leuprolide and deoxypyridinoline

It has generally been held that estrogen and testosterone are the major sex steroids regulating bone metabolism in women and men, respectively. However, the description of several "experiments of nature" led to a reconsideration of this notion. Thus, a male carrying homozygous mutations in the ER-alpha gene and two males with homozygous mutations in the aromatase gene had osteopenia, unfused epiphyses, and elevated indices of bone turnover. Though these findings indicated that estrogen plays a role in regulating the male skeleton, they left unresolved the issue of whether estrogen acted on the male skeleton mainly to enhance bone mass acquisition during growth and maturation, or whether it also acted to retard bone loss in aging individuals. To address this issue, several cross-sectional observational studies have related bone mineral density (BMD) to sex steroids in elderly men, and found that estrogen correlated better than testosterone with BMD. In addition, recent longitudinal studies from our group indicate that bioavailable estrogen correlated better than testosterone both with the gain in BMD in young men and with loss of BMD in elderly men. These observational studies do not, however, prove causality, which requires direct interventional studies. Thus, we eliminated endogenous testosterone and estrogen production in 59 elderly men (mean age 68 years), studied them first under conditions of physiologic testosterone and estrogen replacement, and then assessed the impact on bone turnover of withdrawing both testosterone and estrogen, withdrawing only testosterone, only estrogen, or continuing both. We found that estrogen played the major role in regulating bone resorption in these men, and that both estrogen and testosterone were important in maintaining bone formation. Collectively then, these findings indicate that estrogen plays a dominant role in regulating the male skeleton.

Topics: Adult; Aged; Aged, 80 and over; Amino Acids; Bone Density; Collagen; Collagen Type I; Cross-Sectional Studies; Estrogens; Humans; Leuprolide; Longitudinal Studies; Male; Middle Aged; Osteocalcin; Osteoporosis; Peptide Fragments; Peptides; Procollagen; Testosterone

Hypogonadism is associated with osteoporosis in men. GnRH- agonist-induced hypogonadism increases bone turnover and bone loss in men, but the mechanism underlying these changes is unknown. To determine whether gonadal steroid deprivation increases the skeletal sensitivity to PTH or blunts the ability of PTH to promote 1,25-dihydroxyvitamin D formation, we infused human PTH-(1-34) at a dose of 0.55 U/kg.h for 24 h, in 11 men (ages, 50-82 yr) with locally advanced, node-positive, or biochemically recurrent prostate cancer but no evidence of bone metastases. PTH infusions were performed before initiation of GnRH agonist therapy (leuprolide acetate, 22.5 mg im, every 3 months) and again after 6 months of confirmed GnRH agonist-induced hypogonadism. Serum osteocalcin (OC), bone- specific alkaline phosphatase (BSAP), N-telopeptide (NTX), whole-blood ionized calcium, and 1,25-dihydroxyvitamin D were measured at baseline and every 6 h during each PTH infusion. Urinary NTX and free deoxypyridinoline (DPD) were assessed on spot morning samples before PTH infusion and on 24-h samples collected during the PTH infusions. Sex steroid levels were lowered to the castrate range in all subjects. Baseline serum NTX levels (drawn before PTH infusion) increased from 9.1 +/- 3.7 before leuprolide therapy to 13.9 +/- 5.0 nmol bone collagen equivalents (BCE)/L after leuprolide therapy (P = 0.003). Spot urine NTX collected before PTH infusion increased from 28 +/- 8 before leuprolide therapy to 49 +/- 17 nmol BCE/mmol creatinine after leuprolide therapy (P < 0.001), and urinary DPD increased from 4.7 +/- 1.1 to 7.4 +/- 1.8 nmol BCE/mmol creatinine (P < 0.001). Baseline serum OC and BSAP levels drawn before each PTH infusion did not change before vs. after leuprolide therapy. Serum NTX levels increased significantly during PTH infusion pre-GnRH agonist therapy (P < 0.001), and the rate of increase was greater after 6 months of GnRH agonist-induced hypogonadism (P < 0.01 for the difference in rates of change before and after GnRH agonist administration). Serum OC and BSAP levels decreased during PTH infusion (P < 0.001 for OC and P = 0.002 for BSAP), but the rates of decrease did not differ before or after leuprolide therapy (P = 0.45 for OC and P: = 0.19 for BSAP). Whole-blood ionized calcium levels increased during PTH infusion (P < 0.001), and the rate of increase was greater after GnRH agonist-induced hypogonadism (P = 0.068). Serum 1,25-dihydroxyvitamin D levels increased in r

Topics: Aged; Aged, 80 and over; Alkaline Phosphatase; Amino Acids; Antineoplastic Agents, Hormonal; Biomarkers; Bone and Bones; Calcitriol; Calcium; Collagen; Collagen Type I; Diphosphonates; Humans; Hypogonadism; Leuprolide; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Recurrence, Local; Osteocalcin; Pamidronate; Peptides; Prostatic Neoplasms; Teriparatide; Time Factors

Collagen cross-link molecules such as pyridinoline (PYD), deoxypyridinoline (DPD), and N-terminal cross-linked peptides (NTX) have been measured in urine as indices of bone resorption. However, very little is known regarding the excretion of pyridinolines into other biological fluids. We report a collection device, normalizing analyte, and high-sensitivity immunoassay for quantitative analysis of free pyridinoline cross-links in sweat.. Flame atomic emission and ion-selective electrode techniques were used to measure potassium as a sweat volume marker. The Pyrilinks immunoassay for urine free pyridinolines was optimized to increase sensitivity for measurements in sweat. The precision, accuracy, and detection limit of this assay were characterized. To assess values and variability of sweat pyridinolines in human subjects, a nonocclusive skin patch was used to collect sweat samples from a reference group and from a mixed group experiencing accelerated bone resorption, postmenopausal women and men receiving gonadotropin-releasing hormone for prostate cancer.. The immunoassay intra- and interassay variations were

Topics: Amino Acids; Antineoplastic Agents, Hormonal; Biomarkers; Bone Resorption; Collagen; Cross-Linking Reagents; Female; Humans; Immunoenzyme Techniques; Leuprolide; Male; Postmenopause; Potassium; Prostatic Neoplasms; Reference Values; Spectrophotometry, Atomic; Sweat

To observe the long-term changes in bone metabolism induced by GnRH agonist (GnRHa) treatment and to determine the factor that affected the change in bone mineral density (BMD).. Prospective observational study.. Department of obstetrics and gynecology in university and general hospitals.. Fifty women with endometriosis treated with GnRHa between 1994 and 1996.. Leuprolide acetate administered for 24 weeks. Bone mineral density measurement by dual energy x-ray absorptiometry and collection of blood and urine samples were conducted until 12 months of posttreatment.. Spinal BMD and bone turnover markers.. Mean BMD percent changes from pretreatment were -4.9% and -3.4% at 6 months of treatment and at 12 months of posttreatment, respectively. When the patients were divided by the median pretreatment deoxypyridinoline (DP) level, recovery of BMD after GnRHa discontinuation was slower in the Low-DP group than in the High-DP group. A significant positive correlation was found between the pretreatment DP level and the percent change in BMD at 12 months of posttreatment. No significant relation between BMD and the other bone turnover markers was noted.. Bone mineral density changes were diverse among patients who were administered GnRHa. The pretreatment DP level may be the predictive factor for GnRHa-induced BMD change.

Topics: Adult; Alkaline Phosphatase; Amino Acids; Biomarkers; Bone and Bones; Bone Density; Endometriosis; Estradiol; Female; Gonadotropin-Releasing Hormone; Humans; Leuprolide; Middle Aged; Peptide Fragments; Predictive Value of Tests; Procollagen; Prospective Studies

The objective of this work was to determine the effect of androgen deprivation therapy (ADT) on rates of bone mineral density (BMD) loss in men with prostate cancer. It was a prospective study comparing men receiving ADT to age matched controls for 2 y. Subjects received a history, physical exam, bone mineral density measurement, and laboratory evaluation every 6 months. Thirty-nine subjects receiving continuous ADT for prostate cancer (subjects) were compared to 39 age-matched controls not receiving ADT (controls). Twenty-three subjects and 30 controls completed the study through 24 months. Men in the ADT group demonstrated greater rates of bone mineral density loss than men in the control group at every site except the lumbar spine. Twenty-four month per cent of bone mineral density loss is presented as mean+/-standard error (s.e.). At the distal forearm, the ADT group value was -9.4%+/-1.0% and -4.4%+/-0.3% for controls (P<0.0005). The ADT group femoral neck values were -1.9%+/-0.7% and 0.6%+/-0.5% in the control group (P=0.0016). The ADT group total hip value was -1.5%+/-1.0% and 0.8%+/-0.5% in the control group (P=0.0018). The ADT group trochanter value was -2.0%+/-1.3% and -0.1%+/-0.5% in the control group (P=0.0019). The ADT group lumbar spine value was -0.2%+/-0.8 % and 1.1%+/-0.6% in the control group (P=0.079). Our data demonstrate greater rates of bone mineral density loss in men receiving androgen deprivation therapy for prostate cancer.

Topics: Absorptiometry, Photon; Adenocarcinoma; Aged; Amino Acids; Androgen Antagonists; Androgens; Anilides; Antineoplastic Agents, Hormonal; Biomarkers; Bone Density; Bone Remodeling; Calcium; Drug Therapy, Combination; Flutamide; Gonadotropin-Releasing Hormone; Goserelin; Humans; Leuprolide; Male; Neoplasms, Hormone-Dependent; Nitriles; Orchiectomy; Osteoporosis; Prospective Studies; Prostatic Neoplasms; Testosterone; Tosyl Compounds