Biomedical subjects

L Mosekilde

Publications and source records attributed to L Mosekilde.

At least 109 records · Page 6Linked to original sources

PubMed1999

Primary hyperparathyroidism: effect of parathyroidectomy on regional bone mineral density in Danish patients: a three-year follow-up study.

Changes in skeletal remodeling (biochemical bone markers) and regional bone mineral density (spine, hip, and forearm bone mineral density [BMD]) were observed for 3 years in 20 patients (15 women and 5 men; age 54 +/- 11 years, range 29-69 years) after successful surgery for primary hyperparathyroidism (PHPT). Fifteen PHPT patients were compared with 15 normal controls who were exactly matched with respect to age, gender, and menopausal status (10 women and 5 men; age 53 +/- 12 years, range 29-65 years [PHPT] and 29-66 years [controls]). All bone markers (serum osteocalcin, bone alkaline phosphatase, and type I collagen telopeptide [ICTP], and urinary hydroxyproline and NTx/creatinine ratio) declined significantly and reached normal levels within 6 months. No major changes took place during the remaining 2.5 years, apart from urine hydroxyproline, which disclosed a small peak around 12 months with a further decline towards study end (p < 0.05). Bone mineral density increased significantly in all regions (p < 0.001). At all locations, except the intertrochanteric region of the hip, the increase continued from 6 months until study end (p < 0.05). The increase in BMD was unequally distributed among regions (p < 0.001). The increase at the proximal forearm was less than in the spine (p < 0.05), the trochanteric region of the hip (p < 0.05), and the distal forearm (p < 0.05). No difference in BMD increase was observed between men, and pre- and postmenopausal women. Compared with the matched control group, PHPT patients had significantly lower BMD at baseline in the proximal (p < 0.02) and distal (p < 0.05) forearm. Furthermore, during the 3-year follow-up period, the PHPT patients showed a significant increase in BMD compared with controls in the spine (p < 0.005), the trochanteric and intertrochanteric regions of the hip (p < 0.005 and p < 0.05, respectively), and the distal forearm (p < 0.005). In conclusion, bone remodeling is normalized within the first 6 months after successful parathyroid surgery, with no major changes during the following 2.5 years. Bone mineral density increases at both cancellous and cortical sites, but in predominantly cortical bone, the recovery in BMD is less than in cancellous bone-rich areas.

Adenoma↗

PubMed1999

Primary hyperparathyroidism: whole-body bone mineral density in surgically treated Danish patients: a three-year follow-up study.

Whole-body bone mineral density (BMD) and body composition were measured before surgery in 25 patients (20 women and 5 men, aged 53 +/- 13 years, range 26-73 years) with mild to moderate primary hyperparathyroidism (PHPT) and compared with 25 controls exactly matched with respect to age, gender, and menopausal status. Fifteen pairs of matched patients and controls were reexamined 3 years later (5 men and 10 women, aged 53 +/- 12 years in both groups). In the untreated PHPT patients, whole-body BMD was 95.4% +/- 10.5% (SD) of control BMD (p < 0.05). Body weight and height, body mass index, whole-body fat mass, and lean body mass did not differ significantly between the groups. Relative to values in matched controls, whole-body bone mineral content (BMC) and BMD increased by 4.4% and 3.0%, respectively, in PHPT patients (p < 0.005) during the 3-year follow-up. Neither whole-body BMC nor BMD differed between patients and controls after the 3-year follow-up. A positive correlation was observed between initial serum calcium levels and the 3-year increase in whole-body BMD (r(s) = 0.645, p < 0.01). Baseline serum osteocalcin, serum pyridinoline crosslinked telopeptide of Type I collagen and several histomorphometric indices of trabecular bone turnover (eroded and labeled surfaces, bone formation rate, and activation frequency) also correlated positively with the subsequent increase in whole-body BMD. Six patients disclosed transient postoperative secondary hyperparathyroidism, probably due to hungry bones. Four of these patients completed 3 years of follow-up and had higher increases in whole-body BMD than the remaining normo-parathyroid patients (7.9% +/- 4.5%, range 4.3-14.3% versus 1.9% +/- 2.1%, p < 0.01). It is concluded that Danish patients with mild to moderate PHPT only reveal small reductions in whole-body mineral density. Furthermore, within 3 years after parathyroid surgery, most of the lost bone mineral is regained even in patients with initial high bone turnover. Finally, PHPT in these patients is not associated with substantial changes in body compositions.

Adult↗

PubMed1999

Lumbar vertebral body compressive strength evaluated by dual-energy X-ray absorptiometry, quantitative computed tomography, and ashing.

Bone densitometry with DXA (dual energy X-ray absorptiometry) and QCT (quantitative computed tomography) techniques are used for in vivo assessment of bone strength and thereby prediction of fracture risk. However, only few in vitro studies have investigated and compared these techniques' ability to determine vertebral compressive strength. The aim of the present study was to (1) assess the predictive value of DXA, QCT, and pQCT (peripheral QCT) for vertebral bone compressive strength assessed by mechanical testing; (2) describe both linear and power relationship between density and strength; and (3) evaluate whether gender-related differences in the above relations were present. The material comprised human lumbar vertebrae L3 from 51 women and 50 men (age range: 18 to 96 years). The study showed that both DXA and CT techniques (QCT and pQCT) have a high predictive value for vertebral strength. The DXA BMD had a high correlation with maximum compressive load (r2 = 0.86). The QCT and pQCT had high correlations with maximum compressive stress (r2 = 0.75 and r2 = 0.86, respectively). The correlation between ash density of the biomechanically tested specimen and maximum compressive stress was r2 = 0.88. There were no differences between linear and power fit in the degree of determination between density and strength. There was no gender-related difference in the relationship between volumetric density and maximum compressive stress. In conclusion, it was demonstrated that DXA, QCT, and pQCT are ex situ equally capable of predicting vertebral compressive strength with a degree of determination (r2) between 75% and 86%. No differences were found between linear and power analysis of the relationship between density and strength, and no difference was found in the density strength relationship between women and men.

Absorptiometry, Photon↗

PubMed1999

Fracture risk is increased in epilepsy.

OBJECTIVES: To study fracture rates and risk factors for fractures in non-institutionalized patients with epilepsy. MATERIAL AND METHODS: Historical follow-up. Self-administered questionnaires were issued to 755 patients with epilepsy (ICD 10: G40.0 to G40.9) and 1000 randomly selected controls from the background population. RESULTS: A total of 345 patients (median age: 45, range 17-80 years) and 654 control subjects (median age: 43, range 19-93 years) returned the questionnaire. Before epilepsy was diagnosed there was no difference in overall fracture rate between patients and controls (RR = 1.0, 95% CI: 0.8-1.3). After the diagnosis the overall fracture rate was significantly higher in the patients (RR = 2.0, 95% CI: 1.6-2.5). Fractures of the spine, forearms, femurs, lower legs, and feet and toes were significantly increased. Fractures related to seizures accounted for 33.9% (95% CI: 25.3-43.5%) of all fractures. After elimination of seizure related fractures the increase in fracture frequency was only borderline significant: RR = 1.3 (95% CI: 1.0-1.7, P = 0.042). No difference in fracture energy between patients and controls was observed (low energy fractures: 1.7/1.4%, medium energy fractures: 59.8/52.0%, and high energy fractures: 38.3/46.6%). Use of phenytoin (OR = 2.4, 95% CI: 1.1-5.4) and a family fracture history (OR = 2.4, 95% CI: 1.3-4.6) was associated with an increased fracture risk. CONCLUSIONS: Fractures were more common in epileptics than in controls especially among users of phenytoin. Most of the increase in fracture frequency was related to seizures and not to low bone biomechanical competence.

Adolescent↗

PubMed1999

A histomorphometric and scanning electron microscopy study of human condylar cartilage and bone tissue changes in relation to age.

OBJECTIVES: To determine the possibility for adaptive growth in human condyles, quantifying the thickness of fibrocartilage and the constitution of cells with potential activity, the trabecular bone volume, and the structural parameter: marrow space star volume in a larger sample of human autopsy condyles. EXPERIMENTAL SETTING AND DESIGN: A histomorphometric and scanning electron microscopic analysis of cartilage characteristics and bone remodelling activity. The Departments of Orthodontics and Cell Biology at Aarhus University, Denmark. An autopsy sample of condyles from 20 individuals, 18-31 years of age. Correlation analyses between ages and all parameters were conducted. RESULTS: There was a statistically significant correlation between age and the fibrocartilage thickness (r = -0.48, p < 0.05) and age and the trabecular bone volume (r = -0.52, p < 0.05). There was a statistically significant correlation between age and the hypertrophic chondrocytes (r = -0.50, p < 0.05) and age and the hypertrophic chondrocytes in bone (r = -0.48, p < 0.05). There was no significant correlation between age and the two other zones in the fibrocartilage. No statistical analyses were carried out concerning gender differences, as the sample consisted of very few females. Individual morphological description was performed, and is described in the article. Only slight age-related differences were found concerning the quantitative measurements for the fibrocartilage and the underlying bone tissue. CONCLUSIONS: Quantitative and qualitative investigations of the turnover activity in the fibrocartilage and the bone tissue, describing activity of hypertrophic chondrocytes and the trabecular bone tissue, indicated condylar growth potential in the age group until 30 years of age. The growth activity seemed to decline with age.

Adaptation, Physiological↗

PubMed1999

Increased cortical bone content of insulin-like growth factors in acromegalic patients.

To investigate cortical bone composition and the role of the insulin-like growth factor (IGF) system in active acromegaly, iliac crest bone biopsies were obtained from 15 patients (3 women and 12 men), aged 21-64 yr (mean, 45.6 yr), and 25 age- and sex-matched controls (8 women and 17 men), aged 22-66 yr (mean, 44.6 yr). Levels of IGF-I, IGF-II, IGF-binding protein-3 (IGFBP-3), IGFBP-5, and total protein were determined in extracts obtained after ethylenediamine tetraacetate and guanidine hydrochloride extraction. Osteocalcin and calcium were determined in extracts after HCl hydrolysis. Cortical bone contents of IGF-I, IGF-II, and IGFBP-5 were significantly elevated in the acromegalic patients compared with control values [91% (P < 0.001), 44% (P < 0.04), and 115% (P < 0.004), respectively]. There was no significant difference in IGFBP-3, osteocalcin, protein, and calcium between patients and controls. This study suggests that the increased levels of growth factors in cortical bone from acromegalics is a reflection of local production, secondary to a chronic systemic excess of GH and IGF-I.

Acromegaly↗

PubMed1999

Effect of sex hormone replacement on the insulin-like growth factor system and bone mineral: a cross-sectional and longitudinal study in 595 perimenopausal women participating in the Danish Osteoporosis Prevention Study.

This study used a cross-sectional design to investigate relationships among serum insulin-like growth factor (IGF) parameters (total serum IGF-I, IGF-II, and IGF-binding protein-3), serum estradiol, and bone mineral density (BMD) stratified for potential confounders, and a longitudinal design to investigate the effects of hormonal replacement therapy (HRT) on IGFs and BMD. Five hundred and ninety-five perimenopausal women (median age, 50.0 yr; range, 45-56 yr) participating in the Danish Osteoporosis Prevention Study were investigated in a cross-sectional study, and a randomly selected subgroup of 110 was followed after 5 yr in a longitudinal study for changes in serum IGFs and BMD of lumbar spine, femoral neck, and ultradistal forearm during (n = 46) or without HRT (n = 64). In the cross-sectional study, serum IGF-I correlated positively to distal forearm BMD and spine BMD, but not to femoral neck BMD, after stratification for age, body mass index, and other variables. In the follow-up study, HRT decreased IGF-I and IGF-II, but did not influence the age-related decline in IGF-binding protein-3 significantly. Serum alkaline phosphatase and urinary hydroxyproline/creatinine ratio both decreased during HRT, whereas BMD increased compared to control values. After adjustment for age, body mass index, treatment, and other factors, IGF-I correlated positively to changes in forearm and femoral neck BMD, but not to changes in spine BMD. We conclude that serum IGF-I was positively associated to bone mineral density. Oral HRT decreases IGF-I and IGF-II.

Bone Density↗

PubMed1999

Age- and gender-related differences in vertebral bone mass, density, and strength.

This study was designed to evaluate age- and gender-related differences in vertebral bone mass, density, and strength by dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), ash measurements, and biomechanical testing. The material comprised human lumbar vertebral bodies (L3) from 51 females and 50 males (age-range: 18-96 years). The results showed that females had significantly lower vertebral body bone mass (ash weight) than males at any given age. The decline in bone mass with age was parallel for females and males. The different bone density measurements-cancellous ash density, total vertebral body ash density, DXA bone mineral density, QCT, and pQCT-showed no gender-related difference concerning numeric value or changes with age. Morphometrical measurements showed that females had smaller vertebral bodies (volumes) than males. Hence the females had significantly smaller cross-sectional area (CSA) of L3 than males (11.6 cm2 and 14.4 cm2, respectively). This led to females having lower maximum compressive load (N) than males at all ages, whereas maximum compressive stress (load/CSA) showed no gender-related difference. In conclusion, females have lower vertebral body bone mass than males at any given age, due to smaller vertebral bodies. Hence, maximum compressive load (strength not corrected for size) was lower in females. Vertebral body cancellous bone density and total-vertebral body density were equal when comparing genders, and no gender differences were found in the size-corrected strength: maximum compressive stress. The decrease with age in vertebral body compressive strength decrease was twice as large as the age decrease in density.

Absorptiometry, Photon↗

PubMed1999

Hormone replacement therapy affects body composition and leptin differently in obese and non-obese postmenopausal women.

Leptin and oestrogen are both involved in the regulation of adipose tissue deposition and feeding behaviour. We investigated whether 5 years of hormone replacement therapy (HRT) affected serum leptin and body composition differently in 89 postmenopausal women treated with HRT compared with 178 controls. At baseline, leptin was significantly correlated with oestradiol (r=0.13, P<0.05) and in multiple backward regression analysis including oestradiol and any estimate of body fat, oestradiol remained a significant determinant of leptin levels. In the control group, all estimates of body fat determined by dual energy X-ray absorptiometry (DEXA) or anthropometry were increased (3.6-16.9%) and leptin increased 31.3% (16.03+/-1.02 to 20.84+/-1.2 ng/ml (s.e.m.), P<0.001). In the HRT group all estimates of body composition also increased during the 5-year observation but to a lesser extent than observed in the control group (1.0-8.5%). Leptin was raised by 19.7% (17.81+/-1.32 to 20.57+/-1.65 ng/ml, P<0.001). However, the DEXA scans revealed that the control group gained 2.4-fold more fat during the 5-year observation (1.9+/-0.3 vs 0.8+/-0.4 kg, P<0.05), and especially the trunk fat increased (1.4+/-0.2 vs 0.7+/-0.3 kg, P<0.05). This was reflected in the increase in leptin levels, which were increased by 7.4% in the control group compared with the HRT group (4.81+/-0.60 vs 2.76+/-0.87 ng/ml, P<0.05). Adjusting for the difference in adipose tissue revealed that HRT had no independent effect on leptin levels. Comparisons between obese (body mass index>25 kg/m(2)) and non-obese (<25 kg/m(2)) subjects by stratifying for HRT treatment using multiple linear regression revealed that the change in fat mass was significantly less among treated subjects (P=0.038) and especially in the non-obese subjects (P=0.001). The change in trunk fat was similarly correlated with treatment status (P=0.029) and with the degree of obesity (P=0.006). In conclusion, 5 years of HRT treatment significantly reduced fat mass accumulation, especially in the trunk region. This effect of HRT was more pronounced in non-obese as compared with obese subjects. The HRT-induced reduction in fat mass seems not to be mediated by leptin.

Body Composition↗

PubMed1998

Combined hormone replacement therapy does not protect women against the age-related decline in endothelium-dependent vasomotor function.

BACKGROUND: Improvement in endothelial function may be an important mechanism by which estrogen replacement therapy protects postmenopausal women against coronary artery disease. However, combined hormone replacement therapy is more frequently used owing to the risk of uterine cancer with estrogen-only therapy. Concurrent progesterone treatment may attenuate the beneficial effects of estrogens not only on the lipid profile but also on the endothelium. METHODS AND RESULTS: We studied endothelial vasomotor function in 100 healthy postmenopausal women aged 53.3+/-2.9 years randomized to either combined hormone replacement therapy (n=46) or no substitution (n=54) 2.9+/-0.5 years earlier. In addition, 30 healthy premenopausal women aged 30.3+/-4.2 years were studied. With external ultrasound, brachial artery diameter was measured at rest, during reactive hyperemia (with increased flow causing endothelium-dependent dilation), and after sublingual nitroglycerin (causing endothelium-independent dilation). Compared with premenopausal women, flow-mediated dilation was significantly reduced in both postmenopausal groups. In the postmenopausal women, total cholesterol was lower in the treated women (5.66+/-0.83 versus 6.13+/-0.92 mmol/L; P=.025), whereas HDL cholesterol was similar (1.91+/-0.53 versus 1.85+/-0.46 mmol/L; P=NS). Dilation to flow and to nitroglycerin was similar in the two postmenopausal groups (flow: 2.5+/-2.9% versus 2.2+/-2.2%, P=NS; nitrate: 18.7+/-5.9% versus 17.2+/-6.2%, P=NS). CONCLUSIONS: Long-term combined oral hormone replacement therapy is without beneficial effects on endothelial vasomotor function in healthy postmenopausal women. This supports the view that progesterone may attenuate the beneficial effects of unopposed estrogen replacement.

Adult↗

PubMed1998

Does growth hormone therapy in adult patients with growth hormone deficiency protect against bone loss?

Fracture incidence is increased in growth hormone deficiency (GHD). However, the efficacy of growth hormone (GH) in the prevention of fractures in GHD is not documented. GH is important to attain normal peak bone mass; it increases bone mass in children and adolescents, but is less important with increasing age and is insignificant above the age of 55-60 years old. Placebo-controlled trials of 12 months' duration have failed to improve bone mass density, while uncontrolled studies have suggested that GH treatment for 2-4 years may increase bone mass by 0.5 of a standard deviation in adults. Given the current high price of GH treatment, however, routine substitution with the intention to decrease fracture incidence in adult GHD patients is not likely to be cost effective. GH substitution should probably be extended until peak bone mass has been achieved, and repeated dual energy X-ray scan measurements with intervals of 1-2 years could be helpful in deciding when to stop treatment.

Adolescent↗

PubMed1998

Relationships between static histomorphometry and bone strength measurements in human iliac crest bone biopsies.

It has been well established that trabecular bone strength has a power relationship to apparent bone density. It has been argued that the apparent bone density is not the sole factor determining cancellous bone strength, and that bone strength may also depend on the structure of the trabecular network. Various different measures of bone microstructure have been suggested: marrow space star volume; node-strut analysis; connectivity density; trabecular number; and trabecular separation. The aim of this study was to assess which of the histomorphometric measures, trabecular bone volume, marrow space star volume, node-strut analysis, connectivity density, trabecular number, and trabecular separation, give the best prediction of the bone strength. Moreover, a comparison of the suggested "structural" measures was carried out to establish whether they actually quantified the bone structure or something different. Finally, the influence of age and gender was investigated. The material comprised unilateral transiliac crest bone biopsies from 32 females (21-96 years, mean 59.1 years) and 32 males (24-94 years, mean 59.0 years). The bone biopsies were embedded in Technovit 9100, sectioned, and stained with aniline blue. Trabecular bone volume, marrow space star volume, node-terminus ratio, connectivity density, trabecular number, and trabecular separation were measured. A neighboring biopsy was compressed to obtain the compressive strength of the trabecular network. Trabecular bone volume was the measure that gave the strongest correlation with bone strength (r = 0.76 for females and r = 0.86 for males). High correlation was found between trabecular bone volume, marrow space star volume, node-terminus ratio, and trabecular separation--indicating that they carried the same information. A poor correlation was seen between these measures and connectivity density. Connectivity density was the only measure showing gender-dependent behavior. A multiple regression analysis showed that the trabecular bone volume is the best histomorphometric predictor of bone strength, and neither marrow space star volume, node-terminus ratio, connectivity density, trabecular number, nor trabecular separation could improve the predictive value of trabecular bone volume.

Adult↗

PubMed1998

Vertebral bone density evaluated by dual-energy X-ray absorptiometry and quantitative computed tomography in vitro.

Vertebral bone density is evaluated mainly by dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). Densitometry is used as an estimator of bone strength and forms the basis for choice of treatment. DXA expresses bone density in grams per square centimeter (area density) and QCT expresses bone density in milligrams per cubic centimeter (volumetric density). The aim of this study was to identify the differences between the two techniques, DXA and QCT, when applied to a group of female and male subjects over a wide age range. The data consisted of 221 lumbar vertebral bodies (L3 and L4) excised at autopsy. There were 90 females with a mean age of 65.6 (range 18-94) years and 131 males with a mean age of 62.0 (range 21-94) years. The vertebrae were scanned en bloc in demineralized water in Plexiglas containers with both DXA and QCT. DXA was performed using posteroanterior (PA) and lateral projection. QCT was performed in the center of each vertebra with 1 cm slice thickness. Both methods showed decreasing bone density with age. Lateral DXA showed a decrease in bone density with age from approximately 0.8 g/cm2 to approximately 0.4 g/cm2. QCT showed a decrease in bone density with age from approximately 180 mg/cm3 to approximately 30 mg/cm3. Lateral DXA bone mineral densities (BMD) were correlated with QCT densities in both females (r2 = 0.68, p < 0.00001) and males (r2 = 0.53, p < 0.00001), but females had constantly lower DXA BMDs than males at a given QCT density. QCT and width-adjusted midlateral DXA (g/cm3) were significantly correlated, with r2 = 0.64 (p < 0.00001) for females and r2 = 0.61 (p < 0.00001) for males. In conclusion, age- and gender-related differences in human vertebral bone density were shown to be dependent on the scanning method used. DXA bone mineral content (BMC) and BMD showed that females had lower values than males at all ages. When the "volumetric" DXA measurements and QCT were used, the females had the highest densities in the younger decades and males had the highest densities in the oldest decades. Finally, the area density (BMD) measured by DXA was lower in females than in males with identical QCT volumetric bone densities.

Absorptiometry, Photon↗

PubMed1998

Growth hormone increases vertebral and femoral bone strength in osteopenic, ovariectomized, aged rats in a dose-dependent and site-specific manner.

The aim of the study was to assess the effect of growth hormone (GH) as restorative therapy in an aged, ovariectomized rat model with established osteopenia. The study was planned as a dose-response study, and four different skeletal sites were investigated by mechanical testing and measurements of bone mass and dimensions. Twelve-month-old virgin F344 rats were divided into eight groups with ten animals per group: (1) sham operated (sham); (2) ovariectomized (ovx); (3) sham + solvent vehicle (sv); (4) ovx + sv; (5) ovx + GH 50 microg/kg body weight/day; (6) ovx + GH 1.25 mg/kg body weight/day; (7) ovx + GH 2.5 mg/kg body weight/day; and (8) ovx + GH 5.0 mg/kg body weight/day. Groups 1 and 2 were killed after 3 months to establish that bone loss had occurred due to ovx. One month later, the remaining groups began 3 months of treatment, at the end of which the animals were also killed. The effects of ovariectomy (ovx) and GH therapy were measured at four skeletal sites: lumbar vertebrae; femoral diaphysis; femoral neck; and distal femoral metaphysis. Ovariectomy induced a significant loss of bone strength at all sites apart from the femoral neck. The loss was most pronounced at the distal femoral metaphysis. GH was able to reverse the ovx-induced loss of strength at the vertebral site in a dose-dependent manner. At the femoral diaphyseal site, GH not only reversed the ovx-induced changes but increased load values significantly above sham level. However, at the distal femoral metaphysis, which is dominated by cancellous bone, only partial reversal was seen after GH treatment. The lowest GH dose had no significant effect at any site tested. We conclude that GH treatment can reestablish vertebral bone loss due to ovariectomy in a dose-dependent manner. The restorative effect is only partial at the distal femoral metaphysis even at a high dose. At skeletal sites with less pronounced ovx-induced bone loss (femoral neck and diaphysis), GH treatment increased bone strength to sham level or above sham level. Therefore, the effect of ovariectomy is dependent upon the skeletal site investigated, and the effect of GH treatment is dependent on both the skeletal site and the size of the ovx-induced bone loss at this site.

Aging↗

PubMed1998

Fracture rates and risk factors for fractures in patients with spinal cord injury.

AIM: To study fracture rates and risk factors for fractures in patients with spinal cord injuries. MATERIAL AND METHODS: A self-administered questionnaire was mailed to 646 members of the Danish Paraplegic Association and 1000 randomly selected normal controls. 438 patients (309 males, 129 females, 67.8%) and 654 controls (332 males, 322 females, 65.4%) returned the questionnaire. Median age in patients was 42, range 10-80 years, and in controls 43, range 19-93 years (2p = 0.25). RESULTS: The crude fracture rate was 2% per year in patients and 1% per year in controls (RR = 2.0, P < 0.001). Low-energy fractures were much more prominent in patients (19.0% of all fractures) than in controls (1.4%, P < 0.001). The fracture rate did not differ before the injury but increased after the injury to a constant level from the third year and forward. Fractures of the lower extremities were more prominent in patients than controls (femurs: RR = 23.4, P < 0.001, lower legs: RR = 5.2, P < 0.001, feet/toes: RR = 2.4, P = 0.006) while fractures of the forearms (P < 0.001) and clavicles (P = 0.03) were absent among patients. Fractures were more frequent in female patients (RR = 1.6, P = 0.008) and in male patients with a family history of fractures (RR = 2.0, P = 0.004). CONCLUSIONS: Low-energy fractures especially of the lower extremities are frequent in spinal cord injury patients and especially among female patients. The forearms seem protected from fractures.

Adolescent↗

PubMed1998

Effects of growth hormone treatment on serum levels of insulin-like growth factors (IGFs) and IGF binding proteins 1-4 in postmenopausal women.

BACKGROUND AND OBJECTIVE: Insulin-like growth factor binding proteins (IGFBPs) modulate the actions and bioavailability of insulin-like growth factors (IGFs), however, their regulation in vivo is incompletely understood. In this study we investigated the effects of different doses of growth hormone (GH) on circulating levels of IGFs and IGFBPs. DESIGN: The study was double-blind and placebo-controlled. Patients were treated with either GH in doses of 0.05, 0.10, or 0.20 lU/kg/day of placebo for one week. PATIENTS: Forty post-menopausal women aged 52-73 years with low bone mass. MEASUREMENTS: Serum IGF-I and IGF-II were measured by RIA while IGFBP-1-3 were measured by Western ligand blot (WLB) and compared with determinations by specific immunoassays. IGFBP-4 was measured by WLB alone. RESULTS: Both IGF-I (P < 0.001) and IGF-II (P < 0.01) increased significantly during GH treatment. Additionally, IGFBP-1 (P < 0.001) and IGFBP-2 (P < 0.001) decreased significantly while IGFBP-3 (P < 0.001) and IGFBP-4 (P < 0.05) increased all in a dose-dependent manner. Stepwise (backwards) multiple regression analyses showed that the changes in IGF-I and IGF-II, and age correlated with the change in serum IGFBP-1. Both GH-dosage, the increase in IGF-II, and body mass index correlated with the decrease in IGFBP-2. Furthermore, the increase in serum IGF-I, IGF-II, and triiodothyronine correlated with the increase in IGFBP-3. Moreover, GH-dosage correlated with the increase in serum IGFBP-4. CONCLUSION: GH significantly increased serum IGF-I, IGF-II, IGFBP-3, and IGFBP-4 and decreased serum IGFBP-1 and IGFBP-2 in post-menopausal women.

Aged↗

PubMed1998

Agreement between radiographic and photographic trabecular patterns.

PURPOSE: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. MATERIAL AND METHODS: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n = 28) and radiographs (n = 28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital image analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. RESULTS: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach's alpha > 0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed significant correlations (p < 0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the insignificant correlations between the photographs and the biomechanical characteristics. CONCLUSION: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography.

Adult↗

PubMed1998

The effect of modelling and remodelling on human vertebral body architecture.

Vertebral bone strength is determined by several factors: cortical thickness, bone size, trabecular bone density, and microarchitecture. All these factors change with age as a result of the two dynamic processes: remodelling and modelling. When the changes become pronounced, osteoporotic fractures occur. There is a different aging pattern for men and women: 1. Men achieve a higher peak bone mass than women (mainly because of a larger cross-sectional area of their bones); 2. Men have no accelerated bone loss in middle age; and 3. Men seem to be able to compensate for their loss of cancellous bone strength by increasing their vertebral cross-sectional area with age. The general pattern, for both men and women is, though, that of an extreme (70-80%) decline in whole vertebral body strength during normal aging. The accompanying decline in bone density is much less pronounced (35-45%). This clearly illustrates the power relationship between bone density and strength. However, the role of changes in trabecular bone microarchitecture for vertebral bone strength during aging still needs to be determined.

Adult↗