Background Patients with rheumatoid arthritis (RA) are at increased risk of developing cardiovascular (CV) comorbidity compared with the general population. Contradictory results concerning CV disease prior to onset of RA have been reported. Of the known CV risk factors, a more atherogenic lipid profile and smoking have been presented prior to RA onset.
Objectives In this study, lifestyle factors, lipid levels, presence of hypertension, and diabetes were evaluated in individuals prior to onset of symptoms of RA and matched population controls from northern Sweden.
Methods A nested case-control study was based on information from The Västerbotten Intervention Programme (VIP) and the WHO Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA). Data were collected by questionnaire (socioeconomic and lifestyle factors), assessments by a nurse (body mass index;BMI, waist and blood pressure), and blood sampling (lipids and glucose loading). The registers of patients with RA (ARA criteria) attending the Department of Rheumatology, Umeå was co-analysed with the registers from VIP and MONICA. This study included 547 pre-symptomatic individuals (mean age 51.5years; 372f/175m, median (IQR) predating time 5.0 (7.0) years), and 1654 controls (mean age 51.6years; 1123f/531m). CV risk factors were defined as: hypertension (systolic≥140 mmHg, diastolic≥90 mmHg), ApoB/ApoA1 ratio (females ≥0.7, males ≥0.8), BMI≥25, diabetes, and ever smoker.
Results Lower levels of ApoA1 (OR=2.0 (95%CI1.25, 3.25) and increased ApoB/ApoA1 ratio (OR=2.25 95%CI1.25, 4.06) were associated with RA development, particularly in females besides smoking, BMI and waist range. Plasma glucose at baseline was related to disease development, particularly in males (OR=1.18 95%CI1.01, 1.37). Blood pressure did not differ between the groups. Conditional logistic regression models identified elevated ApoB/ApoA1 ratio (OR=1.25 95%CI1.01, 1.56), being ever smoker (OR=2.00 95%CI1.63, 2.47), BMI≥25 (OR=1.33 95%CI1.09, 1.63) and diabetes (OR=1.98 95%CI1.06, 3.68) but not hypertension (OR=0.89 95%CI 0.72–1.11) to be associated with RA development. The pre-symptomatic individuals had significantly higher frequency of these risk factors, 32.3% of these individuals had ≥3 of these factors compared with 23.2% of the matched controls (OR=2.52 95%CI1.67, 3.83).
Conclusions Several of the CV risk factors are present in individuals already years before onset of symptoms of RA. One third of the pre-symptomatic individuals had at least 3 of these factors present. These results urge early CV prevention in patients with RA.
Acknowledgement The Medical Biobank of northern Sweden is acknowledged.
Disclosure of Interest None declared