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- Johannsson, Gudmundur, 1960, et al.
(author)
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Long-term cardiovascular effects of growth hormone treatment in GH-deficient adults. Preliminary data in a small group of patients.
- 1996
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In: Clinical endocrinology. - 0300-0664. ; 45:3, s. 305-14
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Journal article (peer-reviewed)abstract
- The long-term cardiovascular effects of GH administration in adults are of major clinical importance, given the increasing use of such treatment. We have evaluated long-term cardiovascular effects of recombinant human GH (rhGH) substitution in GH deficient men.S.c. rhGH 0.5 U/kg/week or placebo was administered in a 6-month double-blind, cross-over study, followed (after a year without substitution) by a 42-month period of open GH substitution.We evaluated 7 GH-deficient men serially and compared the results with 21 men matched in terms of age and height.Investigations included exercise tests and Doppler-echocardiography to determine exercise capacity and cardiovascular performance.Heart rate and systolic blood pressure at rest increased with GH substitution to the level of the controls, as did diastolic blood pressure after an initial reduction. Age-adjusted exercise capacity increased during the study and we found no evidence of ischaemic heart disease on exercise ECG. Stroke volume increased with GH substitution, thereby normalizing the initially reduced cardiac index. There was no significant change in left atrial or ventricular internal dimensions, systolic function as measured by fractional shortening, or diastolic function as measured by isovolumic relaxation time and left ventricular filling (A/E ratio). However, a lower atrial emptying index than that seen among controls might indicate some diastolic disturbance and there was a definite increase in left ventricular wall thickness compared with controls (to 25.1 +/- 1.5 vs 19.7 +/- 0.4 mm, P < 0.001).We found that GH substitution in GH-deficient adults had a beneficial effect on physical performance and cardiac output. The concomitant increase in left ventricular mass index might be an effect of an excessive substitution dose.
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| 2. |
- Johansson, J O, et al.
(author)
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Long-term treatment with growth hormone decreases plasminogen activator inhibitor-1 and tissue plasminogen activator in growth hormone-deficient adults.
- 1996
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In: Thrombosis and haemostasis. - 0340-6245. ; 76:3, s. 422-8
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Journal article (peer-reviewed)abstract
- The syndrome of growth hormone deficiency (GHD) in adults is associated with premature atherosclerosis, increased cardiovascular mortality, abnormal lipoprotein patterns and abnormal body composition. We have previously shown that GH-deficient adults have increased concentrations of fibrinogen and plasminogen activator inhibitor (PAI-1) activity. The aim of the present investigation was to study coagulation and fibrinolysis in 17 patients with adult-onset GHD during two years of treatment with recombinant human GH (12 micrograms/kg body weight/day). The impact of the contemporary changes in metabolic variables and body composition on coagulation and fibrinolysis was studied. The patients received conventional thyroid, adrenal and gonadal hormone replacement therapy. PAI-1 activity, PAI-1 antigen and tissue plasminogen activator (t-PA) antigen levels decreased during the GH treatment period (p < 0.05). The decrease was more pronounced in patients with high pre-treatment levels of the different variables. alpha 2-antiplasmin decreased (p < 0.05), while plasminogen was unchanged during two years of GH treatment. Fibrinogen concentrations tended to decrease after two years of GH treatment (p = 0.06), while the coagulation factors VII and VIII were unchanged. von Willebrand factor demonstrated a transient decrease after 18 months of GH treatment. The coagulation inhibitor, protein C, decreased (p < 0.05), while antithrombin was unchanged. Fasting plasma insulin increased (p < 0.01), but blood glucose did not differ after two years of GH treatment. Serum high-density lipoprotein cholesterol, total cholesterol and triglycerides were unaltered. Body fat decreased during the initial GH treatment but was unaltered after two years, while lean body mass increased (p < 0.001) and the waist over hip circumference ratio tended to decrease (p = 0.06). In conclusion, PAI-1 activity, PAI-1 antigen and t-PA antigen decreased during long-term GH treatment. These changes may be a direct effect of GH itself or may be secondary to the favourable changes in body composition. It remains to be seen whether changes in these fibrinolytic variables during rhGH treatment reduces the cardiovascular risk in patients with GHD. The present results suggest that GH plays a role in the regulation of fibrinolysis.
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| 3. |
- Boguszewski, C L, et al.
(author)
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22-kD growth hormone exclusion assay: a new approach to measurement of non-22-kD growth hormone isoforms in human blood.
- 1996
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In: European journal of endocrinology. - 0804-4643. ; 135:5, s. 573-82
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Journal article (peer-reviewed)abstract
- Human growth hormone (GH) exists in a variety of isoforms. In the pituitary, the most abundant isoform is 22-kD GH (22 K GH), while other isoforms (non-22 K GH) are present in variable amounts. In human plasma, the GH heterogeneity contributes to the wide variability in GH levels measured by different immunoassays. The physiological role of the non-22 K GH isoforms is poorly understood, but they may represent a spectrum of agonists or antagonists of the GH receptor. It is possible that increased amounts of non-22 K GH isoforms in the circulation contribute to the growth failure observed in some short children and may be involved in the pathophysiology of acromegaly and other unrelated diseases. Currently, there is no method available to evaluate the ratio of non-22 K GH isoforms to total GH in large sets of serum samples. In this report, a novel assay procedure is described in which monomeric and dimeric isoforms of 22 K GH are removed from serum and non-22 K GH isoforms are quantitated. The 22 K GH exclusion assay (22 K GHEA) was established as a screening method to identify conditions in which the ratio of non-22 K GH isoforms to total GH in human blood is altered. A 22 K GH-specific monoclonal antibody (MCB) is used for binding to 22 K GH in serum. Magnetic beads coated with rat anti-mouse immunoglobulin G and a magnetic device are used to remove the 22K GH-MCB complexes from serum. The non-22 K GH isoforms are measured by a polyclonal antibody-based immunoradiometric assay (GH-IRMA). The assay procedure was optimized systematically by statistical experimental designs. In serum spiked with monomeric or dimeric 22 K GH, the 22 K GH extraction was efficient at GH levels up to 100 microg/l (range 96.3-100%). The intra- and interassay precision for non-22K GH levels of 3.9 microg/l were 2.6% and 8.7%, respectively, while for levels of 0.6 microg/l, which were very close to the detection limits of the assay, the coefficients were 17.0% and 21.6%, respectively. The percentage of non-22 K GH isoforms determined in serum samples from three different groups of subjects showed clearly distinctive values. The 22 K GHEA is a new method for evaluation of non-22 K GH isoforms in human blood under different physiological and pathophysiological conditions.
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| 4. |
- Bosaeus, Ingvar, 1950, et al.
(author)
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Comparison of methods to estimate body fat in growth hormone deficient adults.
- 1996
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In: Clinical endocrinology. - 0300-0664. ; 44:4, s. 395-402
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Journal article (peer-reviewed)abstract
- All of the presently used methods for in-vivo determination of body composition have inherent methodological errors and depend on various assumptions. We have therefore compared several different methods used to measure body fat in adult GH deficiency during GH treatment.Comparison of body composition data from a two-phase trial with an initial placebo-controlled, double-blind 6-month period, followed by open treatment with GH until all patients had received GH for 12 months.Twenty-five patients with known GH deficiency entered the study. Baseline examinations were complete in 23 patients, and 22 patients (16 males, 6 females) completed all examinations after treatment.Body fat calculated from total body potassium (TBK) by whole-body 40K counting, total body water (TBW) by tritium dilution, total body nitrogen (TBN) by neutron activation, and bioelectric impedance (BIA) measurements were compared to body fat determinations by dual-energy X-ray absorptiometry (DEXA) in two-compartment and multicompartment body composition models.At baseline, DEXA fat mass agreed well at group level with measurements based on TBW or TBK alone, in a four-compartment model based on TBK and TBW, and a multicompartment model based on bone mineral (by DEXA), TBN and TBW. Body fat by BIA agreed less well. After 12 months of GH treatment, body fat decreased by all methods used. This decrease was smaller by DEXA than by the other methods. The four-compartment model based on TBK and TBW, and TBW alone, showed the best agreement with changes in DEXA fat.All methods showed a decrease of body fat with GH treatment, but variation between methods was considerable.
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| 5. |
- Johannsson, Gudmundur, 1960, et al.
(author)
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Two years of growth hormone (GH) treatment increases bone mineral content and density in hypopituitary patients with adult-onset GH deficiency.
- 1996
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In: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 81:8, s. 2865-73
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Journal article (peer-reviewed)abstract
- The main purpose of this trial was to determine the effects of 2 yr of GH treatment on bone mineral density (BMD) and bone metabolism in patients with adult-onset GH deficiency. Forty-four patients (24 men and 20 women; aged 23-66 yr) participated in a 2-yr open treatment trial with recombinant human GH. BMD was assessed with dual energy x-ray absorptiometry, and serum concentrations of osteocalcin, carboxy-terminal propeptide of type I procollagen (PICP), and carboxy-terminal cross-linked telopeptide of type I collagen (ICTP) were measured. After 2 yr of GH treatment, the BMD increased in the lumbar spine L2-L4 by 3.8% [95% confidence interval (CI), 2.1-5.5], in the femoral neck by 4.1% (CI, 2.1-6.1) in the femoral trochanter by 5.6% (CI, 3.8-7.4) and in Ward's triangle by 4.9% (CI, 2.2-7.6) compared with baseline. Patients with a z-score (difference in SD from the mean of age- and sex-matched subjects) below -1 SD responded with the most marked BMD increment. The serum concentrations of osteocalcin, PICP, and ICTP remained higher throughout the 2 yr of treatment. Women demonstrated a more marked increase in total body BMD and a less pronounced initial increment in osteocalcin, PICP, and ICTP than men. Two years of GH treatment induced a sustained increase in overall bone remodeling activity, which resulted in a net gain in BMD that was more marked in those subjects with a low pretreatment z-score.
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