Independent association of increased trunk fat with increased arterial stiffening in postmenopausal patients with rheumatoid arthritis.

OBJECTIVE: We recently reported increased arterial thickening and stiffening in patients with rheumatoid arthritis (RA) to which inflammation and increased bone resorption contributed. The current study examined the possible involvement of trunk fat in increased arterial stiffening in postmenopausal patients with RA.
METHODS: RA patients (n = 30) and healthy controls (n = 30), all postmenopausal women, were examined for body adiposity and brachial-ankle pulse wave velocity (baPWV) by dual-energy x-ray absorptiometry and waveform analyzer, respectively. Subjects having other diseases and predisposed to atherosclerosis were excluded. Trunk:peripheral fat ratio was calculated as the fat mass of the trunk divided by the sum of the fat mass of arms and legs. Bone mineral density (BMD) at ultradistal radius was measured by peripheral quantitative computed tomography. Inflammation markers and bone resorption markers were also measured.
RESULTS: Age, body mass index, and systolic blood pressure (BP) of RA patients were 60.8 +/- 9.8 years, 22.5 +/- 3.3, and 129.6 +/- 20.8 mm Hg, respectively, which did not differ from data from healthy controls. Duration of RA was 10.4 years with mean daily dose of prednisolone 3.02 +/- 3.85 mg. RA patients exhibited a significantly greater trunk:peripheral fat ratio (1.041 +/- 0.253 vs 0.839 +/- 0.223; p < 0.001) and baPWV value (1544.7 +/- 304.9 vs 1373.8 +/- 256.1; p < 0.005) than healthy controls. In RA patients, age (r = 0.588, p < 0.001), systolic BP (r = 0.553, p < 0.005), trabecular BMD at ultradistal radius (r = -0.346, p = 0.061), and trunk:peripheral fat ratio (r = 0.366, p = 0.046) were correlated with baPWV. Trunk:peripheral fat ratio did not differ significantly between RA patients with and those without prednisolone treatment. In multiple regression analysis that included age, systolic BP, and trunk:peripheral fat ratio as independent variables, the trunk:peripheral fat ratio emerged as an independent factor significantly associated with baPWV in RA patients. When trabecular BMD at ultradistal radius was inserted in place of trunk:peripheral fat ratio, it emerged as a factor that was significantly associated with baPWV.
CONCLUSION: We showed that increased trunk fat was significantly and independently associated with increased arterial stiffening in postmenopausal patients with RA.