Association of blood pressure and hypertension with radiographic damage among the patients with ankyloing spondylitis

To investigate the association of blood pressure and hypertension with disease severity among the patients with ankyloing spondylitis (AS). There were 167 AS patients enrolled in the cross-sectional study. Blood pressure was measured and the presence of hypertension was recorded. Patient’s disease severity, including disease activity, functional ability, patient’s global assessments, physical mobility and radiographic damage were evaluated. ESR and CRP levels were tested. We recorded patient’s medication use of NSAIDs, DMARDs and TNF-α blockers. Smoking, exercise habit, diabetes mellitus, hypercholesterolemia and obesity indices were assessed. Multivariate linear regression showed that systolic blood pressure was associated with TNF-α blocker [standard coefficient (β) = 0.194, P = .007], DMARDs (β = 0.142, P = .046), age (β = 0.211, P = .003), male gender (β = 0.242, P = .001) and body mass index (BMI) (β = 0.245, P = .001). Diastolic blood pressure was associated with cervical rotation (β = −0.174, P = .037), lateral lumbar flexion (β = −0.178, P = .019), m-SASSS (β = 0.198, P = .038) and BMI (β = 0.248, P = .003). Notably, multivariate logistic regression showed that hypertension was associated with m-SASSS (OR = 1.033, P = .033), age (OR = 1.098, P = .0010) and BMI (OR = 1.210, P = .003). Using ROC cure analyses, age, BASMI, BASRI-Total, m-SASSS, waist circumference, BMI and waist-to-height ratio were useful in predicting hypertension, and m-SASSS is the best (AUC = 0.784, P < .001). Advanced radiographic damage is an independent risk factor of hypertension in AS, and m-SASSS is the most useful disease severity parameter in predicting the presence of hypertension. Advanced radiographic damage, poor cervical rotation, lateral lumbar flexion, older age, male gender, TNF-α blocker, DMARDs use and obesity are associated with increased blood pressure.