Reduced cardiorespiratory fitness is a mediator of excess all-cause mortality in rheumatoid arthritis: the Trøndelag Health Study

Abstract

ObjectivesInvestigate if low cardiorespiratory fitness (CRF) was associated with and acted as a mediator of excess all-cause mortality rate in persons suffering from rheumatoid arthritis (RA) compared with the general population.MethodsAll-cause mortality was analysed using Cox regression modelling in patients with RA (n=348) and controls (n=60 938) who took part in the second (1995–1997) and third (2006–2008) waves of the longitudinal population-based Trøndelag Health Study in Norway. A mediation analysis was performed to investigate if excess relative risk of mortality in RA was mediated by low estimated CRF (eCRF).ResultsDuring the follow-up until 31 December 2018 (mean 19.3 years), the mortality rate among patients with RA (n=127, 36.5%) was higher than among controls (n=12 942, 21.2%) (p<0.001). Among controls and patients with RA, 51% and 26%, respectively, had eCRF above the median for their age and sex (p<0.001). The final Cox model included RA status and eCRF, adjusted for hypertension, body mass index, smoking, cholesterol, diabetes and creatinine. eCRF below median for sex and age category was associated with increased mortality (p<0.001). The total excess relative risk of mortality in patients with RA was 28% (95% CI 2% to 55%, p=0.035), in which RA itself contributed 5% and the direct and indirect contributions of low eCRF accounted for 23%.ConclusionsLow eCRF was an important mediator of the increased all-cause mortality rate found in RA. Our data indicate that patients with RA should be given advice to perform physical activity that increases CRF, along with optimised treatment with antirheumatic drugs, from the time of diagnosis.

Inflammation mediates approximately one quarter of excess relative all-cause mortality in persons with rheumatoid arthritis: the Trøndelag Health Study

“…Vibeke Videm 1,2,3* , Ingrid Saether Houge 1 , Marthe Halsan Liff 4,5 & Mari Hoff 6,7 Inflammation may contribute to excess mortality in rheumatoid arthritis (RA) patients. We investigated associations to all-cause mortality of the inflammation markers high-sensitivity C-reactive protein (CRP), lactoferrin (neutrophil activation marker), and neopterin (monocyte activation marker).…”

Use of the Behavioral Regulation in Exercise Questionnaire-2 to assess motivation for physical activity in persons with rheumatoid arthritis: an observational study

“…Previous research has shown that RA patients still have an increased mortality rate compared to the general population [3][4][5][6]. Low cardiorespiratory fitness is an important mediator, with direct and indirect effects accounting for 23% of the totally 28% excess relative risk of mortality [6].…”

“…Previous research has shown that RA patients still have an increased mortality rate compared to the general population [3][4][5][6]. Low cardiorespiratory fitness is an important mediator, with direct and indirect effects accounting for 23% of the totally 28% excess relative risk of mortality [6]. Thus, in addition to adequate medication, stimulating RA patients to improve their fitness level should be an important goal in the overall treatment plan [7].…”

Effect of high-intensity exercise on cardiorespiratory fitness, cardiovascular disease risk and disease activity in patients with inflammatory joint disease: protocol for the ExeHeart randomised controlled trial

“…Furthermore, cardiorespiratory fitness (CRF) is recognised as a clinically important variable given that low levels of CRF are associated with higher risk of CVD and all-cause mortality 11. Inferior levels of physical activity and CRF are reported in patients with IJD12 13 and may serve as a further catalyst in the elevated CVD risk for this patient group 14 15. Implementation of interventions that can mitigate both systemic inflammation and prevalent CVD risk factors is therefore essential to reduce the risk of CVD in patients with IJD 8…”