Ferraz-Amaro Iván, González-Gay Miguel A, Diaz-González Federico
From the Rheumatology Division, Hospital Universitario de Canarias, Tenerife; Rheumatology Division, Hospital Universitario Marqués de Valdecilla, IFIMAV, Santander; Departamento de Medicina, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain.
J Rheumatol. 2014 Apr;41(4):658-65. doi: 10.3899/jrheum.130834. Epub 2014 Feb 15.
Retinol-binding protein 4 (RBP4), an adipokine related to impaired glucose tolerance, has been associated with insulin resistance (IR) and β-cell function in subjects with obesity or diabetes. In our study we assessed RBP4 levels in patients with rheumatoid arthritis (RA). We also determined whether any correlation exists between RBP4 levels and the presence of IR in these patients.
Plasma RBP4, insulin, C-peptide concentrations, and homeostasis model assessment (HOMA)-IR were measured in 101 patients with RA and 115 sex-matched and age-matched controls. A multivariable analysis adjusted for IR classic cardiovascular risk factors and body mass index was performed to establish the correlation between RBP4 plasma concentrations and features of IR in RA. Data were adjusted for glucocorticoid intake in patients with RA.
Patients had higher levels of insulin, C-peptide levels, HOMA-percentage of β-cell secretion (%B) index, and HOMA-IR index than controls. RBP4 levels were significantly lower in the whole group of patients than in controls [13.99 (9.78-19.88) vs 21.50 (10.28-32.59) μg/ml, p<0.01]. However, only those who were glucocorticoid-naive showed significant difference in RBP4 plasma concentration when compared to controls [11.88 (7.93-17.96) vs 21.50 (10.28-32.59) μg/ml, p<0.01]. The HOMA-%B [log β coefficient 0.00 (0.00-0.01), p<0.01] showed positive relationships regarding RBP4 in controls. That was not the case in patients with RA [log β coefficient 0.00 (-0.0-0.00), p=0.93 for HOMA-%B].
RBP4 does not correlate with the presence of IR and β-cell function in patients with RA. The mechanisms leading to IR in RA may be different from those occurring in obesity or diabetes.
视黄醇结合蛋白4（RBP4）是一种与糖耐量受损相关的脂肪因子，已被证实与肥胖或糖尿病患者的胰岛素抵抗（IR）及β细胞功能有关。在本研究中，我们评估了类风湿关节炎（RA）患者的RBP4水平。我们还确定了这些患者的RBP4水平与IR之间是否存在相关性。
对101例RA患者和115例性别及年龄匹配的对照者测量血浆RBP4、胰岛素、C肽浓度及稳态模型评估（HOMA）-IR。进行多变量分析，校正IR经典心血管危险因素和体重指数，以确定RA患者血浆RBP4浓度与IR特征之间的相关性。对RA患者的糖皮质激素摄入量进行数据校正。
患者的胰岛素、C肽水平、HOMA-β细胞分泌百分比（%B）指数和HOMA-IR指数均高于对照者。患者组的RBP4水平显著低于对照组[13.99（9.78-19.88）对21.50（10.28-32.59）μg/ml，p<0.01]。然而，只有未使用糖皮质激素的患者与对照组相比，RBP4血浆浓度有显著差异[11.88（7.93-17.96）对21.50（10.28-32.59）μg/ml，p<0.01]。在对照组中，HOMA-%B[对数β系数0.00（0.00-0.01），p<0.01]与RBP4呈正相关。在RA患者中则不然[HOMA-%B的对数β系数0.00（-0.0-0.00），p=0.93]。
RA患者的RBP4与IR及β细胞功能不存在相关性。导致RA患者IR的机制可能与肥胖或糖尿病患者不同。
