Jan-Ove Johansson

Growth hormone-deficient adults are insulin-resistant

Patients with growth hormone deficiency (GHD) have traditionally been described as having increased insulin sensitivity with a tendency toward fasting hypoglycemia, at least in children. In other studies, impaired glucose tolerance has been found. To evaluate basal insulin sensitivity, a hyperinsulinemic, normoglycemic clamp was performed with an insulin rate of 40 mU/m2/min after an overnight fast. Fifteen patients (four women and 11 men aged 20 to 62 years) with GHD for at least 1 year were compared with 15 healthy controls matched for sex, age, and body mass index (BMI). Thirteen patients had complete pituitary deficiency and were being treated with conventional hormone replacement therapy. Two men had isolated GHD since childhood. Four men were being treated with bromocriptin. There were no significant differences between fasting blood glucose (4.4 +/- 0.1 v 4.7 +/- 0.2 [mean +/- SEM] mmol/L) or fasting plasma insulin (9.5 +/- 1.4 v 8.8 +/- 1.1 mU/L) in patients and controls, respectively. Fasting free fatty acid (FFA) levels were lower in patients (444 +/- 35 v 796 +/- 94 mumol/L, P < .01). Blood glucose levels during the clamp were similar (4.6 +/- 0.1 v 4.9 +/- 0.1 mmol/L), as were insulin levels (81 +/- 4 v 93 +/- 4 mU/L). A decrease in glucose infusion rate (GIR) was seen during the clamp in GHD subjects (3.9 +/- 0.5 v 9.9 +/- 0.7 mg/kg body weight/min) as compared with controls (P = .001). Even if corrections were made for body fat, there was a significant difference (GIR corrected per lean body mass, 5.8 +/- 0.8 v 13.9 +/- 0.9 mg/kg lean body mass/min, P < .001). The results suggest that adults with GHD are insulin-resistant. Despite this finding, normal fasting plasma insulin levels were seen.

Treatment of Growth Hormone-Deficient Adults with Recombinant Human Growth Hormone Increases the Concentration of Growth Hormone in the Cerebrospinal Fluid and Affects Neurotransmitters

In a double-blind, placebo-controlled trial, the effects of recombinant human growth hormone were studied on cerebrospinal fluid concentrations of growth hormone, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), monoamine metabolites, neuropeptides and endogenous opioid peptides. Twenty patients, 10 patients in each of 2 groups, with adult-onset, growth hormone deficiency were treated for 1 month with recombinant human growth hormone (0.25 U/kg/week) or placebo. All the patients received the appropriate thyroid, adrenal and gonadal hormone replacement. In cerebrospinal fluid, the mean concentration of growth hormone increased from 13.3 +/- 4.4 to 149.3 +/- 22.2 muU/l (p = 0.002), during recombinant human growth hormone treatment. The cerebrospinal fluid IGF-I concentration increased from 0.67 +/- 0.04 to 0.99 +/- 0.10 micrograms/l (p = 0.005) and the IGFBP-3 concentration rose from 13.4 +/- 1.25 to 17.5 +/- 1.83 micrograms/l (p = 0.002). The dopamine metabolite homovanillic acid decreased from 282.1 +/- 36.0 to 234.3 +/- 26.5 nmol/l (p = 0.02) and the vasoactive intestinal peptide decreased from 4.1 +/- 0.6 to 3.7 +/- 0.4 pmol/l (p = 0.03). Cerebrospinal fluid immunoreactive beta-endorphin increased from 24.4 +/- 1.8 to 29.9 +/- 2.1 pmol/l (p = 0.002). There were no significant changes compared to baseline in the cerebrospinal fluid concentrations of enkephalins, dynorphin A, the norepinephrine metabolite 3-methoxy-4-hydroxyphenyl-ethyleneglycol, the serotonin metabolite 5-hydroxyindoleacetic acid, gamma-aminobutyric acid, somatostatin or corticotropin-releasing factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Discriminatory Analysis of Biochip-Derived Protein Patterns in CSF and Plasma in Neurodegenerative Diseases

The role of biomarkers in neurodegenerative diseases has been emphasized by recent research. Future clinical demands for identifying diseases at an early stage may render them essential. The aim of this pilot study was to test the analytical performance of two multiplex assays of cerebral markers on a well-defined clinical material consisting of patients with various neurodegenerative diseases. We measured 10 analytes in plasma and cerebrospinal fluid (CSF) from 60 patients suffering from Alzheimers disease (AD), vascular dementia, frontotemporal dementia, dementia with Lewy bodies, or mild cognitive impairment, as well as 20 cognitively healthy controls. We used the Randox biochip-based Evidence Investigator™ system to measure the analytes. We found it possible to measure most analytes in both plasma and CSF, and there were some interesting differences between the diagnostic groups, although with large overlaps. CSF heart-type fatty acid-binding protein was increased in AD. Glial fibrillary acidic protein and neutrophil gelatinase-associated lipocalin in CSF and D-dimer in plasma were elevated in patients with cerebrovascular disease. A multivariate statistical analysis revealed that the pattern of analytes could help to differentiate the conditions, although more studies are required to verify this.

Cerebrospinal Fluid Microglial Markers in Alzheimer’s Disease: Elevated Chitotriosidase Activity but Lack of Diagnostic Utility

Activated microglial cells, which are the resident macrophages of the central nervous system, surround amyloid β-plaques in Alzheimer’s disease (AD) brains. Inflammation including microglial activation may contribute in AD pathogenesis, and biomarkers for this process may thus be of value to study AD pathogenesis and might facilitate development of therapies targeting these cells. We therefore examined cerebrospinal fluid (CSF) biomarkers in patients with AD, other dementias, mild cognitive impairment and in healthy controls. Samples were analyzed for markers with known association to macrophage activity, including chitotriosidase, YKL-40 (CHI3L1, HC gp-39) and chemokine CC motif ligand 2 (CCL2, MCP1). Patients with AD had higher chitotriosidase activity than controls and patients with stable mild cognitive impairment, consistent with the presence of activated microglial cells in AD brains, but with large overlaps between groups. CCL2 and YKL-40 concentrations did not differ among groups. Microglial markers are unlikely to be useful for AD diagnosis, but might be useful for identification of distinct subgroups of patients, and for the development and implementation of drugs targeting microglial pathology.

Two weeks of daily injections and continuous infusion of recombinant human growth hormone (GH) in GH-deficient adults. II. Effects on serum lipoproteins and lipoprotein and hepatic lipase activity

Recombinant human growth hormone (GH) administered as daily subcutaneous (SC) injections has been shown to affect serum lipoproteins in GH-deficient subjects. However, the effects of continuous infusion of GH on serum lipoproteins have not been investigated in GH-deficient adults. The aim of the present study was to compare effects of daily injections and continuous infusion of GH on lipoprotein metabolism. Recombinant human GH (0.25 U/kg/wk) was administered to nine GH-deficient adult men during a period of 14 days in two different ways, ie, as a daily SC injection at 8:00 PM and as a continuous SC infusion, with 1 month of washout between the treatments. Blood samples and tests were performed in the morning after an overnight fast before the start of GH treatment (day 0) and on day 2 and day 14 of treatment. Abdominal SC adipose tissue lipoprotein lipase (LPL), postheparin plasma LPL, and hepatic lipase (HL) activity were measured 120 minutes after the intake of 100 g glucose. Adipose tissue LPL activity decreased and postheparin plasma HL activity increased after 14 days of GH treatment irrespective of the mode of GH administration, whereas GH treatment had no effect on postheparin plasma LPL activity. Serum triglyceride and very-low-density lipoprotein (VLDL) triglyceride concentrations increased during GH treatment. However, VLDL triglyceride concentrations increased to a greater degree during treatment with daily GH injections than during continuous infusion of GH. Serum apolipoprotein (apo) B and low-density lipoprotein (LDL) cholesterol concentrations decreased during treatment with daily GH injections, but were not significantly affected by continuous GH infusion. Thus, apo B and LDL cholesterol concentrations were lower after daily GH injections versus continuous GH infusion. Serum lipoprotein(a) [Lp(a)] and apo E concentrations increased during both modes of GH treatment. However, continuous infusion of GH resulted in a more marked increase in Lp(a) and apo E concentrations than daily GH injections. Minor effects were observed on serum apo A-I concentrations but high-density lipoprotein (HDL) cholesterol concentrations were not affected. In conclusion, GH treatment of GH-deficient men influenced adipose tissue LPL and postheparin plasma HL activity, as well as serum lipoprotein concentrations. Moreover, continuous GH infusion and daily GH injections differed with respect to the magnitude of effects on several lipoprotein fractions including VLDL triglycerides, LDL cholesterol, apo B, apo E, and Lp(a) concentrations.

Two weeks of daily injections and continuous infusion of recombinant human growth hormone (GH) in GH-deficient adults: 1. effects on insulin-like growth factor-I (IGF-I), GH and IGF binding proteins, and glucose homeostasis☆

Recombinant human growth hormone (GH) is routinely administered as daily subcutaneous injections to patients with GH deficiency (GHD). However, in the hypophysectomized rat, pulsatile and continuous infusion of GH has been shown to differ in terms of the magnitude of effect on longitudinal bone growth, serum insulin-like growth factor-I (IGF-I) concentrations, and hepatic metabolism. The aim of the present study was to compare the effects of daily injections and continuous infusion of GH in GHD adults on previously well-documented GH-dependent factors. Recombinant human GH (0.25 U/kg/wk) was administered to nine men with GHD for 14 days in two different ways, ie, as a daily subcutaneous injection at 8 PM and as a continuous subcutaneous infusion, with 1 month of washout between treatments. Blood samples and tests were performed in the morning after an overnight fast before the start of GH treatment (day 0) and on day 2 and day 14 of treatment. An oral glucose tolerance test (OGTT) was performed on day 0 and day 14. Daily injections and continuous infusion of GH exerted similar effects in terms of body weight and body composition. The two modes of administration resulted in similar daily urinary GH excretion and similar serum GH concentrations in the morning. GH binding protein (GHBP) concentrations did not change significantly during the various treatment periods. Serum IGF-I and IGF-I binding protein (IGFBP)-3 concentrations increased to a greater degree during continuous infusion of GH versus daily injections. Serum IGFBP-I concentrations decreased to a similar degree during the two modes of administration. Serum concentrations of free triiodothyronine and total triiodothyronine (T3) increased and free thyroxine (T4) decreased to a similar degree, independent of the mode of administration. However, total T4 concentrations were unchanged during both modes of treatment. Serum thyrotropin (TSH) concentrations decreased during continuous infusion, and there was a similar nonsignificant decrease during daily injections of GH. Fasting free fatty acid (FFA) levels increased during treatment with only daily injection of GH, but there was no significant effect from continuous infusion. Results of measurements of fasting concentrations of blood glucose and oral glucose tolerance (OGT) indicated a more impaired glucose tolerance after daily injections of GH versus continuous infusion. In conclusion, continuous infusion and daily injections of GH have similar effects on the variables described, but the magnitude of the effects differs.

Cerebrospinal Fluid Biomarkers for Alzheimer's Disease: Diagnostic Performance in a Homogeneous Mono-Center Population

The cerebrospinal fluid (CSF) biomarkers amyloid-β (Aβ)(1-42), T-tau, and P-tau have good diagnostic accuracy for clinically diagnosed Alzheimer’s disease (AD). However, in multi-center studies, the predictive values of the CSF biomarkers have been lower, possibly due to differences in procedures for lumbar puncture and CSF handling and storage, and to differences in patient populations, clinical evaluations, and diagnostic procedures. Here we investigate the diagnostic accuracy of CSF biomarkers in a well defined homogeneous mono-center population. We also evaluate an extended panel of amyloid related biomarkers. Sixty consecutive patients admitted for cognitive impairment to a memory clinic were recruited. The participants included patients with AD or mild cognitive impairment (MCI) diagnosed with AD upon follow-up (n = 32), patients with stable MCI (n = 13), patients with other dementias diagnosed at primary evaluation or upon follow-up (n = 15), and healthy controls(n = 20). CSF was analyzed for Aβ(1-42), T-tau, and P-tau, and PA(X-38), Aβ(X-40), Aβ(X-42), sAβPPα, and sAβPPβ. In multivariate analysis, thecore biomarkers Aβ(1-42), T-tau, and P-tau demonstrated a high ability to diagnose AD versus the combined groups of controls and stable MCI, with an area under the receiver operating characteristic curve (AUROC) of 0.97 (95% CI 0.93–1.00, p < 0.0001). The additional biomarkers only marginally increased AUROC to 0.98 (95% CI 0.95–1.00, p < 0.0001), this increase mainly mediated by Aβ(X-42). In conclusion, CSF biomarkers Aβ(1-42), T-tau, and P-tau have very high diagnostic accuracy in a well defined cohort of untreated patients, demonstrating the excellent potency of CSF biomarkers to identify pathological processes in AD when astringent analytical protocol is used.

Diurnal variation in serum insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations during daily subcutaneous injections of recombinant human growth hormone in GH-deficient adults

OBJECTIVE Whereas there seems to be little, if any, circadian variation in circulating concentrations of IGF‐I and IGFBP‐3 in healthy subjects, there are conflicting reports on this issue in GH‐deficient patients treated with GH as a daily subcutaneous injection. We have therefore investigated the 24‐hour serum profiles of IGF‐I and IGFBP‐3 concentrations after one week and more than one year of GH treatment.

Safety and tolerability of growth hormone therapy in multiple system atrophy: A double-blind, placebo-controlled study

The objective of this study was to investigate tolerability and possible neurotrophic effects of growth hormone (GH) in treatment of multiple system atrophy (MSA). In this double‐blind pilot study, MSA patients were randomized to recombinant human growth hormone (r‐hGH, n = 22), 1 mg every second day (6 months) followed by alternating daily injections of 1 mg and 0.5 mg (6 months), or matched placebo (n = 21). Safety analysis demonstrated no obvious between‐group differences. In both groups, there was progressive worsening of Unified Parkinsons Disease Rating Scale total score, which tended to be less in r‐hGH‐treated patients (12.9% at 6 months, 25.3% at 12 months) than in placebo (17.0% and 35.7%). Similarly, there was a trend to less worsening in Unified MSA Rating Scale total score with r‐hGH (13.2% and 21.2%) than with placebo (21.1% and 36.5%). Cardiovascular reflex autonomic testing also tended to show less deterioration with r‐hGH than with placebo at 12 months. However, 95% CI did not indicate treatment differences for any efficacy measures. In conclusion, r‐hGH administration in MSA patients for up to 1 year appears safe and might influence disease symptoms, signs and, possibly, progression. The results support further studies utilizing higher doses in more patients.

Serum but not cerebrospinal fluid levels of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) are increased in Alzheimer's disease

BACKGROUND Although insulin-like growth factor-I (IGF-I) is of importance for the adult function of the central nervous system (CNS), little is known of the significance of IGF-I in cerebrospinal fluid (CSF) in relation to Alzheimers disease (AD). METHODS A cross-sectional study of 60 consecutive patients under primary evaluation of cognitive impairment and 20 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n=32), stable MCI (SMCI, n=13), or other dementias (n=15). IGF-I, IGF-binding protein-3 (IGFBP-3), and insulin were measured in serum and CSF. RESULTS Serum IGF-I level was increased in AD patients and in patients with other dementias compared to healthy controls (P=0.01 and P<0.05, respectively). Serum IGFBP-3 concentration was increased in AD and SMCI patients compared to controls (P=0.001 and P<0.05, respectively). CSF levels of IGF-I and IGFBP-3 as well as serum and CSF levels of insulin were similar in all study groups. In the total study population (n=80), serum levels of IGF-I and IGFBP-3 correlated negatively with CSF β-amyloid₁₋₄₂ (Aβ₁₋₄₂) level (r=-0.29, P=0.01 and r=-0.27, P=0.02, respectively) and in the AD patients (n=32), the increased CSF/serum IGF-I ratio correlated positively with the CSF level of phosphorylated tau protein (P-tau; r=0.42, P=0.02). CONCLUSION Patients with AD as well as other dementias had high levels of IGF-I in serum but not in CSF. In AD patients, the IGF-I system was associated with biomarkers of AD disease status.