The objective was to study sex differences in adolescence regarding prevalence of asthma and current wheeze and to explore the association between respiratory symptoms and hereditary, lifestyle and socioeconomic factors. Young-HUNT included data comprehensive questionnaire on health, disease, lifestyle and social factors from 8817 teenagers 13-19 years conducted in 1995/97 (89% response rate). Questionnaire on respiratory symptoms was based on the International Study of Asthma and Allergy in Childhood (ISAAC). In age groups 13-16 and 17-19 years, current wheeze was reported by 29.0% and 33.5% among girls and 20.4% and 22.1% among boys, whilst the corresponding figures for asthma were 8.5% and 12.2% among girls and 7.1% and 7.0% among boys. Both wheeze and asthma were significantly more prevalent and increased with age in girls compared to boys. Heredity was associated with asthma, but the association was strongest between parents and children of the same sex. Environmental smoking was associated with asthma and wheeze in girls only. Girls reported more asthma and wheeze in association with overweight compared to boys. Girls reported more wheeze and asthma than boys and seemed more susceptible to risk factors such as environmental smoking and overweight than boys. Moreover, girls with mothers having asthma were more likely to be diagnosed as asthmatics themselves.
Genetic studies have shown an association between single-nucleotide polymorphisms on chromosome 15q25 and smoking-related traits and diseases, such as quantity of smoking, lung cancer and chronic obstructive pulmonary disease (COPD). A discussion has centred on the variants and their effects being directly disease related or indirect via nicotine addiction. To address these discrepancies, we genotyped the single-nucleotide polymorphism rs16969968 in the CHRNA5/A3/B4 gene cluster at chromosome 15q25, in 56?307 individuals from a large homogenous population-based cohort, the North Tr?ndelag Health Study (HUNT) in Norway. The variant was examined in relation to four different outcomes: lung cancer, loss of lung function equivalent to that of COPD, smoking behaviour and the use of smokeless tobacco (snus). Novel associations were found between rs16969968 and the motivational factor for starting to use snus, and the quantity of snus used. Our results also confirm and extend previous findings for associations between rs16969968 and lung cancer, loss of lung function equivalent to that of COPD, and smoking quantity. Our data suggest a role for rs16969968 in nicotine addiction, and the novel association with snus strengthens this observation.
Cites: Int J Epidemiol. 2010 Apr;39(2):563-7719776245
Cites: Int J Epidemiol. 2010 Apr;39(2):577-920123949
Psychiatric disorders may be risk factors for reduced bone mineral density (BMD). Longitudinal evidence is limited and this is yet to be examined among community-dwelling adults with anxiety. We aimed to investigate the cross-sectional and longitudinal relationships between anxiety and depressive symptoms and BMD.
This study examined data from the second Nord-Trondelag Health Study (1995-1997; 1194 men and 7842 women) and a follow-up conducted in 2001 (697 men and 2751 women). Symptomatology was ascertained using the Hospital Anxiety and Depression Scale and BMD was measured at the forearm using single-energy X-ray absorptiometry. Information on medication use and lifestyle was self-reported, and these, together with anthropometric measures were tested in multivariate analyses.
In men, adjusted BMD was 2.6% lower at the ultradistal forearm for those with depressive symptoms and 2.6% lower at the ultradistal and 2.0% lower at the distal forearm for those with anxiety symptoms. In women, adjusted BMD at the distal and ultradistal forearm was lower for heavier women with depressive symptoms but this relationship diminished with decreasing weight. Forearm BMD was similar for women with or without anxiety symptoms. Longitudinally, neither depressive nor anxiety symptoms were associated with bone loss over 4.6 years.
Findings cannot be generalised to other skeletal sites and a longer follow-up period may be necessary to detect differences in bone loss.
These results indicate that depressive and anxiety symptoms are cross-sectionally associated with reduced BMD. These findings provide further evidence to support monitoring BMD in individuals diagnosed with psychiatric illness.
K.G. Jebsen Center for Exercise in Medicine, Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU, Norwegian University of Science and Technology, Trondheim, Norway. email@example.com.
Although dynamic lung volume is not considered a limiting factor of peak oxygen uptake (VO2peak) in healthy subjects, an association between forced expiratory lung volume in one second (FEV1) and VO2peak has been reported in a healthy population aged 69 - 77?years. We hypothesized that a corresponding association could be found in a healthy general population including young and middle-aged subjects.
In a population-based study in Norway, we investigated the association between FEV1 above the lower limit of normal (LLN) and VO2peak using linear regression and assessed the ventilatory reserve (VR) in healthy subjects aged 20 - 79?years (n?=?741).
On average, one standard deviation (SD) increase in FEV1 was associated with 1.2?ml/kg/min (95% CI 0.7 - 1.6) higher VO2peak. The association did not differ statistically by sex (p-value for interaction?=?0.16) and was similar (0.9?ml/kg/min, 95% CI 0.2 - 1.5) in a sensitivity analysis including only never-smokers (n?=?376). In subjects below and above 45?years of age, corresponding estimates were 1.2?ml/kg/min (95% CI 0.5 - 1.8) and 1.2?ml/kg/min (95% CI 0.5 - 1.9), respectively. Preserved VR (= 20%) was observed in 66.6% of men and 86.4% of women.
Normal dynamic lung volume, defined as FEV1 above LLN, was positively associated with VO2peak in both men and women, in never-smokers and in subjects below and above 45?years of age. The majority of subjects had preserved VR, and the results suggest that FEV1 within normal limits may influence VO2peak in healthy subjects even when no ventilatory limitation to exercise is evident.
PURPOSE: To analyze the association between recreational and occupational physical activity and forearm bone mineral density (BMD) in healthy premenopausal women. METHODS: During 1984-1986, a population-based health survey (HUNT 1) was conducted among women and men aged >19 years in Nord-Trøndelag county in Norway. The second, follow-up survey (HUNT 2) was conducted during 1995-1997. The subjects in this study consist of healthy premenopausal women (n = 1396)
Although reduced function of the respiratory system limits peak oxygen uptake in diseases affecting the lungs or airways, the healthy respiratory system is thought to have a spare capacity for oxygen transport and uptake, and is not considered a limiting factor for peak oxygen uptake in healthy people. However, lung function declines with age and could theoretically limit peak oxygen uptake in elderly. We examined the association between peak oxygen uptake and lung function indices in an elderly population with the hypothesis that lung function indices would be associated with VO2peak up to a threshold value situated above the lower limits of normal lung function for our population.
Spirometry, gas diffusion tests and incremental work tests were performed in 1443 subjects (714 women) aged 69-77 years. Association between lung function indices and peak oxygen uptake was studied with hockey-stick regression.
Forced expiratory volume in 1 s (FEV1) had a positive association with peak oxygen uptake up to, but not above, a threshold value of 2.86 l for men, and 2.13 l for women (lower limit of normal 2.73 and 1.77 l respectively). A corresponding threshold was found for diffusing capacity of the lung for carbon monoxide (DLCO) for men at 9.18 mmol/min/kPa (lower limit of normal 6.84 mmol/min/kPa). DLCO for women and DLCO divided by alveolar volume (DLCO/VA) for both sexes had a significant linear relationship to VO2peak (p
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.
Bone mass density, fracture history, self-reported osteoporosis as proxy variables for estrogen and the risk of non-small-cell lung cancer--a population based cohort study, the HUNT study: are proxy variables friends or faults?
Lung cancer has the highest mortality of all cancers. Patients with early stage disease have the best cure rates and that emphasizes the importance of early detection. About half of all non-small cell lung cancers (NSCLC) are estrogen receptor positive. The impact of estrogen and its receptors for NSCLC carcinogenesis has been studied but is still unclear. Low estrogen levels are associated with osteoporosis. We hypothesize that low bone mineral density (BMD), a positive history of fracture or self-reported osteoporosis, used as a proxy variable for life time estrogen exposure, are associated with a low incidence of NSCLC. We analyzed data from a cohort study, the Nord-Trøndelag Health Study 2 (1995-1997) linked to the Norwegian Cancer Registry. Using the logistic regression model we calculated the odds ratio (OR) with a 95% confidence interval (CI) for the risk of NSCLC for the three proxy variables, stratified by sex. Participants older than 50 years of age, having measured bone density (N = 18,156), having answered the questions on self-reported fracture (N = 37,883) and osteoporosis (N = 25,701) and known body mass index (BMI) (N = 29,291), were evaluated for inclusion. In 6996 participants all these information was available in addition to tobacco use, and in women also hormonal replacement therapy (HRT). Lung function (FEV1 percent of predicted) was included in a sensitivity analysis. We identified 132 (1.9%) cases of NSCLC, 59 (1.2%) and 73 (3.3%) cases in women and men, respectively. Low BMD was associated with a higher risk of NSCLC, OR: 2.38, 95% CI: 1.09-5.18 and OR: 2.67, 95% CI: 1.39-5.16 in women and men, respectively. No association was found between the two other proxy variables and the risk of NSCLC. Inclusion of lung function in the model did not change the results. Contrary to our hypothesis, women and men with low BMD had a higher risk for NSCLC. In addition the study demonstrates that the risk depends on which proxy variable was chosen, and we may ask: are proxy variables reliable?
Recommendations on interpreting tests of bronchodilator responsiveness (BDR) are conflicting. We investigated the dependence of BDR criteria on sex, age, height, ethnicity, and severity of respiratory impairment.
BDR test data were available from clinical patients in the Netherlands, New Zealand, and the United States (n = 15,278; female subjects, 51.7%) and from surveys in Canada, Norway, and five Latin-American countries (n = 16,250; female subjects, 54.7%). BDR calculated according to FEV1, FVC, and FEV1/FVC was expressed as absolute change, a percentage of the baseline level (% baseline), a percentage of the predicted value (% predicted), and z score.
Change (?) in FEV1 and FVC, in milliliters, was unrelated to the baseline value but was biased toward age, height, sex, and level of airways obstruction; ?FEV1 was significantly lower in African Americans. In 1,106 subjects with low FEV1 (200-1,621 mL) the FEV1 increased by 12% to 44.7% relative to baseline but
The magnitude of participation bias due to non-participation should be considered for cancer patients invited to population-based surveys. We studied participation rates among persons with and without cancer in a large population based study, the Nord-Trøndelag Health Study (HUNT).
Citizens 20 years or above living in the Nord-Trøndelag County of Norway have been invited three times to comprehensive health surveys. The invitation files with data on sex, invitation date and participation were linked to the Cancer Registry of Norway. In a first step unadjusted crude participation rates (participants/invited persons) were estimated for cancer patients (CaPts) and non-cancer persons (NonCaPers), followed by logistic regression analyses with adjustment for age and sex. To evaluate the "practical" significance of the estimated odds ratios in the cancer diagnosis group, relative risks were also estimated comparing the observed rates to the estimated rates under the counterfactual assumption of no earlier cancer diagnosis among CaPts.
Overall 3 % of the participants in the three HUNT studies were CaPts and 59 % of them had been diagnosed with their first life-time cancer >5 years prior to each survey. In each of the three HUNT surveys crude participation rates were similar for CaPts and NonCaPers. Adjusted for sex and age, CaPts' likelihood to participate in HUNT1 (1984-86) and HUNT2 (1995-97), but not in HUNT3 (2006-2008), was statistically significantly reduced compared to NonCaPers, equaling a relative risk of 0.98 and 0.96, respectively. The lowest odds ratio emerged for CaPts diagnosed during the last 2 years preceding a HUNT invitation. Only one-third of CaPts participating in a survey also participated in the subsequent survey compared to approximately two-thirds of NonCaPers, and 11 % of CaPts participated in all three HUNT surveys compared to 37 % of NonCaPers.
In the three HUNT surveys no or only minor participation bias exist as to CaPts' participation rates. In longitudinal studies selection bias as to long-term cancer survivorship should be taken into account, the percentage of repeatedly participating CaPts diminishing more strongly than among NonCaPers.