Rare sequence variants in at least five genes are known to cause monogenic obesity. In this study we aimed to investigate the prevalence of, and characterize, rare coding and splice site variants in LEP, LEPR, MC4R, PCSK1 and POMC in patients with morbid obesity and normal weight controls. Targeted next-generation sequencing of all exons in LEP, LEPR, MC4R, PCSK1 and POMC was performed in 485 patients with morbid obesity and 327 normal weight population-based controls from Norway. In total 151 variants were detected. Twenty-eight (18.5%) of these were rare, coding or splice variants and five (3.3%) were novel. All individuals, except one control, were heterozygous for the 28 variants, and the distribution of the rare variants showed a significantly higher carrier frequency among cases than controls (9.9% vs. 4.9%, p=0.011). Four variants in MC4R were classified as pathogenic or likely pathogenic. Four cases (0.8%) of monogenic obesity were detected, all due to MC4R variants previously linked to monogenic obesity. Significant differences in carrier frequencies among patients with morbid obesity and normal weight controls suggest an association between heterozygous rare coding variants in these five genes and morbid obesity. However, additional studies in larger cohorts and functional testing of the novel variants identified are required to confirm the findings.

The healthy worker effect and incomplete exposure information have been problems in former studies regarding the association between exposure to Portland cement dust and respiratory effects. We included former workers and made an individual estimation of particle exposure to reduce the selection bias in this controlled cross-sectional study on the effects of cement dust exposure on respiratory symptoms and ventilatory function in long-term exposed Norwegian cement plant workers. A total of 119 workers from the largest cement plant in Norway and 50 workers from a nearby control plant, born 1918 to 1938, performed spirometry and gave information on respiratory symptoms in 1998 and 1999. The prevalence of symptoms and mean pulmonary function indices were similar for exposed workers and controls. There was no dose–response-related increase in symptoms or decrease in lung function indices. The estimated power to detect a true difference between forced expiratory volume in one second (FEV1) in the two groups of 0.3l was 0.90, assuming 95% significance level. The prevalence of chronic obstructive pulmonary disease was 14.3% in the exposed group and 14.0% among the controls. These findings do not support the hypothesis that cement dust exposure has a negative impact on lung function or gives an increase in respiratory symptoms.

Objectives Declining participation in epidemiological studies has been reported in recent decades and may lead to biased prevalence estimates and selection bias. The aim of the study was to identify possible causes and effects of non-response in a population-based study of respiratory health in Norway. Design The Telemark study is a longitudinal study that began with a cross-sectional survey in 2013. Setting In 2013, a random sample of 50 000 inhabitants aged 16–50 years, living in Telemark county, received a validated postal questionnaire. The response rate was 33%. In this study, a random sample of 700 non-responders was contacted first by telephone and then by mail. Outcome measures Response rates, prevalence and OR of asthma and respiratory symptoms based on exposure to vapours, gas, dust or fumes (VGDF) and smoking. Causes of non-response. Results A total of 260 non-responders (37%) participated. Non-response was associated with younger age, male sex, living in a rural area and past smoking. The prevalence was similar for responders and non-responders for physician-diagnosed asthma and several respiratory symptoms. The prevalence of chronic cough and use of asthma medication was overestimated in the Telemark study, and adjusted prevalence estimates were 17.4% and 5%, respectively. Current smoking was identified as a risk factor for respiratory symptoms among responders and non-responders, while occupational VGDF exposure was a risk factor only among responders. The Breslow-Day test detected heterogeneity between productive cough and occupational VGDF exposure among responders. Conclusions The Telemark study provided valid estimates for physician-diagnosed asthma and several respiratory symptoms, while it was necessary to adjust prevalence estimates for chronic cough and use of asthma medication. Reminder letters had little effect on risk factor associations. Selection bias should be considered in future investigations of the relationship between respiratory outcomes and exposures.

Cement dust exposure has previously been associated with airway symptoms and ventilatory impairment. The aim of the present study was to examine lung function and airway symptoms among employees in different jobs and at different levels of exposure to thoracic dust in the cement production industry.At the start of a 4-yr prospective cohort study in 2007, exposure to cement dust, symptoms and lung function were recorded cross-sectionally in 4,265 employees in 24 European cement plants. Bronchial exposure was assessed by 2,670 full-shift dust samples with cyclones collecting the thoracic aerosol fraction. A job exposure matrix was constructed by grouping dust concentrations according to job type and plant.Elevated odds ratios for symptoms and airflow limitation (range 1.2–2.6 in the highest quartile), but not for chronic bronchitis, were found in the higher quartiles of exposure compared with the lowest quartile. Forced expiratory volume in 1 s (FEV₁) showed an exposure–response relationship with a 270-mL deficit of FEV₁(95% CI 190–300 mL) in the highest compared with the lowest exposure level.The results support the hypothesis that exposure to dust in cement production may lead to respiratory symptoms and airway obstruction.

Objectives: The aim of this study was to investigate the association between multiple lifestyle-related risk factors (unhealthy diet, low leisure-time physical activity, overweight/obesity and smoking) and self-rated work ability in a general working population. Setting: Population-based cross-sectional study, in Telemark County, Norway, 2013. Participants: A random sample of 50 000 subjects was invited to answer a self-administered questionnaire and 16 099 responded. Complete data on lifestyle and work ability were obtained for 10 355 participants aged 18–50 years all engaged in paid work during the preceding 12 months. Outcome measure: Work ability was assessed using the Work Ability Score (WAS)—the first question in the Work Ability Index. To study the association between multiple lifestyle risk factors and work ability, a lifestyle risk index was constructed and relationships examined using multiple logistic regression analysis. Results: Low work ability was more likely among subjects with an unhealthy diet (OR _adj 1.3, 95% CI 1.02 to 1.5), inactive persons (OR _adj 1.4, 95% CI 1.2 to 1.6), obese respondents (OR _adj 1.5, 95% CI 1.3 to 1.7) and former and current smokers (OR _adj 1.2, 95% CI 1.1 to 1.4 and 1.3, 95% CI 1.2 to 1.5, respectively). An additive relationship was observed between the lifestyle risk index and the likelihood of decreased work ability (moderate-risk score: OR _adj 1.3; 95% CI 1.1 to 1.6; high-risk score: OR _adj 1.9; 95% CI 1.6 to 2.2; very high risk score: OR _adj 2.4; 95% CI 1.9 to 3.0). The overall population attributable fraction (PAF) of low work ability based on the overall risk index was 38%, while the PAFs of physical activity, smoking, body mass index and diet were 16%, 11%, 11% and 6%, respectively. Conclusions: Lifestyle risk factors were associated with low work ability. An additive relationship was observed. The findings are considered relevant to occupational intervention programmes aimed at prevention and improvement of decreased work ability.

Objectives The aim of this study was to estimate the prevalence of respiratory symptoms and physician-diagnosed asthma and assess the impact of current occupational exposure. Design Cross-sectional analyses of the prevalence of self-reported respiratory health and association with current occupational exposure in a random sample of the general population in Telemark County, Norway. Settings In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16–50, in Telemark, Norway. The overall response rate was 33%, comprising 16 099 responders. Outcome measures The prevalence for respiratory symptoms and asthma, and OR of respiratory symptoms and asthma for occupational groups and exposures were calculated. Occupational exposures were assessed using self-reported exposure and an asthma-specific job-exposure matrix (JEM). Results The prevalence of physician-diagnosed asthma was 11.5%. For the occupational groups, the category with agriculture/fishery workers and craft/related trade workers was associated with wheezing and asthma attack in the past 12 months, showing OR 1.3 (1.1 to 1.6) and 1.9 (1.2 to 2.8), respectively. The group including technicians and associated professionals was also associated with wheezing OR 1.2 (1.0 to 1.3) and asthma attack OR 1.4 (1.1 to 1.9). The JEM data show that exposure to flour was associated with wheezing OR 3.2 (1.4 to 7.3) and woken with dyspnoea OR 3.5 (1.3 to 9.5), whereas exposures to diisocyanates, welding/soldering fumes and exposure to vehicle/motor exhaust were associated with dyspnoea OR 2.9 (1.5 to 5.7), 3.2 (1.6 to 6.4) and 1.4 (1.0 to 1.8), respectively. Conclusions The observed prevalence of physician-diagnosed asthma was 11.5%. The ‘manual’ occupations were associated with respiratory symptoms. Occupational exposure to flour, diisocyanates, welding/soldering fumes and vehicle/motor exhaust was associated with respiratory symptoms in the past 12 months and use of asthma medication. However, prospective data are needed to confirm the observed associations.