Division of Rheumatology, Department of Medicine and Pharmacology, Vanderbilt University, Nashville, TN, USA.
Atherosclerosis. 2011 Dec;219(2):869-74. doi: 10.1016/j.atherosclerosis.2011.09.005. Epub 2011 Sep 12.
Free fatty acids (FFAs) affect insulin signaling and are implicated in the pathogenesis of insulin resistance and atherosclerosis. Inflammatory cytokines such as interleukin-6 (IL-6) increase lipolysis and thus levels of FFAs. We hypothesized that increased IL-6 concentrations are associated with increased FFAs resulting in insulin resistance and atherosclerosis in rheumatoid arthritis (RA).
Clinical variables, serum FFAs and inflammatory cytokines, homeostasis model assessment for insulin resistance (HOMA-IR), and coronary artery calcium were measured in 166 patients with RA and 92 controls. We compared serum FFAs in RA and controls using Wilcoxon rank sum tests and further tested for multivariable association by adjusting for age, race, sex and BMI. Among patients with RA, we assessed the relationship between serum FFAs and inflammatory cytokines, HOMA-IR, and coronary artery calcium scores using Spearman correlation and multivariable regression analyses.
Serum FFAs did not differ significantly in patients with RA and controls (0.56mmol/L [0.38-0.75] and 0.56mmol/L [0.45-0.70] respectively, p=0.75). Presence of metabolic syndrome was associated with significantly increased serum FFAs in both RA and controls (p=0.035 and p=0.025). In multivariable regression analysis that adjusted for age, race, sex and BMI, serum FFAs were associated with HOMA-IR (p=0.011), CRP (p=0.01), triglycerides (p=0.005) and Framingham risk score (p=0.048) in RA, but not with IL-6 (p=0.48) or coronary artery calcium score (p=0.62).
Serum FFAs do not differ significantly in patients with RA and controls. FFAs may contribute to insulin resistance, but are not associated with IL-6 and coronary atherosclerosis in RA.
游离脂肪酸（FFAs）会影响胰岛素信号，并且与胰岛素抵抗和动脉粥样硬化的发病机制有关。炎性细胞因子，如白细胞介素-6（IL-6），会增加脂肪分解，从而增加 FFAs 的水平。我们假设，IL-6 浓度的增加与导致类风湿关节炎（RA）中胰岛素抵抗和动脉粥样硬化的 FFAs 增加有关。
我们测量了 166 例 RA 患者和 92 例对照者的临床变量、血清 FFAs 和炎性细胞因子、胰岛素抵抗的稳态模型评估（HOMA-IR）和冠状动脉钙。我们使用 Wilcoxon 秩和检验比较 RA 患者和对照组的血清 FFAs，并进一步通过调整年龄、种族、性别和 BMI 进行多变量关联检验。在 RA 患者中，我们使用 Spearman 相关和多变量回归分析评估了血清 FFAs 与炎性细胞因子、HOMA-IR 和冠状动脉钙评分之间的关系。
RA 患者和对照组的血清 FFAs 无显著差异（分别为 0.56mmol/L [0.38-0.75] 和 0.56mmol/L [0.45-0.70]，p=0.75）。代谢综合征的存在与 RA 和对照组中血清 FFAs 的显著增加相关（p=0.035 和 p=0.025）。在调整年龄、种族、性别和 BMI 的多变量回归分析中，血清 FFAs 与 HOMA-IR（p=0.011）、CRP（p=0.01）、甘油三酯（p=0.005）和 Framingham 风险评分（p=0.048）相关，但与 IL-6（p=0.48）或冠状动脉钙评分（p=0.62）无关。
RA 患者和对照组的血清 FFAs 无显著差异。FFAs 可能导致胰岛素抵抗，但与 RA 中的 IL-6 和冠状动脉粥样硬化无关。
