Sleep disorders in rheumatoid arthritis: Incidence, risk factors and association with dementia

We aimed to examine the incidence of sleep disorders (SD) in individuals with rheumatoid arthritis (RA) vs. non-RA comparators, evaluate risk factors for SD, and assess the association between incident SD and dementia in RA.

This retrospective cohort study included residents aged ≥50 years within an 8-county region of Minnesota who first met the 1987 ACR criteria for RA in 1980-2014. Individuals with RA were matched 1:1 with non-RA individuals on age, sex, and calendar year of RA incidence. Data on SD, cardiovascular disease (CVD) risk factors, CVD and other comorbidities were collected from the medical records.

Nine hundred thirteen individuals with RA and 913 non-RA comparators were included (mean age: 65 years, 65 % female in both cohorts). During the median follow-up of 10.4 years in RA and 11.0 years in non-RA cohort, SD developed in 234 and 206 individuals, respectively. RA patients experienced an increased risk for any incident SD (HR 1.34; 95 % CI:1.11-1.61) and insomnia (HR 1.34; 95 % CI:1.03-1.73). Obesity, dyslipidemia, presence of CVD, depression, anxiety, and more recent calendar year of RA incidence were associated with increased risk of any SD in RA. There were no significant association between SD overall and by subtype with dementia in RA.

Individuals with RA (vs non-RA) experienced a significantly increased risk for any SD, particularly insomnia. CVD and CVD risk factors, as well as depression and anxiety increased the risk for incident SD in RA. There was no significant association between SD and dementia in RA.