Mortality following the first hip fracture in Norwegian women and men (1999-2008). A NOREPOS study.

Hip fractures are associated with increased mortality and their incidence in Norway is one of the highest worldwide. The aim of this nationwide study was to examine short- and long-term mortality after hip fractures, burden of disease (attributable fraction and potential years of life lost), and time trends in mortality compared to the total Norwegian population. Information on incident hip fractures between 1999 and 2008 in all persons aged 50 years and older was collected from Norwegian hospitals. Death and emigration dates of the hip fracture patients were obtained through 31 December 2010. Standardized mortality ratios (SMRs) were calculated and Poisson regression analyses were used for the estimation of time trends in SMRs. Among the 81,867 patients with a first hip fracture, the 1-year excess mortality was 4.6-fold higher in men, and 2.8-fold higher in women compared to the general population. Although the highest excess mortality was observed during the first two weeks post fracture, the excess risk persisted for twelve years. Mortality rates post hip fracture were higher in men compared to women in all age groups studied. In both genders aged 50 years and older, approximately 5% of the total mortality in the population was related to hip fractures. The largest proportion of the potential life-years lost was in the relatively young-old, i.e. less than 80 years. In men, the 1-year absolute mortality rates post hip fracture declined significantly between 1999 and 2008, by contrast, the mortality in women increased significantly relatively to the population mortality.

Spinal deformities and lung function in adults with osteogenesis imperfecta.

INTRODUCTION: There are no larger studies of adults with osteogenesis imperfecta (OI), focusing on the impact of spinal cord deformities on lung function assessment. OBJECTIVES: To assess prevalence and severity of spinal deformities and lung function in an adult population with OI and to explore whether compromise of lung function correlated with deformities of the spine. METHODS: Ninety-two adults with OI had radiographs of the spine, 75 underwent spirometry. Deformities were assessed radiographically using a semi-quantitative (SQ) approach grading each vertebra from mild to severe (0-3 SQ grades). The spinal deformity index (SDI) was calculated by summing the SQ grades of all vertebrae from TH4 to L4. Scoliosis was measured using the Cobb method. Pulmonary function tests were performed; both current measured and arm-span height were used for calculating the predicted lung volumes and flow rates. RESULTS: Vertebral deformities were found in 67%, the majority of deformities were found in the mid thoracic region. Scoliosis was found in 46%, nine patients exhibited torsion scoliosis. Median values of SDI were 2.0 in type I, 4.0 in type IV and 2.5 in the total population. Only correction with arm-span height had a significant impact on the assessment of lung function. Significant negative correlations were obtained when spirometry variables were correlated to spine deformities. CONCLUSIONS: OI patients show spinal deformities influencing body height and lung function. Lung function tests should be corrected for reductions in body height by using arm-span height. OI patients should be evaluated with spirometry when vertebral deformities are suspected.

Secular reduction of excess mortality in hip fracture patients >85 years.

BACKGROUND: More than 20% of the hip fracture patients die within the first year after the incident. Few data are available on the trends in mortality following a hip fracture. The present aim was to study changes in excess mortality after hip fracture from 1978/79 up to 1996/97. METHODS: Data on 5180 hip fracture patients aged ≥ 50 years, identified in three earlier, well validated, incidence studies from Oslo were used. The studies took place in the two years periods 1978-79 and 1989-89 and in a one year period from 1st of May 1996 to 30th of April 1997. The study was designed as a historic cohort study. Exposure was sustaining a hip fracture in the registration periods. Outcome was death of all causes. Age- and sex-specific one year-mortality rates were provided by Statistics Norway. Standardized mortality ratios (SMR) were calculated for the three cohorts for each sex and age-group, for the 0-6 months, 6-12 months, 0-1 year, 1-5 years and 5-10 years intervals after fracture. To assess the duration of the excess mortality in hip fracture patients, time-framed Kaplan-Meier curves for consecutive 5-years intervals were conducted for the hip fracture patients and the corresponding background population. Only patients still alive at the start of the time interval were included. One sample log rank tests were used to test for statistical significance. RESULTS: The one-year SMR ranged from 3.64 (2.82 - 4.61) to 4.53 (3.67 - 5.54) in men and from 2.78 (2.39 - 3.19) to 3.60 (3.19 - 4.05) in women. In the 0-6 months interval a reduction in SMR from 1978/79 to 1996/97 was observed in women aged ≥85 years. The duration of excess mortality ranged from two years in men ≥85 years to more than ten years in men and women aged 65-84 years. CONCLUSION: Excess mortality among hip fracture patients remains high. Over the decades, a reduced excess mortality was mainly seen in the oldest patients, suggesting that specific efforts intending to improve prevention and treatment of osteoporosis and osteoporotic fractures in the youngest elderly are required.

Influence of socioeconomic factors on the adherence of alendronate treatment in incident users in Norway.

PURPOSE: To examine whether socioeconomic factors influence adherence to alendronate drug treatment among incident users in Norway during 2005-2009. METHODS: The study included 7610 incident alendronate users in 2005 (40-79 years), followed until 31 December 2009. Mean age was 66.6 years, and 86.7% of the patients were women. Data were drawn from the Norwegian Prescription Database and linked to marital status, education and income. Adherence was measured by the medication possession ratio (MPR). MPR was defined as the number of dispensed defined daily doses divided by the number of days each patient was included in the study. A patient was adherent if MPR ≥ 80%. ORs with 95%CI were estimated using logistic regression. RESULTS: Among all patients, 45.5% was adherent throughout 4.2 years. A slightly higher proportion of women than men were adherent. Adjusted for all covariates, women aged 70-79 years had an OR of 1.27 (95%CI 1.10-1.45) for adherence compared with those 40-59 years. In women, high household income predicted adherence of alendronate use. In men, a middle educational level compared with a low level, predicted adherence (adjusted OR = 1.47 (95%CI 1.10-1.96)). After adjustments, previous marriage reduced the odds of being adherent compared with present marriage, in both men and women. CONCLUSIONS: In women, the most important factors for being adherent were high age and high income. In men, a middle educational level predicted adherence. Previous marriage reduced the odds of being adherent in both women and men.

Bone mass, bone markers and prevalence of fractures in adults with osteogenesis imperfecta.

UNLABELLED: Still little is known about the manifestations of osteogenesis imperfecta (OI) in adults. We therefore initiated this study of bone mass, bone turnover and prevalence of fractures in a large cohort of adult patients. We found a surprising low prevalence (10%) of osteoporosis. These patients, however, expressed the most severe disease. PURPOSE: To characterize bone mineral density, bone turnover, calcium metabolism and prevalence of fractures in a large cohort of adults with osteogenesis imperfecta. METHODS: One hundred fifty-four patients with adult OI participated and 90 (age range 25-83) provided dual X-ray absorptiometry (DXA) measurements. According to Sillence classification criteria, 68 persons were classified as OI type I, 9 as type III, 11 type IV and 2 were unclassified. Fracture numbers were based on self-reporting. Biochemical markers of bone turnover were measured and bone mineral density (BMD) of the spine, femoral neck and total body were determined by DXA. RESULTS: Only 10% of adults with OI exhibited osteoporotic T scores (T ≤ -2.5) but compared to patients with normal T scores this subgroup had a threefold higher fracture risk (22 vs. 69). s-PTH, s-Ca and 25[OH] vitamin D were all normal. Bone markers did not display major deviations from normal, but patients with OI type III displayed higher resorption marker levels than type I and IV. Multivariate regression analysis showed that only gender and total body BMD were significant determinants of fracture susceptibility, and the differences for total body BMC, BMD and Z scores were significant between the OI subtypes. CONCLUSIONS: In adult OI, DXA measurements only identified few patients as osteoporotic. These patients, however, exhibited a much higher fracture propensity. Due to deformities, low body height and pre-existing fractures, DXA assessment is complicated in this disease, and further studies are needed to work out how to minimize the impact of these confounders.

A population-based study of demographical variables and ability to perform activities of daily living in adults with osteogenesis imperfecta.

PURPOSES: To describe demographical variables, and to study functional ability to perform activities of daily life in adults with osteogenesis imperfecta (OI). METHODS: Population-based study. Ninety-seven patients aged 25 years and older, 41 men and 56 women, were included. For the demographical variables, comparison was made to a matched control-group (475 persons) from the Norwegian general population. Structured interviews concerning social conditions, employment and educational issues and clinical examination were performed. The Sunnaas Activities of Daily Living (ADL) Index was used to assess the ability to perform ADL. RESULTS: The prevalence of clinical manifestations according to Sillence was in accordance with other studies. Demographical variables showed that most adults with OI are married and have children. They had a higher educational level than the control group, but the employment rate was significantly lower. However, the rate of employed men was similar in both groups. Adult persons with OI achieved a high score when tested for ADL. CONCLUSIONS: Adults with OI are well educated compared with the general population, and most of them are employed. High scores when tested for ADL indicate that most of them are able to live their lives independently, even though there are some differences according to the severity of the disorder.

Prescription of anti-osteoporosis drugs during 2004-2007-a nationwide register study in Norway.

PURPOSE: To assess 1-year prevalence, incidence rates and minimum refill of anti-osteoporosis drug use in Norway by age, gender and place of residence during 2004-2007. METHODS: Data from patients aged > or = 40 years receiving anti-osteoporosis drugs (AOD) were retrieved from the Norwegian Prescription Database (NorPD). AOD were defined as bisphosphonates (alendronate with or without cholecalciferol, risedronate, ibandronate and etidronate with or without calcium), raloxifene, teriparatide and nasal calcitonin. The NorPD covers the total Norwegian population in ambulatory care. Key measurements were 1-year prevalence, incidence rate and minimum refill. RESULTS: Among Norwegian women and men > or = 40 years, 4.3 and 0.45% respectively used AOD in 2004. In 2007, the prevalence of AOD use had slightly increased to 4.6% in women and to 0.52% in men. In 2007, 90% of users were women. The use of alendronate, representing 88% of all AOD use in 2007, increased from 2004 to 2007 while the use of other bisphosphonates decreased. The counties with highest overall bisphosphonate use were the counties with the historically lowest incidence of osteoporotic fractures. The incidence rate of overall bisphosphonate use decreased from 2005 to 2007. Among those patients who were dispensed a bisphosphonate in 2005, 72% refilled at least one prescription both in 2006 and 2007. CONCLUSION: There was an increasing prevalence and a decreasing incidence of AOD use over this limited time period. There was substantial geographical variation in the prevalence of anti-osteoporosis drugs. We also observed a high minimum refill rate.

Glucocorticoid replacement therapy and pharmacogenetics in Addison's disease: effects on bone.

UNLABELLED: Context Patients with primary adrenal insufficiency (Addison's disease) receive more glucococorticoids than the normal endogenous production, raising concern about adverse effects on bone. OBJECTIVE: To determine i) the effects of glucocorticoid replacement therapy on bone, and ii) the impact of glucocorticoid pharmacogenetics. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional study of two large Addison's cohorts from Norway (n=187) and from UK and New Zealand (n=105). MAIN OUTCOME MEASURES: Bone mineral density (BMD) was measured; the Z-scores represent comparison with a reference population. Blood samples from 187 Norwegian patients were analysed for bone markers and common polymorphisms in genes that have been associated with glucocorticoid sensitivity. RESULTS: Femoral neck BMD Z-scores were significantly reduced in the patients (Norway: mean -0.28 (95% confidence intervals (CI) -0.42, -0.16); UK and New Zealand: -0.21 (95% CI -0.36, -0.06)). Lumbar spine Z-scores were reduced (Norway: -0.17 (-0.36, +0.01); UK and New Zealand: -0.57 (-0.78, -0.37)), and significantly lower in males compared with females (P=0.02). The common P-glycoprotein (ABCB1) polymorphism C3435T was significantly associated with total BMD (CC and CT>TT P=0.015), with a similar trend at the hip and spine. CONCLUSIONS: BMD at the femoral neck and lumbar spine is reduced in Addison's disease, indicating undesirable effects of the replacement therapy. The findings lend support to the recommendations that 15-25 mg hydrocortisone daily is more appropriate than the higher conventional doses. A common polymorphism in the efflux transporter P-glycoprotein is associated with reduced bone mass and might confer susceptibility to glucocorticoid induced osteoporosis.

Weight change over three decades and the risk of osteoporosis in men: the Norwegian Epidemiological Osteoporosis Studies (NOREPOS).

The purpose of this study was to assess the effect of weight in middle-aged men and subsequent weight change on the risk of osteoporosis three decades later. The authors utilized data from 1,476 Norwegian men participating in two health screenings in Oslo (1972-1973 and 2000-2001) and Tromsø (1974-1975 and 2001). Height and weight were measured at baseline and follow-up. Total hip bone mineral density (BMD) was assessed at follow-up by dual energy x-ray absorptiometry. Baseline body mass index (BMI) was positively related to BMD three decades later. Subsequent weight change was also strongly related to BMD, and the proportion of persons with osteoporosis decreased from 15.1% among those who lost >or=10% of their body weight to 0.6% among those who gained >or=10% of their body weight. Excluding participants with medical conditions did not change the association between weight change and BMD. Taking both BMI and weight change into account, the prevalence of osteoporosis in the lowest quarter of baseline BMI was 31% (95% confidence interval: 24, 37) in persons losing >or=5% of their weight and 4% (95% confidence interval: 1, 7) in persons gaining >or=5% of their weight. In this cohort of middle-aged men, low baseline BMI and weight loss during the following three decades were both strongly and negatively related to total hip BMD.

In vivo and in vitro comparison of densitometers in the NOREPOS study.

The purpose of this study was to assess the agreement of in vivo hip scans on 3 densitometers (1 GE Lunar DPX-IQ and 2 GE Lunar Prodigy scanners) and to evaluate whether the European Spine Phantom (ESP) was able to reproduce the in vivo variability. Sixteen subjects had 3 repeated scans (with repositioning) on each densitometer, and the ESP was measured on each densitometer at least 40 times. Mean differences between hip scans on the Prodigy scanners were small and insignificant, and the in vivo results were not significantly different from the in vitro results. Bland and Altman plots showed no systematic differences between the Prodigy scanners over the range of bone mineral density (BMD). On the other hand, differences between Prodigy and DPX-IQ changed systematically over the range of BMD. The ESP did not fully reproduce the in vivo difference between Prodigy and DPX-IQ. In conclusion, the ESP is a valid substitute when assessing agreement between Prodigy scanners. However, when assessing agreement between different types of scanners, substitution of in vivo with in vitro measurements should be made with caution.

The Oslo Health Study: Is bone mineral density higher in affluent areas?

BACKGROUND: Based on previously reported differences in fracture incidence in the socioeconomic less affluent Oslo East compared to the more privileged West, our aim was to study bone mineral density (BMD) in the same socioeconomic areas in Oslo. We also wanted to study whether possible associations were explained by socio-demographic factors, level of education or lifestyle factors. METHODS: Distal forearm BMD was measured in random samples of the participants in The Oslo Health Study by single energy x-ray absorptiometry (SXA). 578 men and 702 women born in Norway in the age-groups 40/45, 60 and 75 years were included in the analyses. Socioeconomic regions, based on a social index dividing Oslo in two regions - East and West, were used. RESULTS: Age-adjusted mean BMD in women living in the less affluent Eastern region was 0.405 g/cm2 and significantly lower than in West where BMD was 0.419 g/cm2. Similarly, the odds ratio of low BMD (Z-score

Pakistanis living in Oslo have lower serum 1,25-dihydroxyvitamin D levels but higher serum ionized calcium levels compared with ethnic Norwegians. The Oslo Health Study.

BACKGROUND: Persons of Pakistani origin living in Oslo have a much higher prevalence of vitamin D deficiency and secondary hyperparathyroidism but similar bone mineral density compared with ethnic Norwegians. Our objective was to investigate whether Pakistani immigrants living in Oslo have an altered vitamin D metabolism by means of compensatory higher serum levels of 1,25-dihydroxyvitamin D (s-1,25(OH)2D) compared with ethnic Norwegians; and whether serum levels of ionized calcium (s-Ca2+) differ between Pakistanis and Norwegians. METHODS: In a cross-sectional, population-based study venous serum samples were drawn from 94 Pakistani men and 67 Pakistani women aged 30-60 years, and 290 Norwegian men and 270 Norwegian women aged 45-60 years; in total 721 subjects. RESULTS: Pakistanis had lower s-1,25(OH)2D compared with Norwegians (p < 0.001). Age- and gender adjusted mean (95% CI) levels were 93 (86, 99) pmol/l in Pakistanis and 123 (120, 126) pmol/l in Norwegians, p < 0.001. The difference persisted after controlling for body mass index. There was a positive relation between serum 25-hydroxyvitamin D (s-25(OH)D) and s-1,25(OH)2D in both groups. S-Ca2+ was higher in Pakistanis; age-adjusted mean (95% CI) levels were 1.28 (1.27, 1.28) mmol/l in Pakistanis and 1.26 (1.26, 1.26) mmol/l in Norwegians, p < 0.001. In both groups, s-Ca2+ was inversely correlated to serum intact parathyroid hormone levels (s-iPTH). For any s-iPTH, s-Ca2+ was higher in Pakistanis, also when controlling for age. CONCLUSION: Community-dwelling Pakistanis in Oslo with low vitamin D status and secondary hyperparathyroidism have lower s-1,25(OH)2D compared with ethnic Norwegians. However, the Pakistanis have higher s-Ca2+. The cause of the higher s-Ca2+ in Pakistanis in spite of their higher iPTH remains unclear.

Biochemical markers of bone turnover and their relation to forearm bone mineral density in persons of Pakistani and Norwegian background living in Oslo, Norway: The Oslo Health Study.

OBJECTIVE: To evaluate whether Pakistanis have increased bone turnover compared with ethnic Norwegians due to their high prevalence of vitamin D deficiency and secondary hyperparathyroidism, and whether the relation between bone turnover and bone mineral density (BMD) differs between Pakistanis and ethnic Norwegians. DESIGN: A cross-sectional, population-based study conducted in the city of Oslo in 2000-2001. Random samples of 132 community-dwelling Pakistani men and women of ages 40, 45, and 59-60 years, and 580 community-dwelling Norwegian men and women of ages 45 and 59-60 years are included in this substudy. METHODS: Venous serum samples were drawn for measurements of markers of the vitamin D endocrine system and the bone turnover markers osteocalcin (s-OC), bone alkaline phosphatase (s-bone ALP), and tartrate-resistant acid phosphatase (s-TRACP). BMD was measured at the forearm by single-energy X-ray absorptiometry. RESULTS: Pakistanis had higher s-bone ALP compared with Norwegians. Mean (95% CI) age-adjusted levels were 22.5 (21.0, 24.1) U/l in Pakistani men versus 19.3 (18.6, 20.1) U/l in Norwegian men, P < 0.0005, and 20.3 (18.4, 22.1) U/l in Pakistani women versus 16.7 (16.0, 17.4) U/l in Norwegian women, P = 0.001. There tended to be an inverse association between bone turnover and BMD in men and women of both ethnic groups, and it was strongest for s-bone ALP. Overall mean (95% CI) distal BMD decrease was -16 (-20, -11) mg/cm(2) per 1 s.d. increase in s-bone ALP (P < 0.0005) when adjusting for age, sex, and ethnicity. CONCLUSIONS: Except for somewhat higher s-bone ALP levels in Pakistanis, there were only minor ethnic differences in bone turnover, despite a strikingly different prevalence of secondary hyperparathyroidism. Bone turnover was inversely associated with forearm BMD in both ethnic groups.

Differences in stability and bone remodeling between a customized uncemented hydroxyapatite coated and a standard cemented femoral stem A randomized study with use of radiostereometry and bone densitometry.

The custom made Unique stem is designed to fit closely to the metaphyseal region of the femur in order to obtain maximum mechanical stability and optimal load transfer. Thirty-seven patients (38 hips) with non-inflammatory arthritis were randomized to the uncemented custom made Unique stem or the Elite Plus stem inserted with cement. The patients have been followed clinically as well as with radiostereometry (RSA) and Dual-energy X-ray Absorptiometry (DXA) for 2 years. After 2 years the RSA result showed minimal translation and rotation for the Unique stem while the Elite Plus rotated slightly (mean 1.05 degrees) into retroversion. Compared to previous studies the Elite Plus was as stable as the Charnley prosthesis. The DXA results showed a significantly higher proximal and total (10% for the Unique versus 5% for Elite) bone loss for the Unique stem compared to the Elite Plus. Thus the optimal proximal press-fit of the custom made stem did secure a stable fixation, but did not decrease the proximal bone loss.

Tetraplegic subjects have hyperleptinaemia with marked circadian variation.

OBJECTIVE: The disruption between the brain and the spinal cord leads to a decentralized sympathetic nervous system in people with chronic, cervical spinal cord lesions. These tetraplegic subjects are prone to disorders of energy metabolism and osteoporosis, and they experience alterations in their body composition with a relative accumulation of fat. The adipocyte-derived cytokine leptin is a key signal in caloric intake and energy expenditure, and it might modify bone remodelling, possibly regulated by sympathetic neuronal signalling. In able-bodied subjects leptin exhibits circadian variations, possibly mediated via sympathetic neurones. We have examined the plasma concentration of leptin among tetraplegics, to determine whether plasma leptin in these subjects exhibits circadian variations. MEASUREMENTS AND RESULTS: Blood samples were collected during a 24-h study period from tetraplegic subjects (n = 6) and from able-bodied controls (n = 8). Fasting, tetraplegic subjects had mean plasma concentrations of leptin about four times those of able-bodied controls (P < 0.05). In tetraplegia, plasma leptin was negatively correlated with total lean mass (r =-0.88, P < 0.05) but correlated positively with total fat mass (r = 0.89, P < 0.05). A marked circadian variation in plasma leptin concentrations was more evident in tetraplegia than in able-bodied controls. CONCLUSION: Plasma leptin is markedly elevated and it shows more prominent circadian variations in tetraplegia compared with able-bodied subjects. Possibly the regulation of leptin metabolism is impaired among these patients. This might distort thermogenesis and energy expenditure, thus explaining the enhanced risk of the metabolic syndrome and of osteoporosis among tetraplegic subjects.

Incidence of vertebral deformities in 255 female rheumatoid arthritis patients measured by morphometric X-ray absorptiometry.

To date, no studies have been published on incident deformities in patients with rheumatoid arthritis (RA). Morphometric X-ray absorptiometry (MXA) is an alternative to conventional X-rays for identifying vertebral deformities. The aim of the present study was to describe the incidence of vertebral deformities in 255 female RA patients measured by MXA, and the relationship between incident deformities and clinical and demographic variables. MXA is still under evaluation for its ability to identify deformities, so we explored four different cut-off thresholds including fixed percentage reduction and the principle of least significant change (LSC). MXA (T4-L4) and BMD (L2-L4 and total hip; Lunar Expert) were performed on 255 patients (mean age 54.3, range 29.2-70.8 years) at baseline and after a mean period of 2.3 years. MXA scans were analyzed pairwise by the same trained technician, and incident deformities calculated applying LSC with a 99.9% and 99.99% confidence limit, and a fixed reduction of 20% and 25% for anterior, middle or posterior heights. Long term precision (%CV) of height measurements for all vertebrae combined (T4-L4) were 4.8, 4.8 and 4.4, respectively. Frequency and distribution of incident deformities varied from 39 deformities in 33 patients (fixed 20% reduction) to 17 deformities in 15 patients (fixed 25% reduction), and quality control analyses revealed a high number of presumed false deformities. Incidence per 100 patient years varied from 2.9 to 6.7 deformities according to method, and was comparable to those obtained from intervention studies in corticosteroid-induced osteoporosis. Patients with incident deformities were significantly older, had lower BMD, higher disability and more often a previous non-vertebral fractures than those without incident deformities Incident deformities by MXA need further evaluation in secondary osteoporosis. It seems, however, that older patients with previous limb fractures and low BMD are especially prone to this complication.

Bone mineral density in ethnic Norwegians and Pakistani immigrants living in Oslo--The Oslo Health Study.

Bone mineral density (BMD, grams per square centimeter) is scarcely studied in immigrants from the Indian subcontinent. Pakistani immigrants in Oslo, Norway, have a very high prevalence of vitamin D deficiency. Thus, it is of great interest to compare BMD between Pakistani immigrants and ethnic Norwegians in Oslo. The comparison was done with and without adjustment for skeletal size, and we examined whether known risk factors explained possible differences in bone density between these two ethnic groups. BMD was measured at the distal and ultra-distal forearm site in a random sample of the participants in the Oslo Health Study by single energy X-ray absorptiometry (SXA). One hundred and seventy-three Pakistani-born subjects (71 women, 102 men) and 1,386 Norwegian-born subjects (675 women, 711 men) aged 30, 40, 45 and 59/60 years, living in Oslo, were included in the analysis. To account for variation in skeletal size, we computed height-adjusted BMD values, BMD/height (grams per cubic centimeter), and volumetric bone mineral apparent density (BMAD, grams per cubic centimeter). We found no differences in distal or ultra-distal forearm BMD between Pakistanis and Norwegians in either women or men. We found, however, higher values in Pakistani men when BMD was height-adjusted (2% higher in distal sites and 5% in ultra-distal sites). We also found higher bone mass values (both distal and ultra-distal) in Pakistani women and men than in their Norwegian counterparts when volumetric measures, such as BMD/height (7%-8% higher in women, 6%-7% in men) and BMAD (6% higher in women, 8% in men), were used. In a regression model that included ethnicity, anthropometry and lifestyle factors, BMD was higher in Pakistani men than in Norwegian men, but not in women. We conclude that Pakistanis living in Oslo have similar BMD to ethnic Norwegians, but they have higher volumetric bone mass values. When we adjusted for confounders we found higher BMD values in Pakistani men than in Norwegian men.

Vitamin D deficiency and secondary hyperparathyroidism and the association with bone mineral density in persons with Pakistani and Norwegian background living in Oslo, Norway, The Oslo Health Study.

We studied the prevalence of poor vitamin D status and the association with bone density in men and women born in Norway (quoted as Norwegians, n = 869) and Pakistan (quoted as Pakistanis, n = 177) in the population-based Oslo Health Study, 2000-2001. We measured 25-hydroxyvitamin D, iPTH and ionized calcium in serum and bone mineral density at the forearm site with single energy X-ray absorptiometry. Mean 25-hydroxyvitamin D was 74.8 +/- 23.7 nmol/l in the Norwegians and 25.0 +/- 13.6 nmol/l in the Pakistanis (P = 0.000). The prevalence of secondary hyperparathyroidism (iPTH > or = 8.5 pmol/l, 25-hydroxyvitamin D < 50 nmol/l and Ca2+ < or = 1.35 mmol/l) was four times higher in Pakistani compared to Norwegian women. Also in Pakistani men, serious vitamin D deficiency defined as secondary hyperparathyroidism was prevalent, and five times as frequent as in Norwegian men. However, whereas BMD was significantly lower in Norwegian women with, compared to Norwegian women without, secondary hyperparathyroidism, there was no difference in BMD between Pakistani women with and without secondary hyperparathyroidism. In conclusion, vitamin D deficiency was prevalent among Pakistani immigrants, and in great contrast to the vitamin D replete Norwegians. Serious vitamin D deficiency was interestingly not associated with reduced forearm bone density among Pakistani women.