| 51. |
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| 52. |
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| 53. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Growth hormone and bone.
- 1998
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Ingår i: Endocrine reviews. - 0163-769X. ; 19:1, s. 55-79
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that GH is important in the regulation of longitudinal bone growth. Its role in the regulation of bone metabolism in man has not been understood until recently. Several in vivo and in vitro studies have demonstrated that GH is important in the regulation of both bone formation and bone resorption. In Figure 9 a simplified model for the cellular effects of GH in the regulation of bone remodeling is presented (Fig. 9). GH increases bone formation in two ways: via a direct interaction with GHRs on osteoblasts and via an induction of endocrine and autocrine/paracrine IGF-I. It is difficult to say how much of the GH effect is mediated by IGFs and how much is IGF-independent. GH treatment also results in increased bone resorption. It is still unknown whether osteoclasts express functional GHRs, but recent in vitro studies indicate that GH regulates osteoclast formation in bone marrow cultures. Possible modulations of the GH/IGF axis by glucocorticoids and estrogens are also included in Fig. 9. GH deficiency results in a decreased bone mass in both man and experimental animals. Long-term treatment (> 18 months) of GHD patients with GH results in an increased bone mass. GH treatment also increases bone mass and the total mechanical strength of bones in rats with a normal GH secretion. Recent clinical studies demonstrate that GH treatment of patients with normal GH secretion increases biochemical markers for both bone formation and bone resorption. Because of the short duration of GH treatment in man with normal GH secretion, the effect on bone mass is still inconclusive. Interestingly, GH treatment to GHD adults initially results in increased bone resorption with an increased number of bone-remodeling units and more newly produced unmineralized bone, resulting in an apparent low or unchanged bone mass. However, GH treatment for more than 18 months gives increased bone formation and bone mineralization of newly produced bone and a concomitant increase in bone mass as determined with DEXA. Thus, the action of GH on bone metabolism in GHD adults is 2-fold: it stimulates both bone resorption and bone formation. We therefore propose "the biphasic model" of GH action in bone remodeling (Fig. 10). According to this model, GH initially increases bone resorption with a concomitant bone loss that is followed by a phase of increased bone formation. After the moment when bone formation is stimulated more than bone resorption (transition point), bone mass is increased. However, a net gain of bone mass caused by GH may take some time as the initial decrease in bone mass must first be replaced (Fig. 10). When all clinical studies of GH treatment of GHD adults are taken into account, it appears that the "transition point" occurs after approximately 6 months and that a net increase of bone mass will be seen after 12-18 months of GH treatment. It should be emphasized that the biphasic model of GH action in bone remodeling is based on findings in GHD adults. It remains to be clarified whether or not it is valid for subjects with normal GH secretion. A treatment intended to increase the effects of GH/IGF-I axis on bone metabolism might include: 1) GH, 2) IGF, 3) other hormones/factors increasing the local IGF-I production in bone, and 4) GH-releasing factors. Other hormones/growth factors increasing local IGF may be important but are not discussed in this article. IGF-I has been shown to increase bone mass in animal models and biochemical markers in humans. However, no effect on bone mass has yet been presented in humans. Because the financial cost for GH treatment is high it has been suggested that GH-releasing factors might be used to stimulate the GH/IGF-I axis. The advantage of GH-releasing factors over GH is that some of them can be administered orally and that they may induce a more physiological GH secretion. (ABSTRACT TRUNCATED)
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| 54. |
- Olsson, Daniel S, 1983, et al.
(författare)
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Comparing progression of non-functioning pituitary adenomas in hypopituitarism patients with and without long-term GH replacement therapy.
- 2009
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 1479-683X. ; 161:5, s. 663-9
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: An important safety issue with GH replacement therapy (GHRT) in hypopituitary patients with a history of a pituitary adenoma is the risk for tumour recurrence or enlargement. Design Case-control study. SUBJECTS AND METHODS: We studied tumour progression rate in 121 patients with hypopituitarism on the basis of non-functioning pituitary adenomas (NFPA) receiving long-term GHRT. A group of 114 NFPA patients not receiving GHRT who were matched in terms of duration of follow-up, gender, age, age at diagnosis and radiotherapy status were used as a control population. The average duration of GHRT was 10+/-4 years (range 2-17). RESULTS: In patients with a known residual adenoma, 63% had no detectable enlargement of tumour during the study. In patients who had no visible residual tumour prior to GHRT, 90% did not suffer from recurrence. In total, the 10-year tumour progression-free survival rate in patients with NFPA receiving GHRT was 74%. In the control population not receiving GHRT, the 10-year progression-free survival rate was 70%. Radiotherapy as part of the initial tumour treatment reduced the rate of tumour progression in both GHRT and non-GHRT patients to a similar extent. CONCLUSIONS: The rate of tumour progression was similar in this large group of GHRT patients and the control population not receiving GHRT. Our results provide further support that long-term use of GH replacement in hypopituitarism may be considered safe in patients with residual pituitary adenomas.
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| 55. |
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| 56. |
- Olsson, Daniel S, 1983, et al.
(författare)
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Life expectancy in patients with pituitary adenoma receiving growth hormone replacement.
- 2017
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Ingår i: European journal of endocrinology. - 1479-683X. ; 176:1, s. 67-75
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Tidskriftsartikel (refereegranskat)abstract
- Hypopituitarism has been associated with increased mortality. The excess mortality may be due to untreated growth hormone (GH) deficiency but also due to various underlying disorders. We therefore analysed mortality in patients with only one underlying disorder, non-functioning pituitary adenoma (NFPA), with and without GH replacement therapy (GHRT).Patients with NFPA in the western region of Sweden, 1997-2011, were identified through the National Patient Registry and cross-referenced with several National Health Registries. All patient records were reviewed. Standardised mortality ratios (SMRs) with 95% confidence intervals (CIs) were calculated using the general population as reference. Cox-regression models were performed to identify predictors of mortality.A total of 426 NFPA patients with 4599 patient-years were included, of whom 207 had used GHRT and 219 had not received GHRT. Median (range) follow-up in patients with and without GHRT was 12.2 (0-25) and 8.2 (0-27) years, respectively. Other pituitary hormone deficiencies were more frequent in the GHRT group than those in the non-GHRT group. SMR was 0.65 (95% CI, 0.44-0.94; P=0.018) for the GHRT group and 1.16 (0.94-1.42; P=0.17) for the non-GHRT group. Direct comparison between the groups showed reduced mortality among those who were GH replaced (P=0.0063). The SMR for malignant tumours was reduced in the GHRT-group (0.29; 0.08-0.73; P=0.004) but not in untreated patients.Selection bias explaining some of the results cannot be excluded. However, NFPA patients with GHRT had reduced overall mortality compared with the general population, and death due to malignancy was not increased. This suggests that long-term GHRT is safe in adult patients selected for treatment.
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| 57. |
- Olsson, Daniel S, 1983, et al.
(författare)
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Tumour recurrence and enlargement in patients with craniopharyngioma with and without GH replacement therapy during more than 10 years of follow-up.
- 2012
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Ingår i: European journal of endocrinology. - 1479-683X. ; 166:6, s. 1061-8
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Tidskriftsartikel (refereegranskat)abstract
- Most patients who have been treated for craniopharyngioma (CP) are GH deficient (GHD). GH replacement therapy (GHRT) may stimulate tumour regrowth; and one of the concerns with long-term GHRT is the risk of tumour progression. Therefore, the objective was to study tumour progression in CP patients on long-term GHRT.Case-control study.The criteria for inclusion of cases were: i) GHD caused by CP; ii) GHRT >3 years; and iii) regular imaging. This resulted in 56 patients (mean age at diagnosis 25±16 years) with a mean duration of GHRT of 13.6±5.0 years. As controls, 70 CP patients who had not received GHRT were sampled with regard to follow-up, gender, age at diagnosis and initial radiation therapy (RT).The 10-year tumour progression-free survival rate (PFSR) for the entire population was 72%. There was an association (hazard ratio, P value) between PFSR and initial RT (0.13, 0.001) and residual tumour (3.2, 0.001). The 10-year PFSR was 88% for the GHRT group and 57% for the control group. Substitution with GHRT resulted in the following associations to PFSR: GHRT (0.57, 0.17), initial RT (0.16, <0.001), residual tumour (2.6, <0.01) and gender (0.57, 0.10). Adjusted for these factors, the 10-year PFSR was 85% for the GHRT group and 65% for the control group.In patients with CP, the most important prognostic factors for the PFSR were initial RT and residual tumour after initial treatment. Long-term GHRT did not affect the PFSR in patients with CP.
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| 58. |
- Oscarsson, Jan, 1960, et al.
(författare)
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Two weeks of daily injections and continuous infusion of recombinant human growth hormone (GH) in GH-deficient adults. II. Effects on serum lipoproteins and lipoprotein and hepatic lipase activity.
- 1996
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Ingår i: Metabolism: clinical and experimental. - 0026-0495. ; 45:3, s. 370-7
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Tidskriftsartikel (refereegranskat)abstract
- Recombinant human growth hormone (GH) administered as daily subcutaneous (SC) injections has been shown to affect serum lipoproteins in GH-deficient subjects. However, the effects of continuous infusion of GH on serum lipoproteins have not been investigated in GH-deficient adults. The aim of the present study was to compare effects of daily injections and continuous infusion of GH on lipoprotein metabolism. Recombinant human GH (0.25 U/kg/wk) was administered to nine GH-deficient adult men during a period of 14 days in two different ways, ie, as a daily SC injection at 8:00 PM and as a continuous SC infusion, with 1 month of washout between the treatments. Blood samples and tests were performed in the morning after an overnight fast before the start of GH treatment (day 0) and on day 2 and day 14 of treatment. Abdominal SC adipose tissue lipoprotein lipase (LPL), postheparin plasma LPL, and hepatic lipase (HL) activity were measured 120 minutes after the intake of 100 g glucose. Adipose tissue LPL activity decreased and postheparin plasma HL activity increased after 14 days of GH treatment irrespective of the mode of GH administration, whereas GH treatment had no effect on postheparin plasma LPL activity. Serum triglyceride and very-low-density lipoprotein (VLDL) triglyceride concentrations increased during GH treatment. However, VLDL triglyceride concentrations increased to a greater degree during treatment with daily GH injections than during continuous infusion of GH. Serum apolipoprotein (apo) B and low-density lipoprotein (LDL) cholesterol concentrations decreased during treatment with daily GH injections, but were not significantly affected by continuous GH infusion. Thus, apo B and LDL cholesterol concentrations were lower after daily GH injections versus continuous GH infusion. Serum lipoprotein(a) [Lp(a)] and apo E concentrations increased during both modes of GH treatment. However, continuous infusion of GH resulted in a more marked increase in Lp(a) and apo E concentrations than daily GH injections. Minor effects were observed on serum apo A-I concentrations but high-density lipoprotein (HDL) cholesterol concentrations were not affected. In conclusion, GH treatment of GH-deficient men influenced adipose tissue LPL and postheparin plasma HL activity, as well as serum lipoprotein concentrations. Moreover, continuous GH infusion and daily GH injections differed with respect to the magnitude of effects on several lipoprotein fractions including VLDL triglycerides, LDL cholesterol, apo B, apo E, and Lp(a) concentrations.
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| 59. |
- Sigurjónsdóttir, Helga A, 1964, et al.
(författare)
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GH effect on enzyme activity of 11betaHSD in abdominal obesity is dependent on treatment duration.
- 2006
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - : Oxford University Press (OUP). - 0804-4643 .- 1479-683X. ; 154:1, s. 69-74
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In the past years the interaction of GH and 11beta hydroxysteroid dehydrogenase (11betaHSD) in the pathogenesis of central obesity has been suggested. DESIGN: We studied the effects of 9 months of GH treatment on 11betaHSD activity and its relationship with body composition and insulin sensitivity in 30 men with abdominal obesity, aged 48-66 years, in a randomised, double-blind, placebo-controlled trial. METHODS: Urinary steroid profile was used to estimate 11betaHSD type 1 and 2 (11betaHSD1 and 11betaHSD2) activities. Abdominal s.c. and visceral adipose tissues were measured using computed tomography. Glucose disposal rate (GDR) obtained during a euglycaemic-hyperinsulinaemic glucose clamp was used to assess insulin sensitivity. RESULTS: In the GH-treated group the 11betaHSD1 activity decreased transiently after 6 weeks (P < 0.01) whereas 11betaHSD2 increased after 9 months of treatment (P < 0.05). Between 6 weeks and 9 months, GDR increased and visceral fat mass decreased. Changes in 11betaHSD1 correlated with changes in visceral fat mass between baseline and 6 weeks. There were no significant correlations between 11betaHSD1 and 11betaHSD 2 and changes in GDR. DISCUSSION: The study demonstrates that short- and long-term GH treatment has different effects on 11betaHSD1 and 11betaHSD2 activity. Moreover, the data do not support that long-term metabolic effects of GH are mediated through its action on 11betaHSD.
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| 60. |
- Svensson, Johan, 1964, et al.
(författare)
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Effects of growth hormone and its secretagogues on bone.
- 2001
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Ingår i: Endocrine. - 0969-711X. ; 14:1, s. 63-6
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Tidskriftsartikel (refereegranskat)abstract
- The growth hormone (GH)/insulin-like growth factor-1 axis is not only of importance for linear body growth during childhood, but it is also one of the major determinants of adult bone mass. Studies show that GH treatment increases bone mass in rodents as well as in adult GH-deficient humans, but the effect of GH treatment on bone mass in healthy humans has so far not been impressive. Recently, a new class of GH secretagogues (GHSs) has been developed. In humans, GHS treatment affects biochemical markers of bone turnover and increases growth velocity in selected short children with or without GH deficiency. In rodents, GHS treatment increase bone mineral content, but it has not yet been shown that GHS treatment can affect bone mass in adult humans.
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