Biomedical subjects

Pierre D Delmas

Publications and source records attributed to Pierre D Delmas.

63 records · Page 4Linked to original sources

PubMed2003

Review of ibandronate in the treatment of osteoporosis.

Several antiresorptive treatments that reduce the risk of osteoporotic fracture are now available, including bisphosphonates. Ibandronate is a new potent bisphosphonate, currently under development, with unique features. In several animal models of human osteoporosis, it has been shown to inhibit bone resorption and improve bone mechanical properties. Ibandronate is more potent than most current bisphosphonates. Several dosages and schedules have been tested in humans. With the oral daily dose of 2.5 mg, a reduction of 62% in the incidence of vertebral fracture has been demonstrated in a randomised, placebo-controlled trial. In the same trial, a reduction of 50% has been observed - for the first time using a bisphosphonate - with an intermittent regimen (20 mg every other day for the first 24 days, followed by 9 weeks without the treatment). In contrast, another randomised, placebo-controlled trial failed to find a significant reduction in vertebral fracture risk using an dose of 1 mg i.v. every 3 months. Thus, ibandronate can be considered as a promising new option for the treatment of postmenopausal osteoporotic women.

Administration, Oral↗

PubMed2002

[Osteoporosis in the aged male].

A MAJOR PROBLEM: Osteoporosis in elderly men is a public health problem. However, the criteria for its diagnosis remain to be defined. With the aging of the male population, the number of osteoporotic fractures is increasing together with the incidence of fractures per age range. These fractures create handicaps and an excess of mortality and generate great expense for the health budget. VARIOUS PHYSIOPATHOLOGICAL MECHANISMS: In the pathogenesis of osteoporosis of the elderly men, various elements must be taken into account: hormone factors (decreased testicular secretion, vitamin D deficiency), life style (chronic alcoholism, smoking, lack of exercise), certain diseases (rheumatoid arthritis) and certain drugs (corticosteroids, anti-androgenes). THE PROGRESSION OF BONE MINERAL DENSITY (BMD) WITH AGE: Depending on the area measured, the BMD peak is reached before the age of 30 in the hip and in the trabecular bone areas, whilst it is reached around the age of 40 in the cortical bone areas. Bone loss accelerates after the age of 70. After the age of 80, the BMD peak is around 16 to 20% lesser, except for the lumbar spine where the arthrosic calcifications artificially increase the BMD value. Bone formation marker blood levels remain stable in elderly men whereas the urinary excretion of deoxypyridinoline (bone resorption marker) increases after the age of 60. THE DIAGNOSIS OF OSTEOPOROSIS IN ELDERLY MEN: Osteoporosis must be evoked when confronted with a recent fracture, notably of the vertebra, or following moderate trauma and the diagnosis is confirmed by the measurement of a low BMD score (T-score < -2.5). WITH REGARD TO TREATMENT: There are few studies on the treatment of male osteoporosis. In the elderly man, documented hypogonadism justifies testosterone replacement therapy, although its anti-fracture efficacy has not been studied. In elderly men, particularly those living in homes, vitamin D deficiency and the subsequent hyperthyroidism justify treatment with vitamin D and calcium. The new bisphosphonates appear promising. In a randomised study, alendronate increased BMD and reduced the incidence of vertebral fractures. Alendronate and risedronate were also effective in the prevention and treatment of cortisone-induced osteoporosis in men.

Adult↗

PubMed2002

Osteoclast spreading kinetics are correlated with an oscillatory activation of a calcium-dependent potassium current.

Cell movement and spreading involve calcium-dependent processes and ionic channel activation. During bone resorption, osteoclasts alternate between spread, motile and resorptive phases. We investigated whether the electrical membrane properties of osteoclasts were linked to their membrane morphological changes. Rabbit osteoclasts were recorded by time-lapse videomicroscopy performed simultaneously with patch-clamp whole cell and single channel recordings. Original image analysis methods were developed and used to demonstrate for the first time an oscillatory activation of a spontaneous membrane current in osteoclasts, which is directly correlated to the membrane movement rate. This current was identified as a calcium-dependent potassium current (IK(Ca)) that is sensitive to both charybdotoxin and apamin and was generated by a channel with unitary conductance of approximately 25+/-2 pS. Blockade of this current also decreased osteoclast spreading and inhibited bone resorption in vitro, demonstrating a physiological role for this current in osteoclast activity. These results establish for the first time a temporal correlation between lamellipodia formation kinetics and spontaneous peaks of IK(Ca), which are both involved in the control of osteoclast spreading and bone resorption.

Animals↗

PubMed2002

Treatment of postmenopausal osteoporosis.

The aim of treatment of postmenopausal osteoporosis is to reduce the frequency of vertebral and non-vertebral fractures (especially at the hip), which are responsible for morbidity associated with the disease. Results of large placebo controlled trials have shown that alendronate, raloxifene, risedronate, the 1-34 fragment of parathyroid hormone, and nasal calcitonin, greatly reduce the risk of vertebral fractures. Furthermore, a large reduction of non-vertebral fractures has been shown for alendronate, risedronate, and the 1-34 fragment of parathyroid hormone. Calcium and vitamin D supplementation is not sufficient to treat individuals with osteoporosis but is useful, especially in elderly women in care homes. Hormone replacement therapy remains a valuable option for the prevention of osteoporosis in early postmenopausal women. Choice of treatment depends on age, the presence or absence of prevalent fractures, especially at the spine, and the degree of bone mineral density measured at the spine and hip. Non-pharmacological interventions include adequate calcium intake and diet, selected exercise programmes, reduction of other risk factors for osteoporotic fractures, and reduction of the risk of falls in elderly individuals.

Aged↗

PubMed2002

Effects of long-term intravenous ibandronate therapy on skeletal-related events, survival, and bone resorption markers in patients with advanced multiple myeloma.

PURPOSE: Bisphosphonates have been found to reduce the incidence of skeletal-related events (SREs) in patients with multiple myeloma. This is the first double-blind, randomized, placebo-controlled study to assess the efficacy of ibandronate, a third-generation amino-bisphosphonate, in preventing SREs in advanced-stage multiple myeloma patients. PATIENTS AND METHODS: Patients with multiple myeloma stage II or III were randomly assigned to receive either ibandronate 2 mg or placebo as a monthly intravenous (IV) bolus injection for 12 to 24 months in addition to conventional chemotherapy. SREs such as peripheral pathologic or vertebral fractures, hypercalcemia, severe bone pain, and bone radiotherapy or surgery were analyzed. Bone-turnover markers were also studied. Finally, post hoc analyses of bone morbidity and survival were performed. RESULTS: Ninety-nine patients per treatment group were assessable for efficacy analysis. The occurrence of SRE per patient year and the time to first SRE were not significantly different between the two treatment groups. In overall evaluation, no differences were found between the treatment groups regarding bone pain, analgesic drug use, quality of life, and median survival (33.1 v 28.2 months, respectively). Explorative post hoc analyses revealed that ibandronate patients with strongly suppressed bone-turnover markers (> or = 30% and > or = 50% mean reduction of serum osteocalcin and urinary C-terminal telopeptides) developed significantly less bone morbidity. Ibandronate was tolerated well during as many as 25 therapy cycles. CONCLUSION: Monthly injections of ibandronate 2 mg IV neither reduced bone morbidity nor prolonged survival in the overall population of stage II/III multiple myeloma patients.

Bone Resorption↗

PubMed2002

Association of baseline levels of urinary glucosyl-galactosyl-pyridinoline and type II collagen C-telopeptide with progression of joint destruction in patients with early rheumatoid arthritis.

OBJECTIVE: To evaluate whether measurements of urinary glucosyl-galactosyl-pyridinoline (Glc-Gal-PYD) and urinary C-terminal crosslinking telopeptide of type II collagen (CTX-II), 2 new markers of destruction of the synovium and cartilage collagen breakdown, respectively, are associated with the progression of joint damage in patients with early rheumatoid arthritis (RA), and to compare this association with that with serum matrix metalloproteinase 3 (MMP-3), a proteinase expressed by synovial tissue and chondrocytes, and that with serum C-reactive protein (CRP), an index of systemic inflammation. METHODS: The prospective study cohort comprised 116 patients with early RA who were part of a large, double-blind, randomized study comparing the efficacy of etanercept and methotrexate. The relationship between baseline levels of urinary Glc-Gal-PYD, urinary CTX-II, and serum MMP-3 and the progression of joint destruction, as measured by changes in the modified Sharp score (average findings of 2 independent readers) over 1 year, was investigated. RESULTS: Levels of urinary Glc-Gal-PYD (+70%), urinary CTX-II (+104%), and serum MMP-3 (+219%) were elevated compared with the levels in 76 healthy controls. The baseline levels of Glc-Gal-PYD (r = 0.30), CTX-II (r = 0.25), and MMP-3 (r = 0.29) correlated with the changes over 1 year in the total Sharp score (joint space narrowing and bone erosion). Patients with baseline levels of Glc-Gal-PYD, CTX-II, and MMP-3 that were higher than the mean + 2 SD in healthy controls had a significantly greater progression of joint damage, with an increase in the total Sharp score over 1 year that was from 3- to 8-fold higher than that in patients with low baseline levels of these markers. Moreover, patients with these higher levels of Glc-Gal-PYD, CTX-II, and MMP-3 had a higher risk of progression of the disease (increase in total Sharp score > or =0.5 units) than did the other patients (relative risks and 95% confidence intervals [95% CI] 3.3 [95% CI 1.5-7.4], 2.5 [95% CI 1.1-5.7], and 2.5 [95% CI 1.1-5.6], respectively). The baseline serum level of CRP was not significantly associated with the progression of joint damage. Adjustment of the levels of Glc-Gal-PYD, CTX-II, and MMP-3 according to radiologic damage at baseline did not alter their association with progression. After adjustment for serum CRP, the relative risk slightly decreased, but remained significant, for Glc-Gal-PYD (2.6 [95% CI 1.1-6.3]). Patients with both increased levels of the molecular markers and radiologic damage at baseline had a higher risk of progression of joint damage than did those with either high molecular marker levels or radiologic damage. CONCLUSION: High baseline levels of Glc-Gal-PYD, CTX-II, and MMP-3 are associated with increased risk of progression of joint destruction over 1 year in early RA. The association between baseline levels of urinary Glc-Gal-PYD and progression of joint erosion was independent of the severity of radiologic damage and inflammation at baseline. Combining the measurements of these molecular markers with radiologic assessment of joint damage may be useful for identifying patients with RA who are at high risk of rapid progression and for whom early aggressive treatment would be beneficial.

Adult↗

PubMed2002

Uncoupling of type II collagen synthesis and degradation predicts progression of joint damage in patients with knee osteoarthritis.

OBJECTIVE: The hallmark of osteoarthritis (OA) is the loss of articular cartilage. This loss arises from an imbalance between cartilage synthesis and cartilage degradation over a variable period of time. The aims of this study were to investigate the rates of these processes in patients with knee OA using two new molecular markers and to investigate whether the combined use of these markers could predict the progression of joint damage evaluated by both radiography and arthroscopy of the joints during a period of 1 year. METHODS: Seventy-five patients with medial knee OA (51 women, 24 men; mean +/- SD age 63 +/- 8 years, mean +/- SD disease duration 4.8 +/- 5.2 years) were studied prospectively. At baseline, we measured serum levels of N-propeptide of type IIA procollagen (PIIANP) and urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) as markers of type II collagen synthesis and degradation, respectively. Joint space width (JSW) on radiography and medial chondropathy at arthroscopy (assessed using a 100-mm visual analog scale [VAS]) were measured in all patients at baseline and in 52 patients at 1 year. Progression of joint destruction was defined as a decrease of > or =0.5 mm in JSW on radiography and as increased chondropathy (an increase in the VAS score of >8.0 units) between the baseline and 1-year evaluations. RESULTS: At baseline, compared with 58 healthy age- and sex-matched controls, patients with knee OA had decreased serum levels of PIIANP (20 ng/ml versus 29 ng/ml; P < 0.001) and increased urinary excretion of CTX-II (618 ng/mmole creatinine [Cr] versus 367 ng/mmole Cr; P < 0.001). The highest discrimination between OA patients and controls was obtained by combining PIIANP and CTX-II in an uncoupling index (Z score CTX-II - Z score PIIANP), which yielded a mean Z score of 2.9 (P < 0.0001). Increased baseline values in the uncoupling index were associated with greater progression of joint damage evaluated either by changes in JSW (r = -0.46, P = 0.0016) or by VAS score (r = 0.36, P = 0.014). Patients with both low levels of PIIANP (less than or equal to the mean - 1 SD in controls) and high levels of CTX-II (greater than or equal to the mean + 1 SD in controls) had an 8-fold more rapid progression of joint damage than other patients (P = 0.012 and P < 0.0001 as assessed by radiography and arthroscopy, respectively) and had relative risks of progression of 2.9 (95% confidence interval [95% CI] 0.80-11.1) and 9.3 (95% CI 2.2-39) by radiography and arthroscopy, respectively. CONCLUSION: Patients with knee OA are characterized by an uncoupling of type II collagen synthesis and degradation which can be detected by assays for serum PIIANP and urinary CTX-II. The combination of these two new markers could be useful for identifying knee OA patients at high risk for rapid progression of joint damage.

Aged↗

PubMed2002

Efficacy of raloxifene on vertebral fracture risk reduction in postmenopausal women with osteoporosis: four-year results from a randomized clinical trial.

The Multiple Outcomes of Raloxifene Evaluation trial studied 7705 postmenopausal women with osteoporosis randomized to placebo, or raloxifene 60 or 120 mg/d [JAMA 282(1999): 637]. This report assesses the efficacy of raloxifene on the long-term cumulative incidence new vertebral fractures through 4 yr. New vertebral fractures was assessed from radiographs taken at baseline, yr 2-4. The primary analysis was the cumulative incidence of new vertebral fractures through 4 yr. A posthoc analysis compared the vertebral fracture risk in yr 4 alone with that observed in the first 3 yr. The 4-yr cumulative relative risks (RR) for one or more new vertebral fractures were 0.64 [95% confidence interval (CI) 0.53, 0.76] with raloxifene 60 mg/d and 0.57 (95% CI 0.48, 0.69) with raloxifene 120 mg/d. In yr 4 alone, raloxifene 60 mg/d reduced the new vertebral fracture risk by 39% [RR 0.61 (95% CI 0.43, 0.88)], which was not found to be significantly different from the RR observed in the first 3 yr in both raloxifene groups, irrespective of prevalent fracture status. The nonvertebral fracture risk was not significantly reduced [RR 0.93 (95% CI 0.81, 1.06)]. The safety profile after 4 yr was similar to that observed after 3 yr. Raloxifene 60 and 120 mg/d through 4 yr decreased the cumulative risk of new vertebral fractures in postmenopausal women with osteoporosis. The decreased vertebral fracture risk in yr 4 alone was not different from that observed in the first 3 yr.

Aged↗

PubMed2002

Type I collagen racemization and isomerization and the risk of fracture in postmenopausal women: the OFELY prospective study.

The Asp1211 residue of the 1209AHDGGR1214 sequence of the C-terminal cross-linking telopeptide of type I collagen (CTX) can undergo spontaneous post-translational modifications, namely, racemization and isomerization, which result in the formation of four isomers: the native form (alpha-L) and three age-related forms, that is, an isomerized form (beta-L), a racemized form (alpha-D), and an isomerized/racemized (beta-D) form. Previous studies have suggested that changes in the pattern of type I collagen racemization/isomerization, which can be assessed in vivo by measuring the degradation products of the CTX isoforms, may be associated with alterations of bone structure. The aim of this study was to examine prospectively the value of the different urinary CTX isoforms and their related ratio in the prediction of osteoporotic fractures in 408 healthy untreated postmenopausal women aged 50-89 years (mean, 64 years) who were part of the OFELY cohort. During a median 6.8 years follow-up, 16 incident vertebral fractures and 55 peripheral fractures were recorded in 65 women. The baseline levels of the four CTX isoforms in women who subsequently had a fracture were compared with those of the 343 women who did not fracture. At baseline, women with fractures had increased levels of ratios of native alpha-L-CTX to age-related isoforms (beta-L, alpha-D, and beta-D) compared with controls (p < 0.01). In logistic regression analysis after adjustment for age, prevalent fractures, and physical activity, women with levels of alpha-L/beta-L, alpha-L/alpha-D, and alpha-L/beta-D-CTX ratios in the highest quartile had a 1.5- to 2-fold increased risk of fractures compared with women with levels in the three lowest quartiles with relative risk (RR) and 95% CI of 2.0 (1.2-3.5), 1.8 (1.02-2.7), and 1.5 (0.9-2.7), respectively. Adjustment of alpha-L/beta-L and alpha-L/alpha-D-CTX ratios by the level of bone turnover assessed by serum bone alkaline phosphatase (ALP)- or femoral neck bone mineral density (BMD) decreased slightly the RR, which remained significant for the alpha-L/beta-L-CTX ratio (RR [95%] CI, 1.8 [1.1-3.2] after adjustment for bone ALP, 1.8 [1.03-3.1] after adjustment for BMD, and 1.7 [0.95-2.9] after adjustment for both bone ALP and BMD). Women with both high alpha-L/beta-L-CTX ratio and high bone ALP had a 50% higher risk of fracture than women with either one of these two risk factors. Similarly, women with both increased CTX ratio and low femoral neck BMD (T score < -2.5) had a higher risk of fracture with an RR (95% CI) of 4.5 (2.0-10.1). In conclusion, increased urinary ratio between native and age-related forms of CTX, reflecting decreased degree of type I collagen racemization/isomerization, is associated with increased fracture risk independently of BMD and partly of bone turnover rate. This suggests that alterations of type I collagen isomerization/racemization that can be detected by changes in urinary CTX ratios may be associated with increased skeletal fragility.

Aged↗