[Horton's disease, polymyalgia rheumatica, and cardiovascular risk factors. A case-control, prospective multicenter study]

To assess the potential pathogenetic role of cardiovascular risk factors measured at diagnosis in temporal arteritis.Four hundred newly diagnosed patients and their age- and sex-matched controls randomly selected from the general population were included in a prospective multicentric cas-control study.In female patients, smoking increased the disease risk by a factor of 6 (95% CI: 2-17, p = 0.00006), and by a factor of 17 in case of10 pack-years. Pre-existing peripheral arterial disease increased the risk by a 4.5-fold factor (95% CI: 2-11, p = 0.0003), both in patients with a positive and those with a negative biopsy. Smoking alone appeared as a risk factor for polymyalgia rheumatica (OR: 3,64, 95% CI: 1.07-12.40). In male patients, none of the cardiovascular risk factors studied was positivity associated with the disease.Smoking and a pre-existing peripheral arterial disease are independently associated with temporal arteritis in women. Risk factors for disease with an imbalanced sex ratio should be studied separately for each sex in matched case-control studies in order to avoid matching bias.