Background: Untreated endogenous Cushing's syndrome is a serious condition with high morbidity and mortality. New diagnostic procedures make today's assessment more accurate. We describe which tests should be done when there is suspicion of the syndrome.
View Article and Find Full Text PDFObjective: Endogenous Cushing's syndrome (CS) is associated with bone loss and an increased risk of fractures. However, the long-term outcome of treatment on bone health has not been adequately clarified.
Design: We followed 33 patients with active CS prospectively before and twice after treatment (mean follow-up 33 (n = 25) and 71 months (n = 18), respectively).
Unlabelled: Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K.
Introduction: Osteoclasts resorb bone by secretion of acid by the vacuolar H+-adenosine triphosphatase (V-ATPase) and the chloride channel ClC-7, followed by degradation of the matrix, mainly collagen type I, by cathepsin K and possibly by matrix metalloproteinases (MMPs).
Objective: The prevalence of maternal overweight and fetal macrosomia is increasing. Fetal macrosomia is associated with increased risk of maternal and neonatal complications. The objective of the present study was to investigate if maternal metabolic parameters associated with maternal overweight were independent determinants of macrosomia (birth weight > 4500 g or above the 95 percentile of the z-score for standardized birth weight).
View Article and Find Full Text PDFAutosomal dominant osteopetrosis type I (ADOI) is presumably caused by gain-of-function mutations in the LRP5 gene. Patients with a T253I mutation in LRP5 have a high bone mass phenotype, characterized by increased mineralizing surface index but abnormally low numbers of small osteoclasts. To investigate the effect of the T253I mutation in LRP5 on osteoclasts, we isolated CD14+ monocytes from ADOI patients and assessed their ability to generate osteoclasts when treated with RANKL and M-CSF compared to that of age- and sex-matched control osteoclasts.
View Article and Find Full Text PDFFifty-five patients with adult-onset GH deficiency (mean age, 49 years) were enrolled in a placebo-controlled, crossover study to investigate the effects of GH therapy on exercise capacity, body composition, and quality of life (QOL). GH and placebo were administered for 9 months each, separated by a 4-month washout period. GH therapy was individually dosed to obtain an IGF-I concentration within the normal range for age and sex.
View Article and Find Full Text PDFPostmenopausal osteoporosis and bone mass are influenced by multiple factors including genetic variation. The importance of LDL receptor-related protein 5 (LRP5) for the regulation of bone mass has recently been established, where loss of function mutations is followed by severe osteoporosis and gain of function is related to increased bone mass. The aim of this study was to evaluate the role of polymorphisms in the LRP5 gene in regulating bone mass and influencing prospective fracture frequency in a well-described, large cohort of normal, ambulatory Australian women.
View Article and Find Full Text PDFFetal nutrition may permanently affect physiological properties of the new individual and hence the risk of future disease. Epidemiological studies indicate that fetal nutrition may significantly influence the risk of diabetes, cardiovascular disease, and cancer. Controlled animal studies show that even properties traditionally considered as exclusively genetic, like fur colour, may be modified by altered maternal nutrition.
View Article and Find Full Text PDFPatients with defective osteoclastic acidification have increased numbers of osteoclasts, with decreased resorption, but bone formation that remains unchanged. We demonstrate that osteoclast survival is increased when acidification is impaired, and that impairment of acidification results in inhibition of bone resorption without inhibition of bone formation. We investigated the role of acidification in human osteoclastic resorption and life span in vitro using inhibitors of chloride channels (NS5818/NS3696), the proton pump (bafilomycin) and cathepsin K.
View Article and Find Full Text PDFObjectives: We sought to determine the relationship between osteoprotegerin (OPG) and clinical outcomes in patients with heart failure (HF) after acute myocardial infarction (AMI).
Background: Arterial calcification is a prominent feature of arterial atherosclerosis and is associated with the occurrence of AMI. Osteoprotegerin is a recently discovered member of the tumor necrosis superfamily that may link the skeletal with the vascular system.
Unlabelled: A population-based study of 1363 older women showed that the 24% who achieved high physical activity and dietary calcium intakes had a 5.1% higher hip BMD than those who did not, supporting the concept that lifestyle factors play an important role in the maintenance of lower extremity bone mass in older women.
Introduction: Although there is general agreement that increased dietary calcium consumption and exercise can slow bone loss in older women, the amount required to have this effect in an older population remains uncertain.
Autosomal dominant osteopetrosis II (ADOII) is a relatively benign disorder caused by a missense mutation in the ClCN7 gene. In this study, we characterize the osteoclasts from patients with ADOII, caused by a G215R mutation, and investigate the effect on osteoclast function in vitro. Osteoclasts from ADOII patients and healthy age- and sex-matched controls, were used to evaluate osteoclastogenesis, cell fusion, acidification, and resorptive activity.
View Article and Find Full Text PDFThe study gives a further biochemical description of two different forms of autosomal dominant osteopetrosis (ADO) in relation to murine counterparts, with special attention to osteoblast function and the recent discovery of LRP5 gene mutations in ADO I. Patients and controls were investigated for markers of bone formation and resorption at baseline and following stimulation with thyroid hormone. Moreover, four different well-described murine models of osteopetrosis were investigated.
View Article and Find Full Text PDFObjective: To investigate the effects of growth hormone (GH) replacement therapy on bone matrix gene expression of insulin-like growth factors (IGFs) and markers of bone metabolism in women with adult-onset GH deficiency (GHD).
Design And Methods: Nineteen women, mean age 45 (range 24-56) years, were included in a double-blind, placebo-controlled parallel group study for 12 months. Biochemical markers were measured at baseline, 6 and 12 months.
Postmenopausal osteoporosis is a complex and heterogeneous disease influenced by multiple factors and related to peak bone mass achieved in early adult life, followed by a subsequent continuous bone loss. Genetic variance and polymorphisms have been shown to be of clinical significance for osteoporotic fragility fractures. Previous studies have related variations in the calcium sensor receptor (CASR) gene to circulating Ca levels and bone mass in young women and adolescent girls.
View Article and Find Full Text PDFBackground: This paper surveys hormonally inactive pituitary tumours on the basis of the current international literature; it also reflects the experience of the authors.
Interpretation: Pituitary tumours are frequently diagnosed and usually show a low potential for growth. Although benign they may invade adjacent structures such as the cavernous and sphenoid sinuses.
Background: Metabolic bone disease is one of the major long-term complications in liver transplant recipients, but it remains unclear which patients are at highest risk for developing severe bone disease following transplantation.
Methods: A total of 46 consecutive, adult patients with chronic liver disease accepted for a liver transplantation waiting list were prospectively included in the study. The patients were classified into two groups: group A--chronic cholestatic liver disease (n = 28), and group B--chronic non-cholestatic liver disease (n = 18).
The weight gain and visceral obesity associated with Cushing's syndrome (CS) has been linked to elevated plasma leptin levels, although the mechanism behind a central leptin resistance in these patients is unknown. Several studies describe interactions among the hypothalamic-pituitary-adrenal axis, leptin, and the IL-1 system. To investigate these interactions, we have evaluated changes in regional fat distribution, by DEXA, and the role of circulating cortisol, leptin, IL-1beta, and IL-1 receptor antagonist (IL-1Ra), in relation to these changes, in 27 (19 DEXA; 27 serum measurements) patients with CS, before and after surgical treatment (mean follow-up, 31 months; range, 5-80), and compared them with measurements of age-, sex-, and body mass index-matched healthy controls (also obtained longitudinally).
View Article and Find Full Text PDFSerum GH and IGF-I levels decline with increasing age, whereas osteoprotegerin (OPG) increases. IGFs as well as OPG are present in bone matrix and mediate the effects of many upstream hormones (e.g.
View Article and Find Full Text PDFBackground: Metabolic bone disease is one of the major long-term complications in liver transplant recipients, but it remains unclear which patients are at highest risk for developing severe bone disease following transplantation.
Methods: A total of 46 consecutive, adult patients with chronic liver disease accepted for a liver transplantation waiting list were prospectively included in the study. The patients were classified into two groups: group A-chronic cholestatic liver disease (n = 28), and group B-chronic non-cholestatic liver disease (n = 18).
Bone is a dynamic tissue that is subject to the balanced processes of bone formation and bone resorption. Imbalance can give rise to skeletal pathologies with increased bone density. In recent years, several genes underlying such sclerosing bone disorders have been identified.
View Article and Find Full Text PDFMaturation of macrophages to osteoclasts requires the presence of marrow stromal cells or osteoblasts. Most calcitropic hormones act indirectly on osteoclasts through receptors on neighbouring osteoblasts. The discovery of osteoprotegerin (OPG), the receptor activator of nuclear factor-kappa b ligand (RANKL), and its receptor (RANK) has elucidated these phenomena.
View Article and Find Full Text PDFThe osteopetroses are a heterogeneous group of genetic conditions characterized by increased bone density due to impaired bone resorption by osteoclasts. Within the autosomal dominant form of osteopetrosis, the radiological type I (ADOI) is characterized by a generalized osteosclerosis, most pronounced at the cranial vault. The patients are often asymptomatic but some suffer from pain and hearing loss.
View Article and Find Full Text PDF