Although investigations have been performed on the association between inflammatory conditions and cardiovascular events, the effect of different conditions on cardiovascular diseases has not been analyzed on a large scale.
Patients with autoimmune diseases, particularly younger patients and those with systemic sclerosis, systemic lupus erythematosus (SLE), and type 1 diabetes, were more likely to develop cardiovascular disease. Findings warrant cardiovascular prevention measures and further research into pathophysiological mechanisms, according to a study published in The Lancet.1
“Some investigations have been done into the association between selected inflammatory conditions and specific cardiovascular events, but the effect of different conditions on various cardiovascular diseases has not been compared on a large scale,” investigators stated. “As a result, there is insufficient evidence for cardiovascular prevention guidelines to specifically address autoimmunity.”
Linked primary and secondary care records from the Clinical Practice Research Datalink (CPRD) GOLD and Aurum datasets were used to identify patients in the United Kingdom who were newly diagnosed with autoimmune diseases between January 2000 and December 2017, were aged less than 80 years, and did not have cardiovascular disease up to 12 months after diagnosis. Investigators then assembled a matched cohort based on age (within 5 years), sex, region, calendar year, and socioeconomic status, who did not have either an autoimmune diagnosis or cardiovascular disease up to 12 months after entry into the population-based study. Cohorts were followed until June 30, 2019. Cox proportional hazards models examined differences in patients with and without autoimmune diseases.
Of the 22,009,275 individuals in the CPRD databases, 446,449 patients with autoimmune diseases were matched with 2,102,830 controls with similar baseline demographics and clinical characteristics. The mean age at diagnosis in the autoimmune cohort was 46.2 years and most were female (n = 271,410, 60.8%). During the follow-up period (median of 6.2 years), 15.3% (n = 68,413) of people with and 11.0% (n = 231,410) without autoimmune diseases developed cardiovascular disease. Incidence rate of cardiovascular disease was 23.3 events per 1000 patient-years for those with autoimmune disease and 15.0 events per 1000 patient-years for those without autoimmune disease (hazard ratio [HR] 1.56 [95% CI 1.52–1.59]).
An increased risk of cardiovascular disease was present for patients with autoimmune disease for each individual cardiovascular disease, which continued to increase with the number of autoimmune disease diagnoses (1 disease: HR 1.41 [95% CI 1.37–1.45]; 2 diseases: 2.63 [2.49–2.78]); 3 or more diseases: 3.79 [3.36–4.27]). Risk of developing cardiovascular disease was also observed more frequently in younger age groups (age < 45 years: 2.33 [2.16–2.51]; 55–64 years: 1.76 [1.67–1.85]; ≥75 years: 1.30 [1.24–1.36]). The highest overall cardiovascular risk among autoimmune diseases was reported for those with systemic sclerosis (3.59 [2.81–4.59]), Addison’s disease (2.83 [1.96–4.09]), systemic lupus erythematosus (2.82 [2.38–3.33]), and type 1 diabetes (2.36 [2.21–2.52]).
The study was strengthened by the large, representative cohort with additional information on clinical diagnoses and cardiovascular risk factors. Investigators were also able to stratify analyses over a spectrum of conditions and examine trends over time. However, they could not account for the effect of concomitant drug therapy. Results of the adjusted sensitivity analyses should be interpreted with caution as there were instances of missing data, including blood pressure, smoking status, cholesterol measurements, and body mass index (BMI). Further, exercise information and inflammatory biomarkers were unavailable.
“Our findings have important implications for healthcare resource planning and preventive strategies,” investigators concluded. “Although approaches to prevent atherosclerotic disease and stroke such as controlling blood pressure and reducing cholesterol are well established, the causes of cardiovascular conditions associated with autoimmune diseases, and their potential treatments, require further research.”
Conrad N, Verbeke G, Molenberghs G, et al. Autoimmune diseases and cardiovascular risk: a population-based study on 19 autoimmune diseases and 12 cardiovascular diseases in 22 million individuals in the UK. Lancet. 2022;0(0). doi:10.1016/s0140-6736(22)01349-6