Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX.

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX. INTRODUCTION: The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD). METHODS: We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted ß-coefficients. RESULTS: A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination. CONCLUSION: A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan.

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. INTRODUCTION: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors. METHODS: A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible. RESULTS: Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed. CONCLUSIONS: These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Does treatment with bisphosphonates protect against fractures in real life? The HUNT study, Norway.

Bisphosphonates reduce fractures in randomized controlled trials (RCT); however, there is less information from real life. In our population including 14,990 women and 13,239 men, use of bisphosphonates reduced risk of fractures in hip and forearm in women. The magnitude of the effect was comparable to results from RCT. INTRODUCTION: The objective was to examine if treatment with bisphosphonates (BPs) was associated with reduced risk of fractures in the hip and forearm in women and men in the general population. METHODS: In a cohort study based on data from the third wave of the population-based HUNT Study (HUNT3), the fracture registry in Nord-Trøndelag, and the Norwegian Prescription Database, 14,990 women and 13,239 men 50-85 years were followed from the date of participating in HUNT3 (2006-2008) until the date of first fracture in the hip or forearm, death, or end of study (31 December 2012). Hazard ratios with 95% confidence intervals for hip and forearm fracture according to use of BPs were estimated using Cox proportional hazards models with time-dependent exposure. Adjustment for individual FRAX® fracture risk assessment scores was included. RESULTS: BPs, predominantly alendronate, were used by 9.4% of the women and 1.5% of the men. During a median of 5.2 years of follow-up, 265 women and 133 men had a hip fracture, and 662 women and 127 men had a forearm fracture. Compared with non-users of BPs, the hazard ratios with 95% confidence interval for a fracture among users of BPs adjusted for age and FRAX® were 0.67 (0.52-0.86) for women and 1.13 (0.50-2.57) for men. Among users of glucocorticoids, the corresponding figures were 0.35 (0.19-0.66) and 1.16 (0.33-4.09), respectively. CONCLUSIONS: Use of BPs was associated with reduced risk of fractures in hip and forearm in women, and the magnitude of effect is comparable to results from RCTs.

Proton pump inhibitors and fracture risk. The HUNT study, Norway.

Proton pump inhibitors (PPIs) have been linked to increased risk of fracture; the data have, however, been diverging. We did not find any increased risk of fractures among users of PPIs in a Norwegian population of 15,017 women and 13,241 men aged 50-85 years with detailed information about lifestyle and comorbidity. INTRODUCTION: Proton pump inhibitors (PPIs) are widely prescribed and have been linked to increased risk of fracture. METHODS: We used data from the Nord-Trøndelag Health Study (HUNT3), The Fracture registry in Nord-Trøndelag, and the Norwegian Prescription Database, including 15,017 women and 13,241 men aged 50-85 years. The study population was followed from the date of participating in HUNT3 (2006-2008) until the date of first fracture (forearm or hip), death, or end of study (31 December 2012). The Cox proportional hazards model with time-dependent exposure to PPIs was applied, and each individual was considered as unexposed until the first prescriptions was filled. To be included, the prescription of PPIs should minimum be equivalent to 90 defined daily doses (DDD) in the period. Individuals were defined as exposed until 6 months after end of drug supply. RESULTS: The proportion of women and men using PPIs was 17.9% and 15.5%, respectively. During a median of 5.2 years follow-up, 266 women and 134 men had a first hip fracture and 662 women and 127 men, a first forearm fracture. The combined rate/1000 patient-years for forearm and hip fractures in women was 49.2 for users of PPIs compared with 64.1 among non-users; for men 18.6 and 19.8, respectively. The hazard ratios with 95% confidence interval for the first forearm or hip fracture among users of PPIs in the age-adjusted analysis were 0.82 (0.67-1.01) for women and 1.05 (0.72-1.52) for men. Adjusting for age, use of anti-osteoporotic drugs, and FRAX, the HR declined to 0.80 (0.65-0.98) in women and 1.00 (0.69-1.45) in men. CONCLUSIONS: Use of PPIs was not associated with an increased risk of fractures.

Vitamin B6 catabolism and lung cancer risk: results from the Lung Cancer Cohort Consortium (LC3).

BACKGROUND: Increased vitamin B6 catabolism related to inflammation, as measured by the PAr index (the ratio of 4-pyridoxic acid over the sum of pyridoxal and pyridoxal-5'-phosphate), has been positively associated with lung cancer risk in two prospective European studies. However, the extent to which this association translates to more diverse populations is not known. MATERIALS AND METHODS: For this study, we included 5323 incident lung cancer cases and 5323 controls individually matched by age, sex, and smoking status within each of 20 prospective cohorts from the Lung Cancer Cohort Consortium. Cohort-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between PAr and lung cancer risk were calculated using conditional logistic regression and pooled using random-effects models. RESULTS: PAr was positively associated with lung cancer risk in a dose-response fashion. Comparing the fourth versus first quartiles of PAr resulted in an OR of 1.38 (95% CI: 1.19-1.59) for overall lung cancer risk. The association between PAr and lung cancer risk was most prominent in former smokers (OR: 1.69, 95% CI: 1.36-2.10), men (OR: 1.60, 95% CI: 1.28-2.00), and for cancers diagnosed within 3 years of blood draw (OR: 1.73, 95% CI: 1.34-2.23). CONCLUSION: Based on pre-diagnostic data from 20 cohorts across 4 continents, this study confirms that increased vitamin B6 catabolism related to inflammation and immune activation is associated with a higher risk of developing lung cancer. Moreover, PAr may be a pre-diagnostic marker of lung cancer rather than a causal factor.

No association between circulating concentrations of vitamin D and risk of lung cancer: an analysis in 20 prospective studies in the Lung Cancer Cohort Consortium (LC3).

Background: There is observational evidence suggesting that high vitamin D concentrations may protect against lung cancer. To investigate this hypothesis in detail, we measured circulating vitamin D concentrations in prediagnostic blood from 20 cohorts participating in the Lung Cancer Cohort Consortium (LC3). Patients and methods: The study included 5313 lung cancer cases and 5313 controls. Blood samples for the cases were collected, on average, 5 years before lung cancer diagnosis. Controls were individually matched to the cases by cohort, sex, age, race/ethnicity, date of blood collection, and smoking status in five categories. Liquid chromatography coupled with tandem mass spectrometry was used to separately analyze 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] and their concentrations were combined to give an overall measure of 25(OH)D. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 25(OH)D as both continuous and categorical variables. Results: Overall, no apparent association between 25(OH)D and risk of lung cancer was observed (multivariable adjusted OR for a doubling in concentration: 0.98, 95% CI: 0.91, 1.06). Similarly, we found no clear evidence of interaction by cohort, sex, age, smoking status, or histology. Conclusion: This study did not support an association between vitamin D concentrations and lung cancer risk.

Anti-osteoporosis drug use: too little, too much, or just right? The HUNT study, Norway.

Use of anti-osteoporotic drugs (AODs) was examined in a Norwegian population 50-85 years. Among them with Fracture Risk Assessment Tool (FRAX) score for major osteoporotic fracture ≥ 20, 25% of the women and 17% of the men received AODs. The strongest predictors for AODs were high age in women and use of glucocorticoids among men. INTRODUCTION: To examine the use of anti-osteoporotic drugs (AODs) and to identify predictors for prescriptions. METHODS: Data were obtained from the Nord-Trøndelag Health Study (HUNT3) performed in 2006-2008 and the Norwegian Prescription Database, including 15,075 women and 13,386 men aged 50-85 years. Bone mineral density (BMD) in the femoral neck was measured in a subgroup of 4538 women and 2322 men. High fracture risk was defined as a FRAX score for major osteoporotic fracture (MOF) ≥ 20%; in the subgroup with BMD, high risk was in addition defined as FRAXMOF ≥ 20% or T-score ≤ - 2.5. Hazard ratios (HRs) for predictors of incident use of AODs within 2 years after HUNT3 were estimated by Cox' proportional hazards model. RESULTS: Among individuals with FRAX MOF ≥ 20%, 25% of the women and 17% of the men were treated with AODs. Among those with FRAX MOF < 20%, 3% and 1% were treated, respectively. In the subgroup with BMD measurement, 24% of the women and 16% of the men at high risk of fractures were treated, compared to 3 and 1% in women and men not fulfilling the criteria. In women, high age was the strongest predictor for treatment (HR 3.84: 95% confidence interval 2.81-5.24), followed by use of glucocorticoids (GCs) (2.68:1.84-3.89). In men, predictors were use of GCs (5.28: 2.70-10.35) followed by multimorbidity (3.16:1.31-7.63). In the subgroup with BMD, T-score ≤ - 2.5 was the strongest predictor (women 3.98:2.67-5.89; men 13.31:6.17-28.74). CONCLUSIONS: This study suggests an undertreatment of AODs in individuals at high risk of fracture.

Age of menarche is associated with knee joint replacement due to primary osteoarthritis (The HUNT Study and the Norwegian Arthroplasty Register).

OBJECTIVE: To investigate whether parity, age at menarche, menopausal status, age at menopause, use of oral contraceptives (OC) or use of hormone replacement therapy (HRT) were associated with total knee replacement (TKR) or total hip replacement (THR) due to primary osteoarthritis. METHOD: In a prospective cohort study of 30,289 women from the second and third surveys of the Nord-Trøndelag Health Study, data were linked to the Norwegian Arthroplasty Register (NAR) in order to identify TKR or THR due to primary osteoarthritis. Cox proportional hazards models were used to estimate the hazard ratios (HRs). RESULTS: We observed 430 TKRs and 675 THRs during a mean follow-up time of 8.3 years. Increasing age at menarche was inversely associated with the risk of TKR (P-trend < 0.001). Past users and users of systemic HRT were at higher risk of TKR compared to never users (HR 1.42 (95% confidence interval (CI) 1.06-1.90) and HR 1.40 (95% CI 1.03-1.90), respectively). No association was found between parity, age at menarche, menopausal status, age at menopause, oral contraceptive use or HRT use and THR. CONCLUSION: We found that increasing age at menarche reduced the risk of TKR. Past users and users of systemic HRT were at higher risk of TKR compared to never users. Parity did not increase the risk of THR or TKR.

The causal role of smoking on the risk of hip or knee replacement due to primary osteoarthritis: a Mendelian randomisation analysis of the HUNT study.

OBJECTIVE: Smoking has been associated with a reduced risk of hip and knee osteoarthritis (OA) and subsequent joint replacement. The aim of the present study was to assess whether the observed association is likely to be causal. METHOD: 55,745 participants of a population-based cohort were genotyped for the rs1051730 C > T single-nucleotide polymorphism (SNP), a proxy for smoking quantity among smokers. A Mendelian randomization analysis was performed using rs1051730 as an instrument to evaluate the causal role of smoking on the risk of hip or knee replacement (combined as total joint replacement (TJR)). Association between rs1051730 T alleles and TJR was estimated by hazard ratios (HRs) and 95% confidence intervals (CIs). All analyses were adjusted for age and sex. RESULTS: Smoking quantity (no. of cigarettes) was inversely associated with TJR (HR 0.97, 95% CI 0.97-0.98). In the Mendelian randomization analysis, rs1051730 T alleles were associated with reduced risk of TJR among current smokers (HR 0.84, 95% CI 0.76-0.98, per T allele), however we found no evidence of association among former (HR 0.97, 95% CI 0.88-1.07) and never smokers (HR 0.97, 95% CI 0.89-1.06). Neither adjusting for body mass index (BMI), cardiovascular disease (CVD) nor accounting for the competing risk of mortality substantially changed the results. CONCLUSION: This study suggests that smoking may be causally associated with the reduced risk of TJR. Our findings add support to the inverse association found in previous observational studies. More research is needed to further elucidate the underlying mechanisms of this causal association.

Validation of FRAX and the impact of self-reported falls among elderly in a general population: the HUNT study, Norway.

Fracture Risk Assessment Tool (FRAX) without bone mineral density (BMD) for hip fracture prediction was validated in a Norwegian population 50-90 years. Fracture risk increased with higher FRAX score, and the observed number of hip fractures agreed well with the predicted number, except for the youngest and oldest men. Self-reported fall was an independent risk factor for fracture in women. INTRODUCTION: The primary aim was to validate FRAX without BMD for hip fracture prediction in a Norwegian population of men and women 50-90 years. Secondary, to study whether information of falls could improve prediction of fractures in the subgroup aged 70-90 years. METHODS: Data were obtained from the third survey of the Nord-Trøndelag Health Study (HUNT3), the fracture registry in Nord-Trøndelag, and the Norwegian Prescription Database (NorPD), including 15,432 women and 13,585 men. FRAX hip without BMD was calculated, and hip fractures were registered for a median follow-up of 5.2 years. The number of estimated and observed fractures was assessed, ROC curves with area under the curve (AUC), and Cox regression analyses. For the group aged 70-90 years, self-reported falls the last year before HUNT3 were included in the Cox regression model. RESULTS: The risk of fracture increased with higher FRAX score. When FRAX groups were categorized in a 10-year percentage risk for hip fracture as follows, <4, 4-7.9, 8-11.9, and ≥12%, the hazard ratio (HR) for hip fracture between the lowest and the highest group was 17.80 (95% CI: 12.86-24.65) among women and 23.40 (13.93-39.30) in men. Observed number of hip fractures agreed quite well with the predicted number, except for the youngest and oldest men. AUC was 0.81 (0.78-0.83) for women and 0.79 (0.76-0.83) for men. Self-reported fall was an independent risk factor for fracture in women (HR 1.64, 1.20-2.24), and among men, this was not significant (1.09, 0.65-1.83). CONCLUSIONS: FRAX without BMD predicted hip fracture reasonably well. In the age group 70-90 years, falls seemed to imply an additional risk among women.

Psoriasis, fracture risk and bone mineral density: the HUNT Study, Norway.

BACKGROUND: An association between psoriasis and osteoporosis has been reported. OBJECTIVES: To investigate, in a large prospective population-based Norwegian study, whether psoriasis is associated with increased risk of forearm or hip fracture; to investigate the cross-sectional association between psoriasis and bone mineral density (BMD) T-score in a subpopulation. METHODS: Hospital-derived fracture data from Nord-Trøndelag County (1995-2013) were linked to psoriasis information, BMD measurements and lifestyle factors from the third survey of the Nord-Trøndelag Health Study 2006-08 (HUNT3); socioeconomic data from the National Education Database; and use of medication from the Norwegian Prescription Database. RESULTS: Among 48 194 participants in HUNT3, we found no increased risk of forearm or hip fracture in 2804 patients with self-reported psoriasis [overall age- and sex-adjusted hazard ratio 1·03, 95% confidence interval (CI) 0·82-1·31]. No clear association was found between psoriasis and mean BMD T-score; overall age- and sex-adjusted differences in total hip, femoral neck and lumbar spine BMD T-scores were 0·02 (95% CI -0·11 to 0·14), 0·05 (95% CI -0·06 to 0·17) and 0·07 (95% CI -0·09 to 0·24), respectively. No clear association was found between psoriasis and prevalent osteoporosis in either total hip, femoral neck or lumbar spine; overall age- and sex-adjusted odds ratio was 0·77 (95% CI 0·54-1·10). Associations did not change substantially after adjustment for education, smoking, systemic steroid use and body mass index. CONCLUSIONS: We found no association between psoriasis and risk of fracture. The study did not indicate reduced BMD T-score or higher prevalence of osteoporosis among patients with psoriasis.

Serum 25-hydroxyvitamin D levels and self-reported allergic rhinitis in Norwegian adults - The HUNT Study.

BACKGROUND: The role of low vitamin D status in the development of allergic rhinitis is unclear. We aimed to investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] and incidence of allergic rhinitis in adults. METHODS: The study included a random sample from an adult population who participated in the second and third surveys of the Nord-Trøndelag Health Study (HUNT) in Norway (HUNT2, 1995-1997 and HUNT3, 2006-2008). Serum 25(OH)D levels were measured in blood samples collected at baseline. Among 1351 adults who did not report allergic rhinitis at baseline, incident allergic rhinitis was identified by participant report of having or having had allergic rhinitis or hay fever at follow-up. Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated after adjustment for age, smoking, physical activity, socioeconomic status, family history of allergy, body mass index, and season. The analyses were stratified by sex due to its significant interaction with 25(OH)D levels (P < 0.02). RESULTS: Over an average of 11 years, 9% of men and 15% of women developed allergic rhinitis. Among men, serum 25(OH)D level <50 nM was associated with an increased risk of incident allergic rhinitis (AOR 2.55; 95% CI 1.01-6.49); each 25 nM reduction in 25(OH)D level was associated with an AOR of 1.84 (95% CI 1.18-2.87). In women, however, the association was opposite, with AOR being 0.83 (95% CI 0.66-1.05) for each 25 nM reduction in serum 25(OH)D level. CONCLUSIONS: Vitamin D appears to play different roles in the development of allergic rhinitis among men and women.

The associations of anxiety and depression symptoms with weight change and incident obesity: The HUNT Study.

OBJECTIVE: To investigate the associations of anxiety and depression symptoms with weight change and incident obesity in men and women. DESIGN: We conducted a prospective cohort study using the Norwegian Nord-Trøndelag Health Study (HUNT). SUBJECTS: The study cohort included 25 180 men and women, 19-55 years of age from the second survey of the HUNT (1995-1997). MEASUREMENTS: Anxiety and depression symptoms were measured using the Hospital Anxiety and Depression Scale. Weight change was determined for the study period of an average 11 years. Incident obesity was new-onset obesity classified as having a body mass index of 30.0 kg m(2) at follow-up. The associations of anxiety or depression with weight change in kilograms (kg) was estimated using linear regression models. Risk ratios (RRs) for incident obesity associated with anxiety or depression were estimated using log-binomial regression. RESULTS: In men, any anxiety or depression was associated with an average 0.81 kg (95% confidence interval (CI) 0.27-1.34) larger weight change after 11 years compared with those without such symptoms (mean weight change: 5.04 versus 4.24 kg). Women with any anxiety or depression had an average 0.98 kg (95% confidence interval (CI) 0.49-1.47) larger weight change compared with those without such symptoms (mean weight change: 5.02 versus 4.04 kg). Participants with any anxiety or depression had a significantly elevated cumulative incidence of obesity (men: RR 1.37, 95% CI 1.13-1.65; women: RR 1.18, 95% CI 1.00-1.40). CONCLUSION: We found that symptoms of anxiety and depression were associated with larger weight change and an increased cumulative incidence of obesity in both men and women.

Excess mortality after hip fracture among elderly women in Norway. The HUNT study.

UNLABELLED: We wanted to study mortality after hip fractures among elderly women in Norway. We found that excess mortality was highest short time after hip fracture, but persisted for several years after the fracture. The excess mortality was not explained by pre-fracture medical conditions. INTRODUCTION: The purpose of the present study was to investigate short and long term mortality after hip fracture, and to evaluate how comorbidity, bone mineral density, and lifestyle factors affect the survival after hip fractures. METHODS: The study cohort emerges from a population-based health survey in the county of Nord-Trøndelag, Norway. Women aged 65 or more at participation at the health survey who sustained a hip fracture after attending the health survey are cases in this study (n = 781). A comparison cohort was constructed based on participants at HUNT 2 with no history of hip fractures (n = 3, 142). Kaplan-Meier survival curves were used to evaluate crude survival, and Cox regression analyses were used to study age-adjusted hazard ratios for mortality and for multivariable analyses involving relevant covariates. RESULTS: Mean length of follow-up after fracture was 2.8 years. Within the first 3 months of follow-up, 78 (10.0%) of the hip fracture patients died, compared to only 39 (1.7%) in the control group. HR for mortality 3 months after hip fracture was 6.5 (95% CI 4.2-9.6). For the entire follow-up period women who sustained a hip fracture had an HR for mortality of 1.9 (95% CI 1.6-2.3), compared with women without a hip fracture. CONCLUSIONS: We found that elderly women who sustained a hip fracture had increased mortality risk. The excess mortality was highest short time after the fracture, but persisted for several years after the fracture, and was not explained by pre-fracture medical conditions.

Weight loss and distal forearm fractures in postmenopausal women: the Nord-Trøndelag health study, Norway.

SUMMARY: Weight loss is a risk factor for hip fractures, but few studies have evaluated the effect of weight loss on distal forearm fracture risk. In this longitudinal study including 7,871 postmenopausal women, weight loss of 5% or more was associated with an increased risk of distal forearm fractures. INTRODUCTION: Weight loss is an established risk factor for hip fractures, but little is known about weight loss and distal forearm fractures risk. METHODS: The study included 7,871 women aged 65 years or more in the Nord-Trøndelag health study (HUNT) in 1994-1995 (HUNT II) who also had their height and weight measured in 1984-1986 (HUNT I). Forearm bone mineral density (BMD) by single energy x-ray absorptiometry was available for 5,688 women (HUNT II). Fractures sustained after HUNT II were registered during an average of 5.8 years. RESULTS: A total of 536 women sustained a distal forearm fracture. After adjustments for age and body mass index (BMI) at HUNT I, women who lost > or =5% of their weight between HUNT I and HUNT II had a relative risk of fractures of 1.33 (95% confidence interval: 1.09, 1.62) compared with the rest of the women. The higher risk of forearm fracture among women with weight loss was at least partially explained by their lower forearm BMD. CONCLUSION: Weight loss of 5% or more was associated with a 33% increased risk of distal forearm fractures.

Association between level of physical activity and lung function among Norwegian men and women: the HUNT study.

OBJECTIVE: To estimate the association between level of physical activity in 1984-1986 and 1995-1997 and lung function in 1995-1997 among Norwegian men and women aged 28-80 years. DESIGN: In 1984-1986 and 1995-1997, all residents of Nord-Trøndelag County, Norway, aged > or =20 years were invited to participate in the Nord-Trøndelag Health Studies. These analyses included a sample that took part in both studies and underwent spirometry (n = 8047). We used linear regression models adjusting for potential confounders stratified by sex and age groups (28-49 years, 50-69 years and > or =70 years) to estimate the association between forced expiratory volume in 1 second (FEV1) and physical activity. RESULTS: Men and women who were physically active in 1985 and 1995 had the highest lung function in both sexes and in all age groups. The reduction in FEV1 ranged from 20 ml to 170 ml, similar to 1-7% of predicted values dependent on physical activity level. Lung function was also associated with body mass index (BMI), height, smoking and subjective health. CONCLUSIONS: The findings show that a high level of physical activity corresponds to about 3-5 years of normal decline in FEV1 (30 ml/year), and may therefore overcome the disadvantages of a decline in FEV1 from increasing age.

Cigarette smoking gives more respiratory symptoms among women than among men. The Nord-Trondelag Health Study (HUNT).

STUDY OBJECTIVE: Studies have indicated that women are more vulnerable to the effect of tobacco smoking compared with men. The aim of this study was to explore the prevalence of reported respiratory symptoms and diseases according to smoking burden, age and sex. DESIGN: Questionnaire in a cross sectional population based study. SETTING: The BONT (Bronchial obstruction in Nord-Trondelag) study is part of a comprehensive health survey of all inhabitants aged above 19 years in the county of Nord-Trondelag, Norway, which was carried out from 1995 to 1997. PARTICIPANTS: A total of 65 717 subjects, 71.3% of the total population aged 20-100, answered the main questionnaire. MAIN RESULTS: In all, 12.7% men and 12.1% women reported episodes of wheezing or breathlessness during the past 12 months, 8.8% men and 8.4% women reported that they had or had had asthma, 7.5% men and 8.2% women had ever used asthma medication, and 4.0% men and 3.0% women reported chronic bronchitis. Thirty per cent of men and 31% of women were smokers, and average pack years of smoking were 15.9 and 10.3, respectively. Among previous and current smokers, significant more women reported episodes of wheezing or breathlessness, current asthma and persistent coughing compared with men with the same smoke burden (pack years) and daily number of cigarettes. CONCLUSION: The prevalence of reported asthma and use of asthma medication was higher than reported in previous Scandinavian studies. Respiratory symptoms increased by smoking burden. Comparing the prevalence of symptoms and current asthma among women and men with the same smoke burden or daily cigarette consumption, women seemed to be more susceptible to the effect of tobacco smoking than men.

Gender differences in the impact of adolescent smoking on lung function and respiratory symptoms. the Nord-Trøndelag Health Study, Norway, 1995-1997.

Girls take up smoking at least as frequently as boys. Few studies have focused on gender differences in the impact of adolescent smoking. We evaluated the sex-specific effect of adolescent smoking on respiratory symptoms and lung function. All students in junior high and high schools in Nord-Trøndelag County Norway, 1995-97, were invited to participate in a cross-sectional study. Information on smoking habits and respiratory symptoms was obtained by self-administered questionnaires. Spirometry was performed in accordance with ATS standards. Eight-thousand-three-hundred and five students (83%) completed both questionnaire and spirometry. Among 6811 students aged 13-18 years (50.3% girls) with no history of asthma, 2993 (43.9%) reported never smoking, 665 (98%) reported occasional smoking, and 667 (9.9%) reported daily smoking (mean initiation age: 13.9 years). More boys than girls were heavy smokers. In all smoking categories, smokers reported a higher prevalence of respiratory symptoms than nonsmokers; symptoms increased with smoke burden. Girls reported more symptoms compared to boys with comparable smoke burden. A dose-response relation between smoking and reduced lung function was found only in girls. Girls were more vulnerable than boys to the impact of smoking on respiratory symptoms and lung function.

Cohort Profile: the HUNT Study, Norway.

The HUNT Study includes large total population-based cohorts from the 1980ies, covering 125 000 Norwegian participants; HUNT1 (1984-86), HUNT2 (1995-97) and HUNT3 (2006-08). The study was primarily set up to address arterial hypertension, diabetes, screening of tuberculosis, and quality of life. However, the scope has expanded over time. In the latest survey a state of the art biobank was established, with availability of biomaterial for decades ahead. The three population based surveys now contribute to important knowledge regarding health related lifestyle, prevalence and incidence of somatic and mental illness and disease, health determinants, and associations between disease phenotypes and genotypes. Every citizen of Nord-Trøndelag County in Norway being 20 years or older, have been invited to all the surveys for adults. Participants may be linked in families and followed up longitudinally between the surveys and in several national health- and other registers covering the total population. The HUNT Study includes data from questionnaires, interviews, clinical measurements and biological samples (blood and urine). The questionnaires included questions on socioeconomic conditions, health related behaviours, symptoms, illnesses and diseases. Data from the HUNT Study are available for researchers who satisfy some basic requirements (www.ntnu.edu/hunt), whether affiliated in Norway or abroad.