Dietary inflammatory pattern and risk of hip fracture in the Nurses' Health Study

Our immune system activity is impacted by what we eat and can influence fracture risk under certain conditions. In this article, we show that postmenopausal women with a pro-inflammatory dietary pattern have an increased risk of hip fracture.

PURPOSE

The immune system influences bone homeostasis and can increase the risk of fracture under certain pro-inflammatory conditions. Immune system activity is impacted by dietary patterns. Using the empirical dietary inflammatory pattern (EDIP), we investigated whether postmenopausal women with a pro-inflammatory dietary pattern had an increased risk of hip fracture.

METHODS

The study population consisted of postmenopausal women participating in the Nurses' Health Study from 1980 to 2014, who reported information on lifestyle and health, including hip fractures, on biennial questionnaires, while semiquantitative food frequency questionnaires (FFQs) were completed every fourth year. Hazard ratios (HR) for hip fracture were computed using Cox proportional hazards models, adjusting for potential confounders.

RESULTS

EDIP was calculated using intake information from the FFQ for 87,955 postmenopausal participants, of whom 2348 sustained a non-traumatic hip fracture during follow-up. After adjustment for confounders, there was a 7% increase in the risk of hip fracture per 1 SD increase in EDIP (HR 1.07, 95% CI 1.02-1.12), and the uppermost quintile had a 22% greater risk compared to the lowest (HR 1.22, 95% CI 1.06-1.40). For the separate components of the EDIP, we found that higher intakes of low-energy beverages (diet sodas) were independently associated with an increased risk of hip fracture, while higher intakes of green leafy vegetables were associated with a reduced risk.

CONCLUSION

A pro-inflammatory dietary pattern was associated with an increased risk of hip fracture among postmenopausal women.

No change in 24-h sodium intake estimated from spot urine in Norwegian adults from 2006 to 2019: the population-based Trøndelag Health Study (HUNT)

OBJECTIVE

Monitoring time trends in salt consumption is important for evaluating the impact of salt reduction initiatives on public health outcomes. There has so far not been available data to indicate if salt consumption in Norway has changed during the previous decade. We aimed to assess whether average 24-h salt intake estimated from spot urine samples in the adult population of mid-Norway changed from 2006-2008 to 2017-2019 and to describe variations by sex, age and educational level.

DESIGN

Repeated cross-sectional studies.

SETTING

The population-based Trøndelag Health Study (HUNT).

PARTICIPANTS

In each of two consecutive waves (HUNT3: 2006-2008 and HUNT4: 2017-2019), spot urine samples were collected from 500 men and women aged 25-64 years, in addition to 250 men and women aged 70-79 years in HUNT4. Based on spot urine concentrations of Na, K and creatinine and age, sex and BMI, we estimated 24-h Na intake using the International Cooperative Study on Salt and Blood Pressure (INTERSALT) equation for the Northern European region.

RESULTS

Mean (95 % CI) estimated 24-h salt intakes in men were 11·1 (95 % CI 10·8, 11·3) g in HUNT3 and 10·9 (95 % CI 10·6, 11·1) g in HUNT4, P = 0·25. Corresponding values in women were 7·7 (95 % CI 7·5, 7·9) g and 7·7 (95 % CI 7·5, 7·9) g, P = 0·88. Mean estimated salt intake in HUNT4 decreased with increasing age in women, but not in men, and it did not differ significantly across educational level in either sex.

CONCLUSIONS

Estimated 24-h salt intake in adult men and women in mid-Norway did not change from 2006-2008 to 2017-2019.

Iodine status and determinants in adults in Norway - results from a population-based health examination survey (The HUNT Study)

Background

In Norway, there is a lack of knowledge about the iodine status in the general and older adult population, and there is no established national monitoring programme for iodine. Several studies have indicated that iodine deficiency is prevalent in subgroups of the population. Salt iodisation is currently being considered as a measure to increase the population iodine status. In this cross-sectional study, the aim was to evaluate iodine status and determinants in the adult and older adult population in Mid-Norway, before salt iodisation is likely to be initiated.

Methods

The study sample was a subsample of participants in the fourth wave of the population-based Trøndelag Health Study (HUNT4, 2017-2019) with available spot-urine samples. This subsample included participants with 25-64 years (n = 500) and 70-79 years (n = 250). The urine samples were analysed for iodine and creatinine. Information on the habitual intake of milk/yoghurt, fish, supplement use, use of thyroid medication and relevant background factors was collected through a general questionnaire. Multivariable quantile regression was used to model differences in the median urinary iodine concentration (UIC) by determinants. Estimates were weighted to match the age and sex distribution of the Norwegian population aged 25-79 years in 2019.

Results

Median UIC was 97 µg/L (95% confidence interval [CI]: 92, 103) indicating borderline iodine deficiency at a group level. The median UIC increased with age, and iodine status was insufficient in participants below age 55 years (median 92 µg/L [95% CI: 85, 99]). Important determinants of UIC were habitual milk/yoghurt intake, daily supplement use and current use of thyroid medication, but not intake of lean or fatty fish. Risk of mild-to-moderate iodine deficiency was seen in those with a low intake of milk/yoghurt, no supplement use and who did not use thyroid medication. No group was identified as being at risk of iodine excess.

Conclusion

Iodine status was adequate in older adults but mildly deficient in adults under 55 years. Milk intake, supplement use and use of thyroid medication are important determinants of iodine intake in Norway.

Post-injury long-term sickness absence and risk of disability pension: The role of socioeconomic status

INTRODUCTION

Previous research has identified low socioeconomic status (SES) as a risk factor for long-term sickness absence (LTSA) and disability pension (DP) following trauma. However, most studies lack information on medical diagnoses, limiting our understanding of the underlying factors. To address this gap, we retrieved information about diagnostic causes for receipt of welfare benefits to explore the role of SES in the transition from post-injury LTSA to permanent DP among the working population in Norway.

MATERIALS AND METHODS

We conducted a population-based cohort study of all Norwegian residents aged 25-59 years registered with a spell of LTSA due to injury commencing in the period 2000-2003. This cohort was followed through 2014 by linking information on receipt of welfare benefits with sociodemographic data from administrative registers. SES was defined as a composite measure of educational attainment and income level. We used flexible parametric survival models to estimate hazard ratios (HR) with 95 % confidence intervals (CI) for all-cause and diagnosis-specific DP according to SES, adjusting for sex, age, marital status, immigrant status and healthcare region of residence.

RESULTS

Of 53,937 adults with post-injury LTSA, 9,665 (18 %) transferred to DP during follow-up. The crude risk of DP was highest for LTSA spells due to poisoning and head injuries. Overall, individuals in the lowest SES category had twice the risk of DP compared to those in the highest SES category (HR = 2.25, 95 % CI 2.13-2.38). The difference by SES was greatest for LTSA due to poisoning and smallest for LTSA due to head injuries. A majority (75 %) of DP recipients had a non-injury diagnosis as the primary cause of DP. The socioeconomic gradient was more pronounced for non-injury causes of DP (HR = 2.47, 95 % CI 2.31-2.63) than for injury causes (HR = 1.73, 95 % CI 1.56-1.92) and was especially steep for DP due to musculoskeletal diseases and mental and behavioural disorders.

CONCLUSIONS

The relationship between SES and DP varied by both the type of injury that caused LTSA and the diagnosis used to grant DP, highlighting the importance of taking diagnostic information into account when investigating long-term consequences of injuries.

The medication-based Rx-Risk Comorbidity Index and risk of hip fracture - a nationwide NOREPOS cohort study

BACKGROUND

Few previous studies have assessed overall morbidity at the individual level with respect to future risk of hip fracture. The aim of this register-based cohort study was to examine the association between morbidity measured by the medication-based Rx-Risk Comorbidity Index (Rx-Risk) and the risk of first hip fracture.

METHODS

Individual-level data on medications dispensed from pharmacies (2005-2016) was retrieved from the Norwegian Prescription Database and used to calculate Rx-Risk for each calendar year. Information on first hip fractures (2006-2017) was obtained from a nationwide hip fracture database. Individuals ≥ 51 years who filled at least one prescription during the study period comprised the population at risk. Using Rx-Risk as a time-varying exposure variable, relative risk estimates were obtained by a negative binomial model.

RESULTS

During 2006-2017, 94,104 individuals sustained a first hip fracture. A higher Rx-Risk was associated with increased risk of hip fracture within all categories of age and sex. Women with the highest Rx-Risk (> 25) had a relative risk of 6.1 (95% confidence interval (CI): 5.4, 6.8) compared to women with Rx-Risk ≤ 0, whereas the corresponding relative risk in women with Rx-Risk 1-5 was 1.4 (95% CI: 1.3, 1.4). Similar results were found in men. Women > 80 years with Rx-Risk 21-25 had the highest incidence rate (514 (95% CI: 462, 566) per 10, 000 person years). The relative increase in hip fracture risk with higher Rx-Risk was most pronounced in the youngest patients aged 51-65 years.

CONCLUSIONS

Rx-Risk is a strong predictor of hip fracture in the general outpatient population and may be useful to identify individuals at risk in a clinical setting and in future studies.

Postvaccination immune responses and risk of primary total hip arthroplasty-A population-based cohort study

OBJECTIVE

To investigate the relationship between individual postvaccination immune responses and subsequent risk of total hip arthroplasty (THA) due to idiopathic osteoarthritis (OA) or rheumatoid arthritis (RA).

METHOD

Results of tuberculin skin tests (TSTs) following the Bacille Calmette-Guerin (BCG) vaccination were used as a marker of individual immune responses. TST results from the mandatory mass tuberculosis screening program 1948-1975 (n = 236 770) were linked with information on subsequent THA during 1987-2020 from the Norwegian Arthroplasty Register. The multivariable Cox proportional hazard regression was performed.

RESULTS

A total of 10 698 individuals received a THA during follow-up. In men, there was no association between TST and risk of THA due to OA (Hazard ratio [HR] 1.01, 95% confidence interval [CI] 0.92-1.12 for positive versus negative TST and HR 1.06, 95% CI 0.95-1.18 for strong positive vs negative TST), while the risk estimates increased with increasingly restrictive sensitivity analyses. In women, there was no association with THA due to OA for positive versus negative TST (HR 0.98, 95% CI 0.92-1.05), while a strong positive TST was associated with reduced risk of THA (HR 0.90, 95% CI 0.84-0.97). No significant associations were observed in the sensitivity analysis for women or for THA due to RA.

CONCLUSION

Our results suggest that an increased postvaccination immune response is associated with a nonsignificant trend of increased risk of THA among men and a decreased risk among women, although risk estimates were small.

Forearm fractures - are we counting them all? An attempt to identify and include the missing fractures treated in primary care

OBJECTIVE

Norway has a high incidence of forearm fractures, however, the incidence rates based on secondary care registers can be underestimated, as some fractures are treated exclusively in primary care. We estimated the proportion of forearm fracture diagnoses registered exclusively in primary care and assessed the agreement between diagnosis for forearm fractures in primary and secondary care.

DESIGN

Quality assurance study combining nationwide data from 2008 to 2019 on forearm fractures registered in primary care (Norwegian Control and Payment of Health Reimbursement) and secondary care (the Norwegian Patient Registry).

SETTING AND PATIENTS

Forearm fracture diagnoses in patients aged ≥20 treated in primary care (n = 83,357) were combined with injury diagnoses for in- and outpatients in secondary care (n = 3,294,336).

MAIN OUTCOME MEASURES

Proportion of forearm fractures registered exclusively in primary care, and corresponding injury diagnoses for those registered in both primary and secondary care.

RESULTS

Of 189,105 forearm fracture registrations in primary and secondary care, 13,948 (7.4%) were registered exclusively in primary care. The proportion ranged from 4.9% to 13.5% on average between counties, but was higher in some municipalities (>30%). Of 66,747 primary care forearm fractures registered with a diagnosis in secondary care, 62% were incident forearm fractures, 28% follow-up controls, and 10% other fractures or non-fracture injuries.

CONCLUSION

An overall small proportion of forearm fractures were registered only in primary care, but it was larger in some areas of Norway. Failing to include fractures exclusively treated in primary care could underestimate the incidence rates in these areas.

Explaining declining hip fracture rates in Norway: a population-based modelling study

Background

Although age-standardised hip fracture incidence has declined in many countries during recent decades, the number of fractures is forecast to increase as the population ages. Understanding the drivers behind this decline is essential to inform policy for targeted preventive measures. We aimed to quantify how much of this decline could be explained by temporal trends in major risk factors and osteoporosis treatment.

Methods

We developed a new modelling approach, Hip-IMPACT, based on the validated IMPACT coronary heart disease models. The model applied sex- and age stratified hip fracture numbers and prevalence of pharmacologic treatments and risk/preventive factors in 1999 and 2019, and best available evidence for independent relative risks of hip fracture associated with each treatment and risk/preventive factor.

Findings

Hip-IMPACT explained 91% (2500/2756) of the declining hip fracture rates during 1999-2019. Two-thirds of the total decline was attributed to changes in risk/preventive factors and one-fifth to osteoporosis medication. Increased prevalence of total hip replacements explained 474/2756 (17%), increased body mass index 698/2756 (25%), and increased physical activity 434/2756 (16%). Reduced smoking explained 293/2756 (11%), and reduced benzodiazepine use explained (366/2756) 13%. Increased uptake of alendronate, zoledronic acid, and denosumab explained 307/2756 (11%), 104/2756 (4%) and 161/2756 (6%), respectively. The explained decline was partially offset by increased prevalence of type 2 diabetes and users of glucocorticoids, z-drugs, and opioids.

Interpretation

Two-thirds of the decline in hip fractures from 1999 to 2019 was attributed to reductions in major risk factors and approximately one-fifth to osteoporosis medication.

Funding

The Research Council of Norway.

Time-varying exposure to anti-osteoporosis drugs and risk of first-time hip fracture: a population wide study within the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS)

We investigated the association between bisphosphonate and denosumab use and risk of hip fracture in Norway. These drugs protect against fractures in clinical trials, but their population-level effect is unknown. Our results showed lowered risk of hip fracture for treated women. Treatment of high-risk individuals could prevent future hip fractures.

PURPOSE

To investigate whether bisphosphonates and denosumab reduced the risk of first-time hip fracture in Norwegian women when adjusting for a medication-based comorbidity index.

METHODS

Norwegian women aged 50-89 in 2005-2016 were included. The Norwegian prescription database (NorPD) supplied data on exposures to bisphosphonates, denosumab, and other drugs for the calculation of the Rx-Risk Comorbidity Index. Information on all hip fractures treated in hospitals in Norway was available. Flexible parametric survival analysis was used with age as time scale and with time-varying exposure to bisphosphonates and denosumab. Individuals were followed until hip fracture or censoring (death, emigration, age 90 years), or 31 December 2016, whichever occurred first. Rx-Risk score was included as a time-varying covariate. Other covariates were marital status, education, and time-varying use of bisphosphonates or denosumab with other indications than osteoporosis.

RESULTS

Of 1,044,661 women 77,755 (7.2%) were ever-exposed to bisphosphonate and 4483 (0.4%) to denosumab. The fully adjusted hazard ratios (HR) were 0.95 (95% confidence interval (CI): 0.91-0.99) for bisphosphonate use and 0.60 (95% CI: 0.47-0.76) for denosumab use. Bisphosphonate treatment gave a significantly reduced risk of hip fracture compared with the population after 3 years and denosumab after 6 months. Fracture risk was lowest in denosumab users who had previously used bisphosphonate: HR 0.42 (95% CI: 0.29-0.61) compared with the unexposed population.

CONCLUSIONS

In population-wide real-world data, women exposed to bisphosphonates and denosumab had a lower hip fracture risk than the unexposed population after adjusting for comorbidity. Treatment duration and treatment history impacted fracture risk.

Cause-specific excess mortality after hip fracture: the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS)

BACKGROUND

Information on cause of death may help appraise the degree to which the high excess mortality after hip fracture reflects pre-existing comorbidities or the injury itself. We aimed to describe causes of death and cause-specific excess mortality through the first year after hip fracture.

METHODS

For studying the distribution of causes of death by time after hip fracture, we calculated age-adjusted cause-specific mortality at 1, 3, 6 and 12 months in patients hospitalized with hip fracture in Norway 1999-2016. Underlying causes of death were obtained from the Norwegian Cause of Death Registry and grouped by the European Shortlist for Causes of Death. For estimating excess mortality, we performed flexible parametric survival analyses comparing mortality hazard in patients with hip fracture (2002-2017) with that of age- and sex matched controls drawn from the Population and Housing Census 2001.

RESULTS

Of 146,132 Norwegians with a first hip fracture, a total of 35,498 (24.3%) died within one year. By 30 days post-fracture, external causes (mainly the fall causing the fracture) were the underlying cause for 53.8% of deaths, followed by circulatory diseases (19.8%), neoplasms (9.4%), respiratory diseases (5.7%), mental and behavioural disorders (2.0%) and diseases of the nervous system (1.3%). By one-year post-fracture, external causes and circulatory diseases together accounted for approximately half of deaths (26.1% and 27.0%, respectively). In the period 2002-2017, cause-specific one-year relative mortality hazard in hip fracture patients vs. population controls ranged from 1.5 for circulatory diseases to 2.5 for diseases of the nervous system in women, and correspondingly, from 2.4 to 5.3 in men.

CONCLUSIONS

Hip fractures entail high excess mortality from all major causes of death. However, the traumatic injury of a hip fracture is the most frequently reported underlying cause of death among older patients who survive less than one year after their fracture.

Resting heart rate, self-reported physical activity in middle age, and long-term risk of hip fracture. A NOREPOS cohort study of 367,386 men and women

Enhanced knowledge regarding modifiable risk factors for hip fractures are warranted. We aimed to study the associations between two indicators of physical fitness (resting heart rate and level of physical activity) in middle-aged individuals, and the risk of hip fractures during the subsequent three decades. Data on objectively measured resting heart rate and self-reported leisure time physical activity from a national health survey (1985-1999) was linked to a database including all hip fractures treated in Norwegian hospitals from 1994 through 2018. We calculated hazard ratios (HR) with 95 % confidence intervals (95 % CI) for hip fractures according to categories of resting heart rate (mean of two repeated measures), and leisure time physical activity level in adjusted Cox proportional hazard models. In total, 367,386 persons (52 % women) aged 40 to 45 years were included, of whom 5482 persons sustained a hip fracture during a mean follow-up of 24.8 years. Higher resting heart rate was associated with higher hip fracture risk. Men with a resting heart rate above 80 bpm, who also reported low levels of physical activity, had a HR of 1.82 (95 % CI 1.49-2.22) for hip fracture compared to men with a resting heart rate below 70 bpm who reported high levels of physical activity. The same measure of association for women was 1.62 (95 % CI 1.28-2.06). Physical fitness measured by low resting heart rate in middle age, and a high physical activity level were associated with a lower long-term risk of hip fractures in both men and women.

Characteristics of fallers who later sustain a hip fracture: a NOREPOS study

Fall prevention programs have shown inconclusive results concerning hip fracture reduction. We found that fallers with poor health, low societal participation, and use of psychotropics/painkillers had a threefold to fivefold increased hip fracture risk compared to non-fallers without these risk factors. This may help target fall prevention towards high-risk individuals.

INTRODUCTION

To investigate whether self-reported information on health, societal participation, and drug use in older people, easily obtainable by health care providers, contribute to predict future hip fracture beyond self-reported falls.

METHODS

We used data from 3801 women and 6439 men aged 70-79 years participating in population-based studies in five counties in Norway 2000-2003. Height and weight were measured. Socioeconomic status, lifestyle, health status, and history of falling were self-reported through questionnaires. Falls last year were dichotomized into one or more versus no falls. Hip fractures were identified by linkage to hospital data with follow-up through 2013. Hazard ratios (HR) with 95% confidence intervals (95% CI) for hip fracture by combinations of risk factors with history of falling were estimated using Cox proportional hazards regression.

RESULTS

More women (32.4%) than men (27.7%) reported one or more falls during the previous year, and 17.9% of women (n = 682) and 8.9% of men (n = 572) suffered a hip fracture during median 11.6 years of follow-up. Poor health, low societal participation, and use of psychotropics/analgesics among fallers were strong predictors of hip fracture. The presence of all three risk factors and history of falling was associated with HR 2.92 (95% CI 2.10-4.05) for hip fracture in women and HR 4.60 (95% CI 2.71-7.81) in men compared to non-fallers without these factors.

CONCLUSION

Our study indicates that self-assessment of health, information about activities outside home, and drug use among fallers far better identify high risk of hip fracture in older people than information about falls alone.

Impact of Total Hip Replacements on the Incidence of Hip Fractures in Norway During 1999-2019. A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) Study

The knowledge about why hip fracture rates in Norway have declined is sparse. Concurrent with decreasing hip fracture rates, the rates of total hip replacements (THRs) have increased. We wanted to investigate if hip fracture rates continued to decline, and whether the increase in THRs had any influence on this decline, assuming that living with a hip prosthesis precludes fracture of the operated hip. Information on hip fractures in Norway 1999-2019 was available from the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) hip fracture database and population size were available in official population tables from Statistics Norway. Primary THRs (for any cause except hip fracture) 1989-2019 were obtained from the Norwegian Arthroplasty Register. We calculated the annual age-standardized incidence rates of hip fracture by sex for the period 1999-2019. The hip fracture rates in a scenario with no hip prostheses were calculated by subtracting 0.5 persons from the population at risk for each prevalent hip prosthesis, considering that each person has two hips at risk of fracture. We estimated how much of the decline could be attributed to the increased prevalence of hip prostheses. From 1999 to 2019, age-standardized incidence rates of hip fracture decreased by 27% in women and 20% in men. The rates remained stable in those under 70 years and decreased in those 70 years and above. Excluding replaced hips from the population at risk led to higher incidence rates, and this impact was considerably larger at higher ages. The increased prevalence of hip prostheses over the period accounted for approximately 18% (20% in women and 11% in men) of the observed decline in hip fracture rates. In conclusion, the incidence of hip fractures continued to decline, and the increasing number of people living with hip prostheses contributed significantly to the observed declining time trends. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The Association of Cold Ambient Temperature With Fracture Risk and Mortality: National Data From Norway-A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) Study

Norway is an elongated country with large variations in climate and duration of winter season. It is also a high-risk country for osteoporotic fractures, in particular hip fractures, which cause high mortality. Although most hip fractures occur indoors, there is a higher incidence of both forearm and hip fractures during wintertime, compared with summertime. In a nationwide longitudinal cohort study, we investigated whether cold ambient (outdoor) temperatures could be an underlying cause of this high incidence and mortality. Hospitalized/outpatient forearm fractures (International Classification of Diseases and Related Health Problems, 10th Revision [ICD-10] code S52) and hospitalized hip fractures (ICD-10 codes S72.0-S72.2) from 2008 to 2018 were retrieved from the Norwegian Patient Registry. Average monthly ambient temperatures (degrees Celsius, °C) from the years 2008 to 2018 were provided by the Norwegian Meteorological Institute and linked to the residential area of each inhabitant. Poisson models were fitted to estimate the association (incidence rate ratios [IRRs], 95% confidence intervals [CIs]) between temperature and monthly incidence of total number of forearm and hip fractures. Flexible parametric survival models (hazard ratios [HR], 95% CI) were used to estimate the association between temperature and post-hip fracture mortality, taking the population mortality into account. Monthly temperature ranged from -20.2°C to 22.0°C, with a median of -2.0°C in winter and 14.4°C in summer. At low temperatures (<0°C) compared to ≥0°C, there was a 53% higher risk of forearm fracture (95% CI, 51%-55%) and 21% higher risk of hip fracture (95% CI, 19%-22%), adjusting for age, gender, calendar year, urbanization, residential region, elevation, and coastal proximity. When taking the population mortality into account, the post-hip fracture mortality in both men (HR 1.08; 95% CI, 1.02-1.13) and women (HR 1.09; 95% CI, 1.04-1.14) was still higher at cold temperatures. There was a higher risk of forearm and hip fractures, and an excess post-hip fracture mortality at cold ambient temperatures. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Injury severity and increased socioeconomic differences: A population-based cohort study

BACKGROUND

Several studies have documented an inverse gradient between socioeconomic status (SES) and injury mortality, but the evidence is less consistent for injury morbidity. The aim of this study was to investigate the association between SES and injury severity for acute hospitalizations in a nationwide population-based cohort.

METHODS

We conducted a registry-based cohort study of all individuals aged 25-64 years residing in Norway by 1st of January 2008. This cohort was followed from 2008 through 2014 using inpatient registrations for acute hospitalizations due to all-cause injuries. We derived two measures of severity: threat-to-life using the International Classification of Disease-based Injury Severity Score (ICISS), and threat of disability using long-term disability weights from the Injury-VIBES project. Robust Poisson regression models, with adjustment for age, sex, marital status, immigrant status, municipality population size and healthcare region of residence, were used to calculate incidence rate ratios (IRRs) by SES measured as an index of education, income, and occupation.

RESULTS

We identified 177,663 individuals (7% of the population) hospitalized with at least one acute injury in the observation period. Two percent (n = 4,186) had injuries categorized with high threat-to-life, while one quarter (n = 43,530) had injuries with high threat of disability. The overall adjusted IRR of hospitalization among people with low compared to high SES was 1.57 (95% CI 1.55, 1.60). Comparing low to high SES, injuries with low threat-to-life were associated with an IRR of 1.56 (95% CI 1.54, 1.59), while injuries with high threat-to-life had an IRR of 2.25 (95% CI 2.03, 2.51). Comparing low to high SES, injuries with low, medium, and high threat of disability were associated with IRRs of respectively, 1.15 (95% CI 1.11, 1.19), 1.70 (95% CI 1.66, 1.73) and 1.99 (95% CI 1.92, 2.07).

DISCUSSION

We observed an inverse gradient between SES and injury morbidity, with the steepest gradient for the most severe injuries. This suggests a need for targeted preventive measures to reduce the magnitude and burden of severe injuries for patients with low socioeconomic status.

Contribution of an extensive medication-based comorbidity index (Rx-Risk) in explaining the excess mortality after hip fracture in older Norwegians: a NOREPOS cohort study

OBJECTIVES

Patients with hip fracture are typically characterised by extensive comorbidities and excess mortality. Methods that account for a wide range of comorbidities are needed when attempting to identify causal associations in registry-based studies. We aimed to study the association between the prescription-based Rx-Risk Comorbidity Index (abbreviated Rx-Risk) and mortality by history of hip fracture, and to quantify the contribution of Rx-Risk in explaining the excess mortality after hip fracture.

SETTING

In this prospective study, we used nationwide registry data from outpatient care. Rx-Risk was based on filled prescriptions recorded in the Norwegian Prescription Database. Medications were mapped to 46 comorbidity categories by Anatomical Therapeutic Chemical code. Information on hip fractures during 1994-2013 was available from the Norwegian Epidemiologic Osteoporosis Studies hip fracture database, and year of death was obtained from Statistics Norway. We estimated 1-year mortality risk (January through December 2014) according to Rx-Risk score based on dispensed prescriptions in 2013, history of hip fracture, age and sex using Poisson regression.

PARTICIPANTS

All individuals aged 65 years and older who were alive by the end of 2013 and had filled at least one prescription in an outpatient pharmacy in Norway in 2013 (n=735 968).

RESULTS

Mortality increased exponentially with increasing Rx-Risk scores, and it was highest in persons with a history of hip fracture across the major range of Rx-Risk scores. Age- and sex-adjusted mortality risk difference according to history of hip fracture (yes vs no) was 4.4 percentage points (7.8% vs 3.4%). Adjustment for Rx-Risk score further attenuated this risk difference to 3.3 percentage points.

CONCLUSIONS

History of hip fracture and comorbidity assessed by Rx-Risk are independent risk factors for mortality in the community-dwelling older population in Norway. Comorbidity explained a quarter of the excess mortality in persons with a history of hip fracture.

Changes in food habits amongst Norwegian adolescents in 2016 and 2019 according to gender and socioeconomic status

Background

Monitoring dietary habits is important in order to identify risk groups and as a basis for targeted public health initiatives.

Objective

To study trends in consumption of selected foods and beverages from 2016 to 2019 amongst Norwegian adolescents according to gender and parental education.

Design

Repeated cross-sectional study amongst 25,996 adolescents, aged 14–17 years old. Consumption of selected food and beverages was measured by an online food frequency questionnaire and general linear models were applied to estimate changes in dietary habits.

Results

Between 2016 and 2019, we observed a reduced frequency of consumption of vegetables (from 4.7 to 4.4 times/week), fruit and berries (from 4.4 to 4.2 times/week), whole-grain bread (from 5.1 to 4.2 times/week), and fish (from 2.3 to 1.6 times/week). During this time period, we also observed a reduced frequency of consumption of salty snacks (from 2.1 to 1.9 times/week), sweets (from 2.3 to 2.0 times/week), sugar-sweetened beverages (from 2.8 to 2.6 times/week), and artificially sweetened beverages (from 2.2 to 1.5 times/week). In girls, there was a decrease in the reported frequency of consumption of fruit and berries (−4%, vs. no change in boys). The decrease in consumption frequency of whole-grain bread was larger in girls than in boys (−19% vs. −14%). Further, a 17% decrease in consumption of sweets was observed amongst adolescents with no or only one parent having college/university education compared to a 13% decrease in adolescents whose both parents had college/university education.

Conclusion

Our results showed a decrease in frequency of consumption of selected healthy and unhealthy food and beverages amongst adolescents between 2016 and 2019. The gender gap in consumption of fruit and berries and whole-grain bread seemed to decrease during this time period, and the socio-economic gap in consumption of sweets seemed to disappear.

Physical capability, physical activity, and their association with femoral bone mineral density in adults aged 40 years and older: The Tromsø study 2015-2016

Since muscles can influence bone growth and vice versa, we examined if level of physical activity and physical capability tests can predict areal bone mineral density (aBMD). Both high activity level and good test performance were associated with higher aBMD, especially in women.

INTRODUCTION

Muscle influences bone formation and vice versa. Tests of physical capability and level of physical activity reflect various muscle qualities. We assessed the associations between total hip aBMD and physical activity as well as a range of standardized physical capability tests in an adult general population.

METHODS

A total of 3 533 women and men aged 40-84 years, participating in the population-based cross-sectional Tromsø study in Norway in 2015-2016, were included. Linear regression was used to assess associations between aBMD and physical activity and the physical capability tests grip strength, Timed Up and Go (TUG), Short Physical Performance Battery (SPPB), and standing balance. Non-linear associations were examined in cubic spline models. Standardized regression coefficients were calculated to compare effect sizes across physical capability measures.

RESULTS

In fully adjusted models, higher physical activity was positively associated with total hip aBMD in both sexes compared to a sedentary lifestyle. All tests of physical capability were associated with aBMD in women, SPPB showing the strongest association although effect sizes were too small to indicate clinically significant differences (1 point increase corresponded to an aBMD increase of 0.009 g/cm², CI = 0.005 to 0.012). In men, SPPB and its subtests were associated with aBMD with chair rises showing the strongest association (1 s increase in execution time corresponded to an aBMD decrease of 0.005 g/cm², CI = 0.008 to 0.002).

CONCLUSION

Physical activity was associated with aBMD, and tests of physical capability can account for some of the aBMD variations in adults aged 40 years and older, especially in women.

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.

Contribution of elevation and residential proximity to the coast in explaining geographic variations in hip fracture incidence. A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) study

A higher risk of hip fracture was found in areas of Norway at higher elevation and farther from the coast. However, the previously seen county variations could not be explained by these geographical factors.

INTRODUCTION

Norway is an elongated country extending north of the Arctic Circle with substantial coast-inland variation in topography and climate. Differences in hip fracture incidence between counties and a distinct seasonal variation have previously been shown. The aim of the current study was to explore these variations further by considering associations of height above sea level (elevation) and distance to the coast with hip fracture incidence.

METHODS

All patients with hip fractures admitted to Norwegian hospitals in the period 2009-2018 were included. Individual residential elevation and distance to the coast was calculated in Geographic Information Systems and combined with individual-level population data on all Norwegians 50 years of age or older during the observation period, including hospital information on fractures. Age-standardized incidences rate and incidence rate ratios with 95% confidence intervals (IRR, 95% CI) according to elevation and coastal proximity were estimated. The associations were tested using Poisson models adjusting for sex, urban/rural location of residency, country of birth, and season of hip fracture occurrence.

RESULTS

From 2009 to 2018, there were 85,776 first hip fractures. There was an increasing risk with higher residential elevation (above versus below mean) for women: IRR = 1.04, 95% CI: 1.02, 1.05), but not for men (IRR = 1.00, 95% CI: 0.97, 1.02). Incidence of hip fracture increased with distance from the coast. Women residing the farthest away from the coast (above versus below mean distance) had a higher age-adjusted incidence of hip fracture compared to those living closer to the coast (IRR = 1.04 (95% CI: 1.02, 1.06), whereas no association was found in men (IRR = 1.00 (95% CI: 1.00, 1.01). Combining elevation and distance to coast showed a higher incidence in women living at high elevation far from the coast compared with women living at low elevation near the coast (IRR = 1.07, 95% CI: 1.04, 1.10). A similar result was found in men but only for hip fractures occurring during March-May (IRR = 1.07, 95% CI: 1.00, 1.15). The previously shown patterns of county differences and seasonal variations were unchanged when considering geography.

CONCLUSION

We found a somewhat higher incidence of hip fracture in inland residents living in areas of high elevation, as compared to those living in more coastal proximity; however, the geographic variation did not explain county and seasonal differences in fracture incidence in Norway. More in-depth analyses on temperature and climate factors may give further clues.

Increased Mortality in Hip Fracture Patients Living Alone: A NOREPOS Study

Hip fracture is associated with excess mortality, persisting for many years after the fracture. Several factors may affect survival; however, the role of social support has been less studied. Living situation could be an indicator of a person's social support, which predicts mortality in the general population. In this longitudinal cohort study, we considered whether living alone was a risk factor for post-hip fracture mortality compared with living with a partner. Information on hip fractures from all hospitals in Norway from 2002 to 2013 was combined with the 2001 National Population and Housing Census. The association between living situation and mortality during 12.8 years of follow-up in 12,770 men and 22,067 women aged 50 to 79 years at fracture was investigated using flexible parametric survival analysis. We also estimated relative survival of hip fracture patients compared with that of the non-fractured background population in the same living situation (alone or with a partner). Higher mortality after hip fracture was found in both men and women living alone versus with a partner (hazard ratio [HR] men = 1.37, 95% confidence interval [CI] 1.29-1.44; HR women = 1.23, 95% CI 1.18-1.28, adjusting for age, education level, urbanization degree, and number of children). We demonstrated the strongest association in male hip fracture patients aged <60 years (long-term mortality HR = 3.29, 95% CI 2.25-6.49). Compared with the general population, relative survival 8 years after a hip fracture was 43% in men and 61% in women living alone, whereas relative survival in those living with a partner was 51% in men and 67% in women. In conclusion, hip fracture patients who lived alone had higher mortality than those living with a partner and lower survival relative to the general population. © 2021 American Society for Bone and Mineral Research (ASBMR).

Individual Variation in Adaptive Immune Responses and Risk of Hip Fracture-A NOREPOS Population-Based Cohort Study

Immune-mediated bone loss significantly impacts fracture risk in patients with autoimmune disease, but to what extent individual variations in immune responses affect fracture risk on a population level is unknown. To examine how immune responses relate to risk of hip fracture, we looked at the individual variation in a post-vaccination skin test response that involves some of the immune pathways that also drive bone loss. From 1963 to 1975, the vast majority of the Norwegian adult population was examined as part of the compulsory nationwide Norwegian mass tuberculosis screening. These examinations included standardized tuberculin skin tests (TSTs). Our study population included young individuals (born 1940 to 1960 and aged 14 to 30 years at examination) who had all received Bacille Calmette-Guerin (BCG) vaccination after a negative TST at least 1 year prior and had no signs of tuberculosis upon clinical examination. The study population ultimately included 244,607 individuals, whose data were linked with a national database of all hospitalized hip fractures in Norway from 1994 to 2013. There were 3517 incident hip fractures during follow-up. Using a predefined Cox model, we found that men with a positive or a strong positive TST result had a 20% (hazard ratio [HR] = 1.20, 95% confidence interval [CI] 1.01-1.44) and 24% (HR = 1.24, 95% CI 1.03-1.49) increased risk of hip fracture, respectively, compared with men with a negative TST. This association was strengthened in sensitivity analyses. Total hip bone mineral density (BMD) was available for a limited subsample and similarly revealed a non-significantly reduced BMD among men with a positive TST. Interestingly, no such clear association was observed in women. An increased immune response after vaccination is associated with an increased risk of hip fracture decades later among men, possibly because of increased immune-mediated bone loss. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Health care utilisation for treatment of injuries among immigrants in Norway: a nationwide register linkage study

Background

Previous research has generally found lower rates of injury incidence in immigrant populations than in native-born populations. Most of this literature relies on mortality statistics or hospital data, and we know less about injuries treated in primary health care. The aim of the present study was to assess use of primary and secondary care for treatment of injuries among immigrants in Norway according to geographic origin and type of injury.

Methods

We conducted a nationwide register-based cohort study of all individuals aged 25–64 years who resided in Norway as of January 1st 2008. This cohort was followed through 2014 by linking sociodemographic information and injury data from primary and secondary care. We grouped immigrants into six world regions of origin and identified immigrants from the ten most frequently represented countries of origin. Six categories of injury were defined: fractures, superficial injuries, open wounds, dislocations/sprains/strains, burns and poisoning. Poisson regression models were fitted to estimate incidence rate ratios separately for injuries treated in primary and secondary care according to immigrant status, geographic origin and type of injury, with adjustment for sex, age, county of residence, marital status and socioeconomic status.

Results

Immigrants had a 16% lower incidence of injury in primary care than non-immigrants (adjusted IRR = 0.84, 95% CI 0.83–0.84), and a 10% lower incidence of injury in secondary care (adjusted IRR = 0.90, 95% CI 0.90–0.91). Immigrants from Asia, Africa and European countries outside EU/EEA had lower rates than non-immigrants for injuries treated in both primary and secondary care. Rates were lower in immigrants for most injury types, and in particular for fractures and poisoning. For a subset of injuries treated in secondary care, we found that immigrants had lower rates than non-immigrants for treatment of self-harm, falls, sports injuries and home injuries, but higher rates for treatment of assault, traffic injuries and occupational injuries.

Conclusions

Health care utilisation for treatment of injuries in primary and secondary care in Norway was lower for immigrants compared to non-immigrants. Incidence rates were especially low for immigrants originating from Asia, Africa and European countries outside EU/EEA, and for treatment of fractures, poisoning, self-harm and sports injuries.

Geographic variations in hip fracture incidence in a high-risk country stretching into the Arctic: a NOREPOS study

There are geographic variations in hip fracture incidence rates across Norway, with a lower incidence in the coastal areas of the southwest and in the Arctic north, contrary to what may be expected with regard to vitamin D exposure from sunlight. The regional differences have become smaller in recent years.

INTRODUCTION

To investigate geographic variation in hip fracture incidence within Norway and regional differences in time trends.

METHODS

All hip fractures treated in Norwegian hospitals 2002-2013 were included, and demographic information was obtained from Statistics Norway. Age-standardized incidence rates were calculated separately for 19 counties. Incidence rate ratios with 95% confidence intervals for county differences and time trends were estimated using Poisson regression.

RESULTS

Age-standardized number of hip fractures per 10,000 person-years varied between counties from 69 to 84 in women and from 34 to 41 in men. The highest rates were observed in the southeastern capital city of Oslo, while rates were low in the four northernmost counties. There was an east-west gradient, with lower incidence in the coastal southwest compared with the southeast. Women showed a statistically significant decline during 2002-2013 in almost all counties (up to 31%). In men, only a few counties showed a decline. In both genders, hip fracture rates at age 80 in the combined five counties with the highest rates were significantly higher than in the combined five counties with the lowest rates across the period, although the trends converged over time.

CONCLUSIONS

In Norway, the hip fracture incidence was lower in the north compared with the south. In addition, we observed an east-west gradient with the highest incidence in the southeast and lower incidence in the coastal southwest. While there has been an overall declining trend in hip fracture incidence over time, regional differences are still apparent.

Can bone mineral density loss in the non-weight bearing distal forearm predict mortality?

PURPOSE

Low bone mineral density (BMD) is associated with increased risk of fractures and mortality. We investigated if rate of BMD loss in the distal forearm over seven years predicted mortality.

METHODS

1725 postmenopausal women and 1879 men aged 50-74 who participated in the longitudinal Tromsø Study waves 4 (1994-95) and 5 (2001-2002) were included. Cox regression models adjusted for lifestyle- and health related variables were used to assess associations between BMD change over seven years and subsequent mortality during up to 17 years of follow-up in participants with normal and low BMD at baseline.

RESULTS

Baseline BMD decreased and seven-year bone loss increased with increasing age. Overall, mortality rates were higher among those with low versus normal BMD (38 vs 19 per 1000 py in women, 56 vs 34 in men) and at higher bone loss rates (rate ratio high:low = 1.2 in women, 1.7 in men). BMD change was associated with increased mortality only in men with normal baseline BMD. In this group, men with a BMD loss of >4% had significantly higher mortality (HR 1.50, 95% CI 1.21, 1.87) than men with increased or unchanged BMD. BMD change was not significantly associated with increased mortality in women or in men with low BMD at baseline.

CONCLUSIONS

BMD loss in the distal forearm was associated with increased mortality in men with normal BMD at baseline, but not in women. We found no clear association between BMD loss and mortality in those with low BMD at baseline.

Vitamin D status and current policies to achieve adequate vitamin D intake in the Nordic countries

Aims: Nordic countries share fairly similar food culture and geographical location as well as common nutrition recommendations. The aim of this paper was to review the latest data on vitamin D status and intake and to describe the national supplementation and food fortification policies to achieve adequate vitamin D intake in the Nordic countries. Methods: The data are based on results derived from a literature search presented in a workshop held in Helsinki in November 2018 and completed by recent studies. Results: Vitamin D policies and the implementation of the recommendations differ among the Nordic countries. Vitamin D fortification policies can be mandatory or voluntary and widespread, moderate or non-existent. Vitamin D supplementation recommendations differ, ranging from all age groups being advised to take supplements to only infants. In the general adult population of the Nordic countries, vitamin D status and intake are better than in the risk groups that are not consuming vitamin D supplements or foods containing vitamin D. Non-Western immigrant populations in all Nordic countries share the problem of vitamin D insufficiency and deficiency. Conclusions: Despite the common nutrition recommendations, there are differences between the Nordic countries in the implementation of the recommendations and policies to achieve adequate vitamin D intake and status. There is a need for wider Nordic collaboration studies as well as strategies to improve vitamin D status, especially in risk groups.

Grip strength in men and women aged 50-79 years is associated with non-vertebral osteoporotic fracture during 15 years follow-up: The Tromsø Study 1994-1995

In 50-79-year-olds who participated in the Tromsø Study (1994-1995), the risk of non-vertebral osteoporotic fractures during 15 years follow-up increased by 22% in men and 9% in women per 1 SD lower grip strength. The strongest association was observed in men aged 50-64 years.

INTRODUCTION

We aimed to explore whether low grip strength was associated with increased risk of non-vertebral osteoporotic fracture in the population-based Tromsø Study 1994-1995.

METHODS

Grip strength (bar) was measured by a Martin Vigorimeter and fractures were retrieved from the X-ray archives at the University Hospital of North Norway between 1994 and 2010. At baseline, weight and height were measured, whereas information on the other covariates were obtained through self-reported questionnaires. Cox regression was used to estimate the hazard ratio (HR) of fracture in age- and gender-specific quintiles of grip-strength, and per 1 SD lower grip strength. Similar analyses were done solely for hip fractures. Adjustments were made for age, height, body mass index (BMI), marital status, education, smoking, physical activity, use of alcohol, self-perceived health, and self-reported diseases.

RESULTS

In 2891 men and 4002 women aged 50-79 years, 1099 non-vertebral osteoporotic fractures-including 393 hip fractures-were sustained during the median 15 years follow-up. Risk of non-vertebral osteoporotic fracture increased with declining grip strength: hazard ratios per SD decline was 1.22 (95% CI 1.05-1.43) in men and 1.09 (95% CI 1.01-1.18) in women. HR for fracture in lower vs. upper quintile was 1.58 (95% CI 1.02-2.45) in men and 1.28 (95% CI 1.03-1.59) in women. The association was most pronounced in men aged 50-64 years with HR = 3.39 (95% CI 1.76-6.53) in the lower compared to the upper quintile.

CONCLUSIONS

The risk of non-vertebral osteoporotic fracture increased with declining grip-strength in both genders, particularly in men aged 50-64 years.

Urban-Rural Differences in Hip Fracture Mortality: A Nationwide NOREPOS Study

Higher hip fracture incidence in urban than in rural areas has been demonstrated, but urban–rural differences in posthip fracture mortality have been less investigated, and the results are disparate. Hence, the aims of the present register‐based cohort study were to examine possible urban–rural differences in short‐ and long‐term mortality in Norwegian hip fracture patients and their potential associations with sociodemographic variables, and to investigate possible urban–rural differences in excess mortality in hip fracture patients compared with the general population. Data were provided from the NOREPOS hip fracture database, the 2001 Population and Housing Census, and the National Registry. The urbanization degree in each municipality was determined by the proportion of inhabitants living in densely populated areas (rural: <1/3, semirural: 1/3 to 2/3, and urban: >2/3). Age‐adjusted mortality rates and standardized mortality ratios were calculated for hip fracture patients living in rural, semirural, and urban municipalities. A flexible parametric model was used to estimate age‐adjusted average and time‐varying HRs by category of urbanization with the rural category as reference. Among 96,693 hip fracture patients, urban residents had higher mortality than their rural‐dwelling counterparts. The HR of mortality in urban compared with rural areas peaked during the first 1 to 2 years postfracture with a maximum HR of 1.20 (95% CI, 1.10 to 1.30) in men and 1.15 (95% CI, 1.08 to 1.21) in women. The differences were significant during approximately 5 years after fracture. Adjusting for sociodemographic variables did not substantially change the results. However, absolute 30‐day mortality was not significantly different between urban and rural residents, suggesting that health‐care quality immediately postfracture does not vary by urbanization. The novel findings of a higher long‐term mortality in urban hip fracture patients might reflect disparities in health status or lifestyle, differences in posthip fracture health care or rehabilitation, or a combination of several factors. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Means of increasing response rates in a Norwegian dietary survey among infants - results from a pseudo-randomized pilot study

Background

Postal surveys are widely used in scientific studies, including dietary surveys, but few studies about methods to increase participation in national dietary surveys are published. In the present study we compared response rates in a pilot study to a national dietary survey among infants using two different incentives (gift certificate or lottery), personalization in the form of handwritten name and address vs. a printed label and mode of sending out invitations (e-mail or postal invitation).

Methods

In this parallel-design pseudo-randomized pilot trial, a nationally representative sample of 698 mothers of infants aged 6 and 12 months was drawn from the Norwegian National Registry and invited to complete a food frequency questionnaire about their infant’s diet. One half of the mothers of 6 month olds were randomized by alternation to the lottery group (n = 198) and offered to participate in a lottery of two prizes (500 EUR and 1000 EUR). The other half (n = 200) was offered a gift certificate (50 EUR) upon completion of the questionnaire. Each incentive group was randomized by alternation to receiving an invitation with handwritten name and address or a printed label. For the mothers of infants aged 12 months (n = 300), 150 mothers received an e-mail invitation and 150 mothers received a postal invitation. Logistic regression was used for testing differences between the groups.

Results

The response rate was significantly higher (p = 0.028) in the gift certificate group (72%) than in the lottery group (62%). No difference was seen between those receiving an invitation with a handwritten name and address (68%) compared to a printed label (66%, p = 0.72). A somewhat higher response rate was seen when using the postal (50%) compared to the e-mail invitation (43%, p = 0.25).

Conclusions

In this pseudo-randomized parallel-design trial of women participating in a national dietary survey among infants, the response rate was higher when offered a gift certificate than when participating in a lottery. Handwritten name and address did not affect participation compared to a printed label. Only a moderate difference was seen between the postal and e-mail invitation. Others conducting similar methodological studies are encouraged to publish their results to expand the knowledge basis in this area.

Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: the Norwegian Mother and Child Cohort

Background

Western diets may provide excess vitamin A, which is potentially toxic and could adversely affect respiratory health and counteract benefits from vitamin D.

Objective

The aim of this study was to examine child asthma at age 7 y in relation to maternal intake of vitamins A and D during pregnancy, infant supplementation with these vitamins, and their potential interaction.

Design

We studied 61,676 school-age children (born during 2002-2007) from the Norwegian Mother and Child Cohort with data on maternal total (food and supplement) nutrient intake in pregnancy (food-frequency questionnaire validated against biomarkers) and infant supplement use at age 6 mo (n = 54,142 children). Linkage with the Norwegian Prescription Database enabled near-complete follow-up (end of second quarter in 2015) for dispensed medications to classify asthma. We used log-binomial regression to calculate adjusted RRs (aRRs) for asthma with 95% CIs.

Results

Asthma increased according to maternal intake of total vitamin A [retinol activity equivalents (RAEs)] in the highest (≥2031 RAEs/d) compared with the lowest (≤779 RAEs/d) quintile (aRR: 1.21; 95% CI: 1.05, 1.40) and decreased for total vitamin D in the highest (≥13.6 µg/d) compared with the lowest (≤3.5 µg/d) quintile (aRR: 0.81; 95% CI: 0.67, 0.97) during pregnancy. No association was observed for maternal intake in the highest quintiles of both nutrients (aRR: 0.99; 95% CI: 0.83, 1.18) and infant supplementation with vitamin D or cod liver oil.

Conclusions

Excess vitamin A (≥2.5 times the recommended intake) during pregnancy was associated with increased risk, whereas vitamin D intake close to recommendations was associated with a reduced risk of asthma in school-age children. No association for high intakes of both nutrients suggests antagonistic effects of vitamins A and D. This trial was registered at http://www.clinicaltrials.gov as NCT03197233.

Association of High Intakes of Vitamins B6 and B12 From Food and Supplements With Risk of Hip Fracture Among Postmenopausal Women in the Nurses' Health Study

IMPORTANCE

Vitamin supplementation far exceeding recommended doses is popular in segments of the population. However, adverse effects can occur. In a previous secondary analysis of combined data from 2 double-blind randomized clinical trials (RCTs), an unexpected increased risk of hip fracture was found among those treated with high doses of vitamin B6 in combination with vitamin B12.

OBJECTIVES

To study if high intakes of vitamins B6 and B12 from food and supplements were associated with a risk of hip fracture in the Nurses' Health Study and to investigate whether combined high intakes of both vitamins conferred a particularly increased fracture risk.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort study, 75 864 postmenopausal women in the United States were followed up from June 1984 through May 2014. The dates of analysis were July 2016 to June 2018. Information on hip fracture and a wide range of potential confounders was collected at baseline and with biennial follow-up questionnaires. Extensive dietary information was collected approximately every 4 years with a semiquantitative food frequency questionnaire. Relative risks (RRs) were calculated by Cox proportional hazards regression, with cumulative average intakes of vitamins B6 and B12 as main exposures, adjusting for potential confounders.

MAIN OUTCOME AND MEASURE

Hip fracture.

RESULTS

During follow-up, 2304 of 75 864 women had a hip fracture. Among the women with hip fractures, the median (range) age at hip fracture was 75.8 (46.7-93.0) years and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 24.3 (4.6). Median (interquartile range) cumulative average intakes of total vitamins B6 and B12 were 3.6 (4.8) mg/d and 12.1 (11.7) μg/d, respectively. Both vitamin B6 (RR, 1.29; 95% CI, 1.04-1.59 for an intake of ≥35 vs <2 mg/d; P = .06 for linear trend) and vitamin B12 (RR, 1.25; 95% CI, 0.98-1.58 for an intake of ≥30 vs <5 μg/d; P = .02 for linear trend) were associated with increased fracture risk. Risk was highest in women with a combined high intake of both vitamins (B6 ≥35 mg/d and B12 ≥20 μg/d), exhibiting an almost 50% increased risk of hip fracture (RR, 1.47; 95% CI, 1.15-1.89) compared with women with a low intake of both vitamins (B6 <2 mg/d and B12 <10 μg/d).

CONCLUSIONS AND RELEVANCE

In this cohort study, a combined high intake of vitamins B6 and B12 was associated with an increased risk of hip fracture. The intakes were far higher than the recommended dietary allowances. These findings add to previous studies suggesting that vitamin supplements should be used cautiously because adverse effects can occur.

Incidence of injuries in Norway: linking primary and secondary care data

Aims: Most studies of injury incidence underestimate the total burden of injury, as they do not include injuries treated in primary care. The aim of this study was to measure the total incidence of medically treated injuries in Norway. We further investigated the epidemiology of injuries treated in primary and secondary care. Methods: We collected individual-level data on injury diagnoses from the Norwegian Patient Registry and the national registry dataset for reimbursement of primary care providers for the period 2009-2014, and estimated the annual incidence of patients registered with an injury diagnosis in either or both of these registries. We also converted ICD-10 codes in secondary care into ICPC-2 codes to compare the types of injuries treated in primary and secondary care. Results: The annual incidence of medically treated injuries in Norway was 125 patients per 1000 inhabitants. Fifty-five per cent of injured patients received treatment exclusively in primary care. We observed stable time trends over the six-year period. Incidence rates were higher in primary care for the youngest children and in middle adulthood, but were higher in secondary care for older people. Overall, injury incidence was higher for men, but women became more injury prone with age. We only observed this gender reversal in secondary care. With the exception of fractures, all injury types were predominantly treated in primary care. Conclusions: A substantial proportion of injured patients in Norway are treated exclusively in primary care. The demographic profile of these patients differs from those treated in secondary care.

The association between alcohol consumption and risk of hip fracture differs by age and gender in Cohort of Norway: a NOREPOS study

The association between alcohol consumption and hip fracture differed by gender: Men aged 30-59 years drinking frequently or 14+ gl/week had higher risk than moderate drinkers. No significant association was seen in older men. Women not drinking alcohol had higher risk than those drinking moderately both regarding frequency and amount.

INTRODUCTION

We aimed to examine alcohol consumption and risk of hip fracture according to age and gender in the population-based Cohort of Norway (1994-2003).

METHODS

Socio-demographics, lifestyle, and health were self-reported and weight and height were measured in 70,568 men and 71,357 women ≥ 30 years. Information on subsequent hip fractures was retrieved from hospitals' electronic patient registries during 1994-2013. Frequency of alcohol consumption was categorized: never/seldom, moderate (≤ 2-3 times/week), or frequent (≥ 4 times/week), and amount as number of glasses per week: 0, 1-6, 7-13, 14-27, and 28+. Type of alcohol (wine vs. beer/hard liquor) was also examined. Cox's proportional hazards regression was used to estimate hazard ratios (HRs) stratified on gender and baseline age < 60 and ≥ 60 years.

RESULTS

During median 15-year follow-up, 1558 men and 2511 women suffered a hip fracture. Using moderate drinkers as reference, men < 60 years drinking frequently had multivariable adjusted HR = 1.73 (CI 1.02-2.96) for hip fracture and more than 2.5 times higher risk if they consumed 14+ glasses compared to 1-6 glasses per week. In other groups of age and gender, no statistically significant increased risk was found in those consuming the highest levels of alcohol. Compared to women with moderate or frequent alcohol use, never/seldom-drinking women had the highest fracture risk. In women, use of wine was associated with lower fracture risk than other types of alcohol.

CONCLUSIONS

Risk of hip fracture was highest in men < 60 years with the highest frequency and amount of alcohol consumption and in non-drinking women.

Osteoporosis and osteopenia in the distal forearm predict all-cause mortality independent of grip strength: 22-year follow-up in the population-based Tromsø Study

Low bone mineral density (BMD) gives an increased risk of fractures, which can lead to premature death. Can BMD of the wrist predict mortality? BMD consistent with osteopenia and osteoporosis gave a significantly increased risk of death for both men and women in a general population in Tromsø, Norway.

INTRODUCTION

To investigate if bone mineral density (BMD) levels of the distal forearm, consistent with osteopenia and osteoporosis, can predict mortality and if grip strength is an effect modifier.

METHODS

The study population constituted 6565 participants aged 50-79 years at baseline in the Tromsø Study wave 4 conducted in 1994-1995. Forearm BMD measured by SXA was categorized as "normal," "osteopenia," or "osteoporosis" following WHO's definition. Cox regression with all-cause mortality as the outcome over 22 years of follow-up was performed for men and women separately, adjusting for health-related factors, as well as BMD by grip strength interaction. A secondary analysis with a 15-year follow-up also adjusted for hip fractures and osteoporotic fractures.

RESULTS

During follow-up, 3176 of participants died (47%). Those categorized as osteoporotic had higher mortality hazard ratio (HR) compared to those with normal BMD; men HR = 1.37 (95% confidence interval (CI) 1.19, 1.58) and women HR = 1.32 (1.14, 1.53) were adjusted for age, body mass index, physical activity, smoking habits, education, health status, chronic diseases, and grip strength. Corresponding HRs for osteopenia were men HR = 1.13 (1.00, 1.27) and women HR = 1.17 (1.01, 1.35). Further adjustments for fractures did only marginally attenuate the results, and HRs were still significant. There was no grip strength by BMD interaction.

CONCLUSION

Men and women with low distal forearm BMD values, consistent with osteoporosis or osteopenia, had an increased mortality compared to normal BMD participants. High grip strength did not modify this association, and the association remained after adjustment for a range of health-related factors.

Does the Association of Comorbidity with 1-Year Mortality After Hip Fracture Differ According to Gender? The Norwegian Epidemiologic Osteoporosis Studies (NOREPOS)

BACKGROUND/OBJECTIVES

Excess mortality after hip fracture is higher in men than in women. The objective was to study whether comorbidity differs in men and women with hip fracture and to what degree differences in comorbidity according to gender may explain the higher excess mortality in men.

DESIGN

Population-based matched cohort covering the population aged 50 and older in Norway.

SETTING

Specialist healthcare (individuals with hip fracture) and general population (controls).

PARTICIPANTS

All individuals with hip fracture aged 50 and older from 2005 to 2008 (n = 32,175) and individuals without hip fracture matched 3:1 to those with hip fracture on gender, age, and county of residence (n = 96,410).

MEASUREMENTS

Comorbid diagnoses were recorded during the hospital stay. Relative and absolute excess 1-year mortality in individuals with hip fracture according to gender and Charlson Comorbidity Index (CCI) were investigated using Cox regression and linear regression, respectively.

RESULTS

Despite lower age (mean 78.7 vs 81.7), men had higher comorbidity than women. Compared with controls, women (hazard ratio (HR) = 6.5, 95% confidence interval (CI) = 6.2-6.9) and men (HR = 7.8, 95% CI = 7.3-8.3) with a CCI of 2 or greater were more likely to die. Women with a CCI of 2 or greater had an estimated 1-year risk of dying of 44%, and controls had an 11% risk; men with a CCI of 2 or greater had an estimated risk of dying of 53%, and controls had a 12% risk. Men were twice as likely as women to die within 1 year (HR = 2.0, 95% CI = 1.9-2.1). When adjusting for comorbidity, the difference was only slightly smaller (HR = 1.8, 95% CI = 1.7-1.8).

CONCLUSION

Men had greater comorbidity than women, but this did not explain the difference according to gender in excess mortality after hip fracture. Men who fracture a hip are an especially vulnerable subpopulation, even when there is no apparent comorbidity, and warrant special attention in follow-up and care.

Excess mortality following hip fracture: impact of self-perceived health, smoking, and body mass index. A NOREPOS study

Self-perceived health, smoking, and body mass index measured years before the hip fracture predicted excess post-hip fracture mortality, and even hip fracture patients with the most favorable levels of these risk factors had higher mortality than subjects who did not fracture.

INTRODUCTION

This study aimed to investigate the impact of pre-fracture self-perceived health, smoking, and body mass index (BMI) on excess post-hip fracture mortality using matched peers without hip fracture as reference.

METHODS

The study was based on the Cohort of Norway (CONOR) consisting of 10 regional health studies (1994-2003) and the NOREPOS hip fracture database (1994-2008). A matched cohort design was used to compare survival between hip fracture patients and subjects without fracture (matched on gender, age at participation in CONOR, and study site). Subjects aged ≥60 years were included. Hazard ratios were estimated using stratified Cox regression. Age-standardized mortality was also calculated.

RESULTS

Overall, hip fracture patients (N = 3177) had a 2.26-fold (95 % CI 2.13, 2.40) increased mortality compared to matched subjects (N = 20,282). The highest excess mortality was found in hip fracture patients reporting poor health (HR 4.08, 95 % CI 3.17, 5.26) and daily smoking (HR 3.25, 95 % CI 2.89, 3.66) and in patients with BMI <18.5 (HR 3.07, 95 % CI 2.11, 4.47) prior to the fracture. However, excess mortality was also observed in hip fracture patients in all other categories of BMI, self-perceived health, and smoking.

CONCLUSIONS

Information on self-perceived health, smoking, and BMI collected years before hip fracture predicted excess post-hip fracture mortality, and even hip fracture patients with the most favorable levels of these risk factors had higher mortality than the matched subjects who did not fracture. This suggests that both pre-fracture health status and factors related to the hip fracture itself might affect post-hip fracture mortality.

Age and Sex Differences in Body Mass Index as a Predictor of Hip Fracture: A NOREPOS Study

It is unclear whether very high body mass index (BMI; weight (kg)/height (m)²) lowers risk of hip fracture. Our objectives in this study were 1) to examine the association between BMI and subsequent hip fracture according to sex and age and 2) to explore whether the importance of known risk factors varied across BMI. We followed 61,787 participants (29,511 female and 32,276 male) in the Cohort of Norway (ages 50-79 years at baseline in 1994-2003) with regard to hip fracture. BMI was calculated from measured height and weight. During a median follow-up period of 8.4 years, 1,603 women and 951 men suffered a hip fracture. Hazard ratios for hip fracture and associated 95% confidence intervals were estimated. After adjustment for potential confounders, women with BMI <22 had a hazard ratio of 1.38 (95% confidence interval (CI): 1.18, 1.60) for hip fracture, as compared with women with BMI 22-24.9; and women with BMI ≥30 had a hazard ratio of 0.57 (95% CI: 0.49, 0.66). Corresponding results in men were hazard ratio = 1.66 (95% CI: 1.35, 2.05) and hazard ratio = 0.77 (95% CI: 0.62, 0.96), respectively. Below age 70 years, there was no further decrease in fracture risk at BMIs of 25 or more, while in women aged 70-79 years, the risk continued to decrease with increasing BMI. The associations between risk factors and hip fracture were similar in strength across BMI strata.

Standardizing serum 25-hydroxyvitamin D data from four Nordic population samples using the Vitamin D Standardization Program protocols: Shedding new light on vitamin D status in Nordic individuals

Knowledge about the distributions of serum 25-hydroxyvitamin D (25(OH)D) concentrations in representative population samples is critical for the quantification of vitamin D deficiency as well as for setting dietary reference values and food-based strategies for its prevention. Such data for the European Union are of variable quality making it difficult to estimate the prevalence of vitamin D deficiency across member states. As a consequence of the widespread, method-related differences in measurements of serum 25(OH)D concentrations, the Vitamin D Standardization Program (VDSP) developed protocols for standardizing existing serum 25(OH)D data from national surveys around the world. The objective of the present work was to apply the VDSP protocols to existing serum 25(OH)D data from a Danish, a Norwegian, and a Finnish population-based health survey and from a Danish randomized controlled trial. A specifically-selected subset (n 100-150) of bio-banked serum samples from each of the studies were reanalyzed for 25(OH)D by LC-MS/MS and a calibration equation developed between old and new 25(OH)D data, and this equation was applied to the entire data-sets from each study. Compared to estimates based on the original serum 25(OH)D data, the percentage vitamin D deficiency (< 30 nmol/L) decreased by 21.5% in the Danish health survey but by only 1.4% in the Norwegian health survey; but was relatively unchanged (0% and 0.2%) in the Finish survey or Danish RCT, respectively, following VDSP standardization. In conclusion, standardization of serum 25(OH)D concentrations is absolutely necessary in order to compare serum 25(OH)D concentrations across different study populations, which is needed to quantify and prevent vitamin D deficiency.

Continued decline in hip fracture incidence in Norway: a NOREPOS study

The previously reported decline in age-adjusted hip fracture rates in Norway during 1999-2008 continued after 2008. The annual number of hip fractures decreased in women and increased in men.

INTRODUCTION

Norway has among the highest hip fracture incidence rates ever reported despite previously observed declining rates from 1999 through 2008. The aim of the present study was to investigate whether this downward trend continued through 2013, and to compare gender-specific trends in 5 year age-groups during three time periods: 1999-2003, 2004-2008, and 2009-2013.

METHODS

All hip fractures (cervical, trochanteric, and sub-trochanteric) admitted to Norwegian hospitals were retrieved. Annual age-standardized incidence rates of hip fracture per 10,000 person-years by gender were calculated for the period 1999-2013. Time trends were tested by age-adjusted Poisson regression.

RESULTS

From 1999 through 2013 there were 140,136 hip fractures in persons aged 50 years and above. Age-adjusted hip fracture incidence rates declined by 20.4 % (95 % CI: 18.6-20.1) in women and 10.8 % (95 % CI: 7.8-13.8) in men, corresponding to an average annual age-adjusted decline of 1.5 % in women and 0.8 % in men. Except for the oldest men, hip fracture rates declined in all age-groups 70 years and older. The average annual number of fractures decreased in women (-0.3 %) and increased in men (+1.1 %).

CONCLUSIONS

During the past 15 years, hip fracture rates have declined in Norway. The forecasted growing number of older individuals might, however, cause an increase in the absolute number of fractures, with a substantial societal economic and public health burden.

25-Hydroxyvitamin D in pregnancy and genome wide cord blood DNA methylation in two pregnancy cohorts (MoBa and ALSPAC)

The aim of the study was to investigate whether maternal mid-pregnancy 25-hydroxyvitamin D concentrations are associated with cord blood DNA methylation. DNA methylation was assessed using the Illumina HumanMethylation450 BeadChip, and maternal plasma 25-hydroxyvitamin D was measured in 819 mothers/newborn pairs participating in the Norwegian Mother and Child Cohort (MoBa) and 597 mothers/newborn pairs participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Across 473,731CpG DNA methylation sites in cord blood DNA, none were strongly associated with maternal 25-hydroxyvitamin D after adjusting for multiple tests (false discovery rate (FDR)>0.5; 473,731 tests). A meta-analysis of the results from both cohorts, using the Fisher method for combining p-values, also did not strengthen findings (FDR>0.2). Further exploration of a set of CpG sites in the proximity of four a priori defined candidate genes (CYP24A1, CYP27B1, CYP27A1 and CYP2R1) did not result in any associations with FDR<0.05 (56 tests). In this large genome wide assessment of the potential influence of maternal vitamin D status on DNA methylation, we did not find any convincing associations in 1416 newborns. If true associations do exist, their identification might require much larger consortium studies, expanded genomic coverage, investigation of alternative cell types or measurements of 25-hydroxyvitamin D at different gestational time points.

A combination of low serum concentrations of vitamins K1 and D is associated with increased risk of hip fractures in elderly Norwegians: a NOREPOS study

The present study investigated the risk of incident hip fractures according to serum concentrations of vitamin K1 and 25-hydroxyvitamin D in elderly Norwegians during long-term follow-up. The results showed that the combination of low concentrations of both vitamin D and K1 provides a significant risk factor for hip fractures.

INTRODUCTION

This case-cohort study aims to investigate the associations between serum vitamin K1 and hip fracture and the possible effect of 25-hydroxyvitamin D (25(OH)D) on this association.

METHODS

The source cohort was 21,774 men and women aged 65 to 79 years who attended Norwegian community-based health studies during 1994-2001. Hip fractures were identified through hospital registers during median follow-up of 8.2 years. Vitamins were determined in serum obtained at baseline in all hip fracture cases (n = 1090) and in a randomly selected subcohort (n = 1318). Cox proportional hazards regression with quartiles of serum vitamin K1 as explanatory variable was performed. Analyses were further performed with the following four groups as explanatory variable: I: vitamin K1 ≥ 0.76 and 25(OH)D ≥ 50 nmol/l, II: vitamin K1 ≥ 0.76 and 25(OH)D < 50 nmol/l, III: vitamin K1 < 0.76 and 25(OH)D ≥ 50 nmol/l, and IV: vitamin K1 < 0.76 and 25(OH)D < 50 nmol/l.

RESULTS

Age- and sex-adjusted analyses revealed an inverse association between quartiles of vitamin K1 and the risk of hip fracture. Further, a 50 % higher risk of hip fracture was observed in subjects with both low vitamin K1 and 25(OH)D compared with subjects with high vitamin K1 and 25(OH)D (HR 1.50, 95 % CI 1.18-1.90). The association remained statistically significant after adjusting for body mass index, smoking, triglycerides, and serum α-tocopherol. No increased risk was observed in the groups low in one vitamin only.

CONCLUSION

Combination of low concentrations of vitamin K1 and 25(OH)D is associated with increased risk of hip fractures.

A restrictive policy for red blood cell transfusion in older hip fracture patients: experiences from a patient register

Background

Allogeneic red blood cell transfusions (ABT) are common in older hip fracture patients. Recent research supports a restrictive transfusion policy. The aim was to study variation in hemoglobin (Hb) concentration, and clinical outcomes in these patients.

Results

Cross-sectional study with one-year follow-up in an orthogeriatric unit. Data were obtained from a quality register with demographic and medical information collected by an interdisciplinary team. 106 (22 %) of the 491 patients admitted from September 2011 throughout September 2012 (76 % women, mean age 85 years) received ABT. When given ABT, 80 % had Hb <80 g/l and mean Hb was 78 g/l. Mean Hb, regardless ABT, showed variation from 125 g/l (±16) on admission to 106 g/l (±17), 101 g/l (±16) and 102 g/l (±14) on 1st, 3rd and 5th postoperative day respectively. Patients with per-/subtrochanteric fractures more often received ABT than those with femur neck fractures (p < 0.001), 70 % of the patients receiving ABT had a per-/subtrochanteric fracture. Patients who received ABT were older, had more chronic diseases and lower mean Hb throughout the hospital stay. Length of stay was longer (median 7 vs. 6 days, p = 0.01), and medical complications more common. In-hospital and 30-day mortalities were similar in patients given ABT and in those who were not, but 1-year mortality was higher among patients who were given ABT (p = 0.008).

Conclusions

Hb had a tendency to fall during the three first days after surgery and seemed to be stabilized on day 5. Patients who received ABT had poorer health, but not significantly higher short-term mortality. This study demonstrates a restrictive transfusion policy.