The association between hormonal/reproductive factors and the risk of developing rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease which leads to joint damage and bone destruction, with a complex interplay of genetic and environmental factors involved in its etiology. RA is more common among women than men at all ages, but the gender difference seems to be highest before menopause. It has been hypothesized that changes in female hormonal levels might have a role in RA pathogenesis. The overall aim of this thesis was to study the association between hormonal/reproductive factors and the risk of RA and to determine whether these factors were differently associated with serological phenotypes of the disease (according to the presence/absence of anti-citrullinated peptides antibodies (ACPA) and rheumatoid factor (RF)). This thesis is based on information from two large studies. Three articles were based on the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA), a population-based case- control study comprising incident RA cases. The study population were people aged 18 and above, living in diverse geographical parts of Sweden from 1996. Controls were randomly selected from the population register and matched to the cases by age, sex and residential area. Cases and controls completed an extensive questionnaire, collecting information about life- style/environmental exposures. One article was based on the Nurses’ Health Study (NHS), which consists of two prospective cohorts of female nurses in the USA. Data collection started in 1976 (women aged 30-55 years) and 1989 (women aged 25-42 years). Both cohorts of the NHS were followed via biennial questionnaires about diseases, lifestyle and health practices. According to our results, parous women had an increased risk of ACPA-negative RA compared with nulliparous women, aged 18-44 years. The increased risk was attributable to an elevated risk during the postpartum period, and to a young age at first birth. Older age at first birth seemed to be associated with a decreased risk of ACPA-positive RA. Parous women who breastfed for more than a year had a decreased risk of ACPA-positive RA compared with parous women who breastfed for up to 6 months. This decreased risk was non-significant after adjustment for smoking. Ever oral contraceptive use was significantly associated with a decreased risk of ACPA- positive RA, while a longer duration of use was significantly associated with a decreased risk for both RA subsets. Postmenopausal women had an increased risk of seronegative RA, but they had no association with the onset of seropositive RA. Women with a long duration of postmenopausal hormone therapy (PMH) had an increased risk of seropositive RA in the NHS. Finally, in the EIRA study, postmenopausal women who were currently using PMH at onset of their disease had a decreased risk of ACPA-positive RA. This decreased risk was mainly observed among women aged 50-59 years, with a short duration of use (<7 years), and only among users of a combined therapy of estrogen and progestogens. Further research is required to explore the biological mechanisms behind our findings, but our results contribute to the knowledge of hormonal/reproductive factors, and their impact on the serological phenotypes of RA

Salud de los trabajadores

Actividad f&iacute;sica y su relaci&oacute;n con los factores de riesgo cardiovascular de carteros chilenosAn&aacute;lisis de resultados: riesgos psicosociales en el trabajo Suceso-Istas 21 en Cesfam Quell&oacute;nAusentismo laboral por enfermedades oftalmol&oacute;gicas, Chile 2009Brote de diarreas por norovirus, posterremoto-tsunami, Constituci&oacute;n, Regi&oacute;n del MauleCalidad de vida en profesionales de la salud p&uacute;blica chilenaCaracterizaci&oacute;n del reposo laboral en personal del SSMN durante el primer semestre de 2010Concentraci&oacute;n de nicotina en pelo en trabajadores no fumadores expuestos a humo de tabaco ambientalCondiciones de trabajo y bienestar/malestar docente en profesores de ense&ntilde;anza media de SantiagoDisfunci&oacute;n auditiva inducida por exposici&oacute;n a xilenoErgonom&iacute;a aplicada al estudio del s&iacute;ndrome de dolor lumbar en el trabajoEstimaci&oacute;n de la frecuencia de factores de riesgo cardiovascular en trabajadores de una empresa mineraExposici&oacute;n a plaguicidas inhibidores de la acetilcolinesterasa en Colombia, 2006-2009Factores de riesgo y da&ntilde;os de salud en conductores de una empresa peruana de transporte terrestre, 2009Las consecuencias de la cultura en salud y seguridad ocupacional en una empresa mineraPercepci&oacute;n de cambios en la pr&aacute;ctica m&eacute;dica y estrategias de afrontamientoPercepci&oacute;n de la calidad de vida en la Universidad del Biob&iacute;oPesos m&aacute;ximos aceptables para tareas de levantamiento manual de carga en poblaci&oacute;n laboral femeninaRiesgo coronario en trabajadores mineros seg&uacute;n la funci&oacute;n de Framingham adaptada para la poblaci&oacute;n chilenaTrastornos emocionales y riesgo cardiovascular en trabajadores de la salu

Power resources and the battle against precarious employment : Trade union activities within a tripartite initiative tackling undeclared work in Sweden

The aim of this case study was to explore the abilities and limitations of trade unions in their response to undeclared work, which has received scant attention in research on working conditions and industrial relations. The authors use power resource theory to examine the outcome of a Swedish government initiative aimed to boost the ability of the social partners to tackle undeclared work. The findings confirm previous literature suggesting cross-sectoral differences in the extent and nature of undeclared work and an association between low levels of power resources and high risk of undeclared work. The authors recommend that future initiatives take account of cross-sectoral differences in the nature and extent of undeclared work and available power resources. Future research should consider how different actors can contribute to the ability of the social partners in different sectors to engage in the battle against undeclared work.

Occupational Exposure to Polycyclic Aromatic Hydrocarbons: A Cross-Sectional Study in Bars and Restaurants in Santiago, Chile

Objective To evaluate indoor polycyclic aromatic hydrocarbon (PAH) concentrations in bars and restaurants and identify the main determinants of airborne PAH concentrations. Methods This study included 57 bars/restaurants in Santiago, Chile. PAH concentrations (ng/m(3)) were measured using photoelectric aerosol sensor equipment (PAS 2000CE model). Nicotine concentrations (mg/m(3)) were measured using active sampling pumps followed by gas-chromatography. Linear regression models were used to identify determinants of PAH concentrations. Results PAH concentrations were higher in venues that allowed smoking compared to smoke-free venues. After adjusting, the air PAH concentrations were 1.40 (0.64-3.10) and 3.34 (1.43-7.83) ng/m(3) higher for tertiles 2 and 3 of air nicotine compared to the lowest tertile. Conclusions In hospitality venues where smoking is allowed, secondhand smoke exposure is a major source of PAHs in the environment. This research further supports the importance of implementing complete smoking bans to protect service industry workers from PAH exposure.This study was supported by National Fund for Research and Development in Health FONIS, CONICYT-MINSAL, Research Grant #SA09I062. One of the authors was supported by the Flight Attendant Medical Research Institute (FAMRI), the Bloomberg Initiative to Reduce Tobacco Use, and from the U.S. National Cancer Institute (R03CA153959)

Salud de los trabajadores

Actividad f&iacute;sica y su relaci&oacute;n con los factores de riesgo cardiovascular de carteros chilenosAn&aacute;lisis de resultados: riesgos psicosociales en el trabajo Suceso-Istas 21 en Cesfam Quell&oacute;nAusentismo laboral por enfermedades oftalmol&oacute;gicas, Chile 2009Brote de diarreas por norovirus, posterremoto-tsunami, Constituci&oacute;n, Regi&oacute;n del MauleCalidad de vida en profesionales de la salud p&uacute;blica chilenaCaracterizaci&oacute;n del reposo laboral en personal del SSMN durante el primer semestre de 2010Concentraci&oacute;n de nicotina en pelo en trabajadores no fumadores expuestos a humo de tabaco ambientalCondiciones de trabajo y bienestar/malestar docente en profesores de ense&ntilde;anza media de SantiagoDisfunci&oacute;n auditiva inducida por exposici&oacute;n a xilenoErgonom&iacute;a aplicada al estudio del s&iacute;ndrome de dolor lumbar en el trabajoEstimaci&oacute;n de la frecuencia de factores de riesgo cardiovascular en trabajadores de una empresa mineraExposici&oacute;n a plaguicidas inhibidores de la acetilcolinesterasa en Colombia, 2006-2009Factores de riesgo y da&ntilde;os de salud en conductores de una empresa peruana de transporte terrestre, 2009Las consecuencias de la cultura en salud y seguridad ocupacional en una empresa mineraPercepci&oacute;n de cambios en la pr&aacute;ctica m&eacute;dica y estrategias de afrontamientoPercepci&oacute;n de la calidad de vida en la Universidad del Biob&iacute;oPesos m&aacute;ximos aceptables para tareas de levantamiento manual de carga en poblaci&oacute;n laboral femeninaRiesgo coronario en trabajadores mineros seg&uacute;n la funci&oacute;n de Framingham adaptada para la poblaci&oacute;n chilenaTrastornos emocionales y riesgo cardiovascular en trabajadores de la salu