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C H Chesnut

Publications and source records attributed to C H Chesnut.

At least 19 recordsLinked to original sources
PubMed2002

Risedronate reduces the risk of first vertebral fracture in osteoporotic women.

Risedronate treatment reduces the risk of vertebral fracture in women with existing vertebral fractures, but its efficacy in prevention of the first vertebral fracture in women with osteoporosis but without vertebral fractures has not been determined. We examined the risk of first vertebral fracture in postmenopausal women who were enrolled in four placebo-controlled clinical trials of risedronate and who had low lumbar spine bone mineral density (BMD) (mean T-score = -3.3) and no vertebral fractures at baseline. Subjects received risedronate 5 mg ( n = 328) or placebo ( n = 312) daily for up to 3 years; all subjects were given calcium (1000 mg daily), as well as vitamin D supplementation (up to 500 IU daily) if baseline serum 25-hydroxyvitamin D levels were low. The incidence of first vertebral fracture was 9.4% in the women treated with placebo and 2.6% in those treated with risedronate 5 mg (risk reduction of 75%, 95% confidence interval 37% to 90%; P = 0.002). The number of patients who would need to be treated to prevent one new vertebral fracture is 15. When subjects were stratified by age, similar significant reductions were observed in patients with a mean age of 64 years (risk reduction of 70%, 95% CI 8% to 90%; P = 0.030) and in those with a mean age of 76 years (risk reduction of 80%, 95% CI 7% to 96%; P = 0.024). Risedronate treatment therefore significantly reduces the risk of first vertebral fracture in postmenopausal women with osteoporosis, with a similar magnitude of effect early and late after the menopause.

Aged↗
PubMed2001

An interactive tutorial-based training technique for vertebral morphometry.

The purpose of this work was to develop a computer-based procedure for training technologists in vertebral morphometry. The utility of the resulting interactive, tutorial based training method was evaluated in this study. The training program was composed of four steps: (1) review of an online tutorial, (2) review of analyzed spine images, (3) practice in fiducial point placement and (4) testing. During testing, vertebral heights were measured from digital, lateral spine images containing osteoporotic fractures. Inter-observer measurement precision was compared between research technicians, and between technologists and radiologist. The technologists participating in this study had no prior experience in vertebral morphometry. Following completion of the online training program, good inter-observer measurement precision was seen between technologists, showing mean coefficients of variation of 2.33% for anterior, 2.87% for central and 2.65% for posterior vertebral heights. Comparisons between the technicians and radiologist ranged from 2.19% to 3.18%. Slightly better precision values were seen with height measurements compared with height ratios, and with unfractured compared with fractured vertebral bodies. The findings of this study indicate that self-directed, tutorial-based training for spine image analyses is effective, resulting in good inter-observer measurement precision. The interactive tutorial-based approach provides standardized training methods and assures consistency of instructional technique over time.

Allied Health Personnel↗
PubMed2001

Reconsidering the effects of antiresorptive therapies in reducing osteoporotic fracture.

Concepts of what constitutes osteoporosis have evolved from the single criterion of low bone mass to a more inclusive consideration of bone strength, based on both quantity and quality. The evidence driving this shift is drawn from many sources. For example, recent studies of bone geometry have shown what engineers have always known: material properties and structural strength are inseparable. Genetic factors also argue against a one-dimensional (ID) view of osteoporosis. Large-scale family studies present a strong case for genetic influences on bone mass and predisposition to fracture. The contribution of aging to fracture risk has long been known, but we are only now beginning to understand what happens to bone remodeling and microstructure in an aging skeleton. The recognition that osteoporosis is far more complex than previously thought suggests that factors in addition to bone mineral density (BMD) may be useful for evaluating bone fragility and therapeutic effectiveness. Although assessment of BMD is noninvasive and widely available, the degree of increase in BMD alone fails to account for the broader effectiveness of antiresorptive agents in reducing the risk of fractures related to osteoporosis. Indeed, the very multiplicity of factors that determine fracture risk implies that response to therapy may be equally complex. Studies of response to antiresorptive agents and the cellular processes they induce are at best preliminary at this time. Although new technologies have been applied to studying bone microarchitecture, their invasive nature limits wide use. New methods are needed to provide insight into the causes and effects of bone fragility. The definition of osteoporosis, meanwhile, must still be considered a work in progress.

Animals↗
PubMed2001

The relationship between skeletal and oral bone mineral density: an overview.

Is oral osteopenia (bone loss of the jaws) a component of systemic osteopenia/osteoporosis (systemic bone loss, with or without fracture) or only an accompanying manifestation of periodontal disease? Put other ways: 1) is systemic osteopenia a risk factor for periodontitis; 2) is systemic osteopenia a risk factor for oral osteopenia independent of periodontal disease; or 3) is periodontal disease the primary (exclusive) risk factor for oral osteopenia? Despite 2 decades of scientific inquiry into these questions, the answers remain elusive.

Alveolar Bone Loss↗
PubMed2000

Clinical use of biochemical markers of bone remodeling: current status and future directions.

Biochemical markers of bone turnover provide a means of evaluating skeletal dynamics that complements static measurements of bone mineral density (BMD). This review evaluates the use of commercially available bone turnover markers as aids in diagnosis and monitoring response to treatment in patients with osteoporosis. High within-person variability complicates but does not preclude their use. Elevated bone resorption markers appear to be associated with increased fracture risk in elderly women, but there is less evidence of a relationship between bone formation markers and fracture risk. The critical question of predicting fracture efficacy with treatment has not been answered. Changes in bone markers as currently determined do not predict BMD response to either bisphosphonates or hormone replacement therapy. Single measurements of markers do not predict BMD cross-sectionally (except possibly in the very elderly), or change in BMD in individual patients, either treated or untreated. On the other hand, research applications of bone turnover markers are of value in investigating the pathogenesis and treatment of bone diseases. Markers have potential in the clinical management of osteoporosis, but their use in this regard is not established. Additional studies with fracture endpoints and information on negative and positive predictive value are needed to evaluate fully the utility of bone turnover markers in individual patients.

Biomarkers↗
PubMed2000

A randomized trial of nasal spray salmon calcitonin in postmenopausal women with established osteoporosis: the prevent recurrence of osteoporotic fractures study. PROOF Study Group.

PURPOSE: We conducted a 5-year, double-blind, randomized, placebo-controlled study to determine whether salmon calcitonin nasal spray reduced the risk of new vertebral fractures in postmenopausal women with osteoporosis. SUBJECTS AND METHODS: A total of 1,255 postmenopausal women with established osteoporosis were randomly assigned to receive salmon calcitonin nasal spray (100, 200, or 400 IU) or placebo daily. All participants received elemental calcium (1,000 mg) and vitamin D (400 IU) daily. Vertebral fractures were assessed with lateral radiographs of the spine. The primary efficacy endpoint was the risk of new vertebral fractures in the salmon calcitonin nasal spray 200-IU group compared with the placebo group. RESULTS: During 5 years, 1,108 participants had at least one follow-up radiograph. A total of 783 women completed 3 years of treatment, and 511 completed 5 years. The 200-IU dose of salmon calcitonin nasal spray significantly reduced the risk of new vertebral fractures by 33% compared with placebo [200 IU: 51 of 287, placebo: 70 of 270, relative risk (RR) = 0.67, 95% confidence interval (CI): 0.47- to 0.97, P = 0.03]. In the 817 women with one to five prevalent vertebral fractures at enrollment, the risk was reduced by 36% (RR = 0.64, 95% CI: 0.43- to 0.96, P = 0.03). The reductions in vertebral fractures in the 100-IU (RR = 0.85, 95% CI: 0.60- to 1.21) and the 400-IU (RR = 0.84, 95% CI: 0.59- to 1.18) groups were not significantly different from placebo. Lumbar spine bone mineral density increased significantly from baseline (1% to 1. 5%, P<0.01) in all active treatment groups. Bone turnover was inhibited, as shown by suppression of serum type-I collagen cross-linked telopeptide (C-telopeptide) by 12% in the 200-IU group (P <0.01) and by 14% in the 400-IU group (P<0.01) as compared with placebo. CONCLUSION: Salmon calcitonin nasal spray at a dose of 200 IU daily significantly reduces the risk of new vertebral fractures in postmenopausal women with osteoporosis.

Aged↗
PubMed1999

Effects of risedronate treatment on vertebral and nonvertebral fractures in women with postmenopausal osteoporosis: a randomized controlled trial. Vertebral Efficacy With Risedronate Therapy (VERT) Study Group.

CONTEXT: Risedronate, a potent bisphosphonate, has been shown to be effective in the treatment of Paget disease of bone and other metabolic bone diseases but, to our knowledge, it has not been evaluated in the treatment of established postmenopausal osteoporosis. OBJECTIVE: To test the efficacy and safety of daily treatment with risedronate to reduce the risk of vertebral and other fractures in postmenopausal women with established osteoporosis. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial of 2458 ambulatory postmenopausal women younger than 85 years with at least 1 vertebral fracture at baseline who were enrolled at 1 of 110 centers in North America conducted between December 1993 and January 1998. INTERVENTIONS: Subjects were randomly assigned to receive oral treatment for 3 years with risedronate (2.5 or 5 mg/d) or placebo. All subjects received calcium, 1000 mg/d. Vitamin D (cholecalciferol, up to 500 IU/d) was provided if baseline levels of 25-hydroxyvitamin D were low. MAIN OUTCOME MEASURES: Incidence of new vertebral fractures as detected by quantitative and semiquantitative assessments of radiographs; incidence of radiographically confirmed nonvertebral fractures and change from baseline in bone mineral density as determined by dual x-ray absorptiometry. RESULTS: The 2.5 mg/d of risedronate arm was discontinued after 1 year; in the placebo and 5 mg/d of risedronate arms, 450 and 489 subjects, respectively, completed all 3 years of the trial. Treatment with 5 mg/d of risedronate, compared with placebo, decreased the cumulative incidence of new vertebral fractures by 41 % (95% confidence interval [CI], 18%-58%) over 3 years (11.3 % vs 16.3%; P= .003). A fracture reduction of 65% (95% CI, 38%-81 %) was observed after the first year (2.4% vs 6.4%; P<.001). The cumulative incidence of nonvertebral fractures over 3 years was reduced by 39% (95% CI, 6%-61 %) (5.2 % vs 8.4%; P = .02). Bone mineral density increased significantly compared with placebo at the lumbar spine (5.4% vs 1.1 %), femoral neck (1.6% vs -1.2%), femoral trochanter (3.3% vs -0.7%), and midshaft of the radius (0.2% vs -1.4%). Bone formed during risedronate treatment was histologically normal. The overall safety profile of risedronate, including gastrointestinal safety, was similar to that of placebo. CONCLUSIONS: These data suggest that risedronate therapy is effective and well tolerated in the treatment of women with established postmenopausal osteoporosis.

Aged↗
PubMed1998

Women of reproductive age with endometriosis are not osteopenic.

OBJECTIVE: To determine whether women of reproductive age with endometriosis are osteopenic and whether bone density decreases with higher stages of endometriosis. DESIGN: A multicenter cross-sectional study was performed. SETTING: Thirty-nine gynecological clinics in the United States, Canada, and Puerto Rico. PATIENT(S): Two hundred forty-one women of reproductive age with laparoscopically proved endometriosis. INTERVENTION(S): Diagnostic laparoscopy, bone densitometry. MAIN OUTCOME MEASURE(S): Endometriosis stages according to the criteria of the American Society for Reproductive Medicine, lumbar spine bone mineral density (L2-L4) as measured by dual-energy x-ray absorptiometry. RESULT(S): The mean lumbar spine bone mineral density, as well as the distribution of bone mineral density, of the women with endometriosis was similar to that of a normal population. There were no significant differences between endometriosis stage groups I-IV regarding bone mineral density as well as body weight, body mass index, and height. CONCLUSION(S): Women of reproductive age with endometriosis are not osteopenic. More advanced stages of endometriosis are not associated with a decrease in lumbar spine bone mineral density.

Adolescent↗
PubMed1997

Implementation of an osteoporosis research program with a mobile dual-energy X-ray absorptiometry unit: the Montana/Wyoming experience.

To expedite recruitment, and subject participation, for a large clinical osteoporosis therapy trial utilizing the bisphosphonate ibandronate, an integrated network of 13 satellite clinical sites was developed, linked by a mobile clinic vehicle transporting a dual-energy X-ray absorptiometry (DXA) unit. A predominantly rural area of the United States (Montana, northern Wyoming) was accessed for the project, due to the large pool of potential subjects living in this area who were not yet involved in osteoporosis clinical studies. The results of the project to date (through 10 months) confirm the feasibility of such a study design, with 1774 subjects screened by DXA for the study, and 280 (15.8%) accepted. The mobile DXA unit has functioned according to specifications for a stationary DXA machine, with the stability of spine phantom measurements over 10 months assessed as a coefficient of variation of 0.46%. The success of the project validates the concept of performing clinical osteoporosis therapy trials in previously underutilized rural community settings, facilitated by a satellite site network and mobile clinic.

Absorptiometry, Photon↗
PubMed1997

Hormone replacement therapy in postmenopausal women: urinary N-telopeptide of type I collagen monitors therapeutic effect and predicts response of bone mineral density.

PURPOSE: To assess the ability of the urinary N-telopeptide of type I collagen (NTx) to monitor and predict therapeutic effects of hormone replacement therapy (HRT) in postmenopausal women. PATIENTS AND METHODS: To assess the relationship between baseline or change in NTx (predictive variable), and change in lumbar and hip bone mineral density (BMD; outcome variable), we conducted a 2-year randomized controlled study at academic university and private practice medical centers in 236 healthy women 1 to 3 years postmenopausal; 227 women completed the study. Women received estrogen plus progesterone plus calcium (treated group) or calcium alone (control group). RESULTS: In the treated group NTx significantly (P < 0.0001) decreased, and spine and hip BMD significantly (P < 0.00001 and P < 0.005, respectively) increased; in the control group NTx did not change but BMD decreased significantly (P < 0.01). Subjects in the highest quartiles for baseline NTx (67 to 188 units) or decreasing NTx (-66% to -87%) through 6 months demonstrated the greatest gain in BMD in response to HRT (P < 0.05 and P < 0.005). For every increase of 30 units in baseline NTx the odds of gain in BMD in response to HRT increased by a factor of 5.0 (95% confidence interval [CI] 1.9 to 13.3); for every 30% decrease in NTx through 6 months, the odds of gaining BMD in response to HRT increased by a factor of 2.6 (95% CI 1.6 to 4.4). In the control group an increase of 30 units in mean NTx across the study indicated a higher odds of losing BMD by a factor of 3.2 (95% CI 1.6 to 6.5). A high baseline NTx (> 67 units) indicated a 17.3 times higher risk of BMD loss if not treated with HRT. CONCLUSION: These data support the clinical utility of NTx to monitor the antiresorptive effect of HRT in recently postmenopausal women, and to predict changes in BMD in response to HRT.

Absorptiometry, Photon↗
PubMed1997

Increments in bone mineral density of the lumbar spine and hip and suppression of bone turnover are maintained after discontinuation of alendronate in postmenopausal women.

PURPOSE: Previously we have reported a significant increase in bone mineral density (BMD) of the spine and the hip and reductions in biochemical indices of bone turnover in postmenopausal women with osteoporosis treated with alendronate at various doses over 1 to 2 years. We have followed BMD and biochemical parameters in these patients for 1 or 2 years after discontinuation of alendronate to determine resolution of alendronate effects. PATIENTS AND METHODS: Participants received daily oral doses of placebo, 5 or 10 mg of alendronate for 2 years, or 20 or 40 mg of alendronate for 1 year followed by 1 year of placebo. No treatment was given in the third year of study. RESULTS: Lumbar spine BMD changes in the 5- and 10-mg groups (-1.4 and -0.4%) were similar to those in the placebo group (-1.2%) 1 year after discontinuation of drug and lumbar spine BMD changes in the 20- and 40-mg groups (-1.2% and 0.8%) were similar to those in the placebo group (-0.9%) 2 years after discontinuation of drug. BMD of the total hip followed the same pattern of resolution. The difference in BMD between alendronate and placebo groups at the end of alendronate treatment was maintained up to 2 years. Residual reductions in the bone resorption markers urinary deoxypyridinoline (D-Pyr) and collagen type 1 cross-linked N telopeptides and the bone formation markers serum bone-specific alkaline phosphatase and osteocalcin remained for 1 year after discontinuation of 5 and 10 mg of alendronate and for 2 years after discontinuation of 20 and 40 mg of alendronate, other than return of D-Pyr to baseline 1 year after cessation of treatment with the 5- and 10-mg doses. CONCLUSIONS: A residual decrease in bone turnover may be found up to 2 years after discontinuation of alendronate. Accelerated bone loss is not observed when treatment is discontinued. However, continuous therapy with alendronate is required to achieve a continuous gain in BMD.

Adult↗
PubMed1997

Cyclical etidronate in the treatment of postmenopausal osteoporosis: efficacy and safety after seven years of treatment.

PURPOSE: To determine the efficacy and safety of cyclical etidronate for up to 7 years in the treatment of postmenopausal osteoporosis and to examine the effects of discontinuing treatment after 2 or 5 years of therapy. PATIENTS AND METHODS: Patients were randomized at entry into the original study in 1986 to blinded treatment for 2 years with either a calcium (placebo) or an intermittent cyclical etidronate regimen, which most patients continued for a third year. Following this phase of the study, patients were enrolled into an open-label, follow-up study (years 4 and 5), during which all patients received cyclical etidronate treatment. In the present double-blind study (years 6 and 7), patients were rerandomized to receive intermittent cyclical therapy with either etidronate or placebo; all patients received calcium. The treatment regimen consisted of 400 mg/day etidronate or placebo for 14 days, followed by 76 days of elemental calcium (500 mg/day); this cycle was repeated approximately 4 times in each year. Of the 193 patients who continued in years 6 and 7 of the study, 93 were randomized to receive cyclical etidronate and 100 were randomized to receive calcium only. For purposes of efficacy analyses, patients were categorized by their total years of cumulative etidronate treatment (7, 5, 4, or 2 years). There were 51, 46, 42, and 54 patients in the 7-, 5-, 4-, and 2-year groups, respectively. Annual assessments included lumbar spine bone mineral density (BMD), as measured by densitometry, and vertebral radiographs. RESULTS: The groups receiving cyclical etidronate during this 2-year study period (7- and 4-year groups) had statistically significant mean percent increases in spinal BMD of 1.8% and 2.2%, respectively (P < 0.05) at the week 104 observation time. The 5- and 2-year groups, which did not receive etidronate during this period, had mean values of 1.4% and 0.2%, respectively (not significant) at week 104. In the 7-, 5-, 4-, and 2-year groups, the increases in spinal BMD at the end of 7 years were 7.6%, 8.6%, 8.1%, and 3.9%, respectively; these values were statistically significant for all groups compared with original baseline (year 0) (P < 0.05). BMD of the femur and wrist was maintained throughout the 7-year period. The incidence and rate of vertebral fractures were lowest in patients with the longest exposure to etidronate. Etidronate was well tolerated during the study, with low incidences of gastrointestinal side effects and nonvertebral fractures. CONCLUSIONS: Long-term cyclical etidronate is a safe, effective, and well-tolerated treatment for postmenopausal osteoporosis. Bone mass is maintained for at least 2 years after treatment with etidronate is stopped; however, further gains in spinal bone mass are seen in patients who continue therapy.

Aged↗
PubMed1997

The predictive value of biochemical markers of bone turnover for bone mineral density in early postmenopausal women treated with hormone replacement or calcium supplementation.

To compare the relative sensitivity and specificity of bone turnover indexes for bone loss or gain in early postmenopausal women, we performed a multicenter trial in 236 menopausal women (mean age, 51 yr), who were randomized to hormone replacement therapy (HRT) or calcium supplementation (CS; 500 mg/day) for 1 yr. Two markers of bone formation, osteocalcin (OC) and bone alkaline phosphatase (BSAP), and two markers of bone resorption, urinary N-telopeptide (NTx) and urinary free deoxypyridinoline (fDpd), as well as spine and femoral neck bone mineral density (BMD) were measured at baseline and 3, 6, and 12 months after treatment. Women receiving HRT (n = 105) showed a significant increase in spine BMD (+2.5%; P < 0.0001) and hip BMD (+1.0%; P = 0.02) compared to women receiving CS, who showed a decline at both sites (-1.1%; P < 0.01). All four markers showed time-dependent decreases in women receiving HRT (P < 0.001) and no change in women receiving CS alone. When baseline indexes of turnover were stratified by quartile, there was a significantly greater increase in BMD among those with the highest NTx, OC, and BSAP levels compared to that in those with the lowest NTx, OC, and BSAP levels (P < 0.05). The highest quartile for percent change from baseline to 6 months in fDpd, BSAP, and NTx was also associated with the greatest change in spine BMD at 1 yr. Receiver operator characteristic curves for percent change from baseline to 6 months in an individual marker to 1 yr change in BMD during HRT revealed that the percent change in NTx provided the greatest discrimination between gain and loss of BMD. When subjects receiving HRT were compared by their positive or negative skeletal response at 1 yr and their baseline turnover marker, initial NTx values were significantly higher in those that gained bone than in those that lost bone (P = 0.0002). CS women in the highest quartile for NTx at baseline had significantly greater decreases in spine BMD than subjects with the lowest NTx values (P < 0.005), although this was not true for fDpd (P < 0.20). In conclusion, for early postmenopausal women there are differential responses of biochemical markers to HRT and CS. Baseline urinary NTx and serum OC were the most sensitive predictors of change in spine BMD after 1 yr of either HRT or CS. Similarly, the percent change in NTx and OC from baseline to 6 months best predicted bone gain or loss. We conclude that markers of bone formation and resorption can be used clinically to predict future BMD in early postmenopausal women.

Adult↗
PubMed1997

Fractures attributable to osteoporosis: report from the National Osteoporosis Foundation.

To assess the cost-effectiveness of interventions to prevent osteoporosis, it is necessary to estimate total health care expenditures for the treatment of osteoporotic fractures. Resources utilized for the treatment of many diseases can be estimated from secondary databases using relevant diagnosis codes, but such codes do not indicate which fractures are osteoporotic in nature. Therefore, a panel of experts was convened to make judgments about the probabilities that fractures of different types might be related to osteoporosis according to patient age, gender, and race. A three-round Delphi process was applied to estimate the proportion of fractures related to osteoporosis (i.e., the osteoporosis attribution probabilities) in 72 categories comprised of four specific fracture types (hip, spine, forearm, all other sites combined) stratified by three age groups (45-64 years, 65-84 years, 85 years and older), three racial groups (white, black, all others), and both genders (female, male). It was estimated that at least 90% of all hip and spine fractures among elderly white women should be attributed to osteoporosis. Much smaller proportions of the other fractures were attributed to osteoporosis. Regardless of fracture type, attribution probabilities were less for men than women and generally less for non-whites than whites. These probabilities will be used to estimate the total direct medical costs associated with osteoporosis-related fractures in the United States.

Aged↗
PubMed1996

Bone density at multiple skeletal sites in amenorrheic athletes.

OBJECTIVE: To determine if there is a generalized loss of bone mass at multiple skeletal sites in amenorrheic athletes compared with a group of eumenorrheic athletes. DESIGN: A case-control study examining the differences in bone mineral density (BMD) between amenorrheic and eumenorrheic athletes. SETTING: Seattle, Wash, and surrounding communities. PARTICIPANTS: Forty-nine athletes, aged 17 to 39 years, were selected from those responding to advertisements in local sporting-goods stores and a track-and-field newsletter. Athletes were defined as amenorrheic if they had had fewer than 2 menstrual cycles in the last 12 months or none in the past 6 months, or eumenorrheic if they had had 10 to 13 cycles in the previous year. Only women who met these criteria, confirmed by tests for estradiol and progesterone levels, were enrolled in the study. MAIN OUTCOME MEASURES: Bone mineral density measured by dual-energy x-ray absorptiometry. RESULTS: Amenorrheic athletes had significantly lower BMD (P < .01) at the lumbar spine, femoral neck, trochanter, Ward triangle, intertrochanteric region, femoral shaft, and tibia. No difference was noted at the fibula. Body weight combined with months of amenorrhea and age of menarche predicted the BMD of the lumbar spine for amenorrheic athletes. Duration of amenorrhea and body weight of amenorrheic athletes predicted BMD at the femoral neck, trochanter, intertrochanteric region, and tibia. Weight alone predicted BMD at the femoral shaft and tibia. Age plus weight predicted lumbar BMD of eumenorrheic women. CONCLUSION: Extended periods of amenorrhea may result in low bone density at multiple skeletal sites including those subjected to impact loading during exercise.

Absorptiometry, Photon↗
PubMed1996

Urinary N-telopeptides to monitor bone resorption while on GnRH agonist therapy.

OBJECTIVES: To assess the utility of urinary cross-linked N-telopeptides in monitoring bone resorption and predicting bone loss during GnRH agonist administration. METHODS: Ninety patients who were prescribed GnRH agonist therapy for 3-6 months for treatment of endometriosis, leiomyomas or other gynecologic disorders participated in this prospective multicenter study. N-telopeptides, serum estradiol (E2), and bone mineral density were monitored before, during and up to 3 months after the course of GnRH agonist therapy. RESULTS: N-telopeptide levels increased significantly throughout GnRH agonist therapy and returned to baseline levels by 3 months after treatment was completed. A significant negative correlation was seen between N-telopeptide and E2 measurements after 3 months (r=-0.23, P<.05), 4 months (r=-0.32, P < .05), and 5 months (r=-0.41, P<.005) of GnRH agonist therapy. The percent change in bone mineral density at L1-L4 at 6 months of GnRH agonist treatment correlated inversely with the percent change in N-telopeptides from baseline to 2,3,4, and 5 months of treatment; the percent change of bone mineral density at the femoral neck at 6 months correlated inversely with the percent change of N-telopeptides from baseline to month 4. CONCLUSIONS: Urinary N-telopeptide determinations provide a quantitative measure of bone resorption, due to GnRH agonist-induced hypoestrogenism. Increases in resorption as measured by N-telopeptides parallel decreases in in E2 levels. Increases in N-telopeptides on GnRH agonist therapy may provide a tool to predict decreases in bone mineral density.

Adult↗