Increasing Incidence of Autoimmune Diseases Noted in UK Study

Multiple Autoimmune Diseases Noted to Be Increasing Over the 2000-2019 Study Period

A new study from the Lancet suggests that more and more people are being diagnosed with autoimmune diseases over time.

The study set out to track the incidence of autoimmune diseases over an approximately 20 year period in the UK. Incidence rates in 2000 -2002 were compared to 2017-2019.

There were 22 009 375 individuals included in the study, and 978 872 individuals had a new diagnosis of at least one autoimmune disease between Jan 1, 2000, and June 30, 2019. Mean age was 54.  625 879 (63·9%) of these diagnosed individuals were female and 352 993 (36·1%) were male.

Over the study period, the age and sex standardised incidence rates of any autoimmune diseases increased very slightly (IRR 2017–19 vs 2000–02 1·04 [95% CI 1·00–1·09]).

The largest increases were seen in celiac disease (2·19 fold increase), Sjogren's syndrome (2·09 fold increase) and Graves' disease (2·07 fold increase) followed by Addison’s disease (1.87 fold increase), Ankylosing spondylitis (1.78 fold increase) and rheumatoid arthritis (1.64 fold increase).

Some autoimmune diseases were found to decrease in incidence over the period including pernicious anaemia and Hashimoto's thyroiditis.

Overall, about 1 in 10 adults in UK have an autoimmune disease and the rate appears to be increasing slowly over time.

The exact reasons are not clear but environmental factors have been proposed to have a role.

Reference

Conrad N et al. Incidence, prevalence, and co-occurrence of autoimmune disorders over time and by age, sex, and socioeconomic status: a population-based cohort study of 22 million individuals in the UK. Lancet 2023