BACKGROUND: An association between dampness at home and respiratory conditions has been convincingly demonstrated in children. Fewer studies have been performed in adults, and data are lacking for chronic rhinosinusitis (CRS). With a prevalence of 10.9% in Europe, CRS imposes a significant burden on quality of life, as well as economy.

OBJECTIVE: Our aim was to study CRS and other respiratory conditions in relation to dampness at home in a representative sample of adults.

METHODS: The Swedish GA2 LEN questionnaire was answered by 26 577 adults (16-75 years) and included questions on respiratory symptoms, smoking, education and environmental exposure. CRS was defined according to the EP3 OS criteria. Dampness was defined as reporting water damage, floor dampness or visible moulds in the home during the last 12 months. The dampness score was ranked from 0 to 3, counting the number of signs of dampness reported.

RESULTS: Dampness at home was reported by 11.3% and was independently related to respiratory conditions after adjustment for demographic and socio-economic factors and smoking: CRS odds ratio (OR) 1.71; allergic rhinitis OR 1.24; current asthma OR 1.21; wheeze OR 1.37; nocturnal dyspnoea OR 1.80; nocturnal coughing OR 1.34; and chronic bronchitis OR 1.64. The risk of CRS and most of the other respiratory conditions was further elevated in subjects reporting multiple signs of dampness.

CONCLUSIONS AND CLINICAL RELEVANCE: This study demonstrated an independent association between dampness at home and CRS in adults. The high burden of this and the other respiratory conditions studied is a strong argument in favour of countering indoor dampness by improving building standards.

BACKGROUND: Disturbed sleep and pain often co-exist and the relationship between the two conditions is complex and likely reciprocal. This 5-year prospective study examines whether disturbed sleep can predict the onset of multi-site pain, and whether non-disturbed sleep can predict the resolution of multi-site pain.

METHODS: The cohort (n = 1599) was stratified by the number of self-reported pain sites: no pain, pain from 1-2 sites and multi-site pain (≥3 pain sites). Sleep was categorized by self-reported sleep disturbance: sleep A (best sleep), sleep B and sleep C (worst sleep). In the no-pain and pain-from-1-2 sites strata, the association between sleep (A, B and C) and multi-site pain 5 years later was analysed. Further, the prognostic value of sleep for the resolution of multi-site pain at follow-up was calculated for the stratum with multi-site pain at baseline. In the analyses, gender, age, body mass index, smoking, physical activity and work-related exposures were treated as potential confounders.

RESULTS: For individuals with no pain at baseline, a significantly higher odds ratio for multi-site pain 5 years later was seen for the tertile reporting worst sleep [odds ratio (OR) 4.55; 95% confidence interval (CI) 1.28-16.12]. Non-disturbed (or less disturbed) sleep had a significant effect when predicting the resolution of multi-site pain (to no pain) (OR 3.96; 95% CI 1.69-9.31).

CONCLUSION: In conclusion, sleep could be relevant for predicting both the onset and the resolution of multi-site pain. It seems to be a significant factor to include in research on multi-site pain and when conducting or evaluating intervention programmes for pain.

Background: Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP). Methods: The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtalje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and oncurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated. Results: Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90days) 5 years later, compared to the group with the best sleep. Conclusions: Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.

STUDY OBJECTIVES: The aim of the study was to investigate how many nights of measurement are needed for a reliable measure of sleep in a working population including adult women and men.

METHODS: In all, 54 individuals participated in the study. Sleep was assessed for 7 consecutive nights using actigraphy as an objective measure, and the Karolinska sleep diary for a subjective measure of quality. Using intra-class correlation and the Spearman-Brown formula, calculations of how many nights of measurements were required for a reliable measure were performed. Differences in reliability according to whether or not weekend measurements were included were investigated. Further, the correlation between objectively (actigraphy) measured sleep and subjectively measured sleep quality was studied over the different days of the week.

RESULTS/CONCLUSIONS: The results concerning actigraphy sleep measures suggest that data from at least 2 nights are to be recommended when assessing sleep percent and at least 5 nights when assessing sleep efficiency. For actigraphy-measured total sleep time, more than 7 nights are needed. At least 6 nights of measurements are required for a reliable measure of self-reported sleep. Fewer nights (days) are required if measurements include only week nights. Overall, there was a low correlation between the investigated actigraphy sleep parameters and subjective sleep quality, suggesting that the two methods of measurement capture different dimensions of sleep.

Bisphenol A (BPA) exposure has been linked to neurodevelopmental disorders and to effects on epigenetic regulation, such as DNA methylation, at genes involved in brain function. High doses of BPA have been shown to change expression and regulation of one such gene, Grin2b, in mice. Yet, if such changes occur at relevant doses in animals and humans has not been addressed. We investigated if low-dose developmental BPA exposure affects DNA methylation and expression of Grin2b in brains of adult rats. Furthermore, we assessed associations between prenatal BPA exposure and Grin2b methylation in 7-year old children. We found that Grin2b mRNA expression was increased and DNA methylation decreased in female, but not in male rats. In humans, prenatal BPA exposure was associated with increased methylation levels in girls. Additionally, Iow APGAR scores, a predictor for increased risk for neurodevelopmental diseases, were associated with higher Grin2b methylation levels in girls. Thus, we could link developmental BPA exposure and Iow APGAR scores to changes in the epigenetic regulation of Grin2b, a gene important for neuronal function, in a sexual dimorphic fashion. Discrepancies in exact locations and directions of the DNA methylation change might reflect differences between species, analysed tissues, exposure level and/or timing.

Aim: The current research aimed to study the association between exposure to low-dose radiation fallout after the Chernobyl accident in 1986 and the incidence of cancer in Sweden.

Methods: A nationwide study population, selecting information from nine counties out of 21 in Sweden for the period from 1980 – 2010.

In the first study, an ecological design was defined for two closed cohorts from 1980 and 1986. A possible exposure response pattern between the exposure to ¹³⁷Cs on the ground and the cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (n=2.2 million). The activity of ¹³⁷Cs at the county, municipality and parish level in 1986 was retrieved from the Swedish Radiation Safety Authority (SSI) and used as a proxy for received dose of ionizing radiation. Information about diagnoses of cancer (ICD-7 code 140-209) from 1958 – 2009 were received from the Swedish Cancer Registry, National Board of Health and Welfare (368,244 cases were reported for the period 1958 to 2009). The incidence rate ratios were calculated by using Poisson Regression for pre-Chernobyl (1980 – 1986) and post-Chernobyl (1986 – 2009) using average deposition of ¹³⁷Cs at three geographical levels: county (n=9), municipality (n=95), and parish level (n=612). Also, a time trend analysis with age standardized cancer incidence in the study population and in the general Swedish population was drawn from 1980 – 2009.

In the second study, a closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of ¹³⁷Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the Swedish Cancer Registry, National Board of Health and Welfare. Individuals were assigned an annual ¹³⁷Cs exposure based on their place of residence (1986 through 1990), from which 5-year cumulative ¹³⁷Cs exposures were calculated, accounting for the physical decay of ¹³⁷Cs and changing residencies. Hazard ratios for having cancer during the follow-up period, adjusted for age, sex, rural/non-rural residence, and pre-Chernobyl total cancer incidence, were calculated.

Results: No obvious exposure-response pattern in the age-standardized total cancer incidence rate ratios could be seen in the first study. However, a spurious association between the fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of cesium-137. Increasing the geographical resolution of exposure from the average values of nine counties to the average values of 612 parishes resulted in two to three times higher degree of variance explanation by regression model. There was a secular trend, with an increase in age standardized incidence of cancer from 1980 – 2009. This trend was stronger in the general Swedish population compared to the nine counties of the present study.

In the second study, 734,537 people identified were divided into three exposure categories: the first quartile was low exposure (0.0 to 45.4 kBq/m²), the second and third quartiles were intermediate exposure (45.41 to 118.8 kBq/m²), and the fourth quartile was highest exposure (118.81 to 564.71 kBq/m²). Between 1991 and 2010, 82,495 cancer cases were registered in the three counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure, and 1.05 (1.03 to 1.07) for the highest exposure, when comparing to the reference exposure.

Conclusion: Using the ecological data, there was no exposure response trend; however, after refining the data to the individual level of exposure, there was an overall exposure response pattern. Nonetheless, due to the time dependency, these results were restricted to the age group of 25 – 49 among males. Using register-based data only, for determining the association between low-dose exposure to radiation and the risk of developing cancer, is difficult since we cannot control for other significant factors that are associated with cancer.

Sweden received about 5 % of the total release of Cs-137 from the Chernobyl nuclear power plant accident in 1986. The distribution of the fallout mainly affected northern Sweden, where some parts of the population could have received an estimated annual effective dose of 1-2 mSv per year. It is disputed whether an increased incidence of cancer can be detected in epidemiological studies after the Chernobyl nuclear power plant accident outside the former Union of Soviet Socialist Republics. In the present paper, a possible exposure-response pattern between deposition of Cs-137 and cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (2.2 million inhabitants in 1986). The activity of Cs-137 from the fallout maps at 1986 was used as a proxy for the received dose of ionizing radiation. Diagnoses of cancer (ICD-7 code 140-209) from 1980 to 2009 were received from the Swedish Cancer Registry (273,222 cases). Age-adjusted incidence rate ratios, stratified by gender, were calculated with Poisson regression in two closed cohorts of the population in the nine counties 1980 and 1986, respectively. The follow-up periods were 1980-1985 and 1986-2009, respectively. The average surface-weighted deposition of Cs-137 at three geographical levels; county (n = 9), municipality (n = 95) and parish level (n = 612) was applied for the two cohorts to study the pre- and the post-Chernobyl periods separately. To analyze time trends, the age-standardized total cancer incidence was calculated for the general Swedish population and the population in the nine counties. Joinpoint regression was used to compare the average annual percent change in the general population and the study population within each gender. No obvious exposure-response pattern was seen in the age-adjusted total cancer incidence rate ratios. A spurious association between fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of Cs-137. Increasing the geographical resolution of exposure from nine county averages to 612 parish averages resulted in a two to three times higher value of variance in the regression model. There was a secular trend with an increase in age-standardized incidence of cancer in both genders from 1980 to 2009, but significant only in females. This trend was stronger and statistically significant for both genders in the general Swedish population compared to the nine counties. In conclusion, using both high quality cancer registry data and high resolution exposure maps of Cs-137 deposition, it was not possible to distinguish an effect of Cs-137 on cancer incidence after the Chernobyl nuclear power plant accident in Sweden.

OBJECTIVES: To determine the total cancer incidence in relation to a 5-year exposure to caesium-137 ((137)Cs) from the 1986 Chernobyl nuclear power plant accident.

METHODS: A closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of (137)Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the National Board of Health and Welfare. Individuals were assigned an annual (137)Cs exposure based on their place of residence (1986-1990), from which 5-year cumulative (137)Cs exposures were calculated, accounting for the physical decay of (137)Cs and changing residencies. HRs were adjusted for age, sex, rural/non-rural residence and pre-Chernobyl total cancer incidence.

RESULTS: The 734 537 people identified were categorised by exposure: the first quartile was low exposure (0.0-45.4 kBq/m(2)), the second and third quartiles were intermediate exposure (45.41-118.8 kBq/m(2)), and the fourth quartile was the highest exposure (118.81-564.71 kBq/m(2)). Between 1991 and 2010, 82 495 cancer cases were registered in the 3 counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure and 1.05 (1.03 to 1.07) for the highest exposure compared to the reference exposure.

CONCLUSIONS: We found a small overall exposure-response pattern of the total cancer incidence related to (137)Cs after adjustment for age, sex, rural residence and pre-Chernobyl cancer incidence.

OBJECTIVES: To investigate the prospective value of the transitional and dynamic patterns of pain disability over time on sick leave in chronic recurrent back/neck pain cases. METHODS: The material used was based on a longitudinal study with three repeated measurements. The graded Chronic Pain Scale was used to assess levels of pain disability. The relationship between the transitional patterns of the pain disability score ( ten defined states of decrease, increase or no change, between two time points) and sick leave was analyzed for 909 chronic/recurrent cases in three different models using logistic regression. RESULTS: Those with high level of pain disability have a more transitional pattern and their pain level changed during the time period studied. When adjusting for age, gender, education and previous sick leave, the final model indicated that the current level of pain disability was a risk factor in taking sick leave. The likelihood of sick leave was highest in the transition of pain into the highest levels of disability, independent of past disability level of pain. Earlier sick leave remained as an important predictor of sick leave. CONCLUSIONS: From a clinical and prognostic perspective the probability of sick leave will be different and can be predicted based on previous sick leave but not from former history of pain disability level or its transitional pattern.

STUDY DESIGN: Four-year prospective cohort study. OBJECTIVE: To find the incidence of sick leave because of neck and shoulder pain (NSP) in industrial workers, and its association with work and lifestyle risk factors. SUMMARY OF BACKGROUND DATA: Longitudinal studies to investigate NSP incidence and risk factors are rare, and even fewer have been conducted in middle- and low-income countries. METHODS: After inviting all full-time employees of an Iranian car manufacturing company with 18,031 employees to participate in a baseline study, they were followed for 4 years. New episodes of sick leave because of NSP have been calculated based on sickness absence registration between the years 2003 and 2007. The incidence was compared for participants and nonparticipants. The association between sick leave, physical, and psychosocial risk factors at work, and previous self-reported NSP, was calculated for the remaining population of baseline participants (12,184 employees) during a 4-year follow-up. RESULTS: During a 4-year follow-up of study subjects for the remaining participants of the baseline study, the incidence of sick leave was 0.8% (98 sick leave cases in 12,184 employees). For nonparticipants this incidence was 4.2% (130 cases in 3127 employees). In the final regression model for sick leave cases, the remaining factors for potential physical risk factors were repetitive work and sitting positions at work; for psychosocial factors unattractive work was the only significant remaining factor. CONCLUSION: The incidence of NSP based on sick leave is definitely very low compared with previous studies in high-income countries. This incidence varies between participants and nonparticipants. Risk factors for sick leave differ from risk factors for self-reported pain. A young population, job security, the insurance system, different health behaviors, and healthy worker bias, are all factors that may affect the results, and sick-leave as an outcome must be interpreted with more caution in middle- and low-income countries.