No abstract

We wanted to compare cancer incidence rates between Parkinson's disease (PD) patients and persons without PD, as well as between siblings of these groups. We conducted a family-based matched cohort study based on nationwide Swedish health registries and the Swedish Multi-Generation Register. We assessed risk of incident cancer in PD patients (n = 11,786) during 1964-2009 versus a matched cohort of PD-free individuals (n = 58,930) and in siblings of PD patients (n = 16,841) versus siblings of PD-free individuals (n = 84,205). Hazard ratios with 95% confidence intervals were estimated using Cox proportional hazards regression. Cancer occurrence was slightly higher in PD patients than in PD-free individuals (hazard ratio (HR) = 1.05, 95% confidence interval (CI): 1.00, 1.10), largely because of cancers arising within 1 year before or after the index date for PD, but risk of smoking-related cancers was lower (HR = 0.87, 95% CI: 0.79, 0.96). PD patients had a higher risk of melanoma both up to 1 year before the PD index date (HR = 1.53, 95% CI: 1.23, 1.91) and from 1 year after the index date onward (HR = 1.46, 95% CI: 1.01, 2.10). In the sibling comparison, cancer occurrence was largely similar. These results indicate that melanoma risk is higher among PD patients and that mechanisms other than familial ones explain the association.

This population- and family-based study failed to find support for a causal effect of smoking during pregnancy on risk of severe mental illness in offspring. Rather, these results suggest that much of the observed population-level association can be explained by measured and unmeasured factors shared by siblings.

BackgroundMore detailed understanding of herpes zoster (HZ) is called for in the context of an increasing observed frequency of disease, and ongoing discussions regarding potential consequences of the disease. Thus, population-based data on incidence and complications of HZ are needed.MethodsWe conducted a register-based cohort study in Västra Götaland County (population 1.5 million) in Sweden. We collected data on all patients diagnosed with HZ during the years 2008 to 2010 from population-based registers. Incidence rates (IR) of HZ and related complications were calculated and stratified by age and sex.ResultsThere were 13 269 new HZ cases during the study period. Overall, the IR of herpes zoster in both genders was 3.25 (95 % CI: 3.16–3.34) per 1000 person years in 2010. The incidence was consistently higher in women than in men and in older than in young. A history of immunosuppression was more common than in the general population. The incidence was highest in individuals over 80 years of age (IR 9.2 per 1000 person years, 95 % CI: 8.8–9.6) during 2008–2010. The most common complications to HZ were ocular engagement and postherpetic neuralgia; risks for stroke and sepsis were significantly elevated during the one year following diagnosis, especially in the youngest age group of patients 0–39 years.ConclusionsHerpes zoster is more common in women, the elderly and immunosuppressed individuals. We verify a population-based association between herpes zoster and risk for stroke and sepsis, which may merit concern.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-015-1170-y) contains supplementary material, which is available to authorized users.

Objectives To examine the associations of specific occupations and occupational exposures with the risk of amyotrophic lateral sclerosis (ALS) in the Swedish population. Methods A nested case-control study was conducted in Sweden. ALS patients diagnosed during 1991–2010 (n=5,020) were identified from the National Patient Register and five controls per case (n=25,100) were randomly selected from the general Swedish population, individually matched to cases by birth year and sex. Occupational history was obtained from the Swedish Censuses in 1970, 1980, and 1990. The Nordic Occupational Cancer Study Job Exposure Matrix was used to identify exposures related to individual occupations. Conditional logistic regression was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs). Results Higher risk of ALS was associated with precision-tool manufacturing (OR: 1.68, 95% CI: 1.11, 2.52) and glass, pottery and tile work (OR: 1.76, 95% CI: 1.03, 3.00), whereas lower risk was associated with textile work (OR: 0.44, 95% CI: 0.21, 0.91). None of the examined occupational exposures were associated with ALS risk overall. However, among individuals younger than 65 years of age, an association with a higher risk of ALS was found for formaldehyde (OR: 1.29, 95% CI: 1.00, 1.65), and an association with a lower risk of ALS was found for methylene chloride (OR: 0.49, 95% CI: 0.26, 0.93). Conclusions We identified several occupations and occupational exposures that may be associated with the risk of ALS in Sweden. Occupational history obtained from censuses every ten years remains a limitation of the study.

Objective To examine whether severe head injury, subtypes of head injury, or repeated head injuries are associated with ALS risk based on Swedish population and health registers. Methods We conducted a case-control study, nested within a cohort of 5,764,522 individuals who were born in Sweden during 1901–1970 and followed between 1991 and 2007. The study included 4,004 ALS patients identified from the Swedish Patient Register during follow-up and 20,020 randomly selected controls matched by sex and birth year. We evaluated hospitalization for severe head injury that was recorded in the Inpatient Register before ALS diagnosis. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results There was an association of ALS risk with severe head injury ≤1 year before diagnosis (OR: 3.9, 95% CI: 2.6–6.1). No association was observed for severe head injury >3 years before ALS diagnosis, nor was ALS associated with subtypes of head injury or repeated injuries occurring >3 years before diagnosis. Conclusions Our findings from the Swedish registers provide no strong support for an etiological relationship between severe head injury in adulthood and ALS risk.

BackgroundWe analyzed temporal trends in the incidence of myocardial infarction and ischemic stroke in Sweden by socioeconomic position and investigated whether social inequalities in incidence of these diseases changed over time.Materials and MethodsWe studied a cohort of almost three million Swedish residents born between 1932 and 1960 followed from 1987 until 2010. Incident cases of myocardial infarction and ischemic stroke were identified in the Swedish National Inpatient Register and Cause of Death Register. Socioeconomic position was retrieved from the Population and Housing Censuses. Incidence rates of myocardial infarction and ischemic stroke and incidence rate ratios comparing levels of socioeconomic position were estimated using flexible parametric survival models adjusted for calendar year, attained age, sex, and birth country.ResultsThe overall incidences of myocardial infarction and ischemic stroke decreased over time among men, but were stable over time among women. With regard to ischemic stroke incidence, socioeconomic inequality increased over time in the age group 55 to 59: the incidence rate ratios for low manual compared to high non-manual increased from 1.3 (95% CI: 1.2–1.4) in 1997 to 1.5 (1.4–1.7) in 2010 among men, and from 1.4 (1.3–1.6) in 1997 to 2.1 (1.8–2.5) in 2010 among women. The socioeconomic inequality in incidence of myocardial infarction was stable over time for both men and women.ConclusionThere was a decrease in myocardial infarction and ischemic stroke incidence over time among men but no significant change for women. Our study highlights existing, and in some cases increasing, social inequalities in the incidence of cardiovascular diseases.

Multidrug-resistant enteric bacilli are becoming a problem in Sweden, despite low antimicrobial use. Men need to be informed about the increasing risks of infectious complications of transrectal prostate biopsy. One out of 50 men undergoing a prostate biopsy will develop symptoms suggestive of a bloodstream infection after the biopsy and one in 100 men will have a positive blood culture.