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Peter Burckhardt

Publications and source records attributed to Peter Burckhardt.

17 recordsLinked to original sources
PubMed2006

Prediction of hip fracture risk by quantitative ultrasound in more than 7000 Swiss women > or =70 years of age: comparison of three technologically different bone ultrasound devices in the SEMOF study.

UNLABELLED: To compare the prediction of hip fracture risk of several bone ultrasounds (QUS), 7062 Swiss women > or =70 years of age were measured with three QUSs (two of the heel, one of the phalanges). Heel QUSs were both predictive of hip fracture risk, whereas the phalanges QUS was not. INTRODUCTION: As the number of hip fracture is expected to increase during these next decades, it is important to develop strategies to detect subjects at risk. Quantitative bone ultrasound (QUS), an ionizing radiation-free method, which is transportable, could be interesting for this purpose. MATERIALS AND METHODS: The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk (SEMOF) study is a multicenter cohort study, which compared three QUSs for the assessment of hip fracture risk in a sample of 7609 elderly ambulatory women > or =70 years of age. Two QUSs measured the heel (Achilles+; GE-Lunar and Sahara; Hologic), and one measured the heel (DBM Sonic 1200; IGEA). The Cox proportional hazards regression was used to estimate the hazard of the first hip fracture, adjusted for age, BMI, and center, and the area under the ROC curves were calculated to compare the devices and their parameters. RESULTS: From the 7609 women who were included in the study, 7062 women 75.2 +/- 3.1 (SD) years of age were prospectively followed for 2.9 +/- 0.8 years. Eighty women reported a hip fracture. A decrease by 1 SD of the QUS variables corresponded to an increase of the hip fracture risk from 2.3 (95% CI, 1.7, 3.1) to 2.6 (95% CI, 1.9, 3.4) for the three variables of Achilles+ and from 2.2 (95% CI, 1.7, 3.0) to 2.4 (95% CI, 1.8, 3.2) for the three variables of Sahara. Risk gradients did not differ significantly among the variables of the two heel QUS devices. On the other hand, the phalanges QUS (DBM Sonic 1200) was not predictive of hip fracture risk, with an adjusted hazard risk of 1.2 (95% CI, 0.9, 1.5), even after reanalysis of the digitalized data and using different cut-off levels (1700 or 1570 m/s). CONCLUSIONS: In this elderly women population, heel QUS devices were both predictive of hip fracture risk, whereas the phalanges QUS device was not.

Aged↗
PubMed2004

[Role of bone ultrasound in predicting hip fracture risk in women 70 years or older: results of the SEMOF study and comparison with literature data].

Because of the high morbidity and mortality associated with osteoporotic fractures, it is essential to detect subjects at risk for such fractures with screening methods. For this purpose, quantitative bone ultrasound (QUS) could be more practical than DXA, because QUS is a transportable, and low cost method. Heel QUS showed that they were predictive of hip fracture risk in elderly women aged 65 years and over, independently of femoral neck DXA. The SEMOF study is a multicenter prospective study which compare the predictive value of hip fracture risk of two heel QUS (Ahilles+, and Sahara), and of one phalanges QUS (DBM sonic 1200) in a population of 7062 Swiss women aged 70 years and over. During the three year follow-up, 80 hip fractures where reported. A decrease of -1 SD of the ultrasonic parameters of the heel was associated to a increase of hip fracture risk of 2.5 times. On the other side, the phalanges QUS was not predictive of hip fracture risk in this population of elderly women. In conclusion, heel QUS represent an important predictive risk factor of fracture. Their integration in a screening strategy, in association with other risk factors should be interesting in order to define an absolute global fracture risk for a given period.

Aged↗
PubMed2004

[Mineral waters and bone health].

Some mineral waters contain minerals in such high concentrations that they can influence bone health when consumed regularly. Calcium from mineral water is readily absorbed, inhibits PTH secretion and bone resorption on the short as well as on the long term. Sodium concentrations are too low to bother, sulfates have no documented bone effect, but fluoride can in rare cases be so high that it increases bone density. Since potassium and bicarbonate lower renal calcium excretion, and since the latter improves calcium balance, mineral waters rich in bicarbonate and potassium have been tested. Indeed, they lowered renal calcium excretion and bone resorption in short and medium term trials, and they could be of particular interest in the prevention of osteoporosis in addition to calcium-rich waters.

Acid-Base Equilibrium↗
PubMed2003

The effects of three-month intravenous ibandronate on bone mineral density and bone remodeling in Klinefelter's syndrome: the influence of vitamin D deficiency and hormonal status.

The aim of this study was to evaluate the effects of a 2-year treatment with intravenous ibandronate (2 mg every 3 months) and calcium (1000 mg daily) on bone mineral density (BMD) and bone markers in 14 patients with Klinefelter's syndrome who served as their own controls. During the follow-up of 5.9 years before the treatment was started, the mean rates of bone loss per year were 1.3, 0.9, and 0.6% in the lumbar spine, femoral neck, and total body, respectively. The rate of bone loss from the spine was significantly inversely related to both serum estradiol and testosterone. At the onset of treatment, the average age of the patients was 55.2 years (48-64 years), and T score, mean +/- SD, at the lumbar spine was -2.6 +/- 1.0. After 6 months, the mean serum CTX and PINP decreased by 39 and 55% below the pretreatment concentrations, respectively (P < 0.05). After 12 months of treatment, the patients gained mean +/- SD, 7.8 +/- 2.3% of BMD in the lumbar spine, 3.8 +/- 4.0% in the femoral neck, and 4.7 +/- 2.2% in the total body (P < 0.05). During the second year of treatment, all patients also received 700 IU of vitamin D daily. After 24 months of treatment, the patients gained 10.1 +/- 4.3% of BMD in the lumbar spine, 6.7 +/- 5.5% in the femoral neck, and 5.5 +/- 2.5% in the total body. The increase in BMD in the second year of ibandronate treatment was not significant. The rate of gain of BMD in the femoral neck was positively related to serum concentrations of testosterone and inversely related to 25-hydroxyvitamin D (P < 0.005). After the discontinuation of treatment, serum CTX and PINP increased to the pretreatment levels, and the lumbar spine and femur neck BMD decreased (P < 0.05). In conclusion, ibandronate was effective in increasing BMD at all sites, but the effects were adversely influenced by vitamin D insufficiency or deficiency. The overall changes in biochemical markers of bone remodeling were consistent with the antiresorptive effect of the drug.

Adult↗
PubMed2003

An economic analysis of hormone replacement therapy for the prevention of fracture in young postmenopausal women.

Osteoporosis is a major public health problem that will become increasingly important as our population ages. It leads to fractures that deeply affect the patients' quality of life. Osteoporosis is recognised as a leading factor in healthcare cost worldwide. For years, experts have recommended hormone replacement therapy (HRT), consisting of oestrogen with or without progestin, as the first-line therapy to prevent bone loss in postmenopausal women. Recently published randomised, controlled trials and well-designed meta-analyses confirm that HRT has both advantages and disadvantages. The advantages include prevention of osteoporotic fractures and colorectal cancer. The disadvantages are the resulting adverse effects such as coronary artery disease, stroke, thromboembolic events, breast cancer and cholecystitis. In the light of these findings, medical associations recommend against the routine use of oestrogen and progestin for the prevention of chronic conditions in postmenopausal women. HRT, administered for the prevention of fractures in all young postmenopausal women, would have an additional cost/year of life gained that is too expensive. However, this strategy seems to be cost-effective when young postmenopausal women at high risk for fractures are selected. Even if this strategy seems attractive, the adverse effects of HRT are not acceptable. This situation implies that other treatments must be found to prevent or treat osteoporosis. Among them, calcium and vitamin D were shown to be cost-saving in osteoporosis and even costs-effective in osteopoenia in young postmenopausal women.

Age Factors↗
PubMed2003

Expression of peroxisome proliferator-activated receptor-gamma1 and peroxisome proliferator-activated receptor-gamma2 in visceral and subcutaneous adipose tissue of obese women.

Data regarding the expression of peroxisome proliferator-activated receptor (PPAR)-gamma(1) and PPAR-gamma(2) in human visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) are conflicting. To clarify this issue, we studied 50 women who had a BMI >35 kg/m(2) were undergoing gastric reduction surgery. Phenotyping included recording of anthropometric parameters and of a biological profile. Quantification of the expression of PPAR-gamma(1) and PPAR-gamma(2) in samples of VAT and SAT was performed by real-time RT-PCR. In both SAT and VAT, the level of expression of PPAR-gamma(2) were >20-fold that of PPAR-gamma(1) (P < 0.001 for both). However, only PPAR-gamma(1) was differentially expressed, its levels in SAT being 216 +/- 34% those in VAT (P < 0.001). In a stepwise, multivariate regression analysis, the levels of PPAR-gamma(1) in both SAT and VAT were the major determinants of waist circumference (R(2) = 21% for both; P < 0.01). Finally, leptin but not PPARs appeared as the single parameter explaining the largest part of the variability of BMI in our cohort of patients (R(2) = 22%, P < 0.001). These results are consistent with the putative roles of PPAR-gamma(1) and PPAR-gamma(2) in carbohydrate metabolism and energy homeostasis, respectively. As such, they constitute an important step toward the identification of potential targets for novel therapeutic strategies in the fields of obesity.

Adipose Tissue↗
PubMed2002

Intravenous zoledronic acid in postmenopausal women with low bone mineral density.

BACKGROUND: Bisphosphonates are effective agents for the management of osteoporosis. Their low bioavailability and low potency necessitate frequent administration on an empty stomach, which may reduce compliance. Gastrointestinal intolerance limits maximal dosing. Although intermittent intravenous treatments have been used, the optimal doses and dosing interval have not been systematically explored. METHODS: We studied the effects of five regimens of zoledronic acid, the most potent bisphosphonate, on bone turnover and density in 351 postmenopausal women with low bone mineral density in a one-year, randomized, double-blind, placebo-controlled trial. Women received placebo or intravenous zoledronic acid in doses of 0.25 mg, 0.5 mg, or 1 mg at three-month intervals. In addition, one group received a total annual dose of 4 mg as a single dose, and another received two doses of 2 mg each, six months apart. Lumbar-spine bone mineral density was the primary end point. RESULTS: There were similar increases in bone mineral density in all the zoledronic acid groups to values for the spine that were 4.3 to 5.1 percent higher than those in the placebo group (P<0.001) and values for the femoral neck that were 3.1 to 3.5 percent higher than those in the placebo group (P<0.001). Biochemical markers of bone resorption were significantly suppressed throughout the study in all zoledronic acid groups. Myalgia and pyrexia occurred more commonly in the zoledronic acid groups, but treatment-related dropout rates were similar to that in the placebo group. CONCLUSIONS: Zoledronic acid infusions given at intervals of up to one year produce effects on bone turnover and bone density as great as those achieved with daily oral dosing with bisphosphonates with proven efficacy against fractures, suggesting that an annual infusion of zoledronic acid might be an effective treatment for postmenopausal osteoporosis.

Aged↗
PubMed2002

Bioavailability and biological efficacy of a new oral formulation of salmon calcitonin in healthy volunteers.

Salmon calcitonin (SCT) is a well-tolerated peptide drug with a wide therapeutic margin and is administered parenterally for long-term treatments of bone diseases. Its clinical usefulness would be enhanced by the development of an orally active formulation. In this randomized crossover double-blinded phase I trial, controlled by both a placebo and a parenteral verum, we have tested a new oral formulation of SCT associated with a caprylic acid derivative as carrier. Eight healthy volunteers received single doses of 400, 800, and 1200 microg of SCT orally, a placebo, and a 10-microg (50 IU) SCT intravenous infusion. SCT was reliably absorbed from the oral formulation, with an absolute bioavailability of 0.5-1.4%, depending on the dose. It induced a marked, dose-dependent drop in blood and urine C-terminal telopeptide of type I collagen (CTX), a sensitive and specific bone resorption marker, with the effects of 1200 microg exceeding those of 10 microg intravenously. It also decreased blood calcium and phosphate, and increased the circulating levels of parathyroid hormone (PTH) and, transiently, the urinary excretion of calcium. It was well-tolerated, with some subjects presenting mild and transient nausea, abdominal cramps, diarrheic stools, and headaches. This study shows that oral delivery of SCT is feasible with reproducible absorption and systemic biological efficacy. Such an oral formulation could facilitate the use of SCT in the treatment of osteoporosis and other bone diseases.

Adult↗
PubMed2002

[Treatment indications for osteoporosis].

The aim of this review is to better identify for which women with osteoporosis the treatment is efficient, without taking into account the bone mineral density only. The age, previous fractures, the severity of vertebral deformity identify women at high risk for subsequent fracture. The development of assessment tools for predicting fracture risk, the use of the NNT (number needed to treat), and economical analyses are particularly helpful. The number of patients needed to treat to prevent one patient having the target event expresses the magnitude of a treatment effect in a clinically useful way. Economical analyses take into account the health care resources needed to get these benefits. We analysed the NNT and the cost of the treatments which significantly reduced the risk of fracture.

Age Factors↗