Increased prevalence of subclinical atherosclerosis in rheumatoid arthritis patients of Indian descent
SS Deo | AR Chogle | KJ Mistry | RR Shetty | UL Nadkar
BACKGROUND: Studies have shown that rheumatoid arthritis (RA) patients are two to five times more likely to develop premature cardiovascular disease, thus shortening their life expectancy by five to 10 years. This risk has risen to approximately 12.6% in the urban population and 7.4% in the rural population of India. The Framingham risk score (FRS) identifies patients at increased cardiovascular risk and helps determine the need for preventive interventions. An investigation of the patients' coronary arteries and coronary artery calcification (CAC) - a measure of atherosclerotic plaque - has been found to be a strong predictor of cardiovascular disease.
OBJECTIVE: To identify important biological markers for easy and non-invasive identification of cardiovascular disease in RA patients, and to investigate whether there is a relationship between the FRS and coronary artery atherosclerosis in RA patients.
METHODS: The present study included 43 established RA patients and 50 healthy individuals (controls). Traditional and nontraditional risk factors were studied and compared with the control group. Insulin resistance was assessed using the homeostasis model of assessment of insulin resistance (HOMA-IR) and the homeostasis model of assessment of beta cell function. The FRS and the 10-year cardiovascular risk were compared between RA patients and controls. The presence of CAC was determined using electron-beam computed tomography, and the association between the FRS and CAC was examined.
RESULTS: Significant differences in body mass index, waist circumference, rheumatoid factors (immunoglobulin [Ig]G, IgM and IgA) and inflammatory markers - C-reactive protein and erythrocyte sedimentation rate - were noted. There was significant correlation between HOMA-IR and body mass index, hypertension and C-reactive protein, but no correlation was seen with the homeostasis model of assessment of beta cell function. Significant differences were observed in the nontraditional biomarkers in RA patients, thus supporting their importance. Calcium deposition was observed in only seven RA patients.
CONCLUSIONS: RA patients with increased C-reactive protein levels and erythrocyte sedimentation rates showed an increase in serum insulin levels and significant differences in HOMA-IR, thus indicating insulin resistance, which could lead to underlying progression of artherosclerosis. Significant differences were observed in the nontraditional risk factors, which could be chosen as biomarkers for endothelial dysfunction. There was a significant correlation between calcium score and the FRS in seven patients, suggestive of an underlying risk of atherosclerosis.