The Prevalence of Rheumatoid Arthritis in Chile: A Nationwide Study Performed as Part of the National Health Survey.

OBJECTIVE: Genetic and environmental backgrounds influence the development of rheumatoid arthritis (RA). In Latin America, epidemiologic data are scarce. We aimed to determine the prevalence of RA in Chile in a population-based study. METHODS: The National Health Survey was a cross-sectional household survey with a stratified multistage probability sample of 6233 participants performed between August 2016 and March 2017. A screening instrument for RA was applied to a random sample of 3847 subjects > 30 years old. Positive screening was defined by at least 1 of the following: 2 swollen joints for at least 4 consecutive weeks (past/present), and/or a diagnosis of arthritis in the past. Individuals with positive screening had rheumatoid factor, anticitrullinated protein antibodies, and C-reactive protein measured, as well as clinical examination performed by a rheumatologist. Self-report of doctor-diagnosed RA was also performed. RESULTS: The screening questionnaire was applied to 2998 subjects. A positive screening was found for 783 (22.1%). Among subjects with positive screening, 493 (66%) had a clinical evaluation performed by a rheumatologist. Using the American College of Rheumatology/European League Against Rheumatism 2010 classification criteria, prevalence was 0.6% (95% CI 0.3-1.2). Prevalence was higher in women, and 3.3% of subjects self-reported having RA. CONCLUSION: According to this national population-based study, RA prevalence in Chile is 0.6% (0.3-1.2), a value similar to what has been found in developed countries and slightly lower than some Latin American countries. Self-reporting leads to overestimating RA.

Contribution of ethnic group and socioeconomic status to degree of disability in rheumatoid arthritis in Chilean patients.

The aim of this study was to estimate the contributions of ethnic group and socioeconomic status as social determinants related to disability and disease activity in Chilean Mapuche and non-Mapuche patients with rheumatoid arthritis (RA). Descriptive cross-sectional study with a stratified hospital-based sample of 189 patients in treatment with disease-modifying anti-rheumatic drugs. We assessed disability as categorical variable with the Health Assessment Questionnaire, disease activity with the Disease Activity Score instrument, and socioeconomic status with a standard questionnaire used by the Chilean government. Measures of association, stratified analyses and a multiple logistic regression model were used to analyze the data using the Stata 12.1 software package. Low socioeconomic status (annual income below US$ 7,200) is associated with disability (OR 3.87 CI 1.68-9.20) and Mapuche ethnic identity also contributes to disability (OR 2.48, CI 1.09-5.89). Relevant but not statistically significant in multivariable models were variables such as age, gender and place of residence. RA patients with a low socioeconomic status have almost three times the odds of having a moderate to high disability, independent of their ethnic group, gender or place of residence. Therefore, healthcare efforts should be aimed at promoting early diagnosis and prompt treatment among populations with high levels of poverty, which in the region of the Araucanía means primarily indigenous rural areas.

[Validation of the chronic respiratory questionnaire in Chilean patients with chronic airflow limitation]. / Validación del Cuestionario de la enfermedad respiratoria crónica en pacientes chilenos con limitación crónica del flujo aéreo.

BACKGROUND: Chronic respiratory diseases are an important problem in Chile, causing disability and worsening the quality of life. AIM: To validate the Spanish version of the Chronic Respiratory Questionnaire (CRQ) to be used in Chilean population. MATERIAL AND METHODS: The CRQ was applied to 38 patients with chronic respiratory diseases. At the same time the functional and physiologic status of patients (the 6 Minute Walking Test and spirometry) was assessed in an independent and blinded fashion. RESULTS: CRQ scores were associated with 6 Minute Walking Test and forced expiratory volume results (p < 0.01 adjusted by age, sex and smoking). The Internal Consistency analysis showed a Cronbach alpha between 0.60 and 0.89. CONCLUSIONS: Considering the construct validation as an on-going process, the present results give additional evidence supporting the use of the CRQ in Chilean population to evaluate the health-related quality of life of patients with chronic respiratory diseases.

[High prevalence of osteoporosis in asymptomatic postmenopausal Mapuche women]. / Alta prevalencia de osteoporosis en mujeres mapuches postmenopáusicas asintomáticas.

BACKGROUND: Genetic and environmental factors are responsible for variations in the frequency of osteoporosis. Prevalence of osteoporosis in Mapuche women (native Chileans) is unknown. AIM: To assess the prevalence and risk factors for osteoporosis in Mapuche women. MATERIAL AND METHOD: A random sample of 95 asymptomatic postmenopausal Mapuche females, stratified by age, was studied. Women with diseases or medications that could interfere with calcium metabolism were excluded. Spine and femoral neck bone mass density was determined using a Lunar DPX Alpha densitometer. RESULTS: Seventeen percent of women had normal bone mineral density in both spine and femoral neck. In the spine, 25.3% had a normal bone mineral density, 17.9% had osteopenia and 56.8% had osteoporosis. In the femoral neck, 34.7% had a normal bone mineral density, 57.9% had osteopenia, and 7.4% had osteoporosis. There was a positive correlation between bone mineral density and body mass index. Women with more than one hour per day of physical activity, had a significantly lower proportion of osteopenia or osteoporosis. No association between bone mineral density and parity or calcium intake, was observed. CONCLUSIONS: There is a high prevalence of osteopenia and osteoporosis among Mapuche women. Osteoporosis was associated with low body mass index.

Evaluación del efecto bociógeno de la alimentación con piñones en ratas / Evaluation of goiter etiology effect of the rat feeding with Pinus cembroides

Con el fin de evaluar el posible efecto bociógeno de la alimentación con piñones (Pinus Cembroides), se alimentaron dos grupos de 10 ratas cada uno con dieta a base de piñones, una normo y otra hipoyódica. Se compararon con dos grupos controles a los cuales no se administró piñones. Al cabo de tres meses los animales fueron sacrificados evaluándose: peso tiroideo e histología. Se observó un peso mayor del tiroides en los grupos alimentados con piñones, el cual aún fue más notorio en el subgrupo hipoyódico. Histológicamente hubo hiperplasia glandular en los grupos alimentados con piñones. Se concluye que el piñón tiene un efecto bociógeno en ratas, tanto si los animales de experimentación reciben dieta normoyódica o hipoyódica