Prevalence of abnormal ankle brachial index in patients with primary Sjogren's syndrome

Chronic inflammatory autoimmune conditions like rheumatoid arthritis and systemic lupus erythematosus are associated with an increased risk of accelerated atherosclerosis (ATS). Very limited data are available about the incidence of ATS in patients with primary Sjogren's syndrome (PSS). Ankle brachial index (ABI) is a recognized method of detecting subclinical atherosclerosis. The objective of this study was to compare the prevalence of abnormal ABI in patients with PSS and in controls without PSS. Twenty-five PSS patients were compared with an age-, ethnicity-, and sex-matched control group. Traditional risk factors such as smoking, high blood pressure, blood sugar, lipids, and family history of atherosclerosis were assessed in both groups. Baseline clinical and laboratory features of PSS patients were recorded. ABI was measured in both groups. ABI less than 1.0 is considered abnormal. Fifty individuals (25 in each group) were studied. PSS patients and controls did not differ significantly in age, sex, and ethnicity. The prevalence of traditional cardiovascular risk factors was the same in both groups. Five out of 25 PSS patients (20%) had an ABI < 1.0 compared to one of 25 (4%) in the control group [P = 0.189 (odds ratio (OR) = 6.000 and 95% confidence interval (CI) 0.6464 to 55.692)]. Eight out of 25 PSS patients (32%) had disease duration of more than 10 years. This group of patients had a higher prevalence of low ABI compared to the individuals with lesser disease duration [P = 0.02 (OR = 16, 95% CI 1.38 to 185)]. PSS patients had a higher prevalence of low ABI, although this did not reach statistical significance. The subgroup of PSS patients with a longer duration of disease had a significantly lower ABI. This study was underpowered and a larger study is required to confirm the findings of this pilot study.