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Abstract
Glucocorticoids induce rapid bone loss and increase the risk for osteoporotic fractures. The mechanisms include a phase of increased bone resorption, probably a result of the increased expression of receptor activator of nuclear factor-k-B ligand and colony stimulating factor-1, followed-up by a decrease in bone formation. This effect is central to the actions of glucocorticoids in bone and it is secondary to the loss of bone forming cells, caused by an inhibition of cell differentiation and an increase in the apoptosis of mature osteoblasts and osteocytes. Glucocorticoids also inhibit the function of mature osteoblasts and suppress the synthesis of insulin-like growth factor-I, an agent that enhances bone formation. Glucocorticoids alter the growth hormone/insulin-like growth factor axis in cartilage and, as a consequence, suppress linear growth.
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Affiliation(s)
- Ernesto Canalis
- Department of Research, Saint Francis Hospital and Medical Center, 114 Woodland Street, Hartford, CT 06105-1299, USA.
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Harpavat M, Keljo DJ. Perspectives on osteoporosis in pediatric inflammatory bowel disease. Curr Gastroenterol Rep 2003; 5:225-32. [PMID: 12734045 DOI: 10.1007/s11894-003-0024-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Osteoporosis is now recognized as a problem in children with chronic illness. Decreased bone mineral density and increased risk of fracture have been reported in children with inflammatory bowel disease (IBD). Recent studies have led to a better understanding of the pathogenesis of bone loss. There are many risk factors for osteopenia and osteoporosis in children with IBD. Dual-energy x-ray absorptiometry remains the diagnostic procedure of choice for assessment of bone mineral density, but other modalities are being explored. Guidelines for diagnosis and treatment of osteoporosis in children have not been established. This article reviews the current understanding of osteopenia and osteoporosis in children with IBD.
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Affiliation(s)
- Manisha Harpavat
- University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213-2583, USA.
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Väänänen KH, Härkönen PL. Bone effects of glucocorticoid therapy. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2003:55-64. [PMID: 12355728 DOI: 10.1007/978-3-662-04660-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- K H Väänänen
- Department of Anatomy, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
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Wu F, Ames R, Evans MC, France JT, Reid IR. Determinants of sex hormone-binding globulin in normal postmenopausal women. Clin Endocrinol (Oxf) 2001; 54:81-7. [PMID: 11167930 DOI: 10.1046/j.1365-2265.2001.01183.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To examine the factors influencing the levels of sex hormone-binding globulin (SHBG) in normal postmenopausal women by assessing the relationship between SHBG and measured anthropometric, metabolic and hormonal variables. DESIGN Cross-sectional, observational study. SUBJECTS AND METHODS Seventy normal postmenopausal women aged 47-71 years (mean 58 years), participated in the study. Information was collected on medical, reproductive and smoking history, alcohol use, dietary intake and physical activity. Body composition measurements using dual-energy absorptiometry, and analyses of biochemical and hormonal indices were performed. RESULTS Bivariate correlation coefficients indicated that SHBG was inversely related to body weight (r = - 0.44), fat mass (r = - 0.35), and abdominal obesity (r = - 0.42). It was also inversely related to the glucose and insulin levels during an oral glucose tolerance test (- 0.24 < r < - 0.40), serum oestradiol (r = - 0.26), and physical activity (r = - 0.24). Multiple regression analysis indicated that significant independent correlates of SHBG concentration were fat mass, physical activity, alcohol intake, serum oestradiol, and insulin-like growth factor-1, all having a negative impact on SHBG. CONCLUSIONS From these observed associations, it is concluded that maintenance of body weight, moderate alcohol consumption, and physical activity will tend to reduce SHBG concentrations in postmenopausal women, thereby increasing the levels of free oestradiol. This mechanism could mediate the beneficial effects of these factors in preventing the development of osteoporosis and cardiovascular disease.
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Affiliation(s)
- F Wu
- Department of Medicine, University of Auckland, Auckland, New Zealand
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Ward WE, Donovan SM, Atkinson SA. Dexamethasone-induced abnormalities in growth and bone metabolism in piglets are partially attenuated by growth hormone with no synergistic effect of insulin-like growth factor-I. Pediatr Res 1998; 44:215-21. [PMID: 9702917 DOI: 10.1203/00006450-199808000-00013] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dexamethasone (DEX) therapy improves pulmonary compliance in premature infants with chronic lung disease; however, normal growth and bone development are impaired. Because DEX may mediate its effects by altering the GH-IGF-I axis, we investigated whether adjunctive therapy with GH or GH + IGF-I during DEX therapy could attenuate these DEX-induced effects. Piglets were randomized to placebo, oral tapered DEX (0.5, 0.3, and 0.2 mg kg(-1) d(-1) over 14 d), DEX + GH (0.1 mg kg(-1) d(-1)) or DEX + GH + IGF-I (0.1 mg kg(-1) d(-1)). Final whole body weight and length were improved with GH or GH + IGF-I compared with the DEX alone group. Plasma GH and IGF-I were not influenced by DEX, but infusion of IGF-I resulted in higher (p < 0.05) plasma IGF-I compared with all other groups at d 15. DEX reduced (p < 0.05) circulating IGFBP-2 and IGFBP-3 and liver IGFBP-2 and IGFBP-4 mRNA expression compared with controls. Treatment with DEX alone resulted in lower (p < 0.05) plasma osteocalcin, urinary N-telopeptide, and whole body and femur bone mineral density compared with controls, whereas results with piglets receiving adjunctive GH or GH + IGF-I were similar to those of controls. Given adjunctively, GH alone appears to partially counter the abnormalities in growth and bone metabolism associated with DEX therapy; however, this improvement cannot be attributed to higher circulating IGF-I, because combined therapy did not further improve growth or bone homeostasis compared with DEX + GH treatment. Growth hormone therapy has the potential to stimulate growth in infants exposed to steroid treatment.
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Affiliation(s)
- W E Ward
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
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Canalis E. Inhibitory actions of glucocorticoids on skeletal growth. Is local insulin-like growth factor I to blame? Endocrinology 1998; 139:3041-2. [PMID: 9645673 DOI: 10.1210/endo.139.7.6169] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Danielsen CC, Flyvbjerg A. Insulin-like growth factor I as a predictor of cortical bone mass in a long-term study of ovariectomized and estrogen-treated rats. Bone 1996; 19:493-8. [PMID: 8922648 DOI: 10.1016/s8756-3282(96)00256-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The relationship between serum insulin-like growth factor I (IGF-I) and cortical bone mass, formation and resorption and length of bone in a long-term experiment on intact, ovariectomized and estrogen-treated/substituted rats was studied by using multiple linear regression analysis. The study comprised intact rats killed at 2, 6, 9, 12, 15, and 24 months of age, rats ovariectomized 6 months old and killed at 9, 12, 15, and 24 months of age, and intact and ovariectomized rats treated with a low dose of estrogen for 8 months before they were killed at 24 months of age. Serum IGF-I, bone length and total, subperiosteal and subendocortical bone mass in mid-diaphyseal cross sections of the femur were determined. Changes in the latter two variables, respectively, represent the net result of subperiosteal bone formation and subendocortical bone resorption. Multiple linear regression analysis showed that IGF-I was a positive determinant of cortical bone mass and subperiosteal bone formation. In aged rats, IGF-I was also a positive determinant of bone length, whereas IGF-I was not found to be a determinant of subendocortical bone resorption. The analyses showed that long-term treatment of aged rats with a low dose of estrogen had a dual effect on cortical bone by inhibiting subperiosteal formation and subendocortical resorption. The results revealed a relationship between endogenous circulating IGF-I and local anabolic actions of the growth factor in bones. Thus, IGF-I may be a valuable serum marker of cortical bone formation and length of long bones when considering estrogen-depleted and estrogen-treated rats.
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Affiliation(s)
- C C Danielsen
- Department of Connective Tissue Biology, University of Aarhus, Denmark.
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Prummel MF, Wiersinga WM, Oosting H, Endert E. The effect of long-term prednisone treatment on growth hormone and insulin-like growth factor-1. J Endocrinol Invest 1996; 19:620-3. [PMID: 8957747 DOI: 10.1007/bf03349028] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Due to a lack of longitudinal data the precise effect of long-term corticosteroid treatment on serum levels of the anabolic hormones Growth Hormone (GH) and Insulin-like Growth Factor-1 (IGF-1) is unknown. Therefore, we prospectively followed GH and IGF-1 levels over a six month period in 18 euthyroid patients with Graves' ophthalmopathy. Ten patients were treated with a three month course of prednisone; eight patients receiving retrobulbar irradiation served as controls. Baseline serum GH and IGF-1 levels were similar in both groups. Whereas no changes were seen in controls, prednisone induced a rapid increase in serum IGF-1 levels, which was sustained during the entire treatment period: 18.2 +/- 5.2 at baseline vs 24.1 +/- 6.7 nmol/l after 12 weeks of treatment (p < 0.001). After discontinuation of prednisone IGF-1 returned to baseline levels. Basal GH levels were frequently undetectable, but during treatment GH values were lower in the prednisone group (median of detectable values 4.0 mU/L [range 2.0-26.0]) than in controls (11.8 [2.8-44.0]; p < 0.01). In conclusion, long-term prednisone treatment is associated with suppressed GH levels and with an increase in total IGF-1 levels. This suggests that prednisone can disrupt the GH/IGF 1 axis.
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Affiliation(s)
- M F Prummel
- Department of Endocrinology, University of Amsterdam, The Netherlands
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Crowley S, Hindmarsh PC, Matthews DR, Brook CG. Growth and the growth hormone axis in prepubertal children with asthma. J Pediatr 1995; 126:297-303. [PMID: 7844682 DOI: 10.1016/s0022-3476(95)70566-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To determine the influence of asthma and its treatment with inhaled corticosteroids on growth, linear growth velocity, and the growth hormone axis in prepubertal children, we performed a longitudinal study for 12 months in 56 children with asthma, aged between 4.4 and 11.7 years. Height, weight, skin-fold thickness, and lung function were measured every 3 months and bone age at entry to and exit from the study. A 24-hour serum growth hormone concentration profile and fasting insulin-like growth factor I levels were measured halfway through the year. Seventy-four percent of boys and 62% of girls had heights below the 50th percentile. Growth velocity in the nonsteroid-treated control group (n = 13) was normal; 10 of 20 children taking beclomethasone grew slowly (14/20 used a dry powder device), and 4 of 19 children taking budesonide grew slowly (15/19 used a spacer). Three of four children using inhaled steroids and prednisolone grew slowly. In none of the treatment groups were measures of growth hormone secretion or levels of radioimmunoassayable serum insulin-like growth factor I affected. We conclude that slow growth in steroid-treated children with asthma does not appear to be associated with major perturbations in the growth hormone axis.
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Affiliation(s)
- S Crowley
- Endocrine Unit, Middlesex Hospital, London, United Kingdom
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Sanchez CP, Goodman WG, Brandli D, Goldenhersh M, Murray C, Carlton E, Hahn T, Salusky IB. Skeletal response to recombinant human growth hormone (rhGH) in children treated with long-term corticosteroids. J Bone Miner Res 1995; 10:2-6. [PMID: 7747627 DOI: 10.1002/jbmr.5650100104] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Corticosteroid therapy causes osteopenia and growth retardation in children; such changes are associated with diminished rates of bone formation and turnover. Since growth hormone activates bone remodeling, the biochemical and skeletal responses to rhGH were evaluated in four pediatric patients, aged 12.8 +/- 3 years, with long-term corticosteroid use (5 +/- 2 years). Recombinant human growth hormone (rhGH), 0.125 mg/kg, was given 3 times/week by subcutaneous injection for 12 months. Iliac crest bone biopsies were obtained after double tetracycline labeling before and at the end of rhGH therapy; serum levels of calcium, phosphorus, alkaline phosphatase, parathyroid hormone (intact), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D3, osteocalcin (BGP), and insulin-like growth factor-1 (IGF-1) were measured every 3 months during the treatment period. The average dose of prednisone was 0.24 +/- 0.05 mg/kg/day initially, and this did not change during the study. Serum calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D3, and BGP were unchanged during the rhGH therapy, but the serum IGF-1 level increased by 71%, p < 0.01. Eroded bone perimeter and cancellous bone area did not change significantly during rhGH therapy. Bone formation rates rose from 423 +/- 475 to 781 +/- 407 microns2/mm2/day, p < 0.05, and the length of double tetracycline-labeled bone perimeter increased by 85%, p < 0.05. The bone formation rate in the growth hormone group exceeded the values of an age-matched reference group (14.3 +/- 3 years), 780 +/- 407 microns2/mm2/day versus 411 +/- 479 microns2/mm2/day, p < 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C P Sanchez
- Department of Pediatrics, UCLA Medical Center, USA
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Lazowski DA, Fraher LJ, Hodsman A, Steer B, Modrowski D, Han VK. Regional variation of insulin-like growth factor-I gene expression in mature rat bone and cartilage. Bone 1994; 15:563-76. [PMID: 7980968 DOI: 10.1016/8756-3282(94)90282-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Regulation of long bone growth by growth hormone and other endocrine factors is mediated by the local synthesis of IGF-I in the growth plate. Recent evidence suggests that different regions of the growth plate exhibit variable growth rates. To investigate whether IGF-I gene expression in the growth plate differs in relation to growth, we examined the distribution of IGF-I mRNA and peptide using in situ hybridization and immunohistochemistry, respectively, in the tibiae of 18-week-old rats (n = 6). Osteoblasts were identified by osteocalcin immunoreactivity, and osteoclasts by tartrate-resistant acid phosphatase (TRAP) histochemistry. The abundance of IGF-I mRNA in growth plate chondrocytes was quantified by counting the autoradiographic signal associated with each cell. IGF-I mRNA was identified in chondrocytes of both the proliferative and hypertrophic zones of the growth plate. Cells in the marginal regions of both zones contained significantly more IGF-I mRNA than those in the central region (p < 0.05). In addition, IGF-I mRNA levels were greater in the periphery of the growth plate on the medial side of the tibia (p < 0.05) in which there was more active growth than the lateral side. IGF-I immunoreactivity was present predominantly in the hypertrophic zone chondrocytes and no regional differences in its distribution were observed. IGF-I mRNA and peptide were also identified in periosteal fibroblasts, notably at sites of muscle attachment to bone, and in osteoblasts at active sites of bone remodelling in the periosteal, endocortical, and endosteal bone envelopes. In the TRAP-positive osteoclasts, IGF-I immunoreactivity, but not IGF-I mRNA, was detected. In addition, both IGF-I mRNA and peptide were identified in the hemopoietic cells of the metaphyseal bone marrow, whereas only IGF-I immunoreactivity was detectable in the diaphysis. We conclude that, in the tibiae of mature rats: (i) IGF-I gene expression in the growth plate is related to its growth and/or synthetic activity; and (ii) the presence of IGF-I in osteoblasts and osteoclasts suggests its involvement in active bone growth and remodeling.
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Affiliation(s)
- D A Lazowski
- Department of Physical Therapy, University of Western Ontario, Lawson Research Institute, London, Ontario, Canada
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Ibbotson KJ, Orcutt CM, D'Souza SM, Paddock CL, Arthur JA, Jankowsky ML, Boyce RW. Contrasting effects of parathyroid hormone and insulin-like growth factor I in an aged ovariectomized rat model of postmenopausal osteoporosis. J Bone Miner Res 1992; 7:425-32. [PMID: 1609630 DOI: 10.1002/jbmr.5650070410] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Agents that exert anabolic effects on bone have generally been tested in young or estrogen-replete animals. It is unclear whether these agents exert similar effects in older ovariectomized (Ovx) animals. In this single study we examined the effects of intermittent (daily) human PTH-(1-34) and continuous infusion of human recombinant IGF-I alone and in combination on bone resorption and formation over a 14 day period in an aged Ovx rat model of postmenopausal osteoporosis (2-year-old rats, Ovx at 1 year). Compared to Ovx controls, PTH treatment increased bone mineral content (BMC) and bone volume and stimulated bone formation but had no effect on bone resorption. In contrast, IGF-I treatment reduced BMC and stimulated resorptive activity as assessed by increases in marrow volume, cortical porosity, osteoclast-positive eroded surfaces, and urinary hydroxyproline excretion. IGF-I had no effect on bone formation, but when combined with PTH, IGF-I blunted the response to PTH on the periosteal and endocortical surfaces. In summary, PTH stimulated bone formation in a manner similar to that observed in younger animals and IGF-I stimulated bone resorption rather than formation and blunted the bone-forming response to PTH. The effects of IGF-I in older Ovx rats may differ from those observed in younger estrogen-replete animals.
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Affiliation(s)
- K J Ibbotson
- Bone Metabolism Department, Norwich Eaton Pharmaceuticals, Inc., New York
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