Incidence of invasive infections with Group B streptococcus in adults in Norway 1996-2019: a nationwide registry-based case-control study.

PURPOSE: Group B streptococcus (GBS) colonizes the gastrointestinal and vaginal mucosa in healthy adults, but has also become an increasing cause of invasive infection. The aims of this study were to describe the incidence and factors associated with the occurrence of invasive GBS disease in adults in Norway. METHODS: We performed a nationwide retrospective case-control study of invasive GBS infections during 1996-2019, with two control groups; invasive Group A streptococcal disease (GAS) to control for changes in surveillance and diagnostics, and a second representing the general population. RESULTS: A total of 3710 GBS episodes were identified. The age-standardized incidence rate increased steadily from 1.10 (95% CI 0.80-1.50) in 1996 to 6.70 (95% CI 5.90-7.50) per 100,000 person-years in 2019. The incidence rate had an average annual increase of 6.44% (95% CI 5.12-7.78). Incidence rates of GAS varied considerably, and there was no evidence of a consistent change over the study period. GBS incidence was highest among adults > 60 years of age. Cardiovascular disease, cancer, and diabetes were the most common comorbid conditions. There was a shift in the distribution of capsular serotypes from three dominant types to more equal distribution among the six most common serotypes. CONCLUSIONS: The incidence of invasive GBS disease in adults increased significantly from 1996 to 2019. The increasing age of the population with accompanying underlying comorbid conditions might contribute to the increasing burden of invasive GBS disease. Interestingly, type 1 diabetes was also associated with the occurrence of invasive GBS disease.

Incidence of sick leave and disability pension in adults with musculoskeletal pain and co-occurring long-term conditions: data from the Norwegian HUNT study and national registries.

BACKGROUND: Musculoskeletal pain is one of the leading causes of work productivity loss. Long-term conditions (LTCs) commonly occur alongside musculoskeletal pain. However, the incidence of sick leave and disability pension according to LTC status in people with musculoskeletal pain has not been previously described. METHODS: Working-age participants (20-65 years) with persistent musculoskeletal pain who participated in the HUNT3 Study (1995-97) were included. Twenty-five LTCs were classified into 8 LTC groups according to the International Classification of Diseases version 11. Data on sickness and disability benefits were obtained from the National Insurance Database and linked to the HUNT3 data using participants' personal identification number. Age-adjusted incidence rates (IRs) (per 10,000 person-years) and hazard ratios (HRs) of sick leave during 5-year follow-up and disability pension during ~ 25-year follow-up were estimated with 95% confidence intervals (CIs) and presented according to LTC status. RESULTS: Overall, 11,080 participants with musculoskeletal pain were included. Of those, 32% reported one LTC and 45% reported ≥ 2 LTCs. During the follow up period, 1,312 participants (12%) received disability pension due to musculoskeletal conditions. The IR of sick leave and disability pension due to musculoskeletal conditions increased with number of LTCs. Specifically, the IR of sick leave was 720 (95% CI 672 to 768) in participants without any LTCs and 968 (95% CI 927 to 1,009) if they had ≥ 2 LTCs. The IRs of disability pension were 87 (95% CI 75 to 98) and 167 (95% CI 154 to 179) among those with no LTCs and ≥ 2 LTCs, respectively. The incidence of sick leave and disability pension due to musculoskeletal conditions was largely similar across LTCs, although the incidence of disability pension was somewhat higher among people with sleep disorders (IR: 223, 95% CI 194 to 252). CONCLUSIONS: Among people with persistent musculoskeletal pain, the incidence of prematurely leaving the work force due to musculoskeletal conditions was twice as high for those with multiple LTCs compared to those without any LTCs. This was largely irrespective of the type of LTC, indicating that the number of LTCs are an important feature when evaluating work participation among people with musculoskeletal pain.

Coding practice for sepsis 2008-21. / Kodepraksis ved sepsis 2008­21.

Background: Sepsis has a high incidence and mortality rate. Accurate data are needed for health service planning and for research, and there is a need to identify coding practices in Norway. Material and method: All patients over 17 years of age who had been admitted to Norwegian hospitals with sepsis in the period 2008-21 were identified using diagnostic codes for infection plus organ failure, and specific codes for sepsis, from the Norwegian Patient Registry. Results: There were 317 705 admissions with diagnostic codes for sepsis, of which 210 391 (66.2 %) were sepsis with a known focus, 77 627 (24.4 %) were of unknown focus and 29 687 (9.3 %) were codes for both a known and unknown focus. The percentage of sepsis episodes coded with a known focus varied between the health regions. The highest percentage was in the Western Norway Regional Health Authority (72.1 %, 95 % confidence interval (CI): 71.8 to 72.5), and the lowest was in the Central Norway Regional Health Authority (59.2 %, 95 %, CI 58.7 to 59.7). The use of codes with a known focus increased each year on average by 3.2 % (95 % CI 2.7 to 3.6, from 47.5 % in 2008 to 82.3 % in 2021), while the use of codes with an unknown focus decreased by 2.3 % (95 % CI -2.7 to -1.9) from 37.8 % in 2008 to 13.0 % in 2021. Known and unknown focus combined also decreased by 0.9 % per year on average (95 % CI -1.0 to -0.8) from 14.3 % in 2008 to 4.1 % in 2021. Interpretation: The coding of sepsis in Norwegian hospitals has become more uniform.

Can the bias of self-reported sitting time be corrected? A statistical model validation study based on data from 23 993 adults in the Norwegian HUNT study.

BACKGROUND: Despite apparent shortcomings such as measurement error and low precision, self-reported sedentary time is still widely used in surveillance and research. The aim of this study was threefold; (i) to examine the agreement between self-reported and device-measured sitting time in a general adult population; (ii), to examine to what extent demographics, lifestyle factors, long-term health conditions, physical work demands, and educational level is associated with measurement bias; and (iii), to explore whether correcting for factors associated with bias improves the prediction of device-measured sitting time based on self-reported sitting time. METHODS: A statistical validation model study based on data from 23 993 adults in the Trøndelag Health Study (HUNT4), Norway. Participants reported usual sitting time on weekdays using a single-item questionnaire and wore two AX3 tri-axial accelerometers on the thigh and low back for an average of 3.8 (standard deviation [SD] 0.7, range 1-5) weekdays to determine their sitting time. Statistical validation was performed by iteratively adding all possible combinations of factors associated with bias between self-reported and device-measured sitting time in a multivariate linear regression. We randomly selected 2/3 of the data (n = 15 995) for model development and used the remaining 1/3 (n = 7 998) to evaluate the model. RESULTS: Mean (SD) self-reported and device-measured sitting time were 6.8 (2.9) h/day and 8.6 (2.2) h/day, respectively, corresponding to a mean difference of 1.8 (3.1) h/day. Limits of agreement ranged from - 8.0 h/day to 4.4 h/day. The discrepancy between the measurements was characterized by a proportional bias with participants device-measured to sit less overestimating their sitting time and participants device-measured to sit more underestimating their sitting time. The crude explained variance of device-measured sitting time based on self-reported sitting time was 10%. This improved to 24% when adding age, body mass index and physical work demands to the model. Adding sex, lifestyle factors, educational level, and long-term health conditions to the model did not improve the explained variance. CONCLUSIONS: Self-reported sitting time had low validity and including a range of factors associated with bias in self-reported sitting time only marginally improved the prediction of device-measured sitting time.

Trends in mortality after a sepsis hospitalization: a nationwide prospective registry study from 2008 to 2021.

BACKGROUND: Few studies have reported on mortality beyond one year after sepsis. We aim to describe trends in short- and long-term mortality among patients admitted with sepsis, and to describe the association between clinical characteristics and mortality for improved monitoring, treatment and prognosis. METHODS: Patients ≥ 18 years admitted to all Norwegian hospitals (2008-2021) with a first sepsis episode were identified using Norwegian Patient Registry and International Classification of Diseases 10th Revision codes. Sepsis was classified as implicit (known infection site plus organ dysfunction), explicit (unknown infection site), or COVID-19-related sepsis. The outcome was all-cause mortality. We describe age-standardized 30-day, 90-day, 1-, 5- and 10-year mortality for each admission year and estimated the annual percentage change with 95% confidence interval (CI). The association between clinical characteristics and all-cause mortality is reported as hazard ratios (HRs) adjusted for age, sex and calendar year in Cox regression. RESULTS: The study included 222,832 patients, of whom 127,059 (57.1%) had implicit, 92,928 (41.7%) had explicit, and 2,845 (1.3%) had COVID-19-related sepsis (data from 2020 and 2021). Trends in overall age-standardized 30-day, 90-day, 1- and 5-year mortality decreased by 0.29 (95% CI - 0.39 to - 0.19), 0.43 (95% CI - 0.56 to - 0.29), 0.61 (95% CI - 0.73 to - 0.49) and 0.66 (95% CI - 0.84 to - 0.48) percent per year, respectively. The decrease was observed for all infections sites but was largest among patients with respiratory tract infections. Implicit, explicit and COVID-19-related sepsis had largely similar overall mortality, with explicit sepsis having an adjusted HR of 0.980 (95% CI 0.969 to 0.991) and COVID-19-related sepsis an adjusted HR of 0.916 (95% CI 0.836 to 1.003) compared to implicit sepsis. Patients with respiratory tract infections have somewhat higher mortality than those with other infection sites. Number of comorbidities was positively associated with mortality, but mortality varied considerably between different comorbidities. Similarly, number of acute organ dysfunctions was strongly associated with mortality, whereas the risk varied for each type of organ dysfunction. CONCLUSION: Overall mortality has declined over the past 14 years among patients with a first sepsis admission. Comorbidity, site of infection, and acute organ dysfunction are patient characteristics that are associated with mortality. This could inform health care workers and raise the awareness toward subgroups of patients that needs particular attention to improve long-term mortality.

Return to work after hospitalization for sepsis: a nationwide, registry-based cohort study.

BACKGROUND: Sepsis survivors commonly experience functional impairment, which may limit return to work. We investigated return to work (RTW) of patients hospitalized with sepsis and the associations with patient and clinical characteristics. METHODS: Working-age patients (18-60 years) admitted to a Norwegian hospital with sepsis between 2010 and 2021 were identified using the Norwegian Patient Registry and linked to sick-leave data from the Norwegian National Social Security System Registry. The main outcome was proportion of RTW in patients hospitalized with sepsis at 6 months, 1 year, and 2 years after discharge. Secondary outcomes were time trends in age-standardized proportions of RTW and probability of sustainable RTW (31 days of consecutive work). The time trends were calculated for each admission year, reported as percentage change with 95% confidence interval (CI). Time-to-event analysis, including crude and adjusted hazard risk (HRs), was used to explore the association between sustainable RTW, characteristics and subgroups of sepsis patients (intensive care unit (ICU) vs. non-ICU and COVID-19 vs. non-COVID-19). RESULTS: Among 35.839 hospitalizations for sepsis among patients aged 18-60 years, 12.260 (34.2%) were working prior to hospitalization and included in this study. The mean age was 43.7 years. At 6 months, 1 year, and 2 years post-discharge, overall estimates showed that 58.6%, 67.5%, and 63.4%, respectively, were working. The time trends in age-standardized RTW for ICU and non-ICU sepsis patients remained stable over the study period, except the 2-year age-standardized RTW for non-ICU patients that declined by 1.51% (95% CI - 2.22 to - 0.79) per year, from 70.01% (95% CI 67.21 to 74.80) in 2010 to 57.04% (95% CI 53.81-60.28) in 2019. Characteristics associated with sustainable RTW were younger age, fewer comorbidities, and fewer acute organ dysfunctions. The probability of sustainable RTW was lower in ICU patients compared to non-ICU patients (HR 0.56; 95% CI 0.52-0.61) and higher in patients with COVID-19-related sepsis than in sepsis patients (HR 1.31; 95% CI 1.15-1.49). CONCLUSION: Absence of improvement in RTW proportions over time and the low probability of sustainable RTW in sepsis patients need attention, and further research to enhance outcomes for sepsis patients is required.

Changes of inflammation in patients with psoriatic arthritis after high intensity interval training assessed by ultrasound and MRI, a randomized controlled trial.

BACKGROUND: In psoriatic arthritis (PsA) there is a theoretical risk of increased disease activity related to strenuous physical activity, including exercise. We evaluated the effect of high intensity interval training (HIIT) on objective measures of inflammation in PsA assessed by ultrasound (US) of peripheral joints and entheses, and by bone marrow edema (BME) on MRI of the sacroiliac joints (SIJ) and spine. METHODS: We randomly assigned 67 PsA patients to an intervention group that performed structured HIIT for 11 weeks, or to a control group instructed not to change their physical exercise habits. Outcome measures included US evaluation of the total cohort and MRI in a subgroup of 41; both assessed at 3 months. We calculated the proportions with an increased US B-mode and power-doppler (PD) signal of joints and entheses and Spondyloarthritis-Research-Consortium-of-Canada (SPARCC)-BME score of the SIJ and spine for both groups. RESULTS: Proportions with an increased US B-mode score of the joints were 32% and 28% in HIIT and control groups, respectively. Corresponding proportions of PD scores of the joints were 7% and 10% and PD scores of entheses were 32% and 31%. The proportions with increased MRI BME of the SIJ were 6% in the HIIT group and 10% in the control group. Corresponding proportions were 6% and 5% for the MRI BME of the spine. CONCLUSION: In PsA patients with a low to moderate disease activity, there was no clear evidence of objectively measured increased inflammation after HIIT, as evaluated by US and MRI. TRIAL REGISTRATION: ClinicalTrials.gov NCT02995460 (16/12/2016).

The interplay between multisite pain and insomnia on the risk of anxiety and depression: the HUNT study.

BACKGROUND: Chronic musculoskeletal pain and insomnia frequently co-occur and are known independent risk factors for anxiety and depression. However, the interplay between these two conditions on the risk of anxiety and depression has not been explored. METHODS: A population-based prospective study of 18,301 adults in the Norwegian HUNT Study without anxiety or depression at baseline (2006-2008). We calculated adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for anxiety and/or depression at follow-up (2017-2019), associated with i) number of chronic pain sites, and ii) chronic pain and insomnia symptoms jointly. RESULTS: At follow-up, 2155 (11.8%) participants reported anxiety and/or depression. The number of pain sites was positively associated with risk of anxiety and/or depression (Ptrend, < 0.001). Compared to people without chronic pain and insomnia symptoms, people with ≥5 pain sites and no insomnia symptoms had a RR of 1.52 (95% CI: 1.28 to 1.81) for anxiety and/or depression, those with no chronic pain but with insomnia had a RR of 1.78 (95% CI: 1.33 to 2.38), whereas the RR among people with both ≥5 pain sites and insomnia was 2.42 (95% CI: 1.85 to 3.16). We observed no synergistic effect above additivity for the combination of ≥5 pain sites and insomnia on risk of anxiety and/or depression. CONCLUSIONS: This study shows that people with multisite chronic pain who also suffer from insomnia are at a particularly high risk for anxiety and/or depression, suggesting that insomnia symptoms are important contributors to the association between multisite pain and common mental health problems.

Long-term changes in self-reported sleep quality and risk of chronic musculoskeletal pain: The HUNT Study.

We examined the association between long-term (~10 years) changes in self-reported sleep quality and risk of any chronic musculoskeletal pain and chronic widespread pain. The study comprised data on 6,033 people who participated in three consecutive surveys in the Norwegian HUNT Study (1995-1997, 2006-2008 and 2017-2019) and who were without chronic musculoskeletal pain at the first two surveys. We used a modified Poisson regression model to calculate adjusted risk ratios for chronic pain at follow-up (2017-2019) associated with categories of poor and good sleep quality reported in 1995-1997 and 2006-2008. Compared with people who reported good sleep at both surveys (crude absolute risk: 32.4%), the risk ratios of any chronic pain were 1.20 (95% confidence interval: 1.02-1.41) for those who changed from poor to good sleep; 1.25 (95% confidence interval: 1.12-1.39) for those who changed from good to poor sleep; and 1.41 (95% confidence interval: 1.21-1.63) for those who reported long-term poor sleep. The corresponding risk ratios for chronic widespread pain were 1.35 (95% confidence interval: 0.82-2.23), 1.55 (95% confidence interval: 1.14-2.12) and 2.09 (95% confidence interval: 1.38-3.17), respectively. In conclusion, these findings indicate that people with long-term poor sleep quality have a markedly higher risk of chronic musculoskeletal pain and chronic widespread pain, compared with people who remain good sleep quality.

Genetic variants related to physical activity or sedentary behaviour: a systematic review.

BACKGROUND: Research shows that part of the variation in physical activity and sedentary behaviour may be explained by genetic factors. Identifying genetic variants associated with physical activity and sedentary behaviour can improve causal inference in physical activity research. The aim of this systematic review was to provide an updated overview of the evidence of genetic variants associated with physical activity or sedentary behaviour. METHODS: We performed systematic literature searches in PubMed and Embase for studies published from 1990 to April 2020 using keywords relating to "physical activity", "exercise", "sedentariness" and "genetics". Physical activity phenotypes were either based on self-report (e.g., questionnaires, diaries) or objective measures (e.g., accelerometry, pedometer). We considered original studies aiming to i) identify new genetic variants associated with physical activity or sedentary behaviour (i.e., genome wide association studies [GWAS]), or ii) assess the association between known genetic variants and physical activity or sedentary behaviour (i.e., candidate gene studies). Study selection, data extraction, and critical appraisal were carried out by independent researchers, and risk of bias and methodological quality was assessed for all included studies. RESULTS: Fifty-four out of 5420 identified records met the inclusion criteria. Six of the included studies were GWAS, whereas 48 used a candidate gene approach. Only one GWAS and three candidate gene studies were considered high-quality. The six GWAS discovered up to 10 single nucleotide polymorphisms (SNPs) associated with physical activity or sedentariness that reached genome-wide significance. In total, the candidate gene studies reported 30 different genes that were associated (p < 0.05) with physical activity or sedentary behaviour. SNPs in or close to nine candidate genes were associated with physical activity or sedentary behaviour in more than one study. CONCLUSION: GWAS have reported up to 10 loci associated with physical activity or sedentary behaviour. Candidate gene studies have pointed to some interesting genetic variants, but few have been replicated. Our review highlights the need for high-quality GWAS in large population-based samples, and with objectively assessed phenotypes, in order to establish robust genetic instruments for physical activity and sedentary behaviour. Furthermore, consistent replications in GWAS are needed to improve credibility of genetic variants. TRIAL REGISTRATION: Prospero CRD42019119456 .

Work-Related Mental Fatigue, Physical Activity and Risk of Insomnia Symptoms: Longitudinal Data from the Norwegian HUNT Study.

OBJECTIVE/BACKGROUND: To examine the prospective association between work-related mental fatigue and risk of insomnia symptoms, and if leisure time physical activity modifies this association. PARTICIPANTS: A total of 8,464 women and 7,480 men who participated in two consecutive surveys of the Norwegian HUNT study. METHODS: The study comprises longitudinal data on persons who were vocationally active and without insomnia symptoms at baseline in 1995-1997. We used a modified Poisson regression model to calculate adjusted risk ratios (RRs) with a 95% confidence interval (CI) for insomnia symptoms at follow-up in 2006-2008 associated with work-related mental fatigue and leisure time physical activity at baseline. RESULTS: Women and men who always experienced mental fatigue after a workday had RRs of insomnia symptoms of 2.55 (95% CI 1.91-3.40) and 2.61 (95% CI 1.80-3.78), respectively, compared to workers who never or seldom had this experience. There was no strong modifying effect of leisure time physical activity on this association, but workers who always experienced mental fatigue had a RR of insomnia symptoms of 3.17 (95% CI 2.28-4.40) if they reported low physical activity and a RR of 2.52 (95% 1.89-3.39) if they reported high physical activity. CONCLUSION: This study shows that work-related mental fatigue, caused by high cognitive workload, is a strong risk factor for insomnia symptoms. There was no clear modifying effect of leisure time physical activity but workers who experienced excessive work-related fatigue accompanied by low physical activity had the highest risk of insomnia symptoms.

It is never too late to start: adherence to physical activity recommendations for 11-22 years and risk of all-cause and cardiovascular disease mortality. The HUNT Study.

OBJECTIVES: To examine associations between long-term (11-22 years) adherence to physical activity recommendations and mortality from all causes and from cardiovascular disease. DESIGN: Prospective population-based study with repeated assessments of self-reported physical activity (1984-86, 1995-97 and 2006-08) and follow-up until the end of 2013. SETTING: County of Nord-Trøndelag, Norway. PARTICIPANTS: Men and women aged ≥20 years; 32 811 who participated in 1984-86 and 1995-97; 22 058 in 1984-86 and 2006-08; 31 948 in 1995-97 and 2006-09 and 19 349 in all three examinations (1984-1986, 1995-95 and 2006-08). MAIN OUTCOME MEASURES: All-cause mortality and cardiovascular disease mortality from the national Cause of Death Registry. RESULTS: Compared with the reference category comprising individuals who adhered to the physical activity recommendations (≥150 min of moderate intensity or ≥60 min of vigorous intensity physical activity per week) over time, individuals who remained inactive (reporting no or very little physical activity) from 1984-86 to 1995-97 had HRs (95% CI) of 1.56 (1.40 to 1.73) for all-cause mortality and 1.94 (1.62 to 2.32) for cardiovascular disease mortality. Individuals who were inactive in 1984-86 and then adhered to recommendations in 2006-08 had HRs of 1.07 (0.85 to 1.35) for all-cause mortality and 1.31 (0.87 to 1.98) for cardiovascular disease mortality. In a subsample of individuals who participated at all three time points, those who were inactive or physically active below the recommended level across three decades (1984-86, 1995-97 and 2006-2008) had an HR of 1.57 (1.22 to 2.03) for all-cause mortality and 1.72 (1.08 to 2.73) for cardiovascular disease mortality. CONCLUSION: Individuals who remained, or became, physically inactive had substantially greater risk of all-cause and cardiovascular disease mortality compared with those who met the physical activity recommendations throughout the lifespan.

The joint association of musculoskeletal pain and domains of physical activity with sleep problems: cross-sectional data from the DPhacto study, Denmark.

PURPOSE: To investigate if occupational physical activity (OPA) and leisure-time physical activity (LTPA) influence the association between musculoskeletal pain and sleep problems. METHODS: Cross-sectional study includes 678 workers in the Danish PHysical ACTivity cohort with Objective measurements (DPhacto). Musculoskeletal pain was assessed by questionnaires, while OPA and LTPA were measured with accelerometers for up to 6 consecutive days. We used logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for self-reported insomnia symptoms and non-restorative sleep. RESULTS: Analyses of the joint association of musculoskeletal pain and OPA showed that workers with high pain and high OPA had ORs of 5.80 (95% CI 2.64-12.67) for insomnia symptoms and 2.50 (95% CI 1.37-4.57) for non-restorative sleep, compared to those with low pain and low OPA, whereas workers with high pain and low OPA had ORs of 4.67 (95% CI 2.17-10.07) for insomnia symptoms, and 2.67 (95% CI 1.46-4.89) for non-restorative sleep, respectively. Furthermore, workers with high pain and high LTPA had ORs of 4.23 (95% CI 2.16-8.32) for insomnia symptoms and 1.95 (95% CI 1.09-3.48) for non-restorative sleep, compared to those with low pain and low LTPA, whereas workers with high pain and low LTPA had ORs of 3.34 (95% CI 1.66-6.70) for insomnia symptoms and 2.14 (95% CI 1.21-3.80) for non-restorative sleep, respectively. CONCLUSIONS: Workers with high musculoskeletal pain who also conducted high levels of OPA or LTPA reported higher prevalence of insomnia symptoms.

Associations of serum 25-hydroxyvitamin D level with incidence of lung cancer and histologic types in Norwegian adults: a case-cohort analysis of the HUNT study.

Previous prospective studies have shown inconsistent associations between serum 25-hydroxyvitamin D [25(OH)D] level and lung cancer incidence. The aim of the present study was to explore the associations of serum 25(OH)D levels with incidence of lung cancer overall and different histologic types. We performed a population-based prospective case-cohort study including 696 incident lung cancer cases and 5804 individuals in a subcohort who participated in the second survey of the Nord-Trøndelag Health Study in Norway. Cox proportional hazards regression models counting for the case-cohort design were used to estimate hazard ratios (HRs) with 95% confidence interval (CIs) for lung cancer overall or histologic types in relation to serum 25(OH)D levels. Compared with the fourth season-specific quartile of 25(OH)D (median 68.0 nmol/L), lower 25(OH)D levels were not associated with the incidence of overall, small or squamous cell lung cancer. However, the risk of adenocarcinoma was lower in the second and third quartiles (median 39.9 and 51.5 nmol/L) compared with the fourth quartile, with HRs of 0.63 (95% CI 0.41-0.98) and 0.58 (0.38-0.88), respectively. The associations of lower levels of 25(OH)D with a reduced risk of adenocarcinoma were only observed in the overweight/obese subjects [HRs for second and third quartiles: 0.40 (0.22-0.72) and 0.50 (0.27-0.92)] but not in the normal weight subjects [HRs: 0.95 (0.52-1.75) and 0.60 (0.32-1.10)]. Serum 25(OH)D levels were not associated with the risk of lung cancer in general. The observation that lower 25(OH)D levels were associated with a lower risk of adenocarcinoma should be interpreted with caution.

Occupational and leisure-time physical activity and risk of disability pension: prospective data from the HUNT Study, Norway.

OBJECTIVES: To prospectively investigate the association between occupational physical activity (OPA) and disability pension due to musculoskeletal cause, mental cause or any cause. We also examined the combined association of OPA and leisure-time physical activity (LTPA) with disability pension. METHODS: A population-based cohort study in Norway on 32 362 persons aged 20-65 years with questionnaire data on OPA and LTPA that were followed up for incident disability pension through the National Insurance Database. We used Cox regression to estimate adjusted HRs with 95% CIs. RESULTS: During a follow-up of 9.3 years, 3837 (12%) received disability pension. Compared with people with mostly sedentary work, those who performed much walking, much walking and lifting, and heavy physical work had HRs of 1.26 (95% CI 1.16 to 1.38), 1.44 (95% CI 1.32 to 1.58) and 1.48 (95% CI 1.33 to 1.70), respectively. These associations were stronger for disability pension due to musculoskeletal disorders, whereas there was no clear association between OPA and risk of disability pension due to mental disorders. People with high OPA and low LTPA had a HR of 1.77 (95% CI 1.58 to 1.98) for overall disability pension and HR of 2.56 (95% CI 2.10 to 3.11) for disability pension due to musculoskeletal disorders, versus low OPA and high LTPA. CONCLUSIONS: We observed a positive association between OPA and risk of disability pension due to all causes and musculoskeletal disorders, but not for mental disorders. Physical activity during leisure time reduced some, but not all of the unfavourable effect of physically demanding work on risk of disability pension.

Physical work exposure, chronic musculoskeletal pain and risk of insomnia: longitudinal data from the HUNT study, Norway.

OBJECTIVES: To prospectively investigate (i) the association of physical work demands and work-related physical fatigue with risk of insomnia symptoms and (ii) if these associations are influenced by chronic musculoskeletal pain. METHODS: Prospective study on a working population of 8563 women and 7598 men participating in the Nord-Trøndelag Health Study (Norway) who reported no insomnia at baseline in 1995-1997. Occurrence of insomnia symptoms was assessed at follow-up in 2006-2008. A Poisson regression model was used to calculate adjusted risk ratios (RRs) for insomnia symptoms with 95% CI. RESULTS: Compared with workers without work-related physical fatigue, women and men who reported that they were always fatigued had RRs of insomnia of 2.34 (95% CI 1.72 to 3.18) and 2.47 (95% CI 1.59 to 3.83), respectively. Overall, physical work demands was not associated with risk of insomnia, although men who reported heavy physical work had an RR of 0.67 (95% CI 0.47 to 0.97) compared with men with mostly sedentary work. Compared with the reference group of workers without work-related physical fatigue and no chronic pain, analyses of joint effects showed that women with excessive work-related fatigue had an RR of 4.20 (95% CI 2.95 to 5.98) if they reported chronic pain and an RR of 1.67 (95% CI 0.87 to 3.18) if they did not. Corresponding RRs in men were 3.55 (95% CI 2.11 to 5.98) and 2.13 (95% CI 1.07 to 4.25). CONCLUSION: These findings suggest that there is an interplay between work-related physical fatigue and musculoskeletal pain that should receive particular attention in the prevention of insomnia in working populations.

Parental chronic pain in relation to chronic pain in their adult offspring: family-linkage within the HUNT Study, Norway.

BACKGROUND: Little is known about the association between parental chronic musculoskeletal pain (CMP) and occurrence of CMP in the adult offspring. The main objective of this study was to assess the parent-offspring association of CMP, and also to examine possible modifying effects of age and sex. METHODS: The study includes 11 248 parent-offspring trios from the Norwegian HUNT Study with information on parental CMP obtained in 1995-97 and offspring CMP obtained in 2006-08. Logistic regression was used to calculate adjusted odds ratios (ORs) for offspring CMP associated with parental CMP. RESULTS: Maternal and paternal CMP was associated with 20-40% increased odds of CMP in sons and daughters. Both sons and daughters had an OR of 1.6 (95% CI 1.4 to 1.9) when both parents reported CMP, compared to when none of the parents had CMP. Restricting the analyses to parental CMP that was associated with limited work ability and leisure time activity did not change the strength of the association. Further, analyses stratified by parental age ± 65 years showed no clear difference in the estimated associations, and there was no evidence of interaction for parental sex (P ≥ 0.39) or offspring age ± 40 years (P ≥ 0.26). CONCLUSIONS: This large family-linkage study show that maternal and paternal CMP are positively associated with CMP in the adult offspring, irrespective of parental and offspring age, and that the associations are strongest when both parents have CMP. Although the high prevalence of CMP in both parents and offspring suggests that not all cases are clinically relevant, the results suggest that chronic pain has a heritable component.

Sleep problems, exercise and obesity and risk of chronic musculoskeletal pain: the Norwegian HUNT study.

BACKGROUND: The objective was to investigate the association between self-reported sleep problems and risk of chronic pain in the low back and neck/shoulders, and whether physical exercise and body mass index (BMI) alter this association. METHODS: The study comprised data on 26 896 women and men in the Nord-Trøndelag Health Study (Norway) without chronic pain or physical impairment at baseline in 1984-86. Occurrence of chronic pain was assessed at follow-up in 1995-97. A generalized linear model was used to calculate adjusted risk ratios. RESULTS: Sleep problems were dose-dependently associated with risk of pain in the low back and neck/shoulders in both women and men (P < 0.001 both genders). Women and men who reported sleep problems 'sometimes' and 'often/always' had a higher risk of chronic pain of 23-32% and 51-66%, respectively, than those who reported sleep problems 'never'. Combined analyses showed that persons with sleep problems 'sometimes' and who exercised ≥1 hour per week had lower risk of chronic pain in the low back (P < 0.04) and neck/shoulders (P < 0.001) than inactive persons with a similar level of sleep problems (P < 0.04). Likewise, persons with BMI <25 kg/cm(2) and sleep problems 'sometimes' had lower risk of chronic pain in the low back (P < 0.001) and neck/shoulders (P < 0.001) than persons with BMI ≥25 kg/cm(2) and a similar level of sleep problems. CONCLUSION: Sleep problems are associated with an increased risk of chronic pain in the low back and neck/shoulders. Regular exercise and maintenance of normal body weight may reduce the adverse effect of mild sleep problems on risk of chronic pain.