Abstract: BACKGROUND: COPD is a major cause of morbidity and mortality across the world and new estimates of prevalence and trend are of great importance. We aimed to estimate the prevalence and trend of COPD from 1995-1997 to 2006-2008 in Norwegian adults >/=40 years from the Nord-Trondelag Health Study. MATERIAL AND METHODS: COPD was assessed using a fixed-ratio and lower limit of normal (LLN) criteria. Pre-bronchodilator spirometry was performed during 1995-1997 (n=7158) and 2006-2008 (n=8788). The prevalence of COPD was weighted using the inverse probability of selection and predicted probability of response. RESULTS: The prevalence of pre-bronchodilator COPD was 16.7% in 1995-1997 and 14.8% in 2006-2008 using fixed-ratio criteria, and 10.4% in 1995-1997 and 7.3% in 2006-2008 using LLN criteria. The prevalence of LLN COPD was higher among men (13.0% in 1995-1997, 7.7% in 2006-2008) than women (8.0% in 1995-1997, 6.9% in 2006-2008). From 1995-1997 to 2006-2008, the prevalence decreased among men but remained relatively stable among women. Over the 11-year period, the cumulative incidence of pre-bronchodilator COPD using LLN criteria was 3.3% and 2.7% among men and women respectively. The prevalence of self-reported asthma and respiratory symptoms increased. CONCLUSIONS: The prevalence declined in men but not in women from 1995-1997 to 2006-2008, and was consistently higher among men than women.

Abstract: BACKGROUND: Cultural participation has been used both in governmental health policies and as medical therapy, based on the assumption that cultural activities will improve health. Previous population studies and a human intervention study have shown that religious, social and cultural activities predict increased survival rate. The aim of this study was to analyse the association between cultural activity and perceived health, anxiety, depression and satisfaction with life in both genders. METHODS: The study is based on the third population-based Nord-Trondelag Health Study (2006-2008), including 50,797 adult participants from Nord-Trondelag County, Norway. Data on cultural activities, both receptive and creative, perceived health, anxiety, depression and satisfaction with life were collected by comprehensive questionnaires. RESULTS: The logistic regression models, adjusted for relevant cofactors, show that participation in receptive and creative cultural activities was significantly associated with good health, good satisfaction with life, low anxiety and depression scores in both genders. Especially in men, attending receptive, rather than creative, cultural activities was more strongly associated with all health-related outcomes. Statistically significant associations between several single receptive, creative cultural activities and the health-related outcome variables were revealed. CONCLUSION: This population-based study suggests gender-dependent associations between cultural participation and perceived health, anxiety, depression and satisfaction with life. The results support hypotheses on the effect of cultural activities in health promotion and healthcare, but further longitudinal and experimental studies are warranted to establish a reliable cause-effect relationship.

Abstract: BACKGROUND: A lot of attention has been paid to the relationship of blood pressure and dementia because epidemiological research has reported conflicting evidence. Observational data has shown that midlife hypertension is a risk factor for cognitive decline and dementia later in life, whereas there is evidence that low blood pressure is predictive in later life. The aim of the present study was to examine the association between dementia and blood pressure measured up to 27 years (mean 17.6 years) prior to ascertainment. METHODS: In Nord-Trondelag County, Norway, incident dementia data were collected during 1995-2011, and the diagnoses were validated by a panel of experts in the field. By using the subjects' personal identification numbers, the dementia data were linked to data from the Nord-Trondelag Health Study (the HUNT Study), a large, population-based health study performed in 1984-1986 (HUNT 1) and 1995-1997 (HUNT 2). A total of 24,638 participants of the HUNT Study were included in the present study, 579 of whom were diagnosed with Alzheimer disease, mixed Alzheimer/vascular dementia, or vascular dementia. Multiple logistic regression analyses were conducted to analyze the association between dementia and blood pressure data from HUNT 1 and HUNT 2. RESULTS: Over the age of 60 years, consistent inverse associations were observed between systolic blood pressure and all-cause dementia, mixed Alzheimer/vascular dementia, and Alzheimer disease, but not with vascular dementia, when adjusting for age, sex, education, and other relevant covariates. This was observed for systolic blood pressure in both HUNT 1 and HUNT 2, regardless of antihypertensive medication use. There was an adverse association between systolic blood pressure, pulse pressure, and Alzheimer disease in individuals treated with antihypertensive medication under the age of 60 years. CONCLUSIONS: Our data are in line with those in previous studies demonstrating an inverse association between dementia and systolic blood pressure in individuals over the age of 60 years. We cannot exclude a survival effect, however. Among middle-aged subjects (<60 years), elevated systolic blood pressure and pulse pressure were associated with eventual Alzheimer disease in individuals who reported using antihypertensive medication.

Abstract: AIM: To prospectively examine whether depressive symptoms increase the risk of diabetes and a diabetic foot ulcer. METHODS: The Nord-Trondelag Health Study (HUNT) is a community-based longitudinal study. The Hospital Anxiety and Depression Scale (HADS-D subscale) assessed depressive symptoms. We followed individuals with complete HADS-D data from HUNT2 (1995-97) and assessed whether they reported diabetes with or without a history of diabetic foot ulcer (DFU) in HUNT3 (2006-08) (n=36,031). Logistic regression was used to investigate the effect of depressive symptoms on subsequent development of diabetes and of DFU. RESULTS: Unadjusted odds for reporting diabetes at follow-up was higher among individuals who reported a HADS-D score>/=8 at baseline (OR 1.30 95% CI, 1.07-1.57) than among those reporting a lower score. After adjusting for age, gender and BMI, this association was no longer significant. The odds of developing a DFU was almost two-fold (OR=1.95 95% CI, 1.02-3.74) for those reporting a HADS-D score of 8-10, and 3-fold (OR=3.06 95% CI, 1.24-7.54) for HADS-D scores>/=11, compared to HADS-D scores

Abstract: ATTENTION: This publication contains an error. In table 2 and table 3 the column labels for genders have been replaced; instead of Women / Men there should be Men /Women
BACKGROUND: Population based studies are important for prevalence, incidence and association studies, but their external validity might be threatened by decreasing participation rates. The 50 807 participants in the third survey of the HUNT Study (HUNT3, 2006-08), represented 54% of the invited, necessitating a nonparticipation study. METHODS: Questionnaire data from HUNT3 were compared with data collected from several sources: a short questionnaire to nonparticipants, anonymous data on specific diagnoses and prescribed medication extracted from randomly selected general practices, registry data from Statistics Norway on socioeconomic factors and mortality, and from the Norwegian Prescription Database on drug consumption. RESULTS: Participation rates for HUNT3 depended on age, sex and type of symptoms and diseases, but only small changes were found in the overall prevalence estimates when including data from 6922 nonparticipants. Among nonparticipants, the prevalences of cardiovascular diseases, diabetes mellitus and psychiatric disorders were higher both in nonparticipant data and data extracted from general practice, compared to that reported by participants, whilst the opposite pattern was found, at least among persons younger than 80 years, for urine incontinence, musculoskeletal pain and headache. Registry data showed that the nonparticipants had lower socioeconomic status and a higher mortality than participants. CONCLUSION: Nonparticipants had lower socioeconomic status, higher mortality and showed higher prevalences of several chronic diseases, whilst opposite patterns were found for common problems like musculoskeletal pain, urine incontinence and headache. The impact on associations should be analyzed for each diagnosis, and data making such analyses possible are provided in the present paper.

Abstract: OBJECTIVE: To explore the hypothesis that insomnia may increase the risk of coronary heart disease through inflammatory mechanisms. METHODS: The association of high-sensitivity C-reactive protein (hsCRP) with self-reported symptoms of insomnia was examined. Participants were 8547 men and nonpregnant women who answered one or more insomnia-related questions and who had available hsCRP measurements in the Nord-Trondelag Health Study. In multivariable linear regression analyses of the logarithm of hsCRP, we adjusted for established cardiovascular risk factors, psychosocial distress, chronic pain, and chronic somatic disorders. RESULTS: Among men, difficulties initiating sleep and nonrestorative sleep were associated with increasing hsCRP levels after adjusting for age (B = 0.07, 95% confidence interval [CI] = 0.01-0.14, p for trend = .02 and B = 0.09, 95% CI = 0.02-0.15, p for trend = .006), but after multivariable adjustment, the associations were attenuated (B = 0.03, 95% CI = -0.03 to 0.09, p for trend = .30 and B = 0.06, 95% CI = -0.00 to 0.12, p for trend = .05). HsCRP was not associated with other insomnia-related symptoms. In women, there was no evidence for any association of symptoms of insomnia with hsCRP levels. Results indicated sex differences in the association between sleep characteristics and CRP (difficulties maintaining sleep, p interaction = .018; cumulative number of symptoms of insomnia, p interaction = .014; and symptoms of insomnia influencing work performance, p interaction = .039). CONCLUSIONS: There were no consistent associations between symptoms of insomnia and hsCRP levels. Our results do not support the hypothesis that inflammation, as reflected by elevated levels of hsCRP, is an important factor linking insomnia to coronary heart disease.

Abstract: BACKGROUND: Endogenous estrogens prevent lipid peroxidation, which is pivotal in atherogenesis. Dyslipidemia may therefore be more dangerous for men than for women as a risk factor for acute myocardial infarction (AMI). A differential effect by sex has not been empirically established. METHODS: In a prospective population-based cohort study of 23,525 women and 20,725 men younger than 60 years of age at baseline, we followed participants for 12 years for a first AMI. By calculating the proportion of AMI among men with dyslipidemia attributable to the synergism between male sex and dyslipidemia, we assessed the degree to which dyslipidemia is more detrimental for men than for women. RESULTS: Dyslipidemia and male sex enhanced the effect of one another in relation to AMI risk. The proportion of AMI cases among men with dyslipidemia attributable to this synergism alone was 0.46 (95% confidence interval = 0.35 to 0.57) for high total serum cholesterol, 0.23 (0.05 to 0.41) for low high-density lipoprotein (HDL) cholesterol, and 0.52 (0.42 to 0.62) for high non-HDL cholesterol. In contrast, obesity and hypertension were equally detrimental for men and women in relation to AMI risk, with a corresponding attributable proportion of 0.02 (-0.21 to 0.25) and -0.01 (-0.27 to 0.24), respectively. CONCLUSIONS: Current clinical guidelines of dyslipidemia management do not distinguish between men and women in relation to primary prevention of AMI. Our results suggest that in middle age, dyslipidemia is much more detrimental for men than for women, and that preventing dyslipidemia has a greater potential to reduce the occurrence of AMI among men.

Abstract: BACKGROUND: Cod liver oil is an important source of vitamin D, but also contains other fat-soluble components such as vitamin A. Before 1999, the cod liver oil formula in Norway contained a high concentration of vitamin A (1000 microg per 5 ml). High vitamin A status is associated with increased risks of several chronic diseases. OBJECTIVE: To investigate the association between cod liver oil intake and asthma development. METHODS: In the Nord-Trondelag Health Study, a total of 25 616 Norwegian adults aged 19-55 years were followed up from 1995-1997 to 2006-2008. Current analysis based on 17 528 subjects who were free of asthma and had complete information on cod liver oil intake at baseline. Cod liver oil intake was defined as daily intake >/= 1 month during the year prior to baseline. Incident asthma was reported as new-onset asthma during the 11-year follow-up. RESULTS: Of the 17 528 subjects, 18% (n=3076) consumed cod liver oil daily for >/= 1 month over the past year. Cod liver oil intake was significantly associated with incident asthma with an OR of 1.62 (95% CI 1.32 to 1.98) after adjustment for age, sex, daily smoking, physical activity, education, socio-economic status, family history of asthma, and body mass index (BMI). The positive association was consistent across age (< 40/>/= 40 years), sex (men/women), family history of asthma (yes/no) and BMI subgroups (< 25/>/= 25 kg/m(2)). CONCLUSIONS: Intake of cod liver oil with high vitamin A content was significantly associated with increased incidence of adult-onset asthma.

Abstract: AIMS: Socioeconomic inequalities in disability pensioning are well established, but we know little about the causes. The main aim of this study was to disentangle educational inequalities in disability pensioning in Norwegian women and men. METHODS: The baseline data consisted of 32,948 participants in the Norwegian Nord-Trondelag Health Study (1995-97), 25-66 years old, without disability pension, and in paid work. Additional analyses were made for housewives and unemployed/laid-off persons. Information on the occurrence of disability pension was obtained from the National Insurance Administration database up to 2008. Data analyses were performed using Cox regression. RESULTS: We found considerable educational inequalities in disability pensioning, and the incidence proportion by 2008 was higher in women (25-49 years 11%, 50-66 years 30%) than men (25-49 years 6%, 50-66 years 24%). Long-standing limiting illness and occupational, psychosocial, and behavioural factors were not sufficient to explain the educational inequalities: young men with primary education had a hazard ratio of 3.1 (95% CI 2.3-4.3) compared to young men with tertiary education. The corresponding numbers for young women were 2.7 (2.1-3.1). We found small educational inequalities in the oldest women in paid work and no inequalities in the oldest unemployed/laid-off women and housewives. CONCLUSIONS: Illness and occupational, psychosocial, and behavioural factors explained some of the educational inequalities in disability pensioning. However, considerable inequalities remain after accounting for these factors. The higher incidence of disability pensioning in women than men and the small or non-existing educational inequalities in the oldest women calls for a gender perspective in future research.