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Biomedical subjects

R Willvonseder

Publications and source records attributed to R Willvonseder.

At least 37 records · Page 2Linked to original sources
PubMed1991

Peripheral and axial bone mass in Austrian free climbers.

The present investigation was carried out in healthy white adult males to determine the effects of exercise, in the form of free climbing, on peripheral and axial bone mass. 13 men who have been regularly engaging in alpine free climbing for a mean period of nine years and, for training purposes, have been performing additional muscle building exercises (4.5 h +/- 1 SEM per week) and 12 age matched controls were included in the study. Bone mineral content of the non-dominant distal forearm was measured by single-photon absorptiometry, and bone mineral density of the lumbar spine was determined by quantitative computed tomography. It was found that consistent exercise in the form of alpine free climbing was associated with increased bone mass of the lumbar spine (162.4 +/- 4.4 vs 184.8 +/- 7.9 mg/ml, p less than 0.025). Peripheral bone mineral content of the distal forearm was slightly but not significantly increased in the free climbers (55.4 +/- 9.0 vs 61.1 +/- 7.4 Units, p less than 0.09 N.S.). The study provides additional evidence that exercise in the form of alpine climbing, is associated with increased lumbar bone mass.

Absorptiometry, Photon↗
PubMed1991

Decreased peripheral bone mineral content in patients under anticoagulant therapy with phenprocoumon.

In experimental and clinical studies, conflicting results regarding the effect of oral anticoagulant therapy on bone metabolism have been reported. To measure a possible influence of long-term anticoagulant therapy with phenprocoumon on peripheral bone mass, measurements of peripheral bone mineral content (BMC) and serum osteocalcin levels were performed with single photon absorptiometry in a total of 78 patients on anticoagulant treatment. We studied 43 women (mean age 66 years +/- 2 SEM) and 35 men (mean age 65 years +/- 2 SEM) with a median duration of phenprocoumon therapy of 1 year (1-9 years). In all patients, the medical history gave no symptoms of metabolic bone disease, or diseases or medications causing osteoporosis. Both in the male and female groups, mean peripheral BMC was significantly decreased (male: P less than 0.01, female: P less than 0.003) when compared with corresponding controls. Serum OC-levels measured in 16 patients were also significantly lower than those of the controls (P less than 0.02). Our data of decreased BMC and low serum OC-levels indicate reduced bone mass in patients on long-term anticoagulant therapy with phenprocoumon. This may imply an influence of anticoagulants on bone metabolism resulting in decreased bone formation.

Aged↗
PubMed1991

Decreased serum osteocalcin levels in patients with postmenopausal osteoporosis.

Osteocalcin is a 49 amino acid non collagenous bone matrix protein which is synthesized by the osteoblasts. The serum levels of osteocalcin have been found to be a specific biochemical parameter of bone formation. We determined the serum levels of osteocalcin, parathyroid hormone, calcitonin and alkaline phosphatase as well as the 2 hour fasting hydroxyproline excretion in 26 patients with postmenopausal osteoporosis and in 24 postmenopausal control subjects. Serum levels of osteocalcin were significantly lower in the patients with postmenopausal osteoporosis than in the control subjects (p less than 0.002). In contrast, serum levels of parathyroid hormone, calcitonin, alkaline phosphatase and the 2 hour hydroxyproline excretion in the patients with postmenopausal osteoporosis and the control subjects were not statistically different. Our data give evidence of a decreased bone formation in patients with postmenopausal osteoporosis.

Aged↗
PubMed1991

Bone mass and bone diminution of the axial and peripheral skeleton in normal and osteoporotic Austrian females.

Measurements of bone mass were performed in 133 healthy Austrian women using the quantitative computed tomography technique of the lumbar spine and single photon absorptiometry of the distal forearm. The data were compared with those of 110 Austrian females with osteoporotic spine fractures. A significant difference in mean bone density of the lumbar spine was observed between normal and osteoporotic patients in every decade, whereas forearm measurements showed statistical differences in the seventh and eighth decade but not in the sixth decade. Compared to age matched controls, bone mass of osteoporotic women showed the following diminution: sixth decade: distal forearm: -12.7%, spine: -46.8%; seventh decade: distal forearm: -19.0%, spine: -36.7%, eighth decade: distal forearm: -15.4%, spine: -33.7%. It appears that postmenopausal osteoporosis involves greater loss of bone in the spine in the first decade after menopause and slows down after this period, whereas loss of forearm bone mineral density (BMD) increases with advancing age.

Absorptiometry, Photon↗
PubMed1990

Decreased serum osteocalcin levels in patients with liver cirrhosis.

Serum levels of osteocalcin (OC) have been found to be a specific biochemical parameter of bone formation. We measured serum levels of osteocalcin, parathyroid hormone (PTH) and 25-hydroxyvitamin D (25(OH)D) in 49 patients with liver cirrhosis, who are known to have an increased prevalence of metabolic bone disease, and a matched control group (n = 35). Serum levels of OC were significantly decreased in the patients with liver cirrhosis when compared to control subjects (P less than 0.001). Serum levels of 25(OH)D were decreased (P less than 0.001), whereas no statistical difference was found between the serum levels of PTH in the patients with liver cirrhosis and those of the controls. In a subgroup of 23 patients with cirrhosis of the liver and 34 control subjects, the bone mineral content (BMC) of the non-dominant forearm was determined by single photon absorptiometry. BMC was significantly lower in the patient with liver cirrhosis than the control subjects (P less than 0.04). Our data demonstrate vitamin D deficiency, decreased bone formation and a decreased BMC in patients with liver cirrhosis.

Bone Density↗
PubMed1990

A circadian rhythm of serum osteocalcin levels in postmenopausal osteoporosis.

The serum levels of osteocalcin, a 49 amino acid bone matrix protein, have been found to be a specific biochemical parameter of bone formation. The aim of our study was to assess the variability of serum osteocalcin and parathyroid hormone levels in postmenopausal osteoporosis. In 16 patients with postmenopausal osteoporosis, serum levels of osteocalcin and parathyroid hormone were determined in 4-hourly intervals by radioimmunoassay. Whereas the serum parathyroid hormone levels were similar throughout the day, the serum osteocalcin levels showed a circadian rhythm, with lowest levels in the morning and maximal levels during the night. These findings might suggest a circadian variation of bone formation in patients with postmenopausal osteoporosis.

Aged↗
PubMed1990

Effects of one-year hormone replacement therapy on peripheral bone mineral content in patients with osteoporotic spine fractures.

A double-blind, placebo-controlled study on 31 patients with osteoporotic spine fractures was performed in order to assess the effects of one-year cyclical estrogen/gestagen replacement therapy (Trisequens, Novo) on peripheral bone mineral content and bone turnover. Bone mineral content was measured by single-photon absorptiometry with 125I before, and 6 and 12 months after start of therapy. Calcium, phosphate, alkaline phosphatase, parathyroid hormone, calcidiol, calcitonin and 2-hour urinary hydroxyproline excretion were measured to evaluate bone turnover. After 12 months, forearm bone mineral content showed a significant increase (p less than 0.02) in the treatment group, whereas in the control group no statistically significant change in peripheral bone mass was observed. Parameters of bone metabolism showed a decrease in hydroxyproline excretion (p less than 0.02) as well as alkaline phosphatase (p less than 0.01) and no changes in parathyroid hormone, calcidiol, and calcitonin. These results demonstrate that one-year cyclical estrogen/gestagen replacement therapy improves peripheral bone mineral content measured by single-photon absorptiometry. This effect appears to be induced by an inhibition of bone resorption.

Alkaline Phosphatase↗
PubMed1990

Broadband ultrasound attenuation: a new diagnostic method in osteoporosis.

Broadband ultrasound attenuation (BUA) measurements of the calcaneus, single-photon absorptiometry (SPA) of the nondominant distal forearm, and quantitative CT (QCT) of the lumbar spine were performed in 37 women with osteoporotic vertebral fractures and 23 female control subjects of similar age distribution to assess the usefulness of sonography in detecting axial osteopenia. In the women with osteoporotic vertebral fractures, all three measuring methods showed significantly reduced values (SPA: p less than .05; QCT: p less than .0001; BUA: p less than .05) compared with those in the control subjects. In addition, for all subjects, a significant positive correlation was found between BUA and QCT (tau = 0.25, p less than .005) and between SPA and QCT (tau = 0.34, p less than .0001). These results suggest that BUA, a simple method that is radiation-free, is a valuable tool in the management of osteoporosis.

Aged↗
PubMed1990

Peripheral bone mineral content in patients with fatty liver and hepatic cirrhosis.

The aim of our study was to determine peripheral bone mineral content (BMC) and serum osteocalcin (OC) levels in two groups of patients with fatty liver and hepatic cirrhosis as compared with a control group comprising healthy subjects. Group I consisted of 18 male patients (mean age, 51 years) with hepatic steatosis, group II included 23 men (mean age, 52 years) with hepatic cirrhosis. In all patients diagnosis was established with ultrasonic examination of the liver; 18 patients in group II underwent additional blind liver biopsies. The control group consisted of 23 subjects. Analysis of variance showed marked differences between the three groups (p less than 0.001). Peripheral BMC was significantly lower in patients with liver cirrhosis (BMC, 46.8 U) than in both patients with fatty liver (BMC, 54.7 U) and the control group (BMC, 60.7 U). However, no statistically significant differences in BMC values occurred between patients with hepatic steatosis and the controls. Serum osteocalcin levels followed a pattern similar to that of BMC values. A statistically significant decrease in osteocalcin values was found in the liver cirrhosis group (OC, 3.9 ng/ml) compared with the control group (OC, 6.6 ng/ml) and with the patients with hepatic steatosis (OC, 6.2 ng/ml). According to these results, clearly reduced BMC and decreased OC levels are found in patients with chronic alcoholic liver disease. However, these reductions are essentially influenced by the extent of morphologic changes in liver structure.

Adult↗
PubMed1989

Estimated long-term effect of calcitonin treatment in acute osteoporotic spine fractures.

A 12-month prospective controlled study was conducted in 28 patients with acute osteoporotic spine fractures to evaluate and compare the effect of calcitonin treatment and cyclical hormone replacement therapy on forearm bone mineral content (BMC) and bone turnover. We established two treatment groups and a control group of women with postmenopausal osteoporosis (n = 28). Group A (n = 10) received 100 U of calcitonin by subcutaneous self-application on alternate days and oral calcium (Ca) for 6-8 weeks. Group B (n = 10) received cyclical estrogen/gestagen replacement therapy over 12 months and oral calcium. The control group (n = 8) received analgetic treatment and 500 mg Ca daily. BMC was measured by single photon absorptiometry (SPA) with I 125 before and 6 and 12 months after the onset of the therapies. Ca, phosphorus (P), alkaline phosphatase, and 2-hour urinary OH-proline excretion were measured to classify bone turnover. One year after the onset of the two therapies, forearm BMC measured by SPA showed a significant increase in the group under hormone replacement therapy (P less than 0.025) as well as in the calcitonin group (P less than 0.05), although the latter underwent treatment only over a short period (6-8 weeks). In the same period, BMC decreased significantly in the control group (P less than 0.025). These results demonstrate that short-term calcitonin treatment over 6-8 weeks is as effective as long-term hormone replacement therapy, both therapies increasing forearm BMC measured by SPA.

Aged↗
PubMed1984

Primary hyperparathyroidism is associated with decreased insulin receptor binding and glucose intolerance.

We studied insulin receptor-binding and carbohydrate and metabolism in 15 patients with symptomatic primary hyperparathyroidism in comparison with 20 healthy controls. Insulin binding to monocytes and erythrocytes was measured by radioreceptor-ligand-assay. Furthermore, patients and controls were characterized by testing oral (100 g glucose load) glucose tolerance as well as insulin tolerance (0.1U insulin/kg body weight). Compared with controls, patients with primary hyperparathyroidism exhibited marked hyperinsulinemia (P less than 0.01) and significantly higher glucose levels (P less than 0.01) after an oral glucose load. The glucose lowering effect of intravenous insulin was significantly diminished in primary hyperparathyroidism compared with controls (P less than 0.01). Receptor studies revealed a significantly lower (P less than 0.01) insulin binding to monocytes and to erythrocytes in patients with primary hyperparathyroidism compared with controls. The present data indicate an insulin-resistant state in primary hyperparathyroidism, which is caused at least in part, by a downregulation of insulin receptors.

Adult↗
PubMed1983

Peripheral insulin resistance in primary hyperparathyroidism.

Carbohydrate metabolism was investigated in 9 patients with symptomatic primary hyperparathyroidism. Before and after parathyroidectomy intravenous and oral glucose tolerance test, tolbutamide test, arginine infusion test and insulin tolerance test were performed. During intravenous and oral glucose tolerance tests, patients with primary hyperparathyroidism exhibited hyperinsulinemia and impaired glucose tolerance without normalization after surgery. Tolbutamide-induced induced insulin release did not differ pre- or postoperatively. After restoration of normocalcemia and normocalcemia and normophosphatemia we found significantly lower glucose and insulin levels following arginine infusion and a significantly increased hypoglycemic response to parenterally administered insulin, probably indicating partial improvement of glucose tolerance after surgery. Our findings suggest that biochemical abnormalities associated with primary hyperparathyroidism, like hypercalcemia, hypophosphatemia, and elevated parathyroid hormone levels may cause and sustain a form of endogenous insulin resistance, which consequently leads to hyperinsulinemia and to impaired glucose tolerance. Since hyperinsulinemia as well as impaired glucose tolerance seem to be only slowly and partially reversible in symptomatic primary hyperparathyroidism, these data could be considered as an additional argument for early surgical intervention in this disorder.

Adult↗
PubMed1983

Growth hormone, prolactin and insulin following arginine infusion in primary hyperparathyroidism before and after parathyroidectomy.

The secretion of growth hormone, prolactin and insulin following arginine infusion was studied in 9 patients with primary hyperparathyroidism before and after parathyroidectomy. Growth hormone, insulin and glucose levels after arginine administration were significantly higher before parathyroidectomy compared with the corresponding data obtained in the post-operative state, whereas plasma prolactin concentrations did not differ before and after operation.

Adult↗
PubMed1983

[Human calcitonin in the treatment of symptomatic Paget's disease].

We evaluated the effect of a 6 months trial with synthetic human calcitonin in 10 symptomatic patients with polyosseous Paget's disease of bone. All patients reported a distinct clinical improvement which correlated with a significant decrease of alkaline phosphatase in the plasma and hydroxyproline and calcium excretion in the urine. Though no changes in skeletal x-rays were observed, the bone lesions showed a significant decrease of activity in tho bone scintigrams. Histologically there was a marked decrease of bone turn-over calcitonin therapy. No patient revealed the formation of autoantibodies against exogenous calcitonin after treatment.

Aged↗
PubMed1983

[Vitamin D metabolism, regulation, function].

In a review of the literature metabolism, regulation and function of vitamin D and its active metabolites is discussed. Vitamin D is absorbed from the gut and produced in the skin. 25-hydroxylation takes place in the liver, producing 25-hydroxy-vitamin-D. This metabolite is transferred and hydroxylated in the kidney. The most potent cholecalciferol is 1,25-dihydroxy-vitamin-D. This hydroxylation process is regulated by the need of phosphorus and calcium and by calcicotropic hormones, e. g. parathyroid-hormone. The active cholecalciferols regulate intestinal, renal and osseous handling of calcium and phosphorus by binding to a specific receptor protein. Thus, the control of serum calcium and -phosphate homeostasis by cholecalciferols guarantees adequate supply of these substances for mineralisation. Accordingly, perinatal period and puberty is associated with a marked increase in active vitamin D metabolites.

Bone and Bones↗