The association between rheumatoid arthritis and daily life functioning in adults - The HUNT4 study

Background: Rheumatoid arthritis (RA) is a chronic, joint destructive progressive autoimmune disease, with 0.24% worldwide prevalence, that causes functional disability and significant pain, and may lead to premature mortality. There is a lack of studies about the association between RA and activities of daily living (ADL) and instrumental activities of daily living (IADL). Furthermore, a potential difference between genders is also a significant knowledge gap. Objectives: This study investigated the potential association between RA and ADL/IADL in adults, as well as potential differences between genders. Methods: A population-based cross-sectional study was conducted using data from the HUNT4 Arthritis study from 2017-2019, with a total of 2684 participants enrolled in the current study. The participants were divided into following two groups: non-RA group (reference group) (n=1682) and RA patients (n=1002). The association between RA and several main ADLs/IADLs ( Wearing clothes, get in/out of bed, lifting a glass and drinking, personal hygiene, bending to pick up a thing, opening a jar, getting in/out of car, and walking outside) was assessed using linear regression, adjusted for the potential confounders of age, sex, education, exercise, body fat (%), and chronic diseases. Furthermore, family history was investigated as an ancestor to RA. The most worsen ADLs/IADLs were identified overall and between genders. Results: Results indicated RA estimated prevalence was 1.7% in the HUNT4 study. In women, prevalence of RA was 1.21% and for men 0.57% in the HUNT4 study. There is a significant association between RA and ADL in adults. Significantly associated ADLs/IADLs overall were get in/out of bed, opening a jar, bending to pick up a thing, and getting in/out of car. For female RA patients, get in/out of bed and opening a jar were significantly associated. For male RA patients, only getting in/out of car was significantly associated. Conclusion: This research indicated that there is a significant association between RA and ADLs in Norwegian people, based on data from HUNT4. Women are more at risk of RA than men, and RA worsen women’s ADL/IADL more. Keywords: Rheumatoid arthritis (RA), ADL, IADL, Prevalence, Sex, HUNT