Rheumatic illnesses are a general umbrella term for almost 200 different disorders affecting the musculoskeletal system (1). The causes and therapies for the almost 100 different types of arthritis have been well-documented. In humans, rheumatoid arthritis (RA) and osteoarthritis are the most well-known types of arthritis. RA, also referred to as an autoimmune disease or a progressive disease, is an example of a chronic systemic condition (2). It is characterized by destructive joint disease and prolonged inflammation, although its etiology is uncertain (3). There are two subtypes of this disease, namely ‘seropositive’ and ‘seronegative’. Elevated blood levels of rheumatoid factor (RF) autoantibodies and, more recently, antibodies to citrullinated protein/peptide antigens (ACPAs) can be used to determine seropositivity (4). RF autoantibodies are a type of antibody that are produced by the immune system.

RA is far more common in certain populations than in others. France (0.19%) and Italy (0.41%) have been found to have a lower reported prevalence of RA compared to other countries of the world, where it varies from 0.19 to 1.1% (5,6). The prevalence of RA in Germany and Sweden has been reported to be ~0.65% (7,8). RA has been reported to affect between 0.5 and 1% of North Americans (8-10). RA is estimated to afflict 0.75% of individuals in India (10,11).

Furthermore, coronary artery calcium (CAC) as it is commonly known, is a characteristic of coronary atherosclerosis (12). Consistent, dependable and convincing evidence of a substantial association between CAC and significant cardiovascular events has also been found in a number of asymptomatic individuals (13,14). Initially, CAC was evaluated using chest X-ray, fluoroscopy, or digital subtraction of fluoroscopy; following the introduction of electron beam computed tomography and multidetector computed tomography, these devices were found to be more useful. The most useful information on cardiovascular risk, or the likelihood of suffering a heart attack or stroke, may be obtained from coronary calcium scores for females aged 35 to 70 years and for males aged 40 to 60 years (15).

The disease activity score (DAS) was developed by a group of Dutch rheumatologists with the goal of offering a standardized method to compare and contrast results from clinical trials of novel medications for the treatment of RA. Clinical practices often use disease activity measurements related to RA. The DAS28, which evaluates a total of 28 joints, is one such instrument.

The present study aimed to examine the association between cardiovascular risk (using CAC) and CIMT in patients with RA and healthy controls, using the DAS28 as a proxy.

The present study examined 45 patients with RA who fulfilled the aforementioned inclusion criteria. These patients were then classified as the cases and another 45 healthy individuals were included as the controls. As demonstrated in Fig. 1, although the sex ratios between the patients with (53.3% females) and the controls (60% males) were comparable, the RA patient group had a higher number of females. The demographic profiles of both groups are presented in Table I.

Only 2 (4.4%) of the 45 patients with RA had a DAS ≤2.6, which is indicative of remission. A total of 40 patients of 45 cases (88.9%), had disease activity ratings that ranged from moderate to high (range, >3.2), whereas 3 patients, which is equivalent to 6.7% of the sample, had low disease activity scores (range, 2.6-3.2) (Table II).

Compared with the controls, the cases had a significantly higher total leucocyte count (TLC; 9311±2877 vs. 8049±1780 per microliter), erythrocyte sedimentation rate (ESR) in the first hour (19.18±6.34 vs. 16.62±3.56 mm/h), C-reactive protein (CRP; 11.36±5.84 vs. 2.44±1.69 mg/l), serum urea (24.76±7.96 vs. 21.99±3.53 mg/dl), serum potassium (4.18±0.69 vs. 3.95±0.23 mmol/l), serum magnesium (1.95±0.18 vs. 2.02±0.14 mg/dl), serum glutamic pyruvic transaminase (SGPT; 44.82±18.60 vs. 37.69±9.58 units/l), serum alkaline phosphatase (ALP; 96.02±36.12 vs. 81.96±21.19 IU/l), serum cholesterol (160.88±30.11 vs. 145.35±17.40 mg/dl), serum high-density lipoprotein (HDL; 7.20±15.83 vs. 43.91±8.17 mg/dl), serum low-density lipoprotein (LDL; 107.74±23.75 vs. 98.11±16.66 mg/dl) and the LDL-HDL ratio (2.85±1.58 vs. 1.57±3.27 mg/dl) (Table III). The results of the analysis of the correlation between the DAS, and BMI, CRP, serum cholesterol, serum triglycerides, serum HDL, serum LDL and serum very low-density lipoprotein (VLDL) are presented in Table IV. An inverse correlation was observed between the DAS and HDL levels. In addition, a strong correlation was found between the DAS and the CRP level. However, a moderate or weak correlation was observed between DAS and the remaining variables, although some correlations were significant.

None of the controls had moderate risk (score 101-400) or severe risk (score ≥401), and the majority of the controls exhibited no evidence of CAD (CAC score 0; 88.9%). The remaining controls had a minimum risk (score 1-10) or mild risk (score 11-100). By contrast, according to the CAC scores, only 22.2% of the patients with RA exhibited no signs of CAD, another 22.2% had a low risk, and the remaining 55.5% had a mild to severe risk. This difference was found to be statistically significant. The proportion of cases was higher as compared to controls in all the risk categories: Minimal (22.2 vs. 6.7%), mild (13.3 vs. 4.4%), moderate (24.4 vs. 0.0%) and severe risk (17.8 vs. 0.0%) (Table V).

The range of CIMT in the patients with RA was 0.712-1.310 mm, while that in the controls was 0.412-0.518 mm. In the patients with RA, the CIMT was determined to be 1.050±0.218 mm, which was substantially larger than the value of the control group (0.479±0.040 mm) (Table VI).

The CIMT exhibited a significant correlation with CRP, serum cholesterol, triglycerides, serum HDL (inverse), LDL and VLDL. A strong correlation was found between CIMT and CRP was strong; however, a moderate or weak correlation was found between CIMT and the remaining variables, although some correlations were significant. The CAC score also exhibited a significant correlation with CRP, serum cholesterol and serum triglycerides, serum VLDL and serum LDL. A moderate correlation was found between the CAC score and CRP, serum triglycerides and VLDL. The CAC scores and CIMT levels of both sexes were comparable. Age was not found to significantly correlate with the aforementioned two markers (CAC and CIMT) (Table VII).

As a chronic inflammatory joint condition, RA restricts everyday activities due to the pain, stiffness, and exhaustion that patients experience regularly. The link between inflammation and the development of cardiovascular disease was recognized only ~10 years ago. Researchers found that patients with RA had a 1.5-2.0-fold greater risk of developing coronary artery disease (CAD) than the general population (18). Another study demonstrated that patients with RA had a prevalence of myocardial infarction (MI) that was >3-fold higher than that of patients without RA (19). Thus, CAD is already more likely to occur before RA is even diagnosed clinically. The signs and symptoms of CAD vary with the disease process throughout time. In certain cases, there may be no obvious symptoms of damage.

The present study aimed to evaluate CIMT and computed tomography-CAC, two relatively novel cardiovascular risk indicators, in patients with RA. For this purpose, the present study recruited 45 patients with RA and 45 individuals who served as the healthy controls. The enrolled patients with RA had an average age of 49.07±12.38 years (ranging from 24 to 80 years), with 53.3% being female. Specifically, the controls in the present study were matched for both sex and age. Although RA may develop at any age, the majority of epidemiological research has shown that the condition is most common in individuals who are in their 50 and 60s. Other studies have suggested a later onset of the illness (19-23).

The mean age of patients with RA included in the clinical studies by Schott et al (24) (53.3 years) and Targońska-Stepniak et al (25) (42.6±8.0 years; range, 27-59) was also very close to that in the present study. In the study by Udachkina et al (26), the median age of the patients was 56 years.

In the present study, two-thirds (53.3%) of the patients had a DAS >5.2 (high disease activity), and16 patients had a DAS of 3.3-5.2 (35.6%) (moderate disease activity). Out of the 45 patients with RA, 2 (4.4%) were not on therapy, 6 (13.3%) were on disease-modifying antirheumatic drugs (DMARDs) treatment for <6 months, and the remaining 37 (82.22%) were on DMARDS treatment for >6 months. The DAS exhibited a substantial correlation with serum cholesterol, LDL and CRP levels among the CAD risk factors. Sengul et al (27) examined Turkish individuals with RA and their DAS28-ESR and DAS28-CRP criteria. While the DAS28-CRP was based on DAS28 without the ESR, the DAS28-ESR was based on the DAS with 28 joints (27). According to that study, the DAS28-CRP and DAS28-ESR exhibited a substantial association, whereas the individual components only exhibited a modest correlation (27).

In the present study, significant differences in the laboratory parameters (TLC, first-hour ESR, CRP, serum urea, serum potassium, serum magnesium, SGPT and serum ALP, and lipid levels) of the RA cases and healthy controls were observed. The TLC, ESR and CRP levels are inflammatory markers and have been found to be increased in ~40% of patients with RA (28). It has been shown that anti-inflammatory medications increase total, HDL and LDL cholesterol levels in patients with RA (29,30). Oxidative alterations caused by chronic inflammation modify the structure of HDL and decrease apolipoprotein-A1 in patients with active RA (31).

In the present study, the CAC score of the patients with RA was significantly higher compared with that of the controls (246.80±330.81 vs. 0.600±0.251). Of note, ~55.6% of patients with RA had been found to have a mild to severe risk of developing CAD (score, 11->400). A significant correlation between CAC and CRP, and lipid levels (apart from HDL) was found. These findings are supported by the findings in the study by Wahlin et al (32), who studied the computed tomography-CAC of 22 patients with RA (mean age, 65 years). They also found that 55.5% of the patients had a CAC score >10(32).

The average age of the 60 female patients with RA in the study by Bernardes et al (33) was 53.6±10.4 years, and their average DAS28 score was 4. Age, BMI, hyperglycemia and cholesterol levels were shown to have a substantial correlation with the mean coronary calcium score, which was 35.192±117.786. In the present study, the CIMT varied significantly (1.050±0.218 vs. 0.479±0.040 mm) between the experimental and control groups. CIMT was substantially linked with levels of lipids and CRP.

Targońska-Stepniak et al (25) found similar results when they evaluated CIMT values in 74 patients with RA without cardiovascular risk, with an average age of 46.4±0.6 years. A total of 31 age-matched control participants had notably higher CIMT values than the controls (25).

As a chronic inflammatory disorder, RA affects more than only the joints and muscles. Multiple risk variables that are also linked to cardiovascular risk govern it. Moreover, medication for RA also has a cardiovascular impact. Aging also contributes as a common risk factor between RA and cardiovascular disorders. Thus, the screening of all patients with RA for cardiovascular disease and associated risks is recommend at regular intervals. Furthermore, according to the data indicating a much larger percentage of these surrogate indicators in patients with RA, it is imperative that more stringent measures be implemented to decrease the cardiovascular risk in this population.

In conclusion, the present study demonstrated that the CIMT and CAC differed substantially between healthy individuals and patients with RA. This difference was shown to be statistically significant. The diagnosis and planning of risk reduction measures for patients with RA may be aided by these surrogate indicators of early atherosclerosis. Consistent results between CIMT and CAC, and established CV risk variables, such as dyslipidemia, suggest that these two methods could assist prevention and treatment efforts. Chronic inflammation significantly increases the risk of developing atherosclerosis, as suggested by the link between the disease activity score, the CIMT and CAC.