A controlled comparison of brachial artery flow mediated dilation (FMD) and digital pulse amplitude tonometry (PAT) in the assessment of endothelial function in systemic lupus erythematosus.

The utility of flow mediated dilation (FMD) a measure of endothelial function is limited by operator dependence. Pulse amplitude tonometry (PAT) is a novel, less operator-dependent technique to assess endothelial function. This study compares PAT to FMD in SLE and controls. Thirty women with SLE and 31 controls were enrolled. Medications, cardiovascular disease and risk factors, SLE activity (SLAM-R) and damage (SLICC-DI) were recorded. FMD and PAT were performed simultaneously. Endothelium-independent function was assessed with nitroglycerin. Average age was 48.3 +/- 10.1 years, SLE duration 16.2 years, SLAM-R 8.3 and SLICC-DI 1.0. Framingham Risk Scores were < or =2% in most subjects. There were no differences between SLE cases and controls in FMD, PAT or response to nitroglycerin. This study found no association between FMD and PAT in SLE or controls. In the 17 SLE cases with a history of Raynaud's, correlation between FMD and PAT was 0.50 (P = 0.04). There was no difference in endothelial function assessed by FMD or PAT in SLE cases versus controls. FMD did not correlate with PAT except in SLE cases with a history of Raynaud's. Correlation between FMD and PAT may be stronger in populations with greater variation in endothelial function and more cardiovascular risk factors.

Predictors of bone density testing in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis (RA) are at increased risk of low bone density and fractures. This study identifies predictors of initiation of dual energy X-ray absorptiometry (DXA) testing in RA. We identified RA patients from the CORRONA registry with >or=1 year follow-up without reported DXA at study entry. The primary outcome was report of DXA in the first year of follow-up (DXA initiation). Variables associated with DXA initiation were considered for the multivariate model. Stepwise logistic regression identified independent predictors. Of the 2,717 RA patients without DXA documented at enrollment, 297 (11%) reported DXA initiation. Independent predictors of DXA initiation included age, female sex, history of fracture, steroid use, and physician's assessment of RA activity. In conclusion, DXA initiation in RA patients in the CORRONA cohort is low despite increased risk of osteoporosis. Predictors of DXA initiation include fracture, common risk factors for osteoporosis, and RA-associated factors.