Autoimmune diseases and cardiovascular risk: a population-based study on 19 autoimmune diseases and 12 cardiovascular diseases in 22 million individuals in the UK

Background Some autoimmune diseases are associated with an increased risk of cardiovascular disease. We aimed to determine whether or not this is true, and to what extent, for a broad range of autoimmune conditions. Methods In this population-based study, we used linked primary and secondary care records from the Clinical Practice Research Datalink (CPRD), GOLD and Aurum datasets, to assemble a cohort of individuals across the UK who were newly diagnosed with any of 19 autoimmune diseases between Jan 1, 2000, and Dec 31, 2017, younger than 80 years at diagnosis, and free of cardiovascular diseases up to 12 months after diagnosis. We also assembled a matched cohort with up to five individuals matched on age, sex, socioeconomic status, region, and calendar year, who were free of autoimmune disease and free of cardiovascular diseases up to 12 months after study entry. Both cohorts were followed up until June 30, 2019. We investigated the incidence of 12 cardiovascular outcomes and used Cox proportional hazards models to examine differences in patients with and without autoimmune diseases. Findings Of 22 009 375 individuals identified from the CPRD databases, we identified 446 449 eligible individuals with autoimmune diseases and 2 102 830 matched controls. In the autoimmune cohort, mean age at diagnosis was 46middot2 years (SD 19 center dot 8), and 271 410 (60 center dot 8%) were women and 175 039 (39 center dot 2%) were men. 68 413 (15 center dot 3%) people with and 231 410 (11 center dot 0%) without autoimmune diseases developed incident cardiovascular disease during a median of 6 center dot 2 years (IQR 2 center dot 7-10 center dot 8) of follow-up. The incidence rate of cardiovascular disease was 23 center dot 3 events per 1000 patient -years among patients with autoimmune disease and 15 center dot 0 events per 1000 patient-years among those without an autoimmune disease (hazard ratio [HR] 1 center dot 56 [95% CI 1 center dot 52-1 center dot 59]). An increased risk of cardiovascular disease with autoimmune disease was seen for every individual cardiovascular disease and increased progressively with the number of autoimmune diseases present (one disease: HR 1 center dot 41 [95% CI 1 center dot 37-1 center dot 45]; two diseases: 2 center dot 63 [2 center dot 49-2 center dot 78]); three or more diseases: 3middot79 [3 center dot 36-4 center dot 27]), and in younger age groups (age < 45 years: 2 center dot 33 [2 center dot 16-2 center dot 51]; 55-64 years: 1 center dot 76 [1 center dot 67-1 center dot 85]; >= 75 years: 1 center dot 30 [1 center dot 24-1 center dot 36]). Among autoimmune diseases, systemic sclerosis (3 center dot 59 [2 center dot 81-4 center dot 59]), Addison's disease (2 center dot 83 [1 center dot 96-4 center dot 09]), systemic lupus erythematosus (2 center dot 82 [2 center dot 38-3 center dot 33]), and type 1 diabetes (2 center dot 36 [2 center dot 21-2 center dot 52]) had the highest overall cardiovascular risk. Interpretation These findings warrant targeted cardiovascular prevention measures, in particular in younger patients with autoimmune diseases, and further research into pathophysiological mechanisms underlying these complications. Copyright (c) 2022 Elsevier Ltd. All rights reserved.