Rheumatoid arthritis in the indigenous qom population of Rosario, Argentina: aggressive and disabling disease with inadequate adherence to treatment in a community-based cohort study.

To describe the baseline and follow up epidemiological/clinical characteristics of rheumatoid arthritis (RA) in a community-based cohort of the qom population. RA (ACR criteria) patients identified (n = 40) or not (n = 25) in the previous study were included. Baseline and follow-up visits (3, 6, and 12 months) were performed. Treatment adherence and modification, disability (Health Assessment Questionnaire Disability Index-HAQ-DI), and Disease Activity [DAS-28 (ESR)] were ascertained. At 12 months, complete and incomplete lost to follow-up patients were identified. The estimated RA prevalence was 3%. The patients' mean (SD) disease duration was 110.5 (17.9) and their median delay in diagnosis 30.4 (IQR 52.8) months; mean (SD) age and years of formal education were 39.8 (1.6) and 5.3 (SD 0.3); 58 (89.2%) were female, and 89.2% were seropositive. At baseline, their mean DAS-28 (ESR) was 4.8 (SD 0.9) with 67.7% having high disease activity and 32.3% moderate; 76.9% reported HAQ-DI ≥ 0.8. At 12 months, three patients have died; 13 (20.9%) were "completely" and 19 (30.6%) "incompletely" lost to follow-up. There were favorable changes over time for disease activity (p Ë‚ 0.001), HAQ-DI (p Ë‚ 0.001), and treatment modifications (p Ë‚ 0.001) but no changes in treatment adherence (p = 0.260). The main cause of lost to follow-up was migration. This population has one of the highest RA prevalence rate reported. Patients had an aggressive and disabling disease, with poor adherence to treatment. Improvements of clinical parameters over time were observed.

Prevalence of musculoskeletal disorders and rheumatic diseases in the indigenous Qom population of Rosario, Argentina.

This study aimed to estimate the prevalence of musculoskeletal disorders and rheumatic diseases among the indigenous Qom (Toba) population in the city of Rosario, Santa Fe, Argentina. An analytical cross-sectional study using methodology of the Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) was performed. Subjects ≥18 years of age were interviewed by advanced students of medicine and nursing, bilingual translator-facilitators, and coordinators. Individuals with musculoskeletal pain (positive cases) were evaluated sequentially for 7 days by internists and rheumatologists for diagnosis and treatment. The study included 1656 individuals (77 % of the census population). Of these, 1020 (61.5 %) were female, with mean age of 35.3 (SD 13.9) years, and 1028 (62.0 %) were bilingual. The public health care system covers 87.1 % of the population. Musculoskeletal pain in the previous 7 days and/or at some time during their life was present in 890 subjects (53.7 %). Of those with pain in the last 7 days, 302 (64.1 %) subjects had an Health Assessment Questionnaire Disability Index (HAQ-DI) score ≥0.8. The most frequent pain sites were lumbar spine (19.3 %), knees (13.0 %), and hands (12.0 %). The prevalence of rheumatic diseases was as follows: mechanical back pain (20.1 %), rheumatic regional pain syndrome (2.9 %), osteoarthritis (4.0 %) rheumatoid arthritis (2.4 %), inflammatory back pain (0.2 %), systemic sclerosis (0.1 %), Sjögren syndrome (0.1 %), fibromyalgia (0.1 %), mixed connective tissue disease (0.06 %), and systemic lupus erythematosus (0.06 %). The prevalence of musculoskeletal disorders was 53.7 % and rheumatic diseases 29.6 %. Rheumatoid arthritis prevalence was 2.4 % using COPCORD methodology, one of the highest reported at present.

Argentine population genetic structure: large variance in Amerindian contribution.

Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.