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Biomedical subjects

Jan A Falch

Publications and source records attributed to Jan A Falch.

14 recordsLinked to original sources
PubMed2006

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.

Acid Phosphatase↗
PubMed2005

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.

Absorptiometry, Photon↗
PubMed2005

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.

Adult↗
PubMed2004

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.

Absorptiometry, Photon↗
PubMed2004

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.

Absorptiometry, Photon↗
PubMed2004

Vertebral deformities in rheumatoid arthritis: a comparison with population-based controls.

BACKGROUND: Previous studies have shown an increased prevalence of osteoporosis in rheumatoid arthritis (RA), but the extent of osteoporotic fractures is not clarified. The aim of this study was to compare the prevalence of vertebral deformities in a representative, population-based cohort of female patients with RA with that in matched controls, and to examine the relationship between deformities and RA, bone mineral density (BMD), and corticosteroid use. METHODS: Female patients (mean age, 63.0 years; range, 50.7-73.6 years) were recruited from a county register of patients with RA. Population controls were matched for age, sex, and residential area. Participants had thoracolumbar radiographs taken according to a standardized procedure, and BMD was measured at the hip and spine (L2-L4). RESULTS: The overall number of vertebral deformities was substantially higher in the RA group compared with controls (147 vs 51, applying the morphometric criteria), with a highly significant difference between patients and controls regarding the presence of multiple deformities measured morphometrically (11.2% vs 4.8%; odds ratio, 2.60; 95% confidence interval, 1.21-6.04) and moderate or severe deformities measured semiquantitatively (17.3% vs 10.0%; odds ratio, 2.00; 95% confidence interval, 1.11-3.74). In Poisson regression analysis, vertebral deformities were independently associated with RA, BMD, and long-term corticosteroid use. CONCLUSIONS: Vertebral deformities are markedly increased in patients with RA compared with controls, especially regarding severe and multiple deformities. A diagnosis of RA was associated with vertebral deformities independently of BMD and long-term corticosteroid use. These findings have important implications for prevention of established osteoporosis in RA.

Aged↗
PubMed2004

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.

Adult↗
PubMed2003

[Increased cortisol levels, frostbite and effects on the muscles and skeleton during extreme polar conditions].

BACKGROUND: We wanted to record physiological changes, injuries and illnesses during a long sledge expedition in North Canada. MATERIAL AND METHODS: The expedition consisted of four men aged 41 to 50, and 16 polar dogs. Measurements of cortisol in saliva were performed before, during and after the expedition. Frostbites and other injuries were registered continuously. Body weight and muscle, fat and bone mass were measured by dual X-ray absorptiometry scanning, and strength and endurance of shoulders, knees and back were tested. The group encountered extreme frost (-30 to -42 degrees C day temperature), wind, unexpected amounts of pack ice, and poorly motivated dogs. RESULTS AND INTERPRETATION: The participants showed increased free cortisol levels during their stay on the ice, probably because of increased mental stress. Three got first degree and two second-degree frostbites, but the affected areas were normal on vascular examination five months later. All members increased their muscle mass, but muscle strength and endurance remained unchanged.

Absorptiometry, Photon↗
PubMed2003

[Pain, functional level and emotional problems of women with osteoporosis and vertebral fractures].

We studied symptoms of pain, anxiety, and depression and physical function in postmenopausal women with low bone mass and vertebral fractures. One hundred patients attending an out-patient clinic for osteoporosis completed a visual analogue scale (VAS) for pain, the Hospital Anxiety Depression Scale (HADS) and Short Form (SF-12). Twenty patients also completed the osteoporosis specific form QUALEFFO, and were compared to a control group. Maximal pain (VAS) during the last week was 5.3 +/- 2.8. Based on HADS, the prevalence of anxiety disorder (29 %) was significantly higher among the patients than in the norm material; for depression, however, there was no difference. For SF-12, the standardized physical component summary (PCS) was significantly lower than norm data. No difference was found for the mental component summary (MCS). Using QUALEFFO, patients reported a worse score for all domains except the mental domain. We conclude that Norwegian women with vertebral fractures sustain a high level of pain probably leading to an increased level of anxiety, but not to increased level of depression compared to age-adjusted norm data.

Aged↗
PubMed2003

Vertebral deformities in 229 female patients with rheumatoid arthritis: associations with clinical variables and bone mineral density.

OBJECTIVE: To examine the occurrence of vertebral deformities in female patients with rheumatoid arthritis (RA), and the relationship between vertebral deformities and bone mineral density (BMD) and between vertebral deformities and clinical variables. METHODS: Lateral radiographs of the spine were obtained in 229 female patients with RA (mean age 63.4 years, range 51.4-73.6 years) recruited from a county RA register. Vertebral deformities were measured semiquantitatively by an experienced radiologist. A clinical examination including core measurements of disease activity and severity was performed, and BMD was measured at the spine (L2-L4) and hip. RESULTS: According to the statistical analysis, 49 patients were considered to have relevant vertebral deformities. The occurrence of vertebral deformities was independently associated with age, long-term corticosteroid use, and previous nonvertebral fracture, as well as reduced BMD. Our results failed to show any independent relationship between vertebral deformities and the activity or severity of disease. CONCLUSION: Corticosteroid use is an important marker of established osteoporosis in patients with RA. Additionally, there seems to be a consistent relationship between BMD and vertebral deformities in this patient group.

Adrenal Cortex Hormones↗
PubMed2002

Bone loss in patients with rheumatoid arthritis: results from a population-based cohort of 366 patients followed up for two years.

OBJECTIVE: To evaluate the extent of and risk factors for bone loss in a population-based cohort of patients with rheumatoid arthritis (RA) receiving conventional health care. METHODS: In a longitudinal study, clinical data were collected and bone mineral density (BMD) measurements were performed at baseline and after 2 years. Dual-energy x-ray absorptiometry was used for hip and spine BMD measurements. At baseline, patients received advice about lifestyle adjustments and calcium and vitamin D supplementation; during the followup period they were treated with antirheumatic and bone-sparing drugs, according to clinical judgment. RESULTS: After a mean +/- SD of 2.2 +/- 0.2 years, 366 (298 women, 68 men) of the 488 patients who were examined at baseline were reexamined. At that time, 47.9% were current users of corticosteroids and 37.0% were using antiresorptive drugs (hormone replacement therapy, bisphosphonates, or calcitonin). The mean BMD reduction was -0.64% in the femoral neck, -0.77% in the total hip, and -0.29% in the spine at L2-4. BMD was increased at all measurement sites in current users of antiresorptive drugs (0.16-1.64%) but was decreased in patients using calcium and vitamin D alone (-1.99% to -1.39%) and in patients not using any osteoporosis treatment (-1.20% to -0.43%). Current use of corticosteroids was independently associated with increased risk for BMD loss in the total hip (odds ratio [OR] 2.63, 95% confidence interval [95% CI] 1.38-5.00) and spine at L2-4 (OR 2.70, 95% CI 1.30-5.63), whereas current use of antiresorptive drugs was associated with decreased risk for bone loss in the total hip (OR 0.43, 95% CI 0.20-0.89). CONCLUSION: Results of this population-based, 2-year followup study indicate that adequate management of patients with RA, addressing both the rheumatic disease and osteoporosis, protects against bone loss.

Absorptiometry, Photon↗
PubMed2002

Can vitamin D supplementation reduce the risk of fracture in the elderly? A randomized controlled trial.

Randomized controlled trials have shown that a combination of vitamin D and calcium can prevent fragility fractures in the elderly. Whether this effect is attributed to the combination of vitamin D and calcium or to one of these nutrients alone is not known. We studied if an intervention with 10 microg of vitamin D3 per day could prevent hip fracture and other osteoporotic fractures in a double-blinded randomized controlled trial. Residents from 51 nursing homes were allocated randomly to receive 5 ml of ordinary cod liver oil (n = 569) or 5 ml of cod liver oil where vitamin D was removed (n = 575). During the study period of 2 years, fractures and deaths were registered, and the principal analysis was performed on the intention-to-treat basis. Biochemical markers were measured at baseline and after 1 year in a subsample. Forty-seven persons in the control group and 50 persons in the vitamin D group suffered a hip fracture. The corresponding figures for all nonvertebral fractures were 76 persons (control group) and 69 persons (vitamin D group). There was no difference in the incidence of hip fracture (p = 0.66, log-rank test), or in the incidence of all nonvertebral fractures (p = 0.60, log-rank test) in the vitamin D group compared with the control group. Compared with the control group, persons in the vitamin D group increased their serum 25-hydroxyvitamin D concentration with 22 nmol/liter (p = 0.001). In conclusion, we found that an intervention with 10 microg of vitamin D3 alone produced no fracture-preventing effect in a nursing home population of frail elderly people.

Aged↗