Brief report: accelerated aging influences cardiovascular disease risk in rheumatoid arthritis

Using Unsupervised Machine Learning Methods to Cluster Comorbidities in a Population-Based Cohort of Patients With Rheumatoid Arthritis

OBJECTIVE

To identify clusters of comorbidities in patients with rheumatoid arthritis (RA) using 4 methods and to compare to patients without RA.

METHODS

In this retrospective, population-based study, residents of 8 Minnesota counties with prevalent RA as of January 1, 2015 were identified. Age-, sex-, and county-matched non-RA comparators were selected from the same underlying population. Diagnostic codes were retrieved for 5 years before January 1, 2015. Using 2 codes ≥30 days apart, 44 previously defined morbidities and 11 nonoverlapping chronic disease categories based on Clinical Classifications Software were defined. Unsupervised machine learning methods of interest included hierarchical clustering, factor analysis, K-means clustering, and network analysis.

RESULTS

Two groups of 1,643 patients with and without RA (72% female; mean age 63.1 years in both groups) were studied. Clustering of comorbidities revealed strong associations among mental/behavioral comorbidities and among cardiovascular risk factors and diseases. The clusters were associated with age and sex. Differences between the 4 clustering methods were driven by comorbidities that are rare and those that were weakly associated with other comorbidities. Common comorbidities tended to group together consistently across approaches. The instability of clusters when using different random seeds or bootstrap sampling impugns the usefulness and reliability of these methods. Clusters of common comorbidities between RA and non-RA cohorts were similar.

CONCLUSION

Despite the higher comorbidity burden in patients with RA compared to the general population, clustering comorbidities did not identify substantial differences in comorbidity patterns between the RA and non-RA cohorts. The instability of clustering methods suggests caution when interpreting clustering using 1 method.

Rationale and Design of the Orencia Atherosclerosis and Rheumatoid Arthritis Study (ORACLE Arthritis Study): Implications of Biologics against Rheumatoid Arthritis and the Vascular Complications, Subclinical Atherosclerosis

To explore the biological and immunological basis of human rheumatoid arthritis and human atherosclerosis, we planned and reported a detailed design and rationale for Orencia Atherosclerosis and Rheumatoid Arthritis Study (ORACLE Arthritis Study) using highly sensitive, high-throughput, human autoantibody measurement methods with cell-free protein synthesis technologies. Our previous study revealed that subjects with atherosclerosis had various autoantibodies in their sera, and the titers of anti-Th2 cytokine antibodies were correlated with the severity of atherosclerosis. Because rheumatoid arthritis is a representative autoimmune disease, we hypothesized that both rheumatoid arthritis and atherosclerosis are commonly developed by autoantibody-mediated autoimmune processes, leading to incessant inflammatory changes in both articular joint tissues and vessel walls. We planned a detailed examination involving carotid artery ultrasonography, measurements of adhesion molecules, such as ICAM-1 (intercellular adhesion molecule 1) and VCAM-1 (vascular cell adhesion molecule 1) for the evaluation of atherosclerosis progression, and high-throughput, high-sensitivity, autoantibody analyses using cell-free technologies, with detailed examinations of the disease activity of rheumatoid arthritis. Analyses of correlations and associations between biological markers and degrees of carotid atherosclerosis over time under consistent conditions may enable us to understand the biological and humoral immunity background of human atherosclerosis and autoimmune diseases.

Evaluation of dysfunctional high-density lipoprotein levels with myeloperoxidase/paraoxonase-1 ratio in rheumatoid arthritis

BACKGROUND

The aim of this study is to evaluate dysfunctional high-density lipoprotein cholesterol (HDL) by measuring myeloperoxidase (MPO)/paraoxonase 1 (PON1) ratio in patients with rheumatoid arthritis (RA) and to investigate the relationship between dysfunctional HDL and cardiovascular disease (CVD) in RA patients.

METHODS

Sixty-seven healthy individuals and 130 RA patients were included in the study. Routine lipid panels (triglyceride (TG), low-density lipoprotein cholesterol (LDL), HDL, total cholesterol (TC), PON1 and MPO levels were measured. Disease activity scores-28 (DAS28) of RA patients were calculated. Cardiological examination records of the patients were assessed to detect patients who also have CVD.

RESULTS

There were no significant differences between RA and control groups in routine lipid profiles (P > .05 for all). MPO/PON1 ratios were significantly elevated in the RA group compared with the control group (P < .001). MPO/PON1 ratios were higher in RA patients with CVD history compared with those without CVD (P < .05). MPO/PON1 ratios were correlated with DAS28 scores (rho: 0.357, P < .001).

CONCLUSION

HDL dysfunction determined by the MPO/PON1 ratio may be associated with the pathophysiology of increased CVD in RA. Thus, evaluating dysfunctional HDL levels by measuring the MPO/PON1 ratio in RA patients may allow more detailed patient follow-up, as well as the reduction of CVD events in RA patients with therapeutic agents aiming to increase the functional properties of HDL by decreasing this ratio.

Sex and Cardiovascular Involvement in Inflammatory Joint Diseases

The term inflammatory joint disease (IJD) encompasses a group of chronic conditions with predominant joint involvement. They share an increased risk of cardiovascular (CV) complications. However, the implication of the sex in the risk of CV disease in IJD has not been specifically addressed. The aim of this work is to assess the influence of sex on the clinical expression of CV manifestations associated to IJD. With this objective, an update of the current knowledge of the sex influence on CV disease in patients with IJD was conducted. A PubMed database search of the most relevant literature on this topic was performed mainly based on studies published in English over the last 10 years. Although most studies on IJD were not specifically designed to address sex differences regarding CV complications, it seems that men with rheumatoid arthritis (RA) are at higher risk of pericarditis, ischemic heart disease, heart failure (HF) with reduced ejection fraction (EF), and CV mortality than women with RA. In contrast, HF with preserved EF and diastolic dysfunction is more frequent in women with RA. Men with ankylosing spondylitis present more frequently disorders of the conduction system and aortic valvulopathy than women. A limited number of studies addressed CV differences according to sex in psoriatic arthritis. Although there are some differences according to sex in the clinical expression of CV complications in patients with IJD, much research is still needed to better identify the implication of sex in the risk of CV disease in these patients.

Prescribing Trend of Antirheumatic Drugs in Taiwan and Risk of Cardiovascular Disease in Patients with Rheumatoid Arthritis: A Nationwide Cohort Study

We aimed to investigate the prescribing trend of antirheumatic drugs and assess the risk of cardiovascular disease in patients with rheumatoid arthritis in Taiwan. This study was a retrospective cohort study, conducted based on the Taiwan National Health Insurance Research Database. The study subjects were 15,366 new rheumatoid arthritis patients from 2003 to 2010. To avoid selection bias, we applied propensity score matching to obtain general patients, as the control group. Cox proportional hazard model was used to evaluate the risk of cardiovascular disease in rheumatoid arthritis patients. The most common prescriptions of rheumatoid arthritis were nonsteroidal anti-inflammatory drugs. After controlling for related variables, rheumatoid arthritis patients had a higher risk of cardiovascular disease than general patients (adjusted hazard ratio [aHR] = 1.31; 95% confidence interval [CI]: 1.23-1.39). Age was the most significantly associated risk factor with the cardiovascular disease. Other observed risk factors for cardiovascular disease included hypertension (aHR = 1.57, 95% CI: 1.48-1.65), diabetes mellitus (aHR = 1.47, 95% CI: 1.38-1.57), and chronic kidney disease (aHR = 1.48, 95% CI: 1.31-1.66). Patients with rheumatoid arthritis indeed had a higher risk of incident cardiovascular diseases. Besides, age, hypertension, diabetes mellitus, and chronic kidney disease were also associated with a higher risk of cardiovascular disease.

Stroke among Rheumatoid Arthritis Patients: Does Age Matter? A Real-Life Study

BACKGROUND/AIMS

Rheumatoid arthritis (RA) is a chronic, debilitating autoimmune disease that affects the joints and it is known to be associated with cardiovascular morbidity. However, the association between RA and stroke among different age groups has not been explored. The objective of our study was to evaluate the association between RA and stroke in different age strata.

METHODS

Cross-sectional study, utilizing the database of Israel's largest healthcare provider. The proportion of stroke was compared between patients diagnosed with RA and age- and gender-matched controls. The study sample was divided into 2 age groups: young (≤65 years) and elderly (>65 years). Multivariable analysis was performed using logistic regression.

RESULTS

The study included 11,782 RA patients and 57,973 age- and gender-matched controls. RA patients, primarily young, had more cardiovascular risk factors than controls. Stroke rates were significantly elevated among young RA patients in comparison with controls (3.74 vs. 2.20%, respectively, p < 0.001). In multivariate analysis, RA was found to be independently associated with stroke (OR 1.18, 95% CI 1.09-1.28).

CONCLUSION

RA is independently associated with stroke, especially among RA patients under 65 years, for whom cardiovascular risk factors were more prominent. Physicians should advise RA patients to manage their risk factors strictly.

Five-year changes in cardiac structure and function in patients with rheumatoid arthritis compared with the general population

BACKGROUND

Patients with rheumatoid arthritis (RA) have increased risk of heart failure with preserved ejection fraction. The development and progression of left ventricular dysfunction before onset of clinical heart failure are unknown. The objective of this study was to evaluate longitudinal changes in cardiac structure and function of patients with RA compared with persons in the general population.

METHODS

A prospective longitudinal study of a population-based cohort of 160 patients with RA and a population-based cohort of 1391 persons without RA (non-RA cohort) was performed. Each participant underwent 2-dimensional, pulsed-wave tissue Doppler echocardiography at baseline and after 4 to 5years of follow-up. Age- and sex-adjusted linear regression models were used to test for differences between the RA and non-RA cohorts in annualized rates of change for echocardiographic parameters.

RESULTS

Mitral A velocity increased more rapidly among the patients with RA than the non-RA cohort (age- and sex-adjusted parameter estimate, 0.030; P<0.001). Correspondingly, the mean mitral inflow E/A ratio decreased faster in the RA cohort than the non-RA cohort (adjusted parameter estimate, -0.096; P<0.001). The left atrial volume index increased at a higher rate in the RA cohort than the non-RA cohort (adjusted parameter estimate, 0.150; P<0.001).

CONCLUSIONS

This pattern of echocardiographic findings confirms previous cross-sectional studies and indicates that subclinical changes in diastolic function occur more rapidly over 5years in RA patients than in the general population. Further research into the mechanisms of myocardial disease in these patients and the relationship with disease activity and treatment is warranted.

Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an excess of cardiovascular disease (CVD) risk, estimated to be at least 50% greater when compared to the general population. Although the widespread diffusion of type 2 diabetes mellitus (T2DM) awareness, there is still a significant proportion of patients with T2DM that remain undiagnosed. Aim of this cross-sectional study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in RA patients. For the present study, 100 consecutive nondiabetic RA patients were recruited. Age- and sex-matched subjects with noninflammatory diseases (osteoarthritis or fibromyalgia) were used as controls. After overnight fasting, blood samples were obtained for laboratory evaluation including serum glucose, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (ACPA). A standard Oral Glucose Tolerance Test (OGTT) with 75 g of glucose was performed and blood samples were collected at time 0, 30, 60, 90, and 120 minutes, for measurement of plasma glucose concentrations. The prevalence of impaired fasting glucose (IFG) (9/100 vs 12/100, P = 0.49), impaired glucose tolerance (IGT) (19/100 vs 12/100, P = 0.17), and concomitant IFG/IGT (5/100 vs 9/100, P = 0.27) was similar between groups, whereas the prevalence of diabetes was significantly higher in RA patients (10/100 vs 2/100, P = 0.02). In a logistic regression analysis, increasing age (OR = 1.13, 95% CI 1.028-1.245, P = 0.01) and disease duration (OR = 1.90, 95% CI 1.210-2.995, P = 0.005) were both associated with an increased likelihood of being classified as prediabetes (i.e. IFG and/or IGT) or T2DM. A ROC curve was built to evaluate the predictivity of disease duration on the likelihood of being diagnosed with T2DM. The area under the ROC curve was 0.67 (95% CI: 0.56-0.78, P = 0.004). We identified the best cut-off of 33 months that yielded a sensitivity of 61% and a specificity of 70% for classification of T2DM patients. According to our data, RA seems to be characterized by an elevated prevalence of undiagnosed diabetes, especially in patients with longer disease duration.

Atherosclerotic vascular disease in the autoimmune rheumatologic patient

Autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, have a strong association with an increased risk of atherosclerotic cardiovascular diseases (ASCVD), particularly ischemic heart disease (IHD). A majority of the autoimmune conditions occur predominantly in women, and as women continue to experience a higher cardiovascular mortality compared to men, this potential added risk factor must be recognized. Inflammation and immune mechanisms have been shown to be an underlying mechanism for the development of atherosclerosis, thus sharing a common mechanism with rheumatologic conditions. There is an under recognition, in both patient and physician, of the increased cardiovascular (CV) risk within the autoimmune population, with present CV risk profile algorithms performing poorly in these patients. Traditional risk factors play a role in the development of IHD in the autoimmune patient, but their overall significance is unclear and does not fully explain the elevated CV risk. The role of inflammation and risk factors in autoimmune conditions, and their link to the elevated CV risk will be explored within this article.

Cardiovascular disease risk scores in the current practice: which to use in rheumatoid arthritis?

Cardiovascular disease (CVD) is the highest prevalence disease in the general population (GP) and it accounts for 20 million deaths worldwide each year. Its prevalence is even higher in rheumatoid arthritis. Early detection of subclinical disease is critical and the use of cardiovascular risk prediction models and calculators is widely spread. The impact of such techniques in the GP was previously studied. Despite their common background and similarities, some disagreement exists between most scores and their importance in special high-risk populations like rheumatoid arthritis (RA), having a low level of evidence. The current article aims to single out those predictive models (models) that could be most useful in the care of rheumatoid arthritis patients.

Cardiovascular comorbidity in rheumatic diseases: a focus on heart failure

Rheumatic diseases are associated with an increased risk of cardiovascular (CV) mortality attributed to a higher incidence of heart failure (HF) and ischemic heart disease. Although traditional CV risk factors contribute to the increased incidence seen in this population, by themselves they do not account for the increased risk; in fact, obesity and hyperlipidemia may play a paradoxic role. Immune-mediated mechanisms and chronic inflammation likely play a role in the pathogenesis of CV disease in patients with rheumatic diseases. The usual clinical features of ischemic heart disease and HF are less likely to be seen in this patient population.