Cardiovascular risk factors associated with polymyalgia rheumatica and giant cell arteritis in a prospective cohort: EPIC-Norfolk Study.

OBJECTIVES

PMR and GCA are associated with increased risk of vascular disease. However, it remains unclear whether this relationship is causal or reflects a common underlying propensity. The aim of this study was to identify whether known cardiovascular risk factors increase the risk of PMR and GCA.

METHODS

Clinical records were examined using key word searches to identify cases of PMR and GCA, applying current classification criteria in a population-based cohort. Associations between cardiovascular risk factors and incident PMR and GCA were analysed using Cox proportional hazards.

RESULTS

In 315 022 person years of follow-up, there were 395 incident diagnoses of PMR and 118 incident diagnoses of GCA that met the clinical definition. Raised diastolic blood pressure (>90 mmHg) at baseline/recruitment was associated with subsequent incident PMR [hazard ratio=1.35 (95% CI 1.01, 1.80) P=0.045], and ever-smoking was associated with incident GCA [hazard ratio=2.01 (95% CI 1.26, 3.20) P=0.003]. Estimates were similar when the analysis was restricted to individuals whose diagnoses satisfied the current classification criteria sets.

CONCLUSION

PMR and GCA shares common risk factors with vascular disease onset, suggesting a common underlying propensity. This may indicate a potential for disease prevention strategies through modifying cardiovascular risk.