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Laura K Bachrach

Publications and source records attributed to Laura K Bachrach.

17 recordsLinked to original sources
PubMed2006

Sequential comparisons of one-month and three-month depot leuprolide regimens in central precocious puberty.

BACKGROUND: Dosing of monthly depot leuprolide (DL) in central precocious puberty (CPP) varies considerably. U.S. practitioners use 7.5-15 mg, in contrast with the international standard of 3.75 mg. Pubertal suppression using the newer 3-month DL also has been reported from Europe. To date there have been no direct comparisons of these different DL doses. OBJECTIVES: In an open 12-month protocol, we tested the efficacy of three DL doses (7.5 mg- and 3.75 mg-1 month and 11.25 mg-3 month) given sequentially to subjects treated for CPP. Primary outcome measures were stimulated gonadotropin (Gn) levels at 12-wk intervals. The null hypothesis was no difference among doses. METHODS: Both existing and new patients with CPP received our standard therapy (DL 7.5 mg every 4 wk) for a minimum of 24 wk. In subjects with DL-stimulated LH 2 IU/liter or less, the dose was changed to 3.75 mg every 4 wk and evaluated 12 wk later. Subjects who met LH criteria (<4.5 IU/liter) on 3.75 mg then received a single dose of 11.25 mg-3 month and were reevaluated 12 wk later. Serum LH/FSH and sex steroids were obtained 40 min after DL injection. RESULTS: Thirty subjects were enrolled (20 naive; 24 girls, 6 boys), and 21 were evaluated on all three DL doses. DL-stimulated LH levels (mean +/- sd) were 1.30 +/- 0.74, 1.73 +/- 0.99, and 2.13 +/- 1.41 on 7.5 mg, 3.75 mg, and 11.25 mg-3 month, respectively (7.5 vs. 3.75 mg, P = 0.019; 7.5 mg vs. 11.25 mg-3 month, P = 0.004, Wilcoxon ranked sign test). Mean FSH levels were 2.86 +/- 1.91, 3.91 +/- 1.98, and 3.96 +/- 1.34, respectively (7.5 vs. 3.75 mg, P = 0.017; 7.5 mg vs. 11.25 mg-3 month, P = 0.020). No differences were detected in mean sex steroid levels. CONCLUSIONS: Stimulated LH and FSH levels were significantly higher during therapy with both the 3.75 mg and 11.25 mg-3 month depot leuprolide doses, compared with 7.5 mg, contradicting the null hypothesis of no difference. These data suggest that low-dose 1- and 3-month DL preparations are associated with persistently greater gonadal stimulation in most CPP patients, but the LH/FSH results were not corroborated by differences in sex steroid levels. Whether various DL doses lead to long-term therapeutic differences remains to be determined.

Child↗
PubMed2006

Measuring bone mass in children: can we really do it?

Bone densitometry is used to assess skeletal health in clinical and research settings, with the goal of achieving reproducible measurements of bone mass that help to identify individuals predisposed to fracture. The search is now on for better methods of capturing additional factors that contribute to bone strength, including bone size, geometry, microarchitecture, and turnover rates. This has proved particularly challenging in growing children, whose bones continually change in size, shape, and mass. Dual energy X-ray absorptiometry is the preferred method for measuring bone mass in children, but the technique has several limitations, and interpreting the findings can be problematic. Peripheral quantitative computed tomography is a promising method for assessing bone mass and other indices correlating with bone strength, but a lack of precision and paediatric norms currently restricts its clinical utility. Although bone mineral density is predictive of future fracture risk in adults, the evidence in children is less conclusive, and a diagnosis of osteoporosis in a child should not be made on densitometric findings alone. Developing a clearer understanding of how measures of bone mass and strength correlate with bone fracture in children will help target preventive strategies for those in greatest need.

Bone Density↗
PubMed2005

Osteoporosis and measurement of bone mass in children and adolescents.

Osteoporosis increasingly is recognized as a pediatric concern. Fragility fractures occur in children and adolescents with genetic disorders and those with a variety of chronic diseases. Others may not fracture in childhood but reach adulthood with a reduced peak bone mass and increased lifelong risk of osteoporosis. This article reviews the indications for pediatric bone density testing, the strengths and limitations of densitometry methods, and the challenges of interpreting the results. The goals are to demystify the densitometry report and to clarify the role of bone density tests in assessing and managing skeletal health in children.

Absorptiometry, Photon↗
PubMed2005

Assessing bone health in children: who to test and what does it mean?

The foundation of bone health is established during childhood and adolescence. Unfortunately, pediatric bone health may be threatened in a variety of genetic and acquired disorders. Low bone mineral density (BMD) and/or fragility fractures may result. This paper addresses the pediatric indications for bone densitometry testing in children at risk for poor bone health and the challenges of interpreting the results. Dual energy x-ray absorptiometry (DXA) is the most commonly used of the bone densitometry methods. Most DXA software programs report BMD in terms of a T-score, which compares the results to adult norms. Z-scores, based upon age- and gender-matched reference data, should be used instead to avoid the mislabeling of a child as "osteoporotic." Delayed growth and maturation also complicate the interpretation of DXA findings in chronically ill patients. Although children with low BMD values may have an increased risk of fracture, a pediatric "fracture threshold" has not been established. Further research is needed to refine the indications for bone density testing in children and to aid in the interpreting the results.

Absorptiometry, Photon↗
PubMed2004

Guide to bone health and disease in cystic fibrosis.

Cystic fibrosis (CF) is the most common genetic disease within the Caucasian population and leads to premature respiratory failure. Approximately 60,000 individuals are currently living with CF in North America and Europe, 40% of whom are adults. The life span of these patients has increased from approximately 2 to 32 yr of age over the last three decades. Bone disease has emerged as a common complication in long-term survivors of CF. Some studies have observed that 50-75% of adults have low bone density and increased rates of fractures. Prevention and treatment of CF-related bone disease must address the myriad risk factors (decreased absorption of fat-soluble vitamins due to pancreatic insufficiency, altered sex hormone production, chronic lung infection with increased levels of bone-active cytokines, physical inactivity, and glucocorticoid therapy) for poor bone health. This review is a condensed and updated summary of the Guide to Bone Health and Disease in Cystic Fibrosis: A Consensus Conference, a statement that evolved from a meeting convened by the Cystic Fibrosis Foundation in May 2002 to address the pathogenesis, diagnosis, and treatment of bone disease in CF. The goal of this conference was to develop practice guidelines for optimizing bone health in patients with CF.

Bone Diseases↗
PubMed2004

Official positions of the international society for clinical densitometry.

The International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences for the purpose of establishing standards and guidelines for indications, acquisition, and interpretation of bone density tests. Topics are selected for consideration by the ISCD Scientific Advisory Committee, reviewed by scientific working groups, and presented to an international panel of experts. Topic categories addressed to date include indications for bone density testing, selection of reference databases for T-scores and Z-scores, clinical applications for central and peripheral bone densitometry, serial bone density testing, instrument precision assessment, phantom scanning and calibration testing, requirements for a bone density report, nomenclature, and diagnosis of osteoporosis in postmenopausal women, premenopausal women, men, and children. After an open session for public comment and discussion, the panel convenes for consideration of each topic and makes recommendations for positions to the ISCD Board of Directors. Recommendations that are accepted become the Official Positions of the ISCD. This Special Report summarizes the methodology of the ISCD Position Development Conferences and presents selected Official Positions of general interest.

Absorptiometry, Photon↗
PubMed2003

Bone mineral density in pediatric transplant recipients.

BACKGROUND: Reduced bone mass and fragility fractures are known complications after transplantation in adults. Far less is known about the skeletal effects of transplantation in children and adolescents. METHODS: This cross-sectional study examined the skeletal status of children (ages 9-18 years) who were at least 1 year post-cardiac (n=13), post-renal (n=8), or post-bone marrow (BMT; n=15) transplantation. Bone mass at total hip, femoral neck, spine (L2-4), and whole body (WB) was determined by dual energy x-ray absorptiometry and compared with age, sex, and ethnic-specific reference data. Standard deviations (z-scores) were calculated for both areal bone mineral density (BMD) and estimated volumetric bone density (bone mineral apparent density [BMAD]). RESULTS: Cardiac transplant patients had significantly lower BMD z-scores compared with the reference population at all skeletal sites. BMT recipients had significantly reduced BMD z-scores at total hip, spine, and WB. Kidney transplant patients had a significantly reduced WB BMD z-score only. Spine BMAD z-scores remained significantly reduced in cardiac and BMT subjects. Three of 36 patients had radiographic evidence of spinal fracture after transplantation. No correlation between steroid dosage and any measure of bone mass was observed. CONCLUSIONS: Cardiac and BMT recipients had reduced BMD at multiple skeletal sites, and renal transplant recipients had reduced WB BMD for age. Deficits in spine bone density persisted after correcting for small bone size using BMAD. Low bone density and the occurrence of vertebral fractures indicate that cardiac, renal, and bone marrow transplantation in children is associated with reduced bone health.

Adolescent↗
PubMed2003

Diet in midpuberty and sedentary activity in prepuberty predict peak bone mass.

BACKGROUND: An average daily calcium intake of 1300 mg is recommended for North American adolescents aged 9-18 y. However, questions remain about these recommendations. OBJECTIVE: We assessed whether there is a stage of puberty when dietary calcium is more strongly related to peak bone mass, as indicated by young adult bone mass (YABM); whether dietary calcium intake > 1000 mg/d in adolescence is associated with higher YABM; and whether race affects any of these associations between dietary calcium and YABM. Secondarily, we evaluated relations between sedentariness and YABM. DESIGN: In a retrospective cohort study, we recruited 693 black and white women aged 21-24 y who had participated in the 10-y National Heart, Lung, and Blood Institute Growth and Health Study and measured YABM with the use of dual-energy X-ray absorptiometry. Dietary calcium and sedentary activity data, gathered through 3-d food records and self-reports of television-video viewing at 8 annual examinations, were averaged over 3 pubertal stages. Complete data were available from 161 black and 180 white females. Multiple regression, controlling for race, weight, and height, was applied to assess diet and activity relations with YABM. RESULTS: Dietary calcium was most strongly associated with YABM in midpuberty. Calcium intake > 1000 mg/d was associated with higher YABM, but this association was not significant at all skeletal sites. Race did not affect the observed relations between calcium and YABM. Sedentary activity in prepuberty was inversely associated with YABM. CONCLUSIONS: Interventions should focus on ensuring adequate calcium intake in midpuberty and on minimizing sedentariness in prepuberty.

Absorptiometry, Photon↗
PubMed2003

Disordered eating, menstrual irregularity, and bone mineral density in female runners.

PURPOSE: To examine the relationships between disordered eating, menstrual irregularity, and low bone mineral density (BMD) in young female runners. METHODS: Subjects were 91 competitive female distance runners aged 18-26 yr. Disordered eating was measured by the Eating Disorder Inventory (EDI). Menstrual irregularity was defined as oligo/amenorrhea (0-9 menses per year). BMD was measured by dual x-ray absorptiometry. RESULTS: An elevated score on the EDI (highest quartile) was associated with oligo/amenorrhea, after adjusting for percent body fat, age, miles run per week, age at menarche, and dietary fat, (OR [95% CI]: 4.6 [1.1-18.6]). Oligo/amenorrheic runners had lower BMD than eumenorrheic runners at the spine (-5%), hip (-6%), and whole body (-3%), even after accounting for weight, percent body fat, EDI score, and age at menarche. Eumenorrheic runners with elevated EDI scores had lower BMD than eumenorrheic runners with normal EDI scores at the spine (-11%), with trends at the hip (-5%), and whole body (-5%), after adjusting for differences in weight and percent body fat. Runners with both an elevated EDI score and oligo/amenorrhea had no further reduction in BMD than runners with only one of these risk factors. CONCLUSION: In young competitive female distance runners, (i) disordered eating is strongly related to menstrual irregularity, (ii) menstrual irregularity is associated with low BMD, and (iii) disordered eating is associated with low BMD in the absence of menstrual irregularity.

Absorptiometry, Photon↗
PubMed2003

Comparison of calcaneus ultrasound and dual X-ray absorptiometry in children at risk of osteopenia.

The optimal method to assess pediatric bone mass remains controversial. Dual X-ray absorptiometry (DXA) is used most commonly for clinical assessments in children, but calcaneus ultrasound (CUS) is less costly, is free of ionizing radiation, and predicts fracture as well as DXA in adults. This study was designed to compare CUS and DXA in 42 young patients (ages 9-21) with chronic disease and/or fragility fractures. Zscores for broadband ultrasound attenuation (BUA) and speed of sound (SOS) determined using the Lunar Achilles Plus ultrasonometer were compared with Z-scores for areal bone mineral density (BMD) and volumetric BMD using DXA (Hologic). Logistic regression was employed to predict low bone density measured by DXA (defined as spinal BMD Z-score < -2) from CUS measurements. Sensitivity/specificity analysis was performed to compare CUS and spinal DXA Z-scores as predictors of previous low-impact fracture. Correlations between CUS and DXA Z-scores were in the range of r = 0.3-0.6. Areas under the receiver operator characteristic (ROC) curves for BUA and SOS predicting low bone density by DXA were similar: 0.81 and 0.82, respectively. ROC curve areas for spinal DXA, BUA, and SOS predicting previous fracture were also similar: 0.85, 0.84, and 0.84, respectively. While CUS correlates only modestly with DXA, ROC curve areas indicate that CUS detects low bone mineral in children with fragility fractures as well as DXA and may be a viable initial screen for osteopenia.

Absorptiometry, Photon↗
PubMedDate not supplied

Low-dose intravenous pamidronate reduces fractures in childhood osteoporosis.

Despite the proven efficacy of low-dose pamidronate in adults with osteoporosis, the efficacy of the low-dose regimen in children has not been studied. Pamidronate (1 mg/kg) was administered intravenously once every 3 months to 11 children with osteoporosis. Treatment was associated with reduced fracture rates and increased areal (BMD) and volumetric (BMAD) bone mineral density measured by dual energy X-ray absorptiometry (DXA). The mean annualized percent gain was 20.1 +/- 16.9 (4.7 to 59.1, n = 9) for spinal BMD and 15.1 +/- 18.1 (-11.0 to 40.2, n = 9) for spinal BMAD. Common adverse effects including fever, muscle aches, nausea and fatigue were self-limited and generally occurred only after the first infusion. Clinically significant hypocalcemia did not occur. Low-dose pamidronate appears promising in the treatment of childhood osteoporosis.

Absorptiometry, Photon↗