Comorbidities in a Mexican Mestizo cohort with established rheumatoid arthritis
In the study recently published in the Annals of Rheumatic Diseases,
Dougados et al.  evaluated the prevalence of comorbidities and compared
their management in Rheumatoid Arthritis (RA) patients from different
countries. We know that RA is a chronic autoimmune disease characterized
by chronic inflammation, progressive deterioration of joint function,
increased comorbidity and mortality; RA patients have about a 50%
increased risk of premature mortality . A comorbid condition may
represent an active, past or transient illness, and may be linked to RA
process itself and/or its treatment or it may be completely independent of
them , the average RA patient has approximately 1.6 comorbidities .
We conducted an observational, cross-sectional, non-comparative study, to
describe the presence of comorbidities in RA mexican mestizo patients in a
period from January to May 2013 in a secondary care center. RA patients
fulfilled the 2010 ACR / EULAR classification criteria .
We collected demographics and the disease characteristics, the history or current evidence of comorbidities. We included 394 patients with established RA.
The baseline patient and therapy disease characteristics are shown in Table 1. We found that 168 (42.6%) patients received disease-modifying antirheumatic drug (DMARD) monotherapy, 175 (44.1%) used two DMARDs and 47 (12.2%) used triple therapy and 4 (1.1%) used only analgesics. We found that 111 (28.1%) patients had no comorbidity. Comorbidities distribution shown in Figure 1. We did not find any patient in this period or earlier with history of myocardial infarction. The three most common comorbidities in our study were hypertension (21.1%), diabetes (12.1%) and hypercholesterolemia (9.9%). As noted, our results were different from those reported by Dougados M et al, when they included patients from the different countries but not mexican mestizo patients, they found depression was the most common comorbidity , and the most prevalent risk factors for cardiovascular disease were an increased Framingham Risk Score, hypertension and hypercholesterolemia. Diabetes (with/without evidence of organ damage target) was the second most prevalent comorbidity in our cohort. The worldwide prevalence of autoimmune thyroid disease in RA varies from 0.5 to 27% , we found in our cohort the presence of thyroid disease in 7.4% . The COMORA study  found a prevalence of lung disease that was less in Asia countries than in European countries and USA, we found in our patients a prevalence of 4.8%. The RA patients have a high risk of lymphoma and lung cancer , we asked to the patients the presence of any cancer, and we found that it was 4.6%.
Other comorbidities less prevalent in our cohort were carpal tunnel syndrome, gastrointestinal ulcer, chronic kidney disease, congestive cardiac failure and dementia.
Most of our patients were on DMARDs, and only 38 (9.6%) patients were on biological DMARD. We observed in this mexican mestizo cohort differences of comorbidities prevalence with the study previously published, and we agree that it is necessary a systematic search of comorbidities in RA patients with the objective to improve the quality of life and reduce mortality.
Figure and table will be available on ARD Electronic Pages shortly.
1. Dougados M, Soubrier M, Antunez A, et al. Prevalence of comorbidities in rheumatoid arthritis and evaluation of their monitoring: results of an international, cross-sectional study (COMORA). Ann Rheum Dis. 2013 Oct 4. doi: 10.1136/annrheumdis-2013-204223. [Epub ahead of print]
2. Myasoedova E, Davis JM 3rd, Crowson CS, et al. Epidemiology of rheumatoid arthritis: rheumatoid arthritis and mortality. Curr Rheumatol Rep. 2010;12(5):379-85
3. Gabriel SE, Michaud K. Epidemiological studies in incidence, prevalence, mortality, and comorbidity of the rheumatic diseases. Arthritis Res Ther. 2009;11(3):229. doi: 10.1186/ar2669. Epub 2009 May 19.
4. Wolfe F, Michaud K. The risk of myocardial infarction and pharmacologic and nonpharmacologic myocardial infarction predictors inrheumatoid arthritis: a cohort and nested case-control analysis. Arthritis Rheum. 2008;58(9):2612-21.
5. Aletaha D, Neogi T, Silman AJ, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis. 2010;69(9):1580-8.
6. Cardenas Roldan J, Amaya-Amaya J, Castellanos-de la Hoz J, et al. Autoimmune thyroid disease in rheumatoid arthritis: a global perspective. Arthritis. 2012; 864907. doi: 10.1155/2012/864907. Epub 2012 Nov 18.
7. Smitten AL, Simon TA, Hochber MC, et al. A meta-analysis of the incidence of malignancy in adult patients with rheumatoid arthritis. Arthritis Res Ther. 2008;10(2):R45. doi: 10.1186/ar2404. Epub 2008 Apr 23.
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