Abdominal obesity increases the risk of hip fracture. A population-based study of 43,000 women and men aged 60-79 years followed for 8 years. Cohort of Norway.

BACKGROUND: The question as to whether abdominal obesity has an adverse effect on hip fracture remains unanswered. The purpose of this study was to investigate the associations of waist circumference, hip circumference, waist-hip ratio, and body mass index with incident hip fracture. METHODS: The data in this prospective study is based on Cohort of Norway, a population-based cohort established during 1994-2003. Altogether 19,918 women and 23,061 men aged 60-79 years were followed for a median of 8.1 years. Height, weight, waist and hip circumference were measured at baseline using standard procedures. Information on covariates was collected by questionnaires. Hip fractures (n = 1,498 in women, n = 889 in men) were identified from electronic discharge registers from all general hospitals in Norway between 1994 and 2008. RESULTS: The risk of hip fracture decreased with increasing body mass index, plateauing in obese men. However, higher waist circumference and higher waist-hip ratio were associated with an increased risk of hip fracture after adjustment for body mass index and other potential confounders. Women in the highest tertile of waist circumference had an 86% (95% CI: 51-129%) higher risk of hip fracture compared to the lowest, with a corresponding increased risk in men of 100% (95% CI 53-161%). Lower body mass index combined with abdominal obesity increased the risk of hip fracture considerably, particularly in men. CONCLUSION: Abdominal obesity was associated with an increased risk of hip fracture when body mass index was taken into account. In view of the increasing prevalence of obesity and the number of older people suffering osteoporotic fractures in Western societies, our findings have important clinical and public health implications.

Hip fracture and other predictors of anti-osteoporosis drug use in Norway.

UNLABELLED: This study aims to find predictors of anti-osteoporosis drug (AOD) use. Known risk factors of osteoporosis, i.e., age, hip fracture, and corticosteroid use were found to be predictors of AOD use, in addition to a number of other drugs used. Higher socioeconomic position did not favor the use of AOD. INTRODUCTION: This study deals with studying predictors of anti-osteoporosis drug treatment in Norwegian women and men. METHODS: All Norwegian women and men≥50 years were included (n=1,407,392). Data were taken from different data sources, (1) the Norwegian Prescription Database (drug use in 2004-2005); (2) the Nationwide Census 2001 (marital status, education and resident county); (3) the National Hip Fracture Database (hip fractures 2003-2005); and (4) the National Population Register (date of death/emigration). We estimated the hazard ratios (HR) for incident treatment by Cox proportional hazard regression. RESULTS: In 2005, 10,332 women (1.5%) and 1,387 men (0.2%) were new users of anti-osteoporosis drugs (incident treatment). Age was a statistically significant predictor of incident treatment in both women and men, with HR ranging from 1.7 to 3.2 (per 10 years). A middle educational level in men strongly predicted incident treatment [HR 2.0 (CI 1.1-3.8)], but not in women after full adjustment. A previous hip fracture, increasing number of drugs used and use of corticosteroids were all predictors of incident treatment in both genders after adjustments. Corticosteroid use [HRwomen=4.0 (CI 3.8-4.2)] had a higher HR for incident treatment than hip fracture [HRwomen=2.0 (CI 1.8-2.3)]. Marital status and area of residency were not predictors of incident treatment in either gender, after adjustments. The predictors of prevalent treatment were only slightly different from incident treatment in 2005. CONCLUSIONS: Age, previous hip fracture, number of drugs used, and use of corticosteroids were positively related to treatment in both genders. In men, a middle educational level predicted treatment.

Hip fracture incidence is decreasing in the high incidence area of Oslo, Norway.

UNLABELLED: This study reports a significant decrease in age-adjusted incidence rates of hip fracture for women in Oslo, Norway, even compared with data from 1978/1979. Use of bisphosphonate may explain up to one third of the decline in the incidence. INTRODUCTION: The aims of the present study were to report the current incidence of hip fractures in Oslo and to estimate the influence of bisphosphonates on the current incidence. METHODS: Using the electronic diagnosis registers and lists from the operating theaters of the hospitals of Oslo, all patients with ICD-10 codes S72.0 and S72.1 (hip fracture) in 2007 were identified. Medical records of all identified patients were reviewed to verify the diagnosis. Age- and gender-specific annual incidence rates were calculated using the population of Oslo on January 1, 2007 as the population at risk. Data on the use of bisphosphonates were obtained from official registers. RESULTS: A total number of 1,005 hip fractures, 712 (71%) in women, were included. The age-adjusted fracture rates per 10,000 for the age group >50 years were 82.0 for women and 39.1 for men in 2007, compared with 110.8 and 41.4 in 1996/1997, 116.5 and 42.9 in 1988/1989, and 97.5 and 34.5 in 1978/1979, respectively. It was estimated that the use of bisphosphonates may explain up to 13% of the decline in incidence in women aged 60-69 years and up to 34% in women aged 70-79 years. CONCLUSIONS: The incidence of hip fractures in women in Oslo has decreased significantly during the last decade and is now at a lower level than in 1978/1979. This reduction was not evident in men. The incidence of hip fractures in Oslo is, however, still the highest in the world.

Does body height reduction influence interpretation of lung function in COPD patients?

Vertebral deformities are prevalent in chronic obstructive pulmonary disease (COPD) patients and may cause excessive loss of height. As height is used for calculating reference values for pulmonary function tests, larger than normal height reduction could cause overestimation of lung function. In this cross-sectional study of 465 COPD patients and 462 controls, we explored how often lung function is misinterpreted due to height reduction in COPD patients, and whether the number or severity of vertebral deformities correlate with height reduction. Measured height was compared to recalled tallest height (RTH) and height calculated from arm span (ASH) to assess height reduction. Vertebral deformities were assessed from radiographs and pulmonary function was assessed using standard formulae. Height reduction was frequent in both the study and control groups, and increased with the number and severity of vertebral deformities. When using current measured height, lung function was overestimated in a significant proportion of COPD patients at relatively modest height reductions. The effects were smallest for forced expiratory volume in 1 s and forced vital capacity, and most pronounced for total lung capacity and residual volume. Therefore, we propose that in COPD patients with excessive height reduction, one might use RTH or ASH in calculating predicted values. Furthermore, such patients should be evaluated for co-existing vertebral deformities and osteoporosis.

Outdoor air pollution, bone density and self-reported forearm fracture: the Oslo Health Study.

UNLABELLED: Air pollution is associated with several adverse health outcomes and increased mortality. In the Oslo Health Study, an association between long-term outdoor air pollution exposure and bone health was suggested in men aged 75/76 years, but not in younger men or in women. INTRODUCTION: Associations have been found between air pollution and a range of diseases, but few have studied whether bone health differs according to the concentration of air pollution. The aim of this study was to investigate the association between indicators of air pollution and bone health. METHODS: Self-reported forearm fracture was assessed in men and women 75/76 and 59/60 years (n = 5,976) participating in the Oslo Health Study 2000-2001. In subsamples of the participants (n = 1,039), we studied the relation between air pollution and forearm bone mineral density (BMD) measured by single X-ray absorptiometry. Exposure to air pollution (particulate matter (PM(10) and PM(2.5)) and nitrogen dioxide (NO(2))) at each participant's home address was estimated from 1992 to 2001. RESULTS: We found no associations between air pollution and self-reported forearm fractures or BMD in men aged 59/60 years or in women. In men aged 75/76 years, an increment of 10 units in PM(2.5) was associated with a reduction in distal forearm BMD of 64 mg/cm(2) (p < 0.05), and with an increased prevalence of forearm fracture after the age of 50 years among current smokers, OR = 7.4 (p < 0.05). Similar patterns of associations were suggested for PM(10) and NO(2). CONCLUSIONS: In this study, bone health was not associated with long-term exposure to air pollution in women and in men 59/60 years of age. However, a negative association was suggested in elderly men. Further studies with improved measures of air pollution are warranted.

High prevalence of vertebral deformities in COPD patients: relationship to disease severity.

Bone mineral density decreases with advancing chronic obstructive pulmonary disease (COPD) severity, but it is not known whether this is reflected in higher fracture rates. The present authors wanted to compare the prevalence of vertebral deformities in COPD patients with those in a population-based reference group to determine whether the number of deformities was related to the severity of COPD and how far the use of oral corticosteroids (OCS) influenced the prevalence of deformities. In the present cross-sectional study of 465 COPD patients and 462 controls, vertebral deformities were found in 31% of the COPD patients and 18% of the controls. In subjects who had never or sporadically used OCS, deformities were found in 29% of the COPD patients and 17% of the controls. In females, the average number of vertebral deformities was almost two-fold when COPD severity increased from Global Initiative of Chronic Obstructive Lung Disease stage II to III. In males, the use of OCS had a small but significant influence. Prevalence of vertebral deformities was significantly higher in chronic obstructive pulmonary disease patients than in the controls. In females, the average number of deformities was related to chronic obstructive pulmonary disease severity even after adjustment for other known risk factors. The difference between patients and controls remained significant even in those who never or sporadically used oral corticosteroids.

Change in the use of hormone replacement therapy and the incidence of fracture in Oslo.

UNLABELLED: Fracture incidence in Oslo decreased from the 1970s to the 1990s in younger postmenopausal women, but not in older women or in men. Concurrently, hormone replacement therapy increased considerably. Using data from the Oslo Health Study, we estimated that roughly half the decline might be attributed hormone replacement therapy. INTRODUCTION: Between the late 1970s and the late 1990s, the incidence of hip fracture and distal forearm fracture decreased in younger postmenopausal women in Oslo, but not in elderly women or in men. The purpose of this report is to evaluate whether the decreased incidence was coherent with trends in use of hormone replacement therapy (HRT). METHODS: Data on estrogens were collected from official drug statistics, data on fractures from published studies and data on bone mineral density (BMD) from the Oslo Health Study. RESULTS: The sale of all estrogens increased 22 times from 1979 to 1999, and the sub-category estradiol combined with progestin increased 35 times. In the corresponding period the incidence of distal forearm fracture in women aged 50-64 years decreased by 33% and hip fracture by 39%. Based on differences in BMD between users and non-users of HRT, we estimated that up to half of this decline might be due to HRT. CONCLUSIONS: The reduction in fracture incidence in postmenopausal women in Oslo occurred in a period with a substantial increase in the use of HRT. Future surveillance will reveal whether the last years' decline in use of HRT will be translated into increasing fracture rates.

Low bone mineral density is related to severity of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) appears to be associated with low bone mineral density (BMD). BMD loss can be accelerated by a number of factors associated with COPD, but it is not known whether COPD itself has a direct effect. Our aim was to investigate in a cross-sectional study whether COPD patients have lower BMD than healthy individuals, and whether the severity of the disease affects BMD. Eighty-eight COPD patients attending a rehabilitation program were classified into stages II, III and IV using GOLD criteria. BMD was measured by dual X-ray absorptiometry in lumbar spine (L2-4), femoral neck (FN) and total body (TB). Values were converted to Z-scores (adjusted for age and sex). Associations between Z-scores and steroid use, body mass index, pack-years and six-min walking distance were analyzed. The Z-scores (mean and (CI)) for all patients were for L2-4: -0.6 (-0.9, -0.3), FN: -0.8 (-1.0, -0.5) and TB: -0.5 (-0.8, -0.2). All scores were significantly different from those of a control population (p<0.001). For all three variables (ZL2-4, ZFN, ZTB) there were significant differences between the stages. The difference for ZL2-4 was still significant after adjustment for risk factors. We conclude that BMD is low in COPD patients and decreases with increasing severity of the disease. Low BMD may to some extent be a disease-specific effect.

Low BMD is less predictive than reported falls for future limb fractures in women across Europe: results from the European Prospective Osteoporosis Study.

We have previously shown that center- and sex-specific fall rates explained one-third of between-center variation in upper limb fractures across Europe. In this current analysis, our aim was to determine how much of the between-center variation in fractures could be attributed to repeated falling, bone mineral density (BMD), and other risk factors in individuals, and to compare the relative contributions of center-specific BMD vs. center-specific fall rates. A clinical history of fracture was assessed prospectively in 2451 men and 2919 women aged 50-80 from 20 centers participating in the European Prospective Osteoporosis Study (EPOS) using standardized questionnaires (mean follow-up = 3 years). Bone mineral density (BMD, femoral neck, trochanter, and/or spine) was measured in 2103 men and 2565 women at these centers. Cox regression was used to model the risk of incident fracture as a function of the person-specific covariates: age, BMD, personal fracture history (PFH), family hip fracture history (FAMHIP), time spent walking/cycling, number of 'all falls' and falls not causing fracture ('fracture-free') during follow-up, alcohol consumption, and body mass index. Center effects were modeled by inclusion of multiplicative gamma-distributed random effects, termed center-shared frailty (CSF), with mean 1 and finite variance theta (theta) acting on the hazard rate. The relative contributions of center-specific fall risk and center-specific BMD on the incidence of limb fractures were evaluated as components of CSF. In women, the risk of any incident nonspine fracture (n = 190) increased with age, PFH, FAMHIP, > or =1 h/day walking/cycling, and number of 'all falls' during follow-up (all P < 0.074). 'Fracture-free' falls (P = 0.726) and femoral neck BMD did not have a significant effect at the individual level, but there was a significant center-shared frailty effect (theta = 0.271, P = 0.001) that was reduced by 4% after adjusting for mean center BMD and reduced by 19% when adjusted for mean center fall rate. Femoral trochanter BMD was a significant determinant of lower limb fractures (n = 53, P = 0.014) and the center-shared frailty effect was significant for upper limb fractures (theta = 0.271, P = 0.011). This upper limb fracture center effect was unchanged after adjusting for mean center BMD but was reduced by 36% after adjusting for center mean fall rates. In men, risk of any nonspine fracture (n = 75) increased with PFH, fall during follow-up (P < 0.026), and with a decrease in trochanteric BMD [RR 1.38 (1.08, 1.79) per 1 SD decrease]. There was no center effect evident (theta = 0.081, P = 0.096). We conclude that BMD alone cannot be validly used to discriminate between the risk of upper limb fractures across populations without taking account of population-specific variations in fall risk and other factors. These variations might reflect shared environmental or possibly genetic factors that contribute quite substantially to the risk of upper limb fractures in women.

Local and national electronic databases in Norway demonstrate a varying degree of validity.

OBJECTIVE: The aim of the present study was to examine the validity of local and national electronic databases using medical records as gold Standard. STUDY DESIGN AND SETTING: All hospital admissions with ICD 9-code 820.X (hip fracture) in a 1-year period were identified in the electronic discharge registers of the hospitals in Oslo and in the national electronic database (The Norwegian Patient Register). Medical records for all patients identified by the discharge registers and the logbooks of the operating theater of the hospitals were retrieved, and the diagnosis was verified. RESULTS: Compared with the total number of fractures confirmed in medical records, the electronic discharge register of one of the hospitals underestimated the number of fractures by 46%, whereas the two other overestimated the number by 17% and 19%. For the national electronic database, an overall overestimation of 19% was found. CONCLUSION: The present findings question the validity of electronic databases and thus have implications for epidemiologic studies.

Bone density variation and its effects on risk of vertebral deformity in men and women studied in thirteen European centers: the EVOS Study.

In Europe there is a 3-fold variation, according to geographical center, in risk of vertebral deformity in men and women over the age of 50. We investigated the relationship between bone density, as assessed by dual-energy X-ray absorptiometry (DEXA) of the spine and hip and prevalent vertebral deformities in 13 of the 36 centers participating in the European Vertebral Osteoporosis Study (EVOS). Each center recruited an age-stratified sample of men and women aged 50 years and over, and of those who agreed to densitometry, 288/2088 women and 233/1908 men were found to have one or more deformities of the vertebrae between T4 and L4 as assessed by the McCloskey algorithm. DEXA was in each case performed on L2-L4, the proximal femur, or both. Bone densitometry results were cross-calibrated between centers using the European Spine Phantom prototype and results expressed as bone mineral density (BMD, g/cm2). In both genders, subjects with deformities involving loss of anterior vertebral body height alone comprised over 20% of the total with deformities and these related poorly to BMD. Other classes of deformity were found by logistic regression to relate significantly to BMD in one or both genders, with odds ratios for the risk of any of these ranging from 1.67 to 2.11 for a 1 SD reduction in bone density at spine, femoral neck, or trochanter (p < 0.001). Adjusting for anthropometric variables and BMD did not remove the effect of age on risk which rose 1.67- to 1.78-fold per decade according to gender. The greater unadjusted rate of increase in deformity risk with age in women was attributable to their faster rate of bone loss with age; after adjusting for age, body mass index (BMI), and BMD at the trochanter in grams per square centimeter, men had a 2-fold higher risk of deformity than women. Analysis of the relationship between mean bone density and the prevalence of deformity in each center demonstrated no significant differences between centers in either gender, after adjusting for BMD, age, and BMI together with an a posteriori statistical adjustment for imperfect cross-calibration of densitometers. It is concluded that BMD is an important determinant of deformity risk in both genders. Together with age, BMD explains much of the differences in risk both between the sexes and between individual geographical centers in Europe.

Early postmenopausal bone loss is not associated with a decrease in circulating levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, or vitamin D-binding protein.

To study changes in the rate of bone loss before and after the menopause, 19 normal premenopausal women of the same age were followed with annual measurements of appendicular bone mass for 8 yr. Their serum estrone, estradiol, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and vitamin D-binding protein levels also were measured annually. The serum estrogen levels declined before the menopause, and the rate of bone loss more than doubled at the time of the menopause. There were no significant changes in the serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin LD or vitamin D-binding protein levels from the pre- to the postmenopausal period. We conclude that changes in vitamin D metabolite levels are not associated with early postmenopausal bone loss.

There is no difference in spontaneous and 17 beta-estradiol-induced interleukin-1 beta release by peripheral blood mononuclear cells from nonosteoporotic women with different rates of early postmenopausal bone loss.

Interleukin-1 (IL-1) is a potent stimulator of bone resorption, and a causal role for IL-1 has been suggested in postmenopausal bone loss. We have examined IL-1 beta release in vitro by peripheral blood mononuclear cells (PBMC) isolated from nonosteoporotic women 9-15 yr after menopause. These women had presented 6 yr previously with significant differences in the rate of early postmenopausal bone loss. Ten women with low rates of bone loss (median 2.0% per year) and 10 women with high rates of bone loss (median 4.9% per year) were included in the study. The women with a high rate of bone loss had a significantly lower bone mass of the lumbar vertebrae compared with that of the other group, but there were no differences in biochemical markers of bone metabolism between the groups (pyridinoline/creatinine ratio in urine and collagen 1 c-terminal telopeptide and bone gla protein in serum). Moreover, there was no difference in spontaneous IL-1 beta release by PBMCs between the two groups and no correlation between IL-1 beta release and present bone turnover, as judged by biochemical markers. Treatment of PBMCs with 10 nmol/L 17 beta-estradiol in vitro significantly stimulated IL-1 beta production in both groups. We conclude that IL-1 beta production by PBMCs in vitro does not correlate with the rate of early postmenopausal bone loss.

Normal bone mass in bulimic women.

The aim of this study was to examine the relationship among exercise, menstrual function, and bone mineral density (BMD) in different groups of age-matched patients with eating disorders. Dieting and eating disorder history, physical activity history, and menstrual history were assessed by clinical interview in 43 bulimic and 13 anorectic young women as well as in 17 healthy control subjects (18-29 yr). BMD was assessed by dual x-ray absorptiometry. All the anorectics but only 30% of the bulimics exercised regularly from the onset of their eating disorder (P < 0.01), mainly using aerobic dancing and running. All of the anorectics had been amenorrheic since the start of their symptoms, and 68% of the bulimics had a history of menstrual dysfunction. Within the exercise subgroups of bulimic patients, there was no significant relationship between BMD and current or previous menstrual function. Anorectic patients had lower BMD than bulimics and controls in all skeletal regions studied (P < 0.01). Bulimic patients who had exercised regularly during their illness had higher total body BMD than bulimics classified as sedentary (P < 0.01). Bulimics who had exercised regularly or intermittently since the onset of their eating disorder had higher BMD than sedentary bulimics in the lumbar vertebrae, femoral neck, and legs (P < 0.05). It appears that weight-bearing exercise can prevent or attenuate bone loss at specific skeletal sites in normal weight bulimic patients, but not in anorectics.

A longitudinal study of pre- and postmenopausal changes in calcium metabolism.

Longitudinal changes in the serum concentration of calcium, phosphate, alkaline phosphatase, PTH, calcitonin and the renal handling of calcium and phosphate were studied in 19 normal women of the same age before and after the menopause. Significant increase in serum calcium, phosphate and calcitonin and urine calcium/creatinine and TmPO4/GF were shown to precede the premenopause. After cessation of the menstruation, no statistically significant further changes were observed in these variables. Changes in PTH were not observed neither during the premenopausal nor the post-menopausal period. Alkaline phosphatase increased in the postmenopausal period suggesting an increase in bone turn-over.

Perimenopausal appendicular bone loss: a 10-year prospective study.

The rate of bone loss before and after the menopause were studied prospectively in 73 healthy women, who were all aged 47 and premenopausal at the start of the study. Bone mass was measured annually by radiogrammetry of 6 metacarpals and by dual photon absorptiometry of the distal and proximal forearm. The rate of bone loss was nearly linear the first 6 years both before and after the menopause. At the menopause, the mean rate increased more than 3-fold. The postmenopausal rate of bone loss in the forearm demonstrated an inter-individual normal distribution with a range from 1% to 6% per year. This prospective study suggests that the menopause, and not age per se determines the start of a period with increased rate of bone loss from the appendicular skeleton. As this rate varies considerably between women, estimation of early postmenopausal rate of bone loss will be of importance when advising women concerning prophylactic treatment against osteoporosis.

Development and evaluation of an index to predict early postmenopausal bone loss.

An index to predict individual postmenopausal bone loss is presented. The index is developed by means of data from a 10-year prospective Norwegian study in which bone mass of the distal forearm was measured annually in 73 women. All the women were 47 years old and premenopausal at inclusion. Independent risk factors for postmenopausal bone loss were identified by applying multivariate regression analysis on anthropometric, biochemical, nutritional, and life-style variables measured at menopause. The analysis identified low body weight, reduced renal phosphate reabsorption, and smoking as significant independent risk factors, and by means of these three factors a predictive index for postmenopausal bone loss was developed. This index was validated by using data from a 10-year longitudinal Dutch study, in which bone mass of the proximal radius was measured annually in 86 women, aged between 49 and 57 years and perimenopausal at inclusion. We defined women with the highest index score as "high-risk persons." According to this definition approximately 25% of the perimenopausal women were classified as high-risk persons, and the estimated sensitivity/specificity/positive predictive power were 36%, 89%, and 74%, respectively, when used to select women with a postmenopausal bone loss above average. We conclude that the index may be helpful in identifying healthy perimenopausal women in whom bone mass measurements should be considered.

Incidence of hip fracture in Oslo, Norway: differences within the city.

Oslo, Norway has the highest incidence of hip fractures ever reported. There are great differences in life expectancy between city regions in Oslo, and we investigated if there were any differences in incidence of hip fracture within the city. In 1989, all new fractures of the proximal femur in Oslo residents 50 years or older were registered with each patient's address. Patients in nursing homes were registered according to preadmission address. All were localized to one of six city regions. The incidence of fracture of the total population of Oslo in 1 year age groups was projected on the population of the city regions to calculate the expected number of fractures compared with all of Oslo. The ratio between observed and expected number of fractures was calculated for each city region. The rural county of Sogn og Fjordane (S&F) has only two thirds the incidence of hip fractures compared with Oslo, and life expectancy is longer for both genders compared to Oslo. New hip fractures in 1989 were registered in S&F as in Oslo, and the ratio between observed and expected number of fractures calculated as for Oslo city regions. There were 1029 new fractures in Oslo women, and 284 in men. The relative risk (RR) for Oslo city regions using Inner Oslo West as the reference, showed significantly higher RRs for hip fracture in Inner Oslo East in women (1.23, 95% confidence interval 1.03-1.48) and in Inner and Outer Oslo East in men (1.67, 95% confidence interval 1.14-2.24; 1.45, 95% confidence interval 1.00-2.11, respectively). The risk in S&F compared with Inner Oslo West was significantly lower for women, but not for men (RR 0.74, 95% confidence interval 0.60-0.92; RR 0.82, 95% confidence interval 0.56-1.21, respectively). There were differences in annual incidence of hip fractures between different city regions in Oslo for both women and men, and the incidences were higher than in the rural county of S&F.

Osteoporosis in the Norwegian moose.

In the last decade, an increased frequency of fractures among wild moose in the southernmost parts of Norway has been reported. This study focuses on bone mass, mechanical strength, and metal levels in the metacarpal bone of moose hunted in Aust-Agder (AA) County in southern Norway compared with control areas (CA) in more eastern and northern parts. Metacarpal bone with soft tissue from 106 AA and 37 CA animals were excised after hunting. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA) at the proximal joint (trabecular bone tissue) and 100 mm distally (cortical bone tissue). Both accuracy and reproducibility of the method in these large bones were tested. Biomechanical strength was carried out using a three point bending test in bones from nine AA and eight CA animals of the same age. Metal concentrations in bone tissue were determined by atomic absorption spectrophotometry (GF-AAS) and atomic emission spectrometry (ICP-AAS). BMD of the proximal region was 1.58 +/- 0.39 g/cm(2) (mean +/- SD) for AA, 1.88 +/- 0.58 g/cm(2) (p < 0.01) for CA, 2.08 +/- 0.36 g/cm(2) for distal AA, and 2.16 +/- 0.48 (not significant) for distal CA. In analysis of covariance (ANCOVA) tests with age and region as factors, together with weight as cofactor, there were significant effects on BMD in both the proximal and distal areas for all factors. The bending strength of metacarpal bone was 9378 +/- 1814 N and 16,707 +/- 3065 N (p < 0.01) in AA and CA animals, respectively. There was no differences in element content except for the concentration of lead, where the mean value for AA animals was 1.5 +/- 0.8 mg/kg and CA 0.4 +/- 0.3 mg/kg (p < 0.01). In conclusion, the animals from the southern part of Norway had lower bone mass, decreased mechanical strength, and an increased bone concentration of lead.

Secular increase and geographical differences in hip fracture incidence in Norway.

In 1988 and 1989, 2790 hip fractures were reported from the urban population of Oslo (annual incidence per 10,000 in the age group 50 years and older: women 118.7, men 45.4). For the same period, 385 fractures were reported from the rural population of the county Sogn og Fjordane (annual incidence per 10,000 in the age-group 50 years and older: women 74.6, men 36.7). The hip fracture incidence in Oslo had increased for all sex and age groups above 50 years (except women 50-59 years) in the 10-year period 1978/79 to 1988/89. The incidence of hip fractures in Sogn og Fjordane was only 65% of the incidence in Oslo. These results support previous reports on a secular increase and geographical differences in hip fracture incidence.