5 Clinical Trials for Various Conditions
Adolescents and young adults with anorexia nervosa (AN) are at high risk for low bone mineral density at a time when healthy adolescents are rapidly accruing bone, with implications for peak bone mass and fracture risk in later life. They are also deficient in insulin-like growth factor 1 (IGF-1), the bone trophic factor made in the liver in response to growth hormone (GH), despite elevated levels of growth hormone. It is possible that deficiency of insulin-like growth factor 1, a hormone very important for the maintenance of skeletal integrity, may contribute to the severe osteopenia seen in anorexia nervosa. The physiologic effects of recombinant human insulin-like growth factor 1 (rhIGF-1) treatment in adolescents and young adults with anorexia nervosa have not been studied. The goal of this proposal is to investigate the effects of recombinant human insulin-like growth factor 1 on bone density and bone microarchitecture in adolescent girls and young adult women with anorexia nervosa over a 6 month period. We hypothesize that adolescent and young adult anorexia nervosa patients, being insulin-like growth factor 1 deficient, will respond to exogenously administered recombinant human insulin-like growth factor 1 with elevations in biochemical indices of bone turnover and an increase in bone density and improvement in bone structure, or maintain bone density (in contrast to the decrease in bone density expected in adolescent girls and women with anorexia nervosa who are not treated).
Changes in maternal calcium metabolism are necessary during lactation to provide adequate calcium in breast milk for development of the newborn skeleton. The calcium in milk is derived from the maternal skeleton, resulting in significant bone loss, a process thought to be mediated by the actions of parathyroid hormone-related protein (PTHrP) in combination with a decreased estrogen levels. After weaning, bone lost during lactation is rapidly regained. Differences between African-American and Caucasian bone metabolism are well documented and include higher bone mineral density (BMD), lower risk of fragility fracture, lower 25-hydroxyvitamin D (25(OH) D), and higher PTH in African-Americans compared to Caucasians. Most studies of bone metabolism in lactating women have been done in Caucasians. Because of differences in bone metabolism between African-Americans and Caucasians, we do not know whether African-Americans will have similar findings. The primary aim of this study is to compare the changes in bone mineral density (BMD) during lactation in African-Americans with those in Caucasians. It is not known whether the loss in BMD during lactation will be the same for both races. African-Americans display skeletal resistance to PTH with short-term infusions and have lower bone resorption, higher BMD and lower fracture risk than Caucasians. A recent study by our group indicated that lactating African-American mothers had slightly lower bone resorption but quantitatively similar bone formation compared to Caucasians. However, there was a significant increase of 2-3 fold in markers of bone formation and resorption in both groups. Therefore, it is currently not known whether the loss in BMD during lactation will be the same for both races. Primary outcome measures in this study will include spine, hip and radius BMD by Dual X-Ray Absorbiometry (DXA)Scans during lactation (at 2,12 and 24 weeks postpartum or at weaning if prior to 24 weeks postpartum, and six months after weaning (+1 week). This longitudinal protocol will distinguish between two hypotheses. Either: a) as measured by BMD, bone loss in African-Americans during lactation will be equal to that in Caucasians, and skeletal recovery will be the same or possibly accelerated compared to Caucasians; or, b) African-Americans will be resistant to bone loss during lactation compared to Caucasians because of resistance to Parathyroid Hormone-related Protein (PTHrP).
The investigators are doing this study to look at how different doses of the Depot medroxyprogesterone acetate (DMPA) shot effect weight gain and bone mineral density in teens. The investigators hope that what the investigators learn from this study will be used to develop ways to keep girls from gaining weight or losing bone density when receiving DMPA.
This is a research study to determine the effects of functional electrical stimulation (FES) rowing and a drug called zoledronic acid in bone health. The investigators hoped to learn if zoledronic acid treatment will increase bone mineral density in persons with chronic spinal cord injury (SCI) who received it. The investigators also want to find out if zoledronic acid is safe for persons with SCI to take without causing too many side effects.
Patients with severe acid reflux and/or Barrett's esophagus are recommended to take Proton pump inhibitors (PPIs)indefinitely to prevent complications such as strictures or the development of a type of esophageal cancer. Recently, some studies suggested that taking these medications on a long-term basis may affect the bone. Therefore, it is important to learn whether these medications may lead to accelerated bone loss so that effective preventive measures can be developed for patients who require these medications for acid-related conditions. Several studies reported that patients receiving PPIs for many years may have increased risk of hip fractures. However, it is unclear whether this is because the PPIs cause reduced bone density or whether the increased risk of fractures has nothing to do with PPIs and is because patients who require PPIs have other illnesses that cause the increased fractures. The purpose of the study is to learn how bone structure and bone mass change after long-term PPI use.