Hemoglobin A1c, Not Glycated Albumin, Can Independently Reflect the Ankylosing Spondylitis Disease Activity Score

OBJECTIVE: This study examined whether glycated hemoglobin (HbA1c) and glycated albumin (GA) are well correlated with the Ankylosing Spondylitis Disease Activity Score (ASDAS)-erythrocyte sedimentation rate (ESR), and ASDAS-C-reactive protein (CRP) in AS patients without medical conditions affecting the glycated protein levels. METHODS: The data of 76 patients with AS were analyzed. Univariate and multivariate analyses of the variables associated with ASDAS-ESR and ASDAS-CRP were performed using a linear regression test. The patients were divided into active and inactive AS groups based on an ASDAS-CRP of 2.1, and the variables between the two groups were compared. RESULTS: ASDAS-ESR did not correlated with either HbA1c or GA. ASDAS-CRP was positively correlated with HbA1c (r=0.315, p=0.006) and the white blood cell (r=0.288, p=0.012), and inversely correlated with hemoglobin (r=−0.241, p=0.036) and serum albumin (r=−0.262, p=0.022), but not GA. Multivariate analysis revealed HbA1c and white blood cell to be significantly correlated with ASDAS-CRP (β=0.234, p=0.033 and β=0.265, p=0.017). The mean HbA1c, not GA, of the active group was significantly higher than that of the inactive group (p=0.020). In addition, the optimal cut-off value of HbA1c was set to 5.6, and the patients with HbA1c ≥5.6 were found to have a 3.3 times higher risk of active AS than those without. CONCLUSION: HbA1c was significantly correlated with ASDAS-CRP, and could be a useful marker to reflect ASDAS-CRP in AS patients without medical conditions affecting the glycated protein levels.

Platelet Distribution Width and Mean Platelet Volume Are Not Correlated with the Disease Activity Indices of Ankylosing Spondylitis

OBJECTIVE: We investigated the association of platelet distribution width (PDW) and mean platelet volume (MPV) with disease activity indices of ankylosing spondylitis (AS) in patients whose laboratory results or medical conditions would not affect PDW and MPV levels. METHODS: We analysed demographic and laboratory data of 88 patients with AS. On the same day as the laboratory tests were done, we assessed AS disease activity using the Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Patients Global Score and Ankylosing Spondylitis Disease Activity Score (ASDAS), including erythrocyte sedimentation rate (ESR) (ASDAS-ESR) and C-reactive protein (CRP) (ASDAS-CRP). The association was analyzed by linear regression. RESULTS: The median age of 88 patients was 38.0 years and the median length of observation was 5.5 years. The median platelet count was 266,500.0/µL, the median PDW was 10.7 fL and the median MPV 9.6 fL. The median ESR was 19.0 mm/hr and CRP was 2.5 mg/L. Among acute reactants, only CRP was negatively correlated with MPV, but not PDW (r=−0.218, p<0.041). However, both PDW and MPV were not significantly correlated with any disease activity index of AS. On multivariate linear regression analysis, only the length of observation was significantly correlated with MPV (β=0.224, p<0.044). CONCLUSION: PDW and MPV were not potent surrogate markers to reflect AS activity, with potential confounding strictly controlled, to affect MPV and PDW levels.