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Colao A, Di Somma C, Filippella M, Rota F, Pivonello R, Orio F, Vitale G, Lombardi G. Insulin-like growth factor-1 deficiency determines increased intima-media thickness at common carotid arteries in adult patients with growth hormone deficiency. Clin Endocrinol (Oxf) 2004; 61:360-6. [PMID: 15355453 DOI: 10.1111/j.1365-2265.2004.02105.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To investigate the role of IGF-1 on intima-media thickness (IMT) at common carotid arteries by Doppler ultrasonography. SUBJECTS Thirty-nine patients (17 women, 22 men, aged 25-70 years) with severe GH deficiency (GHD), 19 with normal and 20 with low IGF-1 levels, and 39 sex-, age- and body mass index (BMI)-matched healthy controls. RESULTS Patients with GHD showed abnormalities in lipid profile, and increased fibrinogen levels, mean IMT (0.88 +/- 0.26 vs. 0.69 +/- 0.14 mm, P < 0.001), and systolic and diastolic peak velocity (P < 0.001) compared to controls. Eight patients (18%) and one control (2.1%, P = 0.04) had well-defined plaques. In controls, but not in patients with GHD, mean carotid IMT was correlated with age (r = 0.78, P < 0.001). In both controls (r = -0.82; P < 0.0001) and patients with GHD (r = -0.84, P < 0.0001), serum IGF-1 levels were inversely correlated with mean IMT at common carotid arteries. At the stepwise multiple regression, the variables most significantly related to IMT in GH-deficient patients were total cholesterol levels (t = 5.2, P < 0.001), followed by disease duration (t = 2.4, P = 0.02), while in controls the variables most significantly related to IMT were IGF-1 levels (t = -9.9, P < 0.001), followed by low density lipoprotein (LDL)-cholesterol levels (t = -2.3, P = 0.02). Compared to patients with normal IGF-1 levels, those with low IGF-1 levels had lower high density lipoprotein (HDL)-cholesterol levels (1.0 +/- 0.2 vs. 1.3 +/- 0.2 mmol/l, P = 0.0002), and higher glucose (54.3 +/- 6.1 vs. 48.9 +/- 5.9 mmol/l, P = 0.008), insulin (25.2 +/- 6.8 vs. 18.8 +/- 6.0 mUl/l, P = 0.004), total cholesterol (7.1 +/- 1.1 vs. 4.9 +/- 0.6 mmol/l, P < 0.0001), total/HDL-cholesterol ratio (7.2 +/- 1.8 vs. 3.9 +/- 0.7, P < 0.0001), fibrinogen levels (319.8 +/- 56.9 vs. 241.8 +/- 53.0 mg/dl, P < 0.0001) and mean IMT at common carotid arteries (1.05 +/- 0.25 vs. 0.69 +/- 0.07 mm, P < 0.0001). Atherosclerotic plaques were found only in GH-deficient patients with low IGF-1 levels. CONCLUSIONS GH-deficient patients have alterations in lipid profile with an increase in the total/HDL-cholesterol ratio, which is an index of increased cardiovascular risk, but only patients with IGF-1 deficiency have increased IMT.
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Affiliation(s)
- Annamaria Colao
- Department of Molecular and Clinical Endocrinology and Oncology, Federico II University of Naples, Italy.
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Lilien MR, Schröder CH, Levtchenko EN, Koomans HA. Growth hormone therapy influences endothelial function in children with renal failure. Pediatr Nephrol 2004; 19:785-9. [PMID: 15173937 DOI: 10.1007/s00467-004-1495-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Revised: 03/22/2004] [Accepted: 03/24/2004] [Indexed: 11/25/2022]
Abstract
Endothelial dysfunction, an early step in atherogenesis, is prevalent in children with renal insufficiency. Endothelial dysfunction in growth hormone deficiency is reversed by growth hormone (rhGH) therapy. Renal failure induces growth hormone resistance at the receptor and post-receptor level, which can be overcome by rhGH therapy. This study investigates the influence of rhGH therapy in children with renal failure on flow-mediated dilation (FMD) of the brachial artery, a marker of endothelial function. We studied 8 patients, who were on rhGH for at least 6 months, and 8 healthy children for comparison. FMD of the brachial artery was measured non-invasively as the percentage increase in diameter during post-ischemic hyperemia. Patients were studied at baseline, after 4 weeks interruption of rhGH therapy, and 4 weeks after resumption of therapy. FMD was significantly lower in patients (4.7%) than healthy controls (13.8%) ( P=0.01). During the administration of rhGH, FMD was significantly higher (3.9%) than during interruption of the treatment (1.4%) ( P=0.04). Our data support the theory that a disturbance in the GH-IGF axis contributes to the endothelial dysfunction of renal failure. Treatment with rhGH not only improves growth but may also favorably influence the risk for atherogenesis.
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Affiliation(s)
- Marc R Lilien
- Department of Pediatric Nephrology, Wilhelmina Children's Hospital, University Medical Center Utrecht, PO Box 85090, 3508 CA Utrecht, The Netherlands.
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103
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Maison P, Griffin S, Nicoue-Beglah M, Haddad N, Balkau B, Chanson P. Impact of growth hormone (GH) treatment on cardiovascular risk factors in GH-deficient adults: a Metaanalysis of Blinded, Randomized, Placebo-Controlled Trials. J Clin Endocrinol Metab 2004; 89:2192-9. [PMID: 15126541 DOI: 10.1210/jc.2003-030840] [Citation(s) in RCA: 220] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Patients with hypopituitarism have an increased risk of cardiovascular mortality. GH treatment could modify the cardiovascular risk in adults with GH deficiency, but most published clinical trials involved few patients and the results are variable. We conducted a systematic review of blinded, randomized, placebo-controlled trials of GH treatment in adult patients with GH deficiency published up to August 2003. Thirty-seven trials were identified. We combined the results for effects on lean and fat body mass; body mass index; triglyceride and cholesterol [high-density lipoprotein, low-density lipoprotein (LDL), and total] levels; blood pressure; glycemia; and insulinemia. Overall effect size was used to evaluate significance, and weighted differences between GH and placebo were used to appreciate the size of the effect. GH treatment significantly reduced LDL cholesterol [-0.5 (SD 0.3) mmol/liter], total cholesterol [-0.3 (0.3) mmol/liter], fat mass [-3.1 (3.3) kg], and diastolic blood pressure [-1.8 (3.8) mm Hg] and significantly increased lean body mass [+2.7 (2.6) kg], fasting plasma glucose [+0.2 (0.1) mmol/liter], and insulin [+8.7 (7.0) pmol/liter]. All effect sizes remained significant in trials with low doses and long-duration GH treatment. Thus, GH treatment has beneficial effects on lean and fat body mass, total and LDL cholesterol levels, and diastolic blood pressure but reduces insulin sensitivity. The global cardiovascular benefit remains to be determined in large trials with appropriate clinical endpoints.
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Affiliation(s)
- Patrick Maison
- Clinical Pharmacology, Clinical Research Unit, Assistance Pubique-Hôpitaux de Paris, Henri Mondor University Hospital, F-94010 Créteil, France
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104
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Salerno M, Esposito V, Spinelli L, Di Somma C, Farina V, Muzzica S, de Horatio LT, Lombardi G, Colao A. Left ventricular mass and function in children with GH deficiency before and during 12 months GH replacement therapy. Clin Endocrinol (Oxf) 2004; 60:630-6. [PMID: 15104568 DOI: 10.1111/j.1365-2265.2004.02026.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This open, prospective study was designed to evaluate the effect of GH deficiency (GHD) on left ventricular (LV) mass (LVM) and performance, by echocardiography, and on lipid profile during childhood. SUBJECTS Twelve prepubertal children with GHD (eight boys and four girls) aged 8.1 +/- 1.7 years were studied before and after 6 and 12 months of GH replacement therapy at a dose of GH of 30 micro g/kg/day. Twelve healthy children sex-, height-, weight- and body surface area-matched with the patients, served as controls. METHODS Echocardiography was performed at study entry and after 12 months both in GHD children and in controls. Only in GHD children, echocardiography was repeated also after 6 months of GH replacement. In all subjects, we measured LV posterior wall thickness (LVPWT), LV end-diastolic diameter (LVEDD), LVM index (LVMi), LV systolic and diastolic function. RESULTS At study entry, LVPWT (5.3 +/- 0.8 vs. 6.2 +/- 1.1 mm, P < 0.05), LVEDD (34.0 +/- 2.4 vs. 36.7 +/- 2.1 mm, P < 0.007) and LVMi (47.0 +/- 6.9 vs. 59.6 +/- 9.5 g/m2, P < 0.005) were significantly lower in GHD children than in controls. Lipid profile, heart rate, blood pressure, LV systolic function and indices of ventricular filling were similar in patients and controls. After 12 months of GH replacement therapy, LVPWT (6.1 +/- 0.7 mm, P < 0.0005), LVEDD (38.8 +/- 4.3 mm, P < 0.002) and LVMi (71.5 +/- 12.7 g/m2, P < 0.0005) significantly increased in GHD children compared to pretreatment values. In particular, after 12 months of therapy GHD children achieved a normal LVMi when compared to controls (60.7 +/- 8.6, P = ns). LVMi increase was significantly correlated with the increase in IGF-I level (r = 0.49; P < 0.004). LV systolic performance, diastolic filling and blood pressure did not change significantly during GH therapy. After 12 months of treatment, the atherogenic index, measured as total/high-density lipoprotein-cholesterol ratio (2.7 +/- 0.8) was significantly lower than both pretreatment (3.4 +/- 0.3, P < 0.03) and control values (3.8 +/- 1.1, P < 0.04). CONCLUSIONS GH deficiency in children affects heart morphology, by inducing a significant decrease in cardiac size, but does not modify cardiac function and lipid profile. Twelve months of GH replacement treatment normalizes cardiac mass, and reduces the atherogenic index.
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105
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Abstract
The homeostatic corrections that have emerged in the course of human evolution to cope with catastrophic events involve a complex multisystem endeavor, of which the endocrine contribution is an integral component. Although the repertoire of endocrine changes has been probed in some detail, discerning the vulnerabilities and failure of this system is far more challenging. The ensuing endocrine topics illustrate some of the current issues reflecting attempts to gain an improved insight and clinical outcome for critical illness.
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Affiliation(s)
- Eric S Nylen
- Department of Medicine, Section of Endocrinology, George Washington University School of Medicine, and Veterans Affairs Medical Center, 50 Irving St, NW, Rm GE246, Washington, DC 20422, USA.
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106
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Hana V, Silha JV, Justova V, Lacinova Z, Stepan JJ, Murphy LJ. The effects of GH replacement in adult GH-deficient patients: changes in body composition without concomitant changes in the adipokines and insulin resistance. Clin Endocrinol (Oxf) 2004; 60:442-50. [PMID: 15049958 DOI: 10.1111/j.1365-2265.2004.02000.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Growth hormone deficiency (GHD) in adult life has been associated with increased central adiposity, decreased insulin sensitivity, dyslipidaemia and increased risk of cardiovascular disease. The effects of GH replacement on adiponectin and resistin, adipokines which have a role in modulating insulin sensitivity have not been previously reported. AIM To examine the effects of GH replacement on adipokine levels and insulin resistance in GHD patients. DESIGN Seventeen adult GHD patients were examined at baseline and after 1 year of treatment with recombinant human GH (mean dose 0.31 mg/day, range 0.13-0.67 mg/day). RESULTS GH replacement significantly increased IGF-I levels. The mean IGF-I SD score increased from -1.98 at baseline to 0.76 at study end. GH replacement was associated with a significant reduction in percentage body fat (34.11 +/- 1.33 vs. 30.65 +/- 1.27%, P < 0.0005) and a significant increase in lean body mass (63.57 +/- 1.24 vs. 66.96 +/- 1.18%, P < 0.0004), before and after treatment, respectively. Surprisingly, there was no effect of GH replacement on the plasma levels of leptin, resistin or adiponectin or on plasma lipid profile. Insulin sensitivity did not deteriorate during GH replacement despite the known 'anti-insulin' effect of GH. Fasting glucose, insulin and insulin resistance as calculated using the homeostasis model assessment insulin resistance index (HOMA-R) were unchanged by GH treatment. CONCLUSION These data demonstrate GH replacement in adult subjects with GHD is effective in changing body composition and restoring IGF-I levels over a 12-month period; however, in our study, these changes were not accompanied by changes in adipokine levels or beneficial effects on plasma lipids or insulin resistance.
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Affiliation(s)
- Vaclav Hana
- Third Department of Internal Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
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107
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Origlia C, Pescarmona G, Capizzi A, Cogotti S, Gambino R, Cassader M, Benso A, Granata R, Martina V. Platelet cGMP inversely correlates with age in healthy subjects. J Endocrinol Invest 2004; 27:RC1-4. [PMID: 15129801 DOI: 10.1007/bf03346251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Biochemical modifications associated with the increase in platelet activity with age are not well defined. Furthermore it is well known that the nitric oxide/cyclic 3', 5'-guanosine monophosphate (cGMP) pathway regulates platelet aggregation. The aim of the present study was to examine the relationship between platelet content of cGMP and age. 120 normal subjects, evaluating the cGMP platelet concentration, 17betaE2, IGF-I, dehydroepiandrosterone sulphate (DHEAS), insulin, plasma glucose, lipid pattern, homocysteine and PAI-I antigen, were studied. The multivariate analysis in a model with cGMP as dependent variable and with age, LDL, apolipoprotein B (ApoB), DHEAS, E2 and insulin-like growth factor (IGF)-I as independent variables shows a negative correlation between cGMP and age (p<0.01, beta=-0.388). In conclusion our data suggest that the reduced efficiency of the system constitutive nitric oxide synthase (cNOS)/guanylate cyclase represents at least one of the reasons of the increased platelet aggregability with age.
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Affiliation(s)
- C Origlia
- Department of Internal Medicine, Division of Endocrinology, University of Turin, Turin, Italy
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108
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Thum T, Tsikas D, Frölich JC, Borlak J. Growth hormone induces eNOS expression and nitric oxide release in a cultured human endothelial cell line. FEBS Lett 2004; 555:567-71. [PMID: 14675775 DOI: 10.1016/s0014-5793(03)01356-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Growth hormone deficiency is linked to cardiovascular disease and particularly increased peripheral vascular resistance. Surprisingly, its role in endothelial nitric oxide (NO) synthetase (eNOS) regulation and NO release is basically unknown. We therefore studied the effects of different doses of somatotropin in cultures of a human endothelial cell line (EAhy926). We investigated expression and activity of eNOS, as well as other target genes known to be deregulated in cardiovascular disease including E-selectin and the lectin-like oxidized low density lipoprotein receptor. Treatment of cultured human endothelial cells with somatotropin resulted in significant (P<0.05) increases of eNOS gene and protein expression, as well as NO release, whereas production of intracellular reactive oxygen species was significantly reduced, at the highest somatotropin dose level. The enhanced eNOS gene/protein expression and enzyme activity correlate well. Our findings are suggestive for a novel role of growth hormone in endothelial biology, and particularly NO production.
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Affiliation(s)
- Thomas Thum
- Fraunhofer Institute of Toxicology and Experimental Medicine (ITEM), Drug Research and Medical Biotechnology, 30625, Hannover, Germany
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109
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McCarty MF. Coping with endothelial superoxide: potential complementarity of arginine and high-dose folate. Med Hypotheses 2004; 63:709-18. [PMID: 15325022 DOI: 10.1016/j.mehy.2002.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2002] [Accepted: 11/11/2002] [Indexed: 01/31/2023]
Abstract
Superoxide overproduction is a prominent mediator of the endothelial dysfunction associated with a range of vascular disorders, acting in a number of complementary ways to inhibit effective endothelial nitric oxide (NO) activity. The ability of superoxide to quench NO is well known, but oxidants derived from superoxide also appear to inhibit dimethylarginine dimethylaminohydrolase (DDAH) and to oxidize tetrahydrobiopterin (THBP). The former effect boosts the level of methylated arginines that act as potent competitive inhibitors of NO synthase, whereas the latter effect decreases the ability of this enzyme to generate NO, while converting it to a form that readily generates superoxide. The adverse impact of DDAH deficiency on NO production can be offset with supplemental arginine. Although supplementation with THBP has the potential to compensate for the rapid oxidative destruction of this compound, and maintaining optimal vitamin C nutrition may protect or restore the endothelial THBP pool to a limited extent, the most practical way to optimize NO synthase activity in the context of THBP deficit may be administration of high-dose folic acid. The primary circulating metabolite of folate, 5-methyltetrahydrofolate (5MTHF), is structurally analogous to THBP, and appears to normalize the activity of NO synthase in THBP-depleted endothelial cells, either because it "pinch hits" for the absent THBP, or interacts allosterically with NO synthase in some other way to promote the proper function of this enzyme. This observation may rationalize recent clinical studies showing a favorable effect of oral folic acid (5-10 mg daily) on dysfunctional endothelium, independent of any concurrent modulation of homocysteine levels. A recent study reports that, whereas either arginine or THBP alone have only a modest impact on dysfunctional aortic endothelium derived from hypercholesterolemic mice, the combination of the two produces a complete normalization of endothelial function. In aggregate, these considerations suggest that joint administration of arginine and high-dose folate may represent a fruitful approach to preventing and treating vascular disorders - albeit the underlying overproduction of superoxide should also be addressed by ameliorating relevant vascular risk factors.
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Affiliation(s)
- Mark F McCarty
- Pantox Laboratories, 4622 Santa Fe St., San Diego, CA 92109, USA.
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110
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Abstract
Growth hormone (GH) profoundly affects the developing and adult myocardium. Adult patients with GH deficiency (GHD) and GH excess (acromegaly) provide important models in which to understand the effects of GH in adult cardiac physiology. An increasing body of clinical and experimental evidence illustrates the specific physiological abnormalities that are likely associated with the excess cardiovascular mortality observed in both acromegaly and GHD. Because human GH replacement is now available to treat adults with GHD, new questions emerge about the long-term cardiovascular effects of replacement therapy. In multiple trials, GH therapy for congestive heart failure has been proved ineffective in the absence of preexisting GHD. Case reports suggest that, in the setting of GHD, GH therapy can exert a potent beneficial effect on congestive heart failure. Long-term studies addressing cardiovascular morbidity and mortality are needed to assess the role of GH therapy for GHD.
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Affiliation(s)
- Deborah E Meyers
- Division of Heart Failure and Transplantation, The Prince Charles Hospital, Chermside, Queensland, Australia.
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111
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Affiliation(s)
- P H Kann
- Division of Endocrinology and Diabetology, Philipps University Hospital Marburg, Baldingerstrasse, D-35033 Marburg, Germany
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112
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Shimizu Y, Nagaya N, Teranishi Y, Imazu M, Yamamoto H, Shokawa T, Kangawa K, Kohno N, Yoshizumi M. Ghrelin improves endothelial dysfunction through growth hormone-independent mechanisms in rats. Biochem Biophys Res Commun 2003; 310:830-5. [PMID: 14550279 DOI: 10.1016/j.bbrc.2003.09.085] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ghrelin is a novel growth hormone (GH)-releasing peptide which was isolated from the stomach. We have reported that ghrelin causes vasorelaxation in rats through GH-independent mechanisms. We investigated whether ghrelin improves endothelial dysfunction. Ghrelin was subcutaneously administered to GH-deficient rats for three weeks. After isolation of the thoracic aorta, aortic ring tension was measured to evaluate vasorelaxation. Acetylcholine-induced vasorelaxation was impaired in GH-deficient rats given placebo compared to that in normal rats given placebo. GH-deficient rats treated with ghrelin, however, showed a significant increase in the maximal relaxation as compared with those given placebo. This improvement by ghrelin was inhibited by N(G)-nitro-L-arginine methyl ester, a nonselective nitric oxide synthase (NOS) inhibitor. Western blot analysis demonstrated that treatment with ghrelin increased endothelial NOS (eNOS) expression in the aorta of GH-deficient rats. These results suggest that administration of ghrelin improves endothelial dysfunction and increases eNOS expression in rats through GH-independent mechanisms.
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Affiliation(s)
- Yoshito Shimizu
- Department of Molecular and Internal Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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113
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The effect of growth hormone (GH) replacement therapy on sympathetic nerve hyperactivity in hypopituitary adults. J Hypertens 2003. [DOI: 10.1097/00004872-200310000-00018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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114
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Ozbey N, Telci A, Cakatay U, Yurci A, Molvalilar S. Determination of oxidative protein and lipid damage in adult hypopituitary patients with GH deficiency. J Endocrinol Invest 2003; 26:1001-7. [PMID: 14759074 DOI: 10.1007/bf03348199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The aim of this study is to determine oxidative protein and lipid damage in adult hypopituitary GH-deficient patients. Eighteen hypopituitary GH-deficient--otherwise healthy-adults on conventional replacement therapy other than GH (9 male, 9 female, age 41.8 +/- 16.4 yr) and 18 healthy subjects (6 male, 12 female, age 40.3 +/- 16.2 yr) participated in the study. Plasma products of oxidative protein damage [protein carbonyl (PCO) and nitrotyrozine (NT)], plasma oxidized LDL (oxLDL), plasma product of oxidative lipid damage [lipid hydroperoxide (LHP)] and antioxidant status of the plasma [total thiol (T-SH)] were measured. Body fat percentage, total and LDL-cholesterol concentrations were significantly higher in the hypopituitary group. Plasma PCO, NT, LHP and T-SH concentrations did not differ significantly between patients and controls. OxLDL concentration was significantly higher in the hypopituitary patients (62.4 +/- 17.8 vs 43.1 +/- 11.3 U/l, p = 0.001). In the patients, oxLDL correlated significantly with the duration of hypopituitarism (r = 0.6323, p = 0.01). In the controls, oxLDL correlated significantly with blood pressure, total and VLDL-cholesterol concentrations. Increased oxLDL concentration may indicate increased oxidative stress within the vascular compartment and may contribute to the proatherogenic state in GH-deficient hypopituitary patients independent from conventional risk factors.
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Affiliation(s)
- N Ozbey
- Department of Internal Medicine, Division of Endocrinology, Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey.
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115
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McCarty MF. IGF-I activity may be a key determinant of stroke risk--a cautionary lesson for vegans. Med Hypotheses 2003; 61:323-34. [PMID: 12944100 DOI: 10.1016/s0306-9877(02)00241-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
IGF-I acts on vascular endothelium to activate nitric oxide synthase, thereby promoting vascular health; there is reason to believe that this protection is especially crucial to the cerebral vasculature, helping to ward off thrombotic strokes. IGF-I may also promote the structural integrity of cerebral arteries, thereby offering protection from hemorrhagic stroke. These considerations may help to explain why tallness is associated with low stroke risk, whereas growth hormone deficiency increases stroke risk--and why age-adjusted stroke mortality has been exceptionally high in rural Asians eating quasi-vegan diets, but has been declining steadily in Asia as diets have become progressively higher in animal products. There is good reason to suspect that low-fat vegan diets tend to down-regulate systemic IGF-I activity; this effect would be expected to increase stroke risk in vegans. Furthermore, epidemiology suggests that low serum cholesterol, and possibly also a low dietary intake of saturated fat--both characteristic of those adopting low-fat vegan diets--may also increase stroke risk. Vegans are thus well advised to adopt practical countermeasures to minimize stroke risk--the most definitive of which may be salt restriction. A high potassium intake, aerobic exercise training, whole grains, moderate alcohol consumption, low-dose aspirin, statin or policosanol therapy, green tea, and supplementation with fish oil, taurine, arginine, and B vitamins--as well as pharmacotherapy of hypertension if warranted--are other practical measures for lowering stroke risk. Although low-fat vegan diets may markedly reduce risk for coronary disease, diabetes, and many common types of cancer, an increased risk for stroke may represent an 'Achilles heel'. Nonetheless, vegans have the potential to achieve a truly exceptional 'healthspan' if they face this problem forthrightly by restricting salt intake and taking other practical measures that promote cerebrovascular health.
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Affiliation(s)
- M F McCarty
- Pantox Laboratories, San Diego, California 92109, USA
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116
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Uckert S, Stief CG, Jonas U. Current and future trends in the oral pharmacotherapy of male erectile dysfunction. Expert Opin Investig Drugs 2003; 12:1521-33. [PMID: 12943496 DOI: 10.1517/13543784.12.9.1521] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The promising clinical data on the use of the first orally active phosphodiesterase inhibitor sildenafil citrate (Viagra) for treatment of male erectile dysfunction have been accompanied by an increase in research activities on the physiology of the male erectile mechanism. This included both peripheral intracellular signal transduction in the corpus cavernosum as well as central brain and spinal cord pathways that control penile erection. This work provided the basis for the development and introduction of several new therapeutic modalities into the management of erectile dysfunction that is now offered to the patients. Since the concept of 'taking a pill' as a cure for an illness or the relief of symptoms of a disease has become widely accepted by consumers, the pharmacological treatment of erectile dysfunction has primarily focused on selective, orally available drugs that act via influencing intracellular or central regulatory mechanisms, combining a high response rate and the advantage of an 'on-demand' intake. These agents are regarded as more efficacious, have a faster onset of drug action in the target tissue and an improved effect-to-side effect ratio than sildenafil. The purpose of this review is to describe the major novel and evolving pharmacological advances in the field of oral pharmacotherapy for the treatment of male erectile dysfunction.
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Affiliation(s)
- Stefan Uckert
- Hannover Medical School, Department of Urology, 30625 Hannover, Germany.
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117
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Nagaya N, Kangawa K. Ghrelin, a novel growth hormone-releasing peptide, in the treatment of chronic heart failure. REGULATORY PEPTIDES 2003; 114:71-7. [PMID: 12832093 DOI: 10.1016/s0167-0115(03)00117-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ghrelin is a novel growth hormone (GH)-releasing peptide, isolated from the stomach, which has been identified as an endogenous ligand for growth-hormone secretagogues receptor (GHS-R). This peptide also causes a positive energy balance by stimulating food intake and inducing adiposity through growth hormone-independent mechanisms. In addition, ghrelin has some cardiovascular effects, as indicated by the presence of its receptor in blood vessels and the cardiac ventricles. In vitro, ghrelin inhibits apoptosis of cardiomyocytes and endothelial cells. In humans, infusion of ghrelin decreases systemic vascular resistance and increases cardiac output in patients with heart failure. Repeated administration of ghrelin improves cardiac structure and function and attenuates the development of cardiac cachexia in rats with heart failure. These results suggest that ghrelin has cardiovascular effects and regulates energy metabolism through GH-dependent and -independent mechanisms. Thus, administration of ghrelin may be a new therapeutic strategy for the treatment of severe chronic heart failure (CHF).
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Affiliation(s)
- Noritoshi Nagaya
- Department of Internal Medicine, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
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118
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Schut AFC, Janssen JAMJL, Deinum J, Vergeer JM, Hofman A, Lamberts SWJ, Oostra BA, Pols HAP, Witteman JCM, van Duijn CM. Polymorphism in the promoter region of the insulin-like growth factor I gene is related to carotid intima-media thickness and aortic pulse wave velocity in subjects with hypertension. Stroke 2003; 34:1623-7. [PMID: 12791939 DOI: 10.1161/01.str.0000076013.00240.b0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Low circulating levels of insulin-like growth factor I (IGF-I) have been associated with an increased risk for atherosclerosis. Absence of the 192-bp (wild-type) allele in the promoter region of the IGF-I gene has been associated with low circulating IGF-I levels. We examined the role of this polymorphism in relation to blood pressure and 2 early markers of atherosclerosis: carotid intima-media thickness (IMT) and aortic pulse wave velocity (PWV). METHODS A total of 5132 subjects of the Rotterdam Study, aged 55 to 75 years, were included in this study. In 3769 subjects who did not use blood pressure-lowering medication, the association between the IGF-I polymorphism and blood pressure was examined. In the total population, and in 3484 normotensive subjects, 1648 hypertensive and 462 untreated hypertensive subjects, the association between this polymorphism and IMT and PWV was examined. RESULTS Mean systolic and diastolic blood pressure did not differ between genotypes. In hypertensive subjects IMT was significantly increased in noncarriers of the 192-bp allele (0.83 mm) compared with heterozygous or homozygous carriers (0.80 mm) (P=0.04). PWV was also significantly higher in hypertensive subjects who were noncarriers of the 192-bp allele (14.3 m/s) compared with heterozygous (14.1 m/s) or homozygous carriers (13.7 m/s) (P=0.02). Findings were more pronounced in hypertensive subjects without medication use. In normotensive subjects, no association between this polymorphism, IMT, and PWV was observed. CONCLUSIONS Our study suggests that hypertensive subjects who have low IGF-I levels because of a genetic polymorphism in the IGF-I gene are at increased risk of developing atherosclerosis.
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Affiliation(s)
- A F C Schut
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Netherlands
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119
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Napoli R, Guardasole V, Angelini V, D'Amico F, Zarra E, Matarazzo M, Saccà L. Acute effects of growth hormone on vascular function in human subjects. J Clin Endocrinol Metab 2003; 88:2817-20. [PMID: 12788893 DOI: 10.1210/jc.2003-030144] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GH is involved in the long-term regulation of peripheral vascular resistance and vascular reactivity. We determined whether GH plays a role in the acute regulation of vascular function in humans. The acute vascular effects of GH were studied in eight healthy subjects according to a double-blind, placebo-controlled design. Forearm blood flow (FBF), vascular resistance, and nitric oxide (NO) production were monitored during a 4-h infusion of GH into the brachial artery at a rate chosen to raise local GH to stress levels (approximately 40 ng/ml). During GH infusion, FBF rose 75% (P < 0.05), whereas forearm vascular resistance decreased comparably (P < 0.05). These changes were paralleled by augmented forearm release of NO (P < 0.02). GH heightened the response of FBF to the endothelium-dependent vasodilator acetylcholine (Ach; P < 0.02). With the highest Ach dose, FBF reached 30.4 +/- 4.2 and 16.9 +/- 3.1 ml/dl x min in the GH and placebo studies, respectively (P < 0.005). The slopes of the dose-response curves also differed markedly (0.45 +/- 0.07 and 0.25 +/- 0.05 ml/dl x min/ microg in the GH and placebo studies, respectively; P < 0.01). GH caused an upward shift of the FBF response to the endothelium-independent vasodilator sodium nitroprusside (P < 0.01), but did not affect the slope of the dose-response curve. GH infusion did not cause any appreciable increment in the venous IGF-I concentration in the test arm. In conclusion, GH acutely lowers peripheral vascular resistance and stimulates endothelial function. These effects are mediated by activation of the NO pathway and appear to be independent of IGF-I.
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Affiliation(s)
- Raffaele Napoli
- Department of Internal Medicine and Cardiovascular Sciences, University Federico II, 80131 Naples, Italy
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120
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Twickler TB, Cramer MJM, Dallinga-Thie GM, Chapman MJ, Erkelens DW, Koppeschaar HPF. Adult-onset growth hormone deficiency: Relation of postprandial dyslipidemia to premature atherosclerosis. J Clin Endocrinol Metab 2003; 88:2479-88. [PMID: 12788843 DOI: 10.1210/jc.2003-030278] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- T B Twickler
- INSERM, Unité 551 Dyslipoproteinemia and Atherosclerosis, Hôpital Pitié-Salpetrière, 75651 Paris, France.
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121
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Boger RH, Frystyk J, Ledet T, Moller N, Flyvbjerg A, Orskov H. Low serum insulin-like growth factor I is associated with increased risk of ischemic heart disease. Circulation 2003; 107:e193; author reply e193. [PMID: 12777324 DOI: 10.1161/01.cir.0000074249.75310.65] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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122
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Ricart W, Fernández-Real JM. [Impact of hormonal deficit and cardiovascular risk factors on life expectancy in hypopituitarism]. Med Clin (Barc) 2003; 120:630-7. [PMID: 12732130 DOI: 10.1016/s0025-7753(03)73792-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Wifredo Ricart
- Unidat de Diabetes, Endocrinología y Nutrición. Hospital Universitari Dr. Josep Trueta. Girona. España.
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123
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Pincelli AI, Bragato R, Scacchi M, Branzi G, Osculati G, Viarengo R, Leonetti G, Cavagnini F. Three weekly injections (TWI) of low-dose growth hormone (GH) restore low normal circulating IGF-I concentrations and reverse cardiac abnormalities associated with adult onset GH deficiency (GHD). J Endocrinol Invest 2003; 26:420-8. [PMID: 12906369 DOI: 10.1007/bf03345197] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
GH replacement therapy given 3 times weekly (TWI) and adjusted to allow serum IGF-I concentrations in the mid-normal range for sex and age has been shown to be as effective as the daily regimen in improving lipid profile, body composition, bone mass and turnover in adult GH deficient (GHD) patients. Only one study has investigated so far the short-term (6 months) effect of a fixed weight-based TWI dosing schedule on heart structure and function in childhood onset (CO) GHD patients, whereas such a schedule in adult onset (AO) GHD patients has not been studied as yet. Aim of this study was to investigate whether a 1-yr low-dose titrated TWI GH-replacement regimen aimed at achieving and maintaining IGF-I levels within the low normal limits for age and sex is able to affect cardiovascular and heart parameters in a group of AO GHD patients. Eight adult patients (4 women and 4 men, age 35.8 +/- 3.37 yr, body mass index, BMI, 28.7 +/- 2.62 kg/m2) with AO GHD were included in the study, along with 10 healthy subjects, matched for age, sex, BMI and physical activity (6 women and 4 men, age 35.2 +/- 4.05 yr, BMI 28.4 +/- 2.34 kg/m2). M- and B- mode ecocardiography and pulsed doppler examination of transmitral flow were performed in GHD patients at baseline and after 3 and 12 months of GH therapy (mean GH dose 6.7 +/- 0.8 microg/kg/day given thrice a week), while normal subjects were studied once. Treatment with GH for 1 yr induced a significant increase in left ventricular (LV) diastolic and systolic volumes (+11.1 and +16.5%, respectively). Systolic LV posterior wall thickness and LV mass were increased (+10.2 and +7.7%, respectively) by GH administration. Systemic vascular resistance was significantly decreased by 1-yr GH therapy (-13.8% after 1 yr), while stroke volume, cardiac output and cardiac index were increased (+9.4, +11.6 and + 11.9%, respectively). LV end-systolic stress was decreased at the end of GH therapy (-11.2%). E and A wave, significantly reduced at baseline, were increased by 1 yr of GH therapy (+23.3% and +28.1%, respectively); likewise, the abnormally high E peak deceleration time was partially reversed by GH administration (-10.7%). Our study, though conducted in a small sample size, demonstrates that a TWI GH treatment schedule is able to reverse the cardiovascular abnormalities in AO GHD patients and to improve body composition and lipid profile. The maintenance of circulating IGF-I concentrations within the low normal range allows to avoid most of the side-effects reported with higher GH doses while being cost-effective and improving the patient's compliance.
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Affiliation(s)
- A I Pincelli
- University of Milan, IRCCS San Luca Hospital, Italian Auxologic Institute, Milan, Italy
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124
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Abstract
Growth hormone deficiency (GHD) in the adult has now been fully recognised as a clinical entity characterised by abnormal body composition, osteopenia, impaired quality of life, cardiac dysfunction and an adverse lipid profile. While short-term studies of GH replacement have demonstrated irrefutably a favourable effect on all if not most features of GHD, data on long-term administration spanning more than 2 years are still scarce. Experience of GH replacement up to 5 to 10 years indicate that the beneficial effects on body composition, predominantly a decrease in body fat and an increase in lean mass, is maintained during treatment. Long-term GH therapy also increases muscle strength and exercise performance. All data, with one exception, are consistent with a significant increase in bone mass during prolonged GH therapy. The most distinct effect on bone was observed in the worst affected individuals and in males. Improvement in quality of life is documented shortly after initiation of GH replacement and is maintained during long-term studies. This may explain the reduction in days of sick leave seen during GH therapy. The beneficial effect on cardiovascular risk factors is sustained over a prolonged period of time, revealing a reduction in intima wall thickness, and an improvement in serum lipid levels and clotting parameters. The increase in lipoprotein(a) levels with GH therapy in some studies may be disturbing, but difficulties in measuring this parameter and inconsistencies between the different studies makes it difficult to estimate its real impact. No data are yet available to show that GH replacement will normalise or even improve mortality rate and fracture rate. Adverse events associated with GH replacement therapy are mainly secondary to fluid retention as a result of excess dose administration. This can be adequately prevented by monitoring GH replacement according to serum insulin-like growth factor (IGF)-I levels. From what is currently known, GH replacement does not increase the prevalence of diabetes mellitus, and does not induce new neoplasms or recurrence of the primary brain tumour; however, longer follow-up studies are needed to provide definitive answers. In conclusion, it appears not only that long-term GH replacement therapy in adults with GHD is a procedure that can be safely used, but that GH replacement should be considered as a possible life-long therapy in order to maintain its benefits.
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Affiliation(s)
- Johan Verhelst
- Departments of Endocrinology, Middelheim Hospital and University Hospital, Antwerp, Belgium
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125
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Affiliation(s)
- Jens Møller
- Medical Department, Aarhus Kommunehospital, Institute of Clinical Experimental Research, University of Aarhus, DK-8000 Aarhus C., Denmark.
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126
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Pöykkö S, Ukkola O, Kauma H, Savolainen MJ, Kesäniemi YA. Ghrelin Arg51Gln mutation is a risk factor for Type 2 diabetes and hypertension in a random sample of middle-aged subjects. Diabetologia 2003; 46:455-8. [PMID: 12739020 DOI: 10.1007/s00125-003-1058-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2002] [Revised: 11/28/2002] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS Experimental studies have suggested that ghrelin, a novel gastrointestinal peptide hormone, could play a role in glucose homeostasis. In addition, ghrelin has been associated with beneficial haemodynamic effects in experimental settings. Since the Arg51Gln mutation changes the carboxyterminal amino acid of the mature hormone and is associated with low ghrelin concentrations, we assessed the hypothesis that Arg51Gln mutation is a risk factor for Type 2 diabetes, impaired glucose tolerance, and hypertension. METHODS Blood pressure recordings and oral glucose tolerance test were carried out in the hypertensive ( n=519) and control cohorts ( n=526) of our well-defined OPERA study. The genotypes and plasma IGF-I and IGFBP-1 concentrations of 1031 subjects were analysed. RESULTS The ghrelin 51Gln allele was a risk factor for Type 2 diabetes, and the effect remained significant after adjustment for age, BMI, and study group (OR=2.53, CI: 1.11-5.75, p=0.027). In addition, the 51Gln allele was a risk factor for hypertension (OR=2.63, CI: 1.37-5.08, p=0.003). 51Gln carriers had lower concentrations of IGF-I and higher concentrations of IGFBP-1 compared to non-carriers. CONCLUSION/INTERPRETATION The ghrelin 51Gln allele could increase the risk for Type 2 diabetes and hypertension. The low IGF-I concentrations in 51Gln carriers suggest that the mechanism might be associated with low GH concentrations.
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Affiliation(s)
- S Pöykkö
- Department of Internal Medicine and Biocenter Oulu, University of Oulu, Finland.
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127
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Svensson J, Johannson G. Long-Term Efficacy and Safety of Somatropin for Adult Growth Hormone Deficiency. ACTA ACUST UNITED AC 2003; 2:109-20. [PMID: 15871547 DOI: 10.2165/00024677-200302020-00004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The beneficial effects of somatropin (growth hormone [GH] replacement therapy) in adults are now established. Long-term somatropin administration in GH-deficient adults improves body composition, muscle strength, quality of life, bone mass and density, and lipoprotein pattern. The extent to which somatropin therapy can also reduce cardiovascular morbidity and mortality in GH-deficient adults remains to be determined. By starting with a low dose of somatropin, which is gradually increased based on clinical response (body composition, well-being, and serum insulin-like growth factor-1 concentration), effective treatment can be achieved with a minimum of fluid-related adverse effects. Thorough long-term monitoring of glucose metabolism, cardiovascular measurements, and underlying pituitary disease, is, however, mandatory.
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Affiliation(s)
- Johan Svensson
- Research Centre for Endocrinology and Metabolism, Sahlgrenska University Hospital, Göteborg, Sweden.
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128
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Johnston DG, Kearney T, Robinson S, Al-Mrayat M. Some elucidation of the mechanisms of vascular disease in hypopituitarism. Clin Endocrinol (Oxf) 2002; 57:159-60. [PMID: 12153593 DOI: 10.1046/j.1365-2265.2002.01587.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- D G Johnston
- Section of Endocrinology & Metabolic Medicine, Imperial College, St. Mary's Hospital, Praed Street, London W2 1NY
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129
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Abstract
The importance of growth hormone deficiency (GHD) in adult life has become more apparent over the last decade. As well as a distinct clinical syndrome there is a significant excess risk of cardiovascular disease. Although it is difficult to ascertain what part is played by the original pituitary disorder and the concomitant replacement hormonal therapies, there is clear evidence that GHD is associated with known cardiovascular risk factors such as body shape, lipid profile, insulin resistance, blood pressure, vessel wall morphology and haemostatic factors. Novel means of assessing vascular risk such as pulse wave velocity and flow-mediated dilatation can also estimate the risk without invasive procedures. The role of possible mediators of endothelial function such as nitric oxide and free radicals is being investigated further. Replacement of GH in GH-deficient patients leads to many effects on the above indices, some but not all of which are associated with reduced vascular risk. Long-term follow-up studies of morbidity and mortality are required for an accurate assessment of the beneficial effects of therapy.
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Affiliation(s)
- Roland W McCallum
- Department of Medicine and Therapeutics, Western Infirmary, Glasgow, UK.
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130
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Okumura H, Nagaya N, Enomoto M, Nakagawa E, Oya H, Kangawa K. Vasodilatory effect of ghrelin, an endogenous peptide from the stomach. J Cardiovasc Pharmacol 2002; 39:779-83. [PMID: 12021570 DOI: 10.1097/00005344-200206000-00001] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ghrelin is a novel growth hormone (GH)-releasing peptide, isolated from the stomach, which is identified as an endogenous ligand for GH secretagogues receptor. Although both ghrelin and its specific receptor are expressed in blood vessels, the cardiovascular effects of ghrelin remain unknown. To clarify whether ghrelin has a vasodilatory effect in humans, the response of forearm blood flow (FBF) to intra-arterial infusion of ghrelin was examined in eight healthy volunteers using a plethysmograph. In addition, hormonal responses to ghrelin were studied. Ghrelin increased FBF in a dose-dependent manner. Pretreatment with NG-monomethyl-l-arginine (l-NMMA), a nitric oxide synthase inhibitor, did not inhibit the FBF response to ghrelin, although l-NMMA significantly inhibited GH release. Serum insulin-like growth factor-I (IGF-I) level was not altered by ghrelin administration. Plasma cyclic guanosine 3', 5'-monophosphate level, a second messenger of nitric oxide, was also not altered. These results suggest that ghrelin has vasodilatory effects possibly through GH/IGF-I/nitric oxide-independent mechanisms.
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Affiliation(s)
- Hiroyuki Okumura
- Department of Cardiovascular Medicine, National Cardiovascular Center, Osaka, Japan
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131
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Smith JC, Evans LM, Wilkinson I, Goodfellow J, Cockcroft JR, Scanlon MF, Davies JS. Effects of GH replacement on endothelial function and large-artery stiffness in GH-deficient adults: a randomized, double-blind, placebo-controlled study. Clin Endocrinol (Oxf) 2002; 56:493-501. [PMID: 11966742 DOI: 10.1046/j.1365-2265.2002.01514.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Hypopituitary adults with growth hormone deficiency (GHD) have an increased cardiovascular mortality, although the mechanisms remain unclear. Endothelial dysfunction, characterized by reduced nitric oxide (NO) bioavailability, is a key early event in atherogenesis and is associated with increased vascular smooth muscle tone and arterial stiffening. DESIGN AND PATIENTS In a randomized, double-blind, placebo-controlled study, we investigated the effects of GH replacement on endothelial function and large-artery stiffness in 32 GHD adults (19 males, 13 females) (age range 19-64 years) over a 6-month period. Thirty-two age- and sex-matched healthy controls were also studied. MEASUREMENTS Endothelial function was assessed using ultrasonic wall tracking to measure flow-mediated dilatation (FMD) of the brachial artery. Large artery stiffness was assessed by pulse wave analysis of the radial artery pressure waveform, allowing determination of the corresponding central arterial pressure waveform and derivation of the augmentation index. Fasting lipid profiles, glucose and insulin were also measured. RESULTS At baseline, FMD (mean +/- SD) was impaired in GH-deficient subjects vs. controls (3.4 +/- 2.3 vs. 5.7 +/- 2.0%, P < 0.0001), although endothelium-independent dilatation was similar. The augmentation index was higher in GH-deficient subjects vs. controls (23 +/- 12 vs. 14 +/- 14%, P < 0.01). GH-deficient subjects had higher LDL cholesterol (4.1 +/- 0.8 vs. 3.5 +/- 0.8 mmol/l, P < 0.01) and lower HDL cholesterol (1.1 +/- 0.3 vs. 1.4 +/- 0.4 mmol/l, P < 0.01). In GH-deficient subjects, there were inverse correlations between LDL cholesterol and FMD (r = -0.40, P < 0.05) and between FMD and the augmentation index (r = - 0.58, P < 0.01). Regression analysis identified FMD as an independent predictor of the augmentation index (P < 0.0001). In comparison with baseline, GH replacement resulted in an increase in FMD (5.0 +/- 2.6 vs. 2.8 +/- 1.9%, P < 0.01). There were decreases in central aortic systolic pressure (117 +/- 15 vs. 123 +/- 17 mmHg, P < 0.01), diastolic pressure (82 +/- 10 vs. 86 +/- 8 mmHg, P < 0.01) and the augmentation index (22 +/- 8% vs. 26 +/- 10%, P < 0.05) despite unchanged brachial pressure indices. LDL cholesterol also decreased (3.5 +/- 0.8 vs. 4.2 +/- 0.8 mmol/l, P < 0.01). There were no significant changes in the placebo group. CONCLUSIONS Adult GHD is associated with endothelial dysfunction and increased large-artery stiffness. An improvement in endothelial function and a reduction in arterial stiffness following GH replacement suggests an important therapeutic role for GH in reducing cardiovascular risk associated with adult GHD.
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Affiliation(s)
- Jamie C Smith
- Department of Medicine, University Hospital of Wales, Heath Park, Cardiff CF14 4XN, Wales, UK.
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132
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Conceição FL, de Rooij Mansur VA, Brasil RRLO, Vaisman M. Ambulatory monitoring of blood pressure in growth hormone-deficient adults. Blood Press Monit 2002; 7:89-94. [PMID: 12048425 DOI: 10.1097/00126097-200204000-00001] [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: 11/26/2022]
Abstract
The aim of this study was to evaluate the 24-h pattern of blood pressure in adults with growth hormone deficiency using ambulatory blood pressure monitoring. We therefore evaluated the mean systolic and diastolic blood pressures, systolic and diastolic blood pressure loads and diurnal blood pressure rhythm. We used an auscultatory-type monitor, the measurements being made at 10-15 min intervals during the day and 20-30 min intervals at night. We included patients with a growth hormone peak of less than 3 ng/ml in at least two stimulation tests: the insulin tolerance and glucagon tests. The exclusion criteria were mental illnesses, pregnancy, diabetes mellitus, blood pressure higher than 160/90 mmHg, the use of growth hormone in the previous 12 months, severe acute illnesses, chronic liver or kidney disease and a history of malignancy. The results were interpreted according to the II Brazilian Consensus for the utilization of ambulatory monitoring. The study population comprised 27 adult patients with growth hormone deficiency, 11 male and 16 female, with an age range of 21-62 years. Five had developed the condition during childhood, whereas the remainder had adult-onset growth hormone deficiency. The mean systolic (115 +/- 16.7 mmHg) and diastolic blood pressure loads (75.51 +/- 1.90 mmHg) were normal. There was a tendency towards a lower blood pressure in patients with childhood-onset growth hormone deficiency when compared with their adult-onset counterparts. Men had a lower systolic blood pressure than women, the same pattern being found for mean diastolic blood pressure. Multiple regression analysis showed that age was the only independent variable with the statistical power to explain the variance of blood pressure in this group of patients. The incidence of non-dippers was 37.03%. Growth hormone deficiency thus seems to be associated with a change in the 24-h blood pressure pattern, with a high incidence of non-dippers.
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Affiliation(s)
- Flávia L Conceição
- Federal University of Rio de Janeiro, University Hospital Clementino Fraga Filho, Rio de Janeiro, Brazil
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133
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Johannsson G, Sverrisdóttir YB, Ellegård L, Lundberg PA, Herlitz H. GH increases extracellular volume by stimulating sodium reabsorption in the distal nephron and preventing pressure natriuresis. J Clin Endocrinol Metab 2002; 87:1743-9. [PMID: 11932310 DOI: 10.1210/jcem.87.4.8394] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although sodium retention and volume expansion occur during GH administration, blood pressure is decreased or unchanged. The aim was to study the effect of short- and long-term GH replacement in adults on sodium balance, renal hemodynamics, and blood pressure. Ten adults with severe GH deficiency were included into a 7-d, randomized, placebo-controlled, cross-over trial followed by 12 months of open GH replacement. All measurements were performed under metabolic ward conditions. Extracellular water (ECW) was determined using multifrequency bioelectrical impedance analysis. Renal plasma flow and glomerular filtration rate were assessed using renal paraminohippurate and Cr(51) EDTA clearances, respectively. Renal tubular sodium reabsorption was assessed using lithium clearance. Plasma renin activity (PRA), plasma concentrations of angiotensin II, aldosterone, atrial natriuretic peptides and brain natriuretic peptides (BNP) and 24-h urinary norepinephrine excretion were measured. Seven days of GH treatment decreased urinary sodium excretion. Lithium clearance as a marker of proximal renal tubular sodium reabsorption was unaffected by GH treatment. ECW was increased after both short- and long-term treatment. This increase was inversely correlated to the decrease in diastolic blood pressure (r = -0.70, P = 0.02) between baseline and 12 months. Short-term treatment increased PRA and decreased BNP. The increase in PRA correlated with an increase in 24-h urinary norepinephrine excretion (r = 0.77, P < 0.01). Glomerular filtration rate and renal plasma flow did not change during treatment. The sodium- and water-retaining effect of GH takes place in the distal nephron. The sustained increase in ECW in response to GH is associated with an unchanged or decreased blood pressure. This together with unchanged or decreased atrial natriuretic peptides and BNP may prevent pressure-induced escape of sodium.
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Affiliation(s)
- Gudmundur Johannsson
- Research Center for Endocrinology and Metabolism, Department of Clinical Neurophysiology, Sahlgrenska University Hospital, Göteborg SE-413 45, Sweden.
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134
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Ahmad AM, Hopkins MT, Weston PJ, Fraser WD, Vora JP. Effects of GH replacement on 24-h ambulatory blood pressure and its circadian rhythm in adult GH deficiency. Clin Endocrinol (Oxf) 2002; 56:431-7. [PMID: 11966735 DOI: 10.1046/j.1365-2265.2002.01491.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Increased prevalence of hypertension and cardiovascular mortality have been reported in hypopituitary patients who had been appropriately replaced with conventional pituitary hormones except GH. Growth hormone replacement (GHR) results in improvement of surrogate markers of cardiovascular function. Data on effects of GHR on blood pressure (BP) in adult growth hormone deficiency (AGHD), however, remain contradictory. There are as yet no reports on BP circadian rhythms in untreated or treated AGHD. Therefore, in a 12-month follow-up study, we evaluated the effects of GHR on ambulatory blood pressure (ABP) in AGHD patients. STUDY DESIGN A prospective, open treatment design study to determine the effects of GHR on ABP and heart rate in AGHD patients. GH was commenced at a daily dose of 0.5 IU, and titrated up by increments of 0.25 IU at 4-weekly intervals to achieve and maintain IGF-I standard deviation score (IGF-I SD) between the median and upper end of the age-related reference range. PATIENTS Twenty-two, post-pituitary surgery, severe AGHD patients (11 men), defined as peak GH response < 9 mU/l to provocative testing were recruited. The mean age +/- SEM was 48.8 +/- 2.5 years. Twenty-one patients required additional pituitary replacement hormones following pituitary surgery and were on optimal doses at recruitment. MEASUREMENTS Twenty-four-hour ABP and heart rate (HR), body mass index (BMI), waist hip ratio (WHR) and total body water (TBW) were measured before and after 12 months on GHR. Cosinor analysis was used to analyse BP and HR circadian rhythm parameter estimates. RESULTS Target IGF-I SD was achieved within 3 months of commencement of GHR in all patients (-3.5 +/- 0.4 at baseline vs. 0.8 +/- 0.2 at 3 months, P < 0.001) and remained within range at 12 months (1.1 +/- 0.2, P < 0.001 compared to baseline). A significant increase in TBW (45.8 +/- 1.2 vs. 47.8 +/- 1.5 kg, P < 0.05) but no significant change in BMI (30.7 +/- 2.2 vs. 31.8 +/- 2.7, P = NS) or WHR (0.95 +/- 0.02 vs. 0.93 +/- 0.02, P = NS) was observed after 12 months on GHR. The 24-h mean systolic ABP (SBP; 126.2 +/- 2.8 vs. 120.1 +/- 2.7 mmHg, P < 0.001) and diastolic ABP (DBP; 78.2 +/- 1.6 vs. 71.4 +/- 1.8 mmHg, P < 0.001) significantly decreased following GHR with a parallel increase in 24-h mean HR (69.6 +/- 2.5 vs. 73.8 +/- 2.5 beats/min; P < 0.001). A significant nocturnal decrease in SBP and DBP was observed both before (SBP; daytime, 129.1 +/- 2.8 vs. night time, 115.9 +/- 3.0 mmHg, P < 0.001 and DBP; daytime, 80.7 +/- 1.6 vs. night time, 69.2 +/- 1.8 mmHg, P < 0.001) and following GHR (SBP; daytime, 122.8 +/- 2.6 vs. night time, 110.0 +/- 3.6 mmHg, P < 0.001 and DBP; daytime, 73.9 +/- 1.8 vs. night time, 62.0 +/- 2.3 mmHg, P < 0.001). Individual and population-mean cosinor analysis demonstrated significant circadian rhythms for SBP, DBP and HR before and after 12 months on GHR (P < 0.001), suggesting that SBP, DBP and HR circadian rhythms were not altered by GHR. There was, however, a significant reduction in SBP (124.2 +/- 2.8 vs. 118.4 +/- 2.8 mmHg, P < 0.001) and DBP (77.0 +/- 1.6 vs. 70.2 +/- 1.8 mmHg, P < 0.001) MESOR with an increase in HR MESOR (68.9 +/- 2.5 vs. 72.2 +/- 2.4 beats/min, P < 0.01) following GHR. CONCLUSIONS Systolic and diastolic BP and HR circadian rhythms are preserved in AGHD following 12 months of GHR. However, there is a significant decrease in 24-h mean SBP and DBP and increase in 24-h mean HR after 12 months on GHR. We postulate that this decrease in 24-h mean SBP and DBP may result in a reduction of cardiovascular morbidity and mortality and may explain the beneficial effects of GHR on cardiovascular system previously reported in AGHD patients.
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Affiliation(s)
- Aftab M Ahmad
- Department of Diabetes & Endocrinology, Royal Liverpool University Hospital, Prescot Street, Liverpool L7 8XP, UK.
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135
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Becker AJ, Uckert S, Stief CG, Scheller F, Knapp WH, Hartmann U, Brabant G, Jonas U. Serum levels of human growth hormone during different penile conditions in the cavernous and systemic blood of healthy men and patients with erectile dysfunction. Urology 2002; 59:609-14. [PMID: 11927337 DOI: 10.1016/s0090-4295(01)01594-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To detect changes in growth hormone (GH) serum levels during different penile conditions in the cavernous and systemic blood of patients with erectile dysfunction and compare them with the course of GH registered in healthy men. It has been suggested that human GH is involved in sexual maturation and plays a regulatory role in male reproductive function. Deficiency may result in fatigability, loss of sexual desire and erection, or oligospermia or azoospermia. It is assumed that the biologic effects of GH include insulin-like growth factor 1-mediated stimulation of endothelial nitric oxide formation. It has recently been demonstrated that GH serum levels in the systemic and cavernous blood of healthy men increases during developing penile erection. METHODS Thirty-five healthy adult men and 45 patients with erectile dysfunction of either organogenic or psychogenic etiology were exposed to visual and tactile erotic stimuli to elicit penile tumescence and, in the group of healthy subjects, rigidity. Whole blood was simultaneously aspirated from the corpus cavernosum and the cubital vein during the different functional conditions of the penis. Serum levels of GH were determined by means of an immunoradiometric assay. RESULTS In the healthy subjects, systemic GH serum levels significantly increased during penile tumescence, followed by a transient decline from tumescence to rigidity and detumescence. In the unselected patients, the mean GH levels during penile flaccidity were determined to be about sevenfold lower than those registered in the blood of the healthy men. During penile tumescence, the mean increase in the GH levels in the systemic and cavernous blood of psychogenic patients was comparable to that seen in healthy men, but, in the group of organogenic patients, this increase was found to be negligible. CONCLUSIONS We believe our data provide strong evidence that GH may be of major importance in the maintenance of male erectile capability-probably through a stimulating effect on cyclic guanosine monophosphate generation in human cavernous smooth muscle-and that a decline in GH release may contribute to the manifestation of erectile dysfunction.
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Affiliation(s)
- Armin J Becker
- Department of Urology, Hannover Medical School, Hannover, Germany
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136
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Smith JC, Lang D, McEneny J, Evans LM, Scanlon MF, Young I, Davies J. Effects of GH on lipid peroxidation and neutrophil superoxide anion-generating capacity in hypopituitary adults with GH deficiency. Clin Endocrinol (Oxf) 2002; 56:449-55. [PMID: 11966737 DOI: 10.1046/j.1365-2265.2002.01493.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Untreated growth hormone deficiency (GHD) is implicated in the increased cardiovascular risk associated with adult hypopituitarism. Oxidative stress, predisposing to lipid peroxidation, may be an important mediator of endothelial dysfunction, a pro-atherogenic state associated with adult GHD. DESIGN AND PATIENTS In a randomized, double-blind, placebo-controlled study we investigated the effects of GH replacement on low-density lipoprotein (LDL) oxidation and neutrophil superoxide (O(-)(2)) generating capacity in 32 GHD adults (19 males, 13 females; age range 19-64 years) over 3 months. Thirty age- and sex-matched healthy controls were also studied. MEASUREMENTS Lipid hydroperoxides (HPOs) in plasma were measured using the ferrous oxidation with xylenol orange (FOX) assay. The susceptibility of LDL to oxidation was assessed by the copper-catalysed lag phase of LDL oxidation. Neutrophil O(-)(2)- generating capacity was assessed by a lucigenin-based chemiluminescent assay of NADPH oxidase activity. Body composition was assessed using bioelectrical impedance analysis. RESULTS Compared to controls, GHD subjects had higher LDL cholesterol (4.0 +/- 0.8 vs. 3.5 +/- 0.9 mmol/l, P < 0.01) and higher triglyceride concentrations (2.3 +/- 1.5 vs. 1.1 +/- 0.7 mmol/l, P < 0.001) but lower HDL cholesterol (1.1 +/- 0.3 mmol/l vs. 1.4 +/- 0.4 mmol/l, P < 0.01), lower levels of HPOs (0.72 +/- 0.35 vs. 0.92 +/- 0.20 microm, P < 0.01) and lower basal (2.5 +/- 1.5 vs. 4.5 +/- 2.3 mV/5 x 10(5) neutrophils, P < 0.01) and peak post-activation levels (23.2 +/- 11.1 vs. 34.4 +/- 15.6 mV/5 x 10(5) neutrophils, P < 0.01) of neutrophil O(-)(2)- generation. GH replacement resulted in an increase in HPOs from 0.70 +/- 0.39 to 0.86 +/- 0.19 microm (P < 0.05), although there was no change in the lag time of LDL oxidation. Neutrophil O(-)(2)- generating capacity was enhanced with a rise in basal O(-)(2)- generation from 2.8 +/- 1.4 to 5.4 +/- 4.6 mV/5 x 10(5) neutrophils (P < 0.05) and in peak post-activation O(-)(2)- generation from 21.9 +/- 9.5 to 35.8 +/- 21.7 mV/5 x 10(5) neutrophils (P < 0.05). LDL cholesterol was reduced from 4.1 +/- 0.8 mmol/l to 3.5 +/- 0.8 mmol/l (P < 0.01). No significant changes in measured parameters occurred in the placebo group. CONCLUSIONS Adult GHD is associated with reduced lipid peroxidation and impaired neutrophil O(-)(2)- generating capacity, both of which are reversible with GH replacement. Our data suggest that: (i) that oxidative stress is not a major feature of the pro-atherogenic state in hypopituitary adults with GHD and (ii) a role for GH in modulating neutrophil function and leucocyte-lipoprotein interactions.
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Affiliation(s)
- Jamie C Smith
- Department of Medicine, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, Wales, UK.
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137
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Simpson H, Savine R, Sönksen P, Bengtsson BA, Carlsson L, Christiansen JS, Clemmons D, Cohen P, Hintz R, Ho K, Mullis P, Robinson I, Strasburger C, Tanaka T, Thorner M. Growth hormone replacement therapy for adults: into the new millennium. Growth Horm IGF Res 2002; 12:1-33. [PMID: 12127299 DOI: 10.1054/ghir.2001.0263] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Helen Simpson
- Medical Department M, Aarhus Kommunehospital, DK-8000, Aarhus C, Denmark
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138
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Napoli R, Guardasole V, Matarazzo M, Palmieri EA, Oliviero U, Fazio S, Saccà L. Growth hormone corrects vascular dysfunction in patients with chronic heart failure. J Am Coll Cardiol 2002; 39:90-5. [PMID: 11755292 DOI: 10.1016/s0735-1097(01)01707-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVES The goal of this study was to test the hypothesis that growth hormone (GH) administration to patients with chronic heart failure (CHF) corrects their vascular dysfunction. BACKGROUND Endothelial dysfunction is a prominent feature of CHF. Recent evidence indicates that GH plays a role in vascular reactivity. METHODS We studied vascular reactivity in 16 patients with CHF (New York Heart Association class II to III) before and after three months of GH (4 IU subcutaneously every other day) or placebo administration in a randomized, double-blind trial. We measured forearm blood flow (FBF) by strain-gauge plethysmography during intrabrachial, graded infusion of acetylcholine (ACh) and sodium nitroprusside (NP). We also measured the forearm balance of nitrite and cyclic guanosine monophosphate (cGMP) before and during ACh infusion. Maximal oxygen uptake (VO2max) was measured by breath-to-breath respiratory gas analysis. RESULTS Before treatment, the response of FBF to ACh was flat (p = NS). Growth hormone, but not placebo, greatly improved this response (p = 0.03) and, concomitantly, increased the forearm release of nitrite and cGMP (p < 0.05). Growth hormone also potentiated the FBF response to NP (p = 0.013). Growth hormone interacted with ACh response (p = 0.01) but not with the response to NP (p = NS). Accordingly, GH enhanced the slope of the dose-response curve to ACh (p < 0.05) but not to NP. The VO2max increased significantly after GH treatment (20 +/- 2 and 26 +/- 2 ml x Kg(-1) x min(-1) before and after GH treatment, respectively, p < 0.05) but not after placebo. CONCLUSIONS A three-month treatment with GH corrected endothelial dysfunction and improved non-endothelium-dependent vasodilation in patients with CHF. The data highlight the potential role of GH in the progression of congestive heart failure.
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Affiliation(s)
- Raffaele Napoli
- Department of Internal Medicine and Cardiovascular Sciences, University Federico II School of Medicine, Naples, Italy
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139
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Pagel I, Langenickel T, Höhnel K, Philipp S, Nüssler AK, Blum WF, Aubert ML, Dietz R, Willenbrock R. Cardiac and renal effects of growth hormone in volume overload-induced heart failure: role of NO. Hypertension 2002; 39:57-62. [PMID: 11799079 DOI: 10.1161/hy0102.098323] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Growth hormone (GH) application is a new strategy in the treatment of heart failure. However, clinical and experimental investigations have shown contradictory effects of GH on cardiac performance. We tested the hypothesis that GH could improve cardiac and renal function in volume overload-induced heart failure. The effect of 4 weeks of GH treatment (2 mg/kg daily) was investigated in Wistar rats with aortocaval shunt. GH application did not influence left ventricular contractility and end-diastolic pressure in rats with aortocaval shunt. In contrast, GH treatment normalized impaired diuresis (vehicle 10.8+/-0.6 mL/d, GH 15.8+/-0.7 mL/d; P<0.05) and sodium excretion (vehicle 1.5+/-0.1 mmol/d, GH 2.2+/-0.1 mmol/d; P<0.001) in shunt-operated rats, with a similar increase of fractional sodium excretion. The urinary excretion of cGMP, the second messenger of atrial natriuretic peptide and NO, was higher in animals with shunts than in sham-operated animals and was further increased by GH (vehicle 293+/-38 nmol/d, GH 463+/-57 nmol/d; P<0.01). Although the atrial natriuretic peptide plasma levels were unchanged after GH, the excretion of NO metabolites (nitrate/nitrite) was elevated (vehicle 2020+/-264 nmol/d, GH 2993+/-375 nmol/d; P<0.05) in parallel with increased renal mRNA levels of inducible NO synthase 2. The changes of renal function after GH and the increased excretion of NO metabolites and cGMP were abolished by simultaneous treatment with the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester. GH treatment did not influence cardiac function in rats with aortocaval shunts. However, GH improved renal function by increasing diuresis and sodium excretion. The responsible mechanism might be the enhanced activity of the renal NO system.
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Affiliation(s)
- Ines Pagel
- Franz-Volhard-Klinik at the Max-Delbrück-Center of Molecular Medicine, Charité, Germany
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140
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Walker RF, Bercu BB. Issues Regarding the Routine and Long-Term Use of Growth Hormone in Anti-Aging Medicine. ACTA ACUST UNITED AC 2001. [DOI: 10.1089/10945450152850623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Richard F. Walker
- Departments of Biochemistry and Molecular Biology, and Pediatrics, University of South Florida, Tampa, Florida
| | - Barry B. Bercu
- Departments of Pediatrics, and Pharmacology and Therapeutics, University of South Florida, Tampa, Florida
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141
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Sverrisdóttir YB, Johannsson G, Jungersten L, Wallin BG, Elam M. Is the somatotropic axis related to sympathetic nerve activity in healthy ageing men? J Hypertens 2001; 19:2019-24. [PMID: 11677367 DOI: 10.1097/00004872-200111000-00012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The mechanisms underlying the age-related increase in blood pressure and sympathetic nerve activity remain largely unknown. The decline in growth hormone (GH) secretion and insulin-like growth factor-I (IGF-I) with age has been related to several cardiovascular risk factors. Low serum IGF-I levels in severe adult GH deficiency is associated with markedly increased sympathetic nerve activity. This study evaluates whether a relationship between serum IGF-I and sympathetic nerve traffic exists in healthy aging men. DESIGN AND METHODS Sympathetic nerve activity to the muscle vascular bed (MSA) was recorded in 56 healthy normotensive males, and related to age (range 21-71 years), body mass index (BMI, range 18.4-32.2), serum IGF-I and plasma nitrate levels. Blood pressure, BMI and MSA increased with age, whereas IGF-I and plasma nitrate decreased. In a forward stepwise multiple regression analysis, age explained 40% of the variability in MSA and excluded other variables. Omitting age, IGF-I became the strongest independent predictor, explaining 23% of the variability in MSA. MSA was an independent predictor of diastolic blood pressure, but its influence (10%) was less than that of BMI (28%). BMI was not related to MSA or IGF-I. CONCLUSIONS Decreased serum IGF-I levels are coupled to increased MSA during ageing, an effect independent from the impact of increased body weight. Although MSA is a weak predictor of rising blood pressure with age, it constitutes one possible pathway for the somatotropic axis to affect cardiovascular function in ageing.
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Affiliation(s)
- Y B Sverrisdóttir
- Department of Clinical Neurophysiology, Sahlgren University Hospital, Göteborg, Sweden.
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142
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Abstract
In the last decade, retrospective cohort data has provided evidence of premature atherosclerosis in patients with hypopituitarism which may account for the recently observed increased death rate from vascular events in these patients. The exact mechanism(s) for such propensity to atherosclerotic vascular disease is not yet completely clear. It is possible that hormonal factors may be the initiating mechanisms with subsequent secondary metabolic abnormalities acting as risk factors for development of atherosclerosis. This seems to be more evident in female hypopituitary patients compared with their male counterparts. Female patients have higher frequency and more pronounced abnormalities of various risk factors as well as surrogate markers of early vascular disease. This may explain why morbidity and mortality in women is in excess of men in retrospective epidemiological studies. Addressing abnormal hormonal factors, especially in females, is a primary objective in managing these patients both in the clinical arena as well as in trials designed to reduce the risk of atherosclerotic vascular disease in these patients. While short-term growth hormone treatment may ameliorate some of the vascular risk factors and improve endothelial function, it remains to be shown whether this translates into long-term reduction in morbidity and mortality from vascular, especially cerebrovascular, disease.
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Affiliation(s)
- T A Elhadd
- Department of Medicine, School of Postgraduate Medicine, Keele University, Stoke-on-Trent, Staffordshire, UK
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143
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Nagaya N, Uematsu M, Kojima M, Ikeda Y, Yoshihara F, Shimizu W, Hosoda H, Hirota Y, Ishida H, Mori H, Kangawa K. Chronic administration of ghrelin improves left ventricular dysfunction and attenuates development of cardiac cachexia in rats with heart failure. Circulation 2001; 104:1430-5. [PMID: 11560861 DOI: 10.1161/hc3601.095575] [Citation(s) in RCA: 371] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Ghrelin is a novel growth hormone (GH)-releasing peptide that may also induce vasodilation and stimulate feeding through GH-independent mechanisms. We investigated whether ghrelin improves left ventricular (LV) dysfunction and attenuates cardiac cachexia in rats with chronic heart failure (CHF). METHODS AND RESULTS Ligation of the left coronary artery or sham operation was performed; 4 weeks after surgery, rat ghrelin (100 microg/kg SC BID) or saline was administered for 3 weeks. Echocardiography and cardiac catheterization were performed. Serum GH and insulin-like growth factor-1 were significantly higher in both CHF and sham rats treated with ghrelin than in those given placebo (P<0.05 for both). CHF rats given placebo showed an impaired increase in body weight compared with sham rats given placebo (P<0.05). CHF rats treated with ghrelin, however, showed a significantly greater increase in body weight than those given placebo (+10% versus +3%, P<0.05). They showed significantly higher cardiac output (315+/-49 versus 266+/-31 mL. min(-1). kg(-1), P<0.05) and LV dP/dt(max) (5738+/-908 versus 4363+/-973 mm Hg/s, P<0.05) than CHF rats given placebo. Ghrelin increased diastolic thickness of the noninfarcted posterior wall, inhibited LV enlargement, and increased LV fractional shortening in CHF rats (from 15+/-3% to 19+/-3%, P<0.05). CONCLUSIONS Chronic subcutaneous administration of ghrelin improved LV dysfunction and attenuated the development of LV remodeling and cardiac cachexia in rats with CHF.
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Affiliation(s)
- N Nagaya
- Department of Internal Medicine, National Cardiovascular Center, Fujishirodai, Suita, Osaka, Japan.
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144
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Stavrou S, Kleinberg DL. Diagnosis and management of growth hormone deficiency in adults. Endocrinol Metab Clin North Am 2001; 30:545-63. [PMID: 11571930 DOI: 10.1016/s0889-8529(05)70201-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In adults, GHD is a clinical syndrome that occurs in patients with pituitary or hypothalamic disease. It may be asymptomatic or present with relatively nonspecific constitutional symptoms. Most patients have abnormal body composition, consisting of increased fat mass and decreased lean mass. Life expectancy is significantly decreased in hypopituitary patients with GHD, with cardiovascular disease a common cause of death. Treatment with growth hormone reverses abnormalities in body composition and may reduce cardiovascular risk factors; however, the long-term treatment outcomes regarding mortality, the incidence of cardiovascular disease, bone fractures, tumor development, and recurrence are not known. Longer prospective clinical studies are needed. The major manufacturers of growth hormone have initiated postmarketing surveillance databases to monitor the safety of growth hormone treatment.
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Affiliation(s)
- S Stavrou
- Department of Medicine, New York University School of Medicine, New York, New York, USA
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145
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Abstract
The importance of growth hormone (GH) deficiency in adults became evident 10 to 15 years ago, when the first clinical studies on GH replacement therapy in adults were published. Since then, a number of studies have been reported showing that GH replacement therapy can improve this condition. Adult GH deficiency (GHD) is now recognized as a specific clinical syndrome and the first reports of long-term use of GH (up to 10 years) are now being published. The aim of this paper was to review the accumulated data on the various clinical aspects of adult GHD.
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Affiliation(s)
- F L Conceição
- Medical Department M, Kommunehospitalet, Aarhus, DK-8000, Denmark.
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146
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Conti E, Andreotti F, Sciahbasi A, Riccardi P, Marra G, Menini E, Ghirlanda G, Maseri A. Markedly reduced insulin-like growth factor-1 in the acute phase of myocardial infarction. J Am Coll Cardiol 2001; 38:26-32. [PMID: 11451284 DOI: 10.1016/s0735-1097(01)01367-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES We investigated whether insulin-like growth factor-1 (IGF-1) is reduced in the early phase of acute myocardial infarction (AMI) and whether such a decrease might influence prognosis. BACKGROUND Insulin-like growth factor-1 protects against insulin resistance and apoptosis. Although insulin resistance has been reported in AMI, IGF-1 levels have not been investigated. METHODS We measured serum IGF-1 in 23 patients with AMI within 24 h of symptom onset and in 11 matched controls. In the first 12 patients and controls, we also measured fasting insulin, diurnal growth hormone (GH) and insulin sensitivity (assessed as glucose disappearance or T/2 after an insulin bolus), and repeated IGF-1, insulin and GH after one year. In all patients, 90-day cardiovascular death, recurrent ischemia, reinfarction, revascularization and late malignant arrhythmias were assessed. RESULTS The AMI patients versus controls showed markedly reduced IGF-1 (115 +/- 112 vs. 615 +/- 300 ng/ml, p < 0.0001) and slower T/2 (-0.98 +/- 1.5 vs. -2.57 +/- 1.0 mg/dl/min, p = 0.01). Low IGF-1 often preceded the rise of myocardial necrosis markers. Patients with 90-day events (n = 12) versus those without had lower IGF-1 (47 +/- 54 vs. 189 +/- 110 ng/ml, p < 0.0001). Acute phase GH and insulin concentrations did not differ significantly from controls. After one year, the patients' IGF-1 values had risen to 460 +/- 242 ng/ml (p = 0.1 vs. controls, p < 0.0005 vs. acute phase), whereas GH levels were lower (0.2 +/- 0.2 vs. 2.5 +/- 2.3 ng/ml, p = 0.01) and insulin levels higher (12.5 +/- 0.2 vs. 3.9 +/- 2.6 microU/ml, p < 0.0001) compared with controls. CONCLUSIONS In the early phase of AMI, serum IGF-1 levels are markedly reduced and may contribute to adverse outcomes. Reduced IGF-1 preceding the rise of myocardial necrosis markers suggests a possible pathogenetic role. A compensatory increase in IGF-1 appears to occur by one year.
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Affiliation(s)
- E Conti
- Institute of Cardiology, Catholic University, Rome, Italy.
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147
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Abstract
L-Arginine (2-amino-5-guanidinovaleric acid) is the precursor of nitric oxide, an endogenous messenger molecule involved in a variety of endothelium-mediated physiological effects in the vascular system. Acute and chronic administration of L-arginine has been shown to improve endothelial function in animal models of hypercholesterolemia and atherosclerosis. L-Arginine also improves endothelium-dependent vasodilation in humans with hypercholesterolemia and atherosclerosis. The responsiveness to L-arginine depends on the specific cardiovascular disease studied, the vessel segment, and morphology of the artery. The pharmacokinetics of L-arginine have recently been investigated. Side effects are rare and mostly mild and dose dependent. The mechanism of action of L-arginine may involve nitric oxide synthase substrate provision, especially in patients with elevated levels of the endogenous NO synthase inhibitor asymmetric dimethylarginine. Endocrine effects and unspecific reactions may contribute to L-arginine-induced vasodilation after higher doses. Several long-term studies have been performed that show that chronic oral administration of L-arginine or intermittent infusion therapy with L-arginine can improve clinical symptoms of cardiovascular disease in man.
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Affiliation(s)
- R H Böger
- Institute of Clinical Pharmacology, Hannover Medical School, D-30623 Hannover, Germany
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148
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Otsuki M, Kasayama S, Yamamoto H, Saito H, Sumitani S, Kouhara H, Saitoh Y, Ohnishi T, Arita N. Characterization of premature atherosclerosis of carotid arteries in acromegalic patients. Clin Endocrinol (Oxf) 2001; 54:791-6. [PMID: 11422114 DOI: 10.1046/j.1365-2265.2001.01281.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Acromegalic patients have increased mortality from vascular diseases. Although atherosclerotic risk factors such as hypertension, diabetes mellitus and dyslipoproteinaemia are highly associated with acromegaly, the prevalence of premature atherosclerosis in acromegalic patients and its relationship to these risk factors have not been reported. DESIGN We measured mean intima-media thickness (IMT) of the carotid arteries in 21 acromegalic patients without symptomatic atherosclerotic vascular disease, by ultrasound high-resolution B-mode imaging. In analysis 1, it was compared with the predicted mean IMT based on data from existing risk factors (age, male sex, dyslipoproteinaemia, hypertension, diabetes mellitus, smoking status) in 282 non-acromegalic subjects. In analysis 2, the mean IMT in the 21 acromegalic patients was compared with that in 42 non-acromegalic subjects matched for age, sex and the other atherosclerotic risk factors. We also analysed clinical characteristics between the acromegalic patients with and without the atherosclerosis. RESULTS Mean IMT in 21 acromegalic patients was 0.92 +/- 0.21 (mean +/- SD) mm. It was significantly (P < 0.05) lower than the mean IMT (1.03 +/- 0.12 mm) predicted from their existing risk factors (analysis 1). It was also less than that in 42 non-acromegalic subjects matched for atherosclerotic risk factors (1.07 +/- 0.37 mm; P < 0.05) (analysis 2). Among the acromegalic patients, 10 patients (48%) had increased mean IMT (> or = 1.1 mm) and/or plaque lesions whereas the other 11 had no such atherosclerotic changes. In the patients without the atherosclerotic changes, plasma insulin-like growth factor-I (IGF-I) concentration was significantly (P < 0.01) higher, and the prevalence of hypertension was significantly (P < 0.05) lower than in those with the atherosclerotic changes. CONCLUSIONS The extent of carotid atherosclerosis in the acromegalic patients was not higher than that in non-acromegalic subjects, considering their atherosclerotic risk factors. Increased concentration of IGF-I might be involved in the lack of susceptibility to atherosclerosis in some acromegalic patients.
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Affiliation(s)
- M Otsuki
- Department of Molecular Medicine, Osaka University Medical School (C-4), Osaka, Japan
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149
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Tivesten A, Caidahl K, Kujacic V, Sun XY, Hedner T, Bengtsson BA, Isgaard J. Similar cardiovascular effects of growth hormone and insulin-like growth factor-I in rats after experimental myocardial infarction. Growth Horm IGF Res 2001; 11:187-195. [PMID: 11735233 DOI: 10.1054/ghir.2001.0202] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Accumulating data show that growth hormone (GH) and insulin-like growth factor-I (IGF-I) have major effects on the cardiovascular system. In the present study we have directly compared GH and IGF-I in an in vivo rat model of experimental myocardial infarction. Four weeks after ligation of the left coronary artery, male rats were treated with recombinant human (rh) GH 1.1 mg/kg per day, rhIGF-I 3.0 mg/kg per day or saline s.c. for 2 weeks. Transthoracic echocardiography was performed before and after the treatment period. Both GH and IGF-I reduced total peripheral resistance (P< 0.01), end-systolic wall stress (P< 0.01) and end-systolic short-axis area (P< 0.001 and P< 0.05). GH also increased area fractional shortening (P< 0.05). Stroke volume (SV) and SV index were improved by IGF-I (P< 0.0001), and SV tended to be increased by GH (P= 0.12). In conclusion, GH and IGF-I had similar beneficial effects on systolic function and peripheral resistance after experimental myocardial infarction.
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Affiliation(s)
- A Tivesten
- Research Centre for Endocrinology and Metabolism, Department of Internal Medicine, Gröna Stråket 8, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden.
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150
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Nagaya N, Kojima M, Uematsu M, Yamagishi M, Hosoda H, Oya H, Hayashi Y, Kangawa K. Hemodynamic and hormonal effects of human ghrelin in healthy volunteers. Am J Physiol Regul Integr Comp Physiol 2001; 280:R1483-7. [PMID: 11294772 DOI: 10.1152/ajpregu.2001.280.5.r1483] [Citation(s) in RCA: 357] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate hemodynamic and hormonal effects of ghrelin, a novel growth hormone (GH)-releasing peptide, we gave six healthy men an intravenous bolus of human ghrelin (10 microg/kg) or placebo and vice versa 1-2 wk apart in a randomized fashion. Ghrelin elicited a marked increase in circulating GH (15-fold). The elevation of GH lasted longer than 60 min after the bolus injection. Injection of ghrelin significantly decreased mean arterial pressure (-12 mmHg, P < 0.05) without a significant change in heart rate (-4 beats/min, P = 0.39). Ghrelin significantly increased cardiac index (+16%, P < 0.05) and stroke volume index (+22%, P < 0.05). We also examined ghrelin receptor [GH secretagogues receptor (GHS-R)] gene expression in the aortas, the left ventricles, and the left atria of rats by RT-PCR. GHS-R mRNA was detectable in the rat aortas, left ventricles, and left atria, suggesting that ghrelin may cause cardiovascular effects through GH-independent mechanisms. In summary, human ghrelin elicited a potent, long-lasting GH release and had beneficial hemodynamic effects via reducing cardiac afterload and increasing cardiac output without an increase in heart rate.
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Affiliation(s)
- N Nagaya
- Department of Internal Medicine, National Cardiovascular Center, Osaka 565 - 8565, Japan
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