Moist smokeless tobacco (Snus) use and risk of Parkinson's disease.

Background: Cigarette smoking is associated with a lower risk of Parkinson's disease. It is unclear what constituent of tobacco smoke may lower the risk. Use of Swedish moist smokeless tobacco (snus) can serve as a model to disentangle what constituent of tobacco smoke may lower the risk. The aim of this study was to determine whether snus use was associated with a lower risk of Parkinson's disease. Methods: Individual participant data were collected from seven prospective cohort studies, including 348 601 men. We used survival analysis with multivariable Cox regression to estimate study-specific relative risk of Parkinson's disease due to snus use, and random-effects models to pool estimates in a meta-analysis. The primary analyses were restricted to never-smokers to eliminate the potential confounding effect of tobacco smoking. Results: During a mean follow-up time of 16.1 years, 1199 incident Parkinson's disease cases were identified. Among men who never smoked, ever-snus users had about 60% lower Parkinson's disease risk compared with never-snus users [pooled hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.28-0.61]. The inverse association between snus use and Parkinson's disease risk was more pronounced in current (pooled HR 0.38, 95% CI 0.23-0.63), moderate-heavy amount (pooled HR 0.41, 95% CI 0.19-0.90) and long-term snus users (pooled HR 0.44, 95% CI 0.24-0.83). Conclusions: Non-smoking men who used snus had a substantially lower risk of Parkinson's disease. Results also indicated an inverse dose-response relationship between snus use and Parkinson's disease risk. Our findings suggest that nicotine or other components of tobacco leaves may influence the development of Parkinson's disease.

Social origin, schooling and individual change in intelligence during childhood influence long-term mortality: a 68-year follow-up study.

BACKGROUND: Intelligence at a single time-point has been linked to health outcomes. An individual's IQ increases with longer schooling, but the validity of such increase is unclear. In this study, we assess the hypothesis that individual change in the performance on IQ tests between ages 10 and 20 years is associated with mortality later in life. METHODS: The analyses are based on a cohort of Swedish boys born in 1928 (n = 610) for whom social background data were collected in 1937, IQ tests were carried out in 1938 and 1948 and own education and mortality were recorded up to 2006. Structural equation models were used to estimate the extent to which two latent intelligence scores, at ages 10 and 20 years, manifested by results on the IQ tests, are related to paternal and own education, and how all these variables are linked to all-cause mortality. RESULTS: Intelligence at the age of 20 years was associated with lower mortality in adulthood, after controlling for intelligence at the age of 10 years. The increases in intelligence partly mediated the link between longer schooling and lower mortality. Social background differences in adult intelligence (and consequently in mortality) were partly explained by the tendency for sons of more educated fathers to receive longer schooling, even when initial intelligence levels had been accounted for. CONCLUSIONS: The results are consistent with a causal link from change in intelligence to mortality, and further, that schooling-induced changes in IQ scores are true and bring about lasting changes in intelligence. In addition, if both these interpretations are correct, social differences in access to longer schooling have consequences for social differences in both adult intelligence and adult health.

Association between labour market trends and trends in young people's mental health in ten European countries 1983-2005.

BACKGROUND: Mental health problems have become more common among young people over the last twenty years, especially in certain countries. The reasons for this have remained unclear. The hypothesis tested in this study is that national trends in young people's mental health are associated with national trends in young people's labour market. METHODS: National secular changes in the proportion of young people with mental health problems and national secular labour market changes were studied from 1983 to 2005 in Austria, Belgium, Denmark, Finland, Hungary, Norway, Spain, Sweden, Switzerland and the United Kingdom. RESULTS: The correlation between the national secular changes in the proportion of young people not in the labour force and the national secular changes in proportion of young people with mental health symptoms was 0.77 for boys and 0.92 for girls. CONCLUSION: Labour market trends may have contributed to the deteriorating trend in mental health among young people. A true relationship, should other studies confirm it, would be an important aspect to take into account when forming labour market policies or policies concerning the delivery of higher education.

Children's overweight and obesity: local and national monitoring using electronic health records.

AIM: To test the feasibility of a system for monitoring children's obesity and overweight based on data from electronic health records in the school health services. METHODS: Data on weight and height from electronic health records at school health services were collected for 10-year-olds in 2003-2004, 2004-2005 and 2005-2006. School health personnel extracted group-level data with a simple program installed on the computer containing the health records. Four Swedish municipalities were included in the study: Karlstad, Umeå, Västerås, and Ystad. RESULTS: The system achieved coverage of 92-96% of all children in 2005-2006. The overall prevalence rates were 4.2% (3.8-4.7%) obese and 22.0% (21.1-23.0%) overweight, including obesity. CONCLUSIONS: A system based on electronic health records from the school health services can successfully provide data. The system has practical, economical and ethical strengths.