Growth Hormone and Bone

Bouillon, Roger

doi:10.1159/000182189

Cited by 119 publications

(65 citation statements)

References 53 publications

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“…The findings of the present analysis extend the results reported by Romagnoli et al and suggest a preferential effect of IGF-I on compact bone. Consistent with this hypothesis, the increase in BMD in clinical conditions of growth hormone excess has been shown to be most pronounced in cortical bone [45].…”

Section: Discussionmentioning

confidence: 59%

Factors Associated with Cortical and Trabecular Bone Loss as Quantified by Peripheral Computed Tomography (pQCT) at the Ultradistal Radius in Aging Women

et al. 1997

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Abstract. Peripheral quantitative computed tomography (pQCT) allows the separate determination of cortical and trabecular bone mineral density in the peripheral skeleton. This cross-sectional study was designed to examine the effects of healthy aging on pQCT measurements at the ultradistal radius. In a well-defined sample of 129 community-based women, aged 70-87 years, the differences in cortical and trabecular density over the age range were equivalent to losses of −0.41% and −0.65% per year, respectively. To investigate the mechanism of this agerelated decline, we assessed relationships between both parameters and height, weight, body mass index, dietary calcium intake, grip strength, and serum concentrations of insulin-like growth factor-I (IGF-I), calcidiol (25(OH)D 3 ), calcitriol (1,25(OH) 2 D 3 ), parathyroid hormone (PTH), and sex hormone binding globulin (SHBG). Multiple regression was used to adjust for potential confounders. Age was not significant after controlling for other covariables. Body mass index, grip strength, serum IGF-I, 25(OH)D 3 , and PTH (1-84) were found to be independent predictors of total bone density. Including (total or free) 1,25(OH) 2 D 3 did not improve the model precision. These findings provide evidence that, among other factors, the activity of the growth hormone-IGF-I-axis is of importance for skeletal integrity. Grip strength, serum IGF-I, and PTH (1-84) were discovered to be significantly related to cortical but not to trabecular density, suggesting that different mechanisms may be involved in compact and cancellous bone loss.Key words: Peripheral quantitative computed tomography (pQCT) -Age-related bone loss -Growth hormone -IGF-I.Low bone mass, as estimated by decreased bone mineral density (BMD), is an established predictor of osteoporotic fractures. Although fracture prediction by bone density is partially site-dependent [1], numerous reports have shown that fractures at all skeletal sites are significantly related to low bone mass at the distal forearm [2][3][4][5]. In all of these studies, BMD was assessed with single-photon absorptiometry. Peripheral quantitative computed tomography (pQCT) has been proposed as an adjunct to conventional densitometry [6,7]. BMD determination with pQCT at the site of the distal radius is a method of high precision and low radiation [8]. In addition, pQCT is the only noninvasive assessment of bone mineral to measure a true-dimensional density (as opposed to an areal density by standard methods) and to allow separate determination of cortical and trabecular bone density [9].Studies have indicated that bone loss in elderly women shows no evidence for an age-related leveling off [10][11][12][13]. Even at advanced ages, interventions to preserve or to enhance bone mass may therefore be an effective approach to prevention of fractures. However, the mechanisms leading to age-related bone loss remain poorly defined. Moreover, whether cortical and trabecular bone losses are mediated by differential mechanisms is virtually unknown. In the pres...

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Section: Discussionmentioning

confidence: 59%

Factors Associated with Cortical and Trabecular Bone Loss as Quantified by Peripheral Computed Tomography (pQCT) at the Ultradistal Radius in Aging Women

et al. 1997

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“…Both clinical and animal studies have demonstrated that growth hormone (GH) is important for normal bone modelling and remodelling (Bouillon 1991, Eriksen et al 1996, Ohlsson et al 1998. In young adult rats, GH treatment increases bone mass by increased longitudinal growth at the growth plate and by increased subperiosteal bone deposition (Ohlsson et al 1998).…”

Section: Introductionmentioning

confidence: 99%

The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats

Svensson

Lall²,

Dickson³

et al. 2000

Journal of Endocrinology

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Growth hormone (GH) is of importance for normal bone remodelling. A recent clinical study demonstrated that MK-677, a member of a class of GH secretagogues (GHSs), increases serum concentrations of biochemical markers of bone formation and bone resorption. The aim of the present study was to investigate whether the GHSs, ipamorelin (IPA) and GH-releasing peptide-6 (GHRP-6), increase bone mineral content (BMC) in young adult female rats. Thirteen-week-old female Sprague-Dawley rats were given IPA (0·5 mg/kg per day; n=7), GHRP-6 (0·5 mg/kg per day; n=8), GH (3·5 mg/kg per day; n=7), or vehicle administered continuously s.c. via osmotic minipumps for 12 weeks. The animals were followed in vivo by dual X-ray absorptiometry (DXA) measurements every 4th week. After the animals were killed, femurs were analysed in vitro by mid-diaphyseal peripheral quantitative computed tomography (pQCT) scans. After this, excised femurs and vertebrae L6 were analysed by the use of Archimedes' principle and by determinations of ash weights. All treatments increased body weight and total tibial and vertebral BMC measured by DXA in vivo compared with vehicle-treated controls. However, total BMC corrected for the increase in body weight (total BMC:body weight ratio) was unaffected. Tibial area bone mineral density (BMD, BMC/area) was increased, but total and vertebral area BMDs were unchanged. The pQCT measurements in vitro revealed that the increase in the cortical BMC was due to an increased cross-sectional bone area, whereas the cortical volumetric BMD was unchanged. Femur and vertebra L6 volumes were increased but no effect was seen on the volumetric BMDs as measured by Archimedes' principle. Ash weight was increased by all treatments, but the mineral concentration was unchanged. We conclude that treatment of adult female rats with the GHSs ipamorelin and GHRP-6 increases BMC as measured by DXA in vivo. The results of in vitro measurements using pQCT and Archimedes' principle, in addition to ash weight determinations, show that the increases in cortical and total BMC were due to an increased growth of the bones with increased bone dimensions, whereas the volumetric BMD was unchanged.

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“…Many of these hormones have an influence on calcium absorption: GH enhances intestinal calcium absorption, increasing 1,25-dihydroxyvitamin D production by stimulating renal 1-α-hydroxylase and supports phosphate retention by increasing the renal threshold for phosphate excretion (Bouillon, 1991). The final effect of these actions is the increase of the calcium-phosphate product in the extracellular fluids, which represents a main mechanism for bone matrix mineralization.…”

Section: Osteoporosis 414mentioning

confidence: 99%

“…Several studies have showed that adequate doses and duration of GH replacement therapy are able to increase bone turnover and to achieve bone mineral density values within the normal range (Saggese et al, 1996), suggesting that GH has a fundamental role in the acquisition of peak of bone mass. Moreover, GH, together with IGF-1 stimulates sex steroids secretion (Bouillon, 1991). Both estrogens and androgens influence phospho-calcium metabolism regulating calcium fluxes and bone calcium deposition, increasing calcium absorption and retention (Mauras, 1999).…”

Section: Osteoporosis 414mentioning

confidence: 99%