Risk factors, coronary artery disease and mortality in giant cell arteritis: a population-based study

Abstract

Giant Cell arteritis (GCA) is a systemic inflammatory disease that affects arteries of medium- and large size. Symptoms of GCA such as headache and fever usually promptly improve with treatment of glucocorticoids. Apart from advanced age, female sex and Northern-European descent, risk factors for GCA are unknown. Most studies have found that life expectancy for patients with GCA is not reduced compared with the general population and studies on cardiovascular disease in GCA have provided conflicting results.

Data for the studies of this thesis are drawn from the Reykjavik Study (RS) that is a general population-based cohort study with continuous surveillance for coronary heart disease and vital status. Subjects born in 1907–1934 and living in Reykjavik, Iceland or adjacent communities in 1966 were invited for study visit from 1967-1994. Information on cardiovascular risk factors were collected at study visit. Diagnosis of GCA for this study was based on re-examination of all temporal arteries biopsies (TAB) from members of the RS cohort; however, information was also obtained from the original pathology report.

Of 19,360 subjects included in the RS, 194 developed GCA during the follow-up period. Body mass index was inversely associated with the occurrence of GCA. Among men, but not women, hypertension was associated and smoking inversely associated with the occurrence of GCA. Among women, but not men, GCA was associated with coronary heart disease. Subjects with GCA had approximately 50% increase in mortality risk compared with the general population. Increase mortality was mainly observed among GCA patients based on the diagnosis of re-examination of TAB; however, no such an association was found if diagnosis of GCA was made based on the original pathology report. Those subjects were likely not clinically diagnosed with GCA, signaling that treatment for GCA might be beneficial with respect to mortality risk.