经前女性中，OC是LGI最强的预测因素（比值比 = 8.98，p<0.001）。此外，体重指数（BMI）和腰围与LGI呈正相关。
高BMI和腹部肥胖强烈预测健康个体中的LGI。然而，最显著的发现是使用复方口服避孕药的绝经前女性中LGI的高患病率。尽管CRP作为炎症标志物的重要性已广为人知，但其在发病机制中的作用仍不确定。然而，在将CRP用于风险评估时，仍应考虑口服避孕药对CRP水平的影响。
