Increased Interleukin-6 levels in pituitary-deficient patients are independently related to their carotid intima-media thickness

Covert actions of growth hormone: fibrosis, cardiovascular diseases and cancer

Since its discovery nearly a century ago, over 100,000 studies of growth hormone (GH) have investigated its structure, how it interacts with the GH receptor and its multiple actions. These include effects on growth, substrate metabolism, body composition, bone mineral density, the cardiovascular system and brain function, among many others. Recombinant human GH is approved for use to promote growth in children with GH deficiency (GHD), along with several additional clinical indications. Studies of humans and animals with altered levels of GH, from complete or partial GHD to GH excess, have revealed several covert or hidden actions of GH, such as effects on fibrosis, cardiovascular function and cancer. In this Review, we do not concentrate on the classic and controversial indications for GH therapy, nor do we cover all covert actions of GH. Instead, we stress the importance of the relationship between GH and fibrosis, and how fibrosis (or lack thereof) might be an emerging factor in both cardiovascular and cancer pathologies. We highlight clinical data from patients with acromegaly or GHD, alongside data from cellular and animal studies, to reveal novel phenotypes and molecular pathways responsible for these actions of GH in fibrosis, cardiovascular function and cancer.

Association between C-reactive protein and carotid plaque in mild-to-moderate idiopathic pulmonary fibrosis

An association between C-reactive protein (CRP) levels and carotid plaque has never been investigated in idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the extent of carotid atherosclerosis in mild-to-moderate IPF and to assess its relationship to serum CRP. This observational retrospective case-control study included 60 consecutive IPF patients (73.8 ± 6.6 years, 45 males) and 60 matched controls, examined between Sep 2017 and Jan 2019. All patients underwent CRP assessment and a carotid Doppler ultrasonography. CRP levels were significantly higher in IPF patients than controls (0.2 ± 0.09 mg/dl vs 0.09 ± 0.04 mg/dl, p < 0.0001). A total of 46 plaques were detected, with higher prevalence in IPF patients than controls (38 vs 8, p < 0.0001). On univariate logistic regression the main variables independently associated with carotid plaque were: age (HR 1.09, 95% CI 1.03-1.16, p = 0.006), hypertension duration (HR 1.05, 95% CI 1.01-1.09, p = 0.01), diabetes duration (HR 1.09, 95% CI 1.01-1.18, p = 0.03), LDL-cholesterol (HR 1.07, 95% CI 1.04-1.10, p < 0.0001) and finally CRP levels (HR 1.73, 95% CI 0.59-5.00, p < 0.0001). Multivariate logistic regression analysis revealed that LDL-cholesterol (HR 1.05, 95% CI 1.01-1.08, p = 0.009) and CRP levels (HR 1.43, 95% CI 0.39-5.19, p < 0.0001) retained statistical significance. Common carotid artery-intima media thickness was significantly correlated with CRP levels in IPF patients (r = 0.86). SerumCRP might represent both an early marker and a potential therapeutic target for carotid atherosclerosis in mild-to-moderate IPF.

Association between neutrophil to lymphocyte ratio and carotid artery wall thickness in healthy pregnant women

OBJECTIVE

Pregnancy may elicit a state of mild inflammation that might affect, either directly or indirectly, haematological parameters associated with systemic inflammation. In particular, both Neutrophil-to-lymphocyte ratio (NLR) and Red blood cells Distribution Width (RDW) have been found to be elevated in complicated pregnancy. However, data regarding the association of these haematological parameters with common carotid artery (CCA) intima-media thickness (IMT) in healthy pregnancy are scanty. Aim of this study was to evaluate possible changes in CCA-IMT during normal pregnancy and in the postpartum period, and to correlate these changes with NLR and RDW.

STUDY DESIGN

Between October 2019 and February 2020, a prospective study was carried out on 73 consecutive healthy pregnant women (32.8 ± 4.9 yrs/old). Women underwent obstetric assessment, complete blood cell counts with calculation of NLR and RDW, two-dimensional transthoracic echocardiography and carotid Doppler ultrasonography.

RESULTS

During normal pregnancy, both NLR and RDW progressively increased (p < 0.0001); likewise, parameters of carotid dimensions also significantly increased (p < 0.0001). Hematological and morphological changes all decreased in postpartum period. By univariable logistic regression, the variables which showed the greatest independent association with CCA-IMT (defined as CCA-IMT ≥0.55 mm) were: age (HR 1.33, 95% CI 1.15-1.53, p < 0.0001), pre-pregnant BMI (HR 2.75, 95% CI 1.72-4.41, p < 0.0001), third trimester E/e' ratio (HR 1.64, 95% CI 1.34-2.02, p < 0.0001), and third trimester NLR (HR 3.00, 95% CI 1.64-5.50, p < 0.0001). Multivariable logistic regression analysis demonstrated that third trimester NLR was the only variable that retained statistical significance (HR 2.49, 95% CI 1.35-4.59, p = 0.003). An NLR ≥ 2 reached 83% of sensitivity and 99% of specificity in identifying a CCA-IMT ≥0.55 mm (AUC = 0.95). A strong linear correlation of both third trimester NLR and RDW with CCA-IMT was observed (r = 0.89 and 0.83, respectively).

CONCLUSIONS

Pregnancy is a state of chronic mild inflammation and the progressive increase in NLR and RDW during normal pregnancy is significantly associated with CCA intimal-medial thickening.

Plasmatic lipocalin-2 levels in chronic low-grade inflammation syndromes: Comparison between metabolic syndrome, total and partial adult growth hormone deficiency

Lipocalin-2 (LCN2) is a secreted glycoprotein involved in several chronic inflammatory processes. Metabolic syndrome (MetS) and adult growth hormone deficiency (GHD) are known as chronic inflammatory conditions. The primary objective of this observational cross-sectional study was to compare LCN2 plasmatic levels in these clinical settings, whereas the secondary objective was to investigate any possible correlation between LCN2 and BMI and/or indexes of insulin sensitivity/resistance. Seventy-four patients were divided as follows: Group A, MetS (18 patients, 13 females and 5 males, mean ± SEM age 45.1 ± 4.11 years, BMI 31.22 ± 1.73 kg/m² ); Group B, total GHD (18 patients, 8 females and 10 males, age 52.44 ± 2.61 years, BMI 30.49 ± 1.87 kg/m² ); Group C, Partial GHD (pGHD; 19 patients, 13 females and 6 males, age 48.63 ± 2.19 years, BMI 29.11 ± 1.85 kg/m² ); Group D, Controls (19 patients, 13 females and 6males, age 40.26 ± 2.87 years, BMI 23.25 ± 0.95 kg/m² ). They were evaluated for glucose and insulin, HOMA-index, QUICKI-index, Total/low-density lipoprotein/high-density lipoprotein cholesterol, triglycerides, uric acid, IGF-1, and LCN2. LCN2 plasmatic levels were significantly increased in MetS, while no significant differences with controls were found in total and pGHD. LCN2 levels did not correlate with BMI. A significant positive correlation between LCN2 and HOMA-index was found in controls, while a trend-like, yet not significant, a positive correlation was observed in pGHD. Our data show an increase in LCN2 plasmatic levels in MetS. Different inflammatory patterns characterize MetS and GHD. The correlation between HOMA index and LCN2 in normal subjects and possibly in pGHD ones suggests a modulatory action of LCN2 on insulin resistance.

Identification of Haptoglobin as a Readout of rhGH Therapy in GH Deficiency

BACKGROUND

GH deficiency (GHD) is characterized by a cluster of cardiovascular risk factors and subtle inflammation. We aimed to demonstrate, through a proteomic approach, molecules directly modulated by GHD and involved in the inflammatory state.

METHODS

Ten children with isolated GHD were studied before and after 1 year of treatment with rhGH and compared with 14 matched controls. A two-dimensional electrophoresis plasma proteomics analysis was performed at baseline and after GH treatment to identify the top molecules modulated by GH. In vitro studies on human hepatoma (HepG2) cells were performed to validate the data.

RESULTS

Twelve of 20 proteomic spots were predicted to be isoforms α and β of haptoglobin (Hp) and confirmed by liquid chromatography tandem mass spectrometry and Western immunoblot analyses. Hp levels were higher in patients with GHD than controls at baseline (P < 0.001) and were reduced following GH treatment (P < 0.01). In HepG2 cells, both GH and IGF-1 were able to downregulate IL-6-induced Hp secretion. Moreover, Hp secretion was restored in pegvisomant-treated HepG2 cells.

CONCLUSIONS

Hp is a molecule acting in the inflammatory state of GHD and a possible biomarker for GH treatment. Nevertheless, the contribution of other factors and the molecular pathways involved in the GH downregulation of Hp remain to be clearly defined.

Serum soluble urokinase plasminogen activator receptor (suPAR) in adults with growth hormone deficiency

Growth hormone deficiency (GHD) syndrome is associated with adverse levels of several risk factors for cardiovascular diseases (CVD), including metabolic inflammation. However, the impact of GHD and GH treatment on low-grade inflammation is unknown. The aim of the study was to establish the level of the low-grade inflammation biomarker soluble urokinase plasminogen activator receptor (suPAR) in adults with GHD and the response to long-term GH treatment. Measurements of suPAR and CRP were performed in bio-bank serum samples from 72 adults, 34 males and 38 females, with GHD before and during at least 5 years of GH treatment. Mean age was 52.5 ± 15.5 years, BMI 27.3 ± 5 kg/m2. Clinical evaluations and blood sampling were performed at routine visits. Data on demography, anthropometry, lab results and clinical events were retrieved from post-marketing surveillance study databases and medical records. suPAR and high-sensitive (hs) CRP were analysed using ELISA and immunochemistry, respectively. At baseline blood pressure, lipid profile and fasting glucose were within the normal reference range. Baseline geometric mean and 95% CI of suPAR was 2.9 (2.7-3.3) ng/mL and of CRP 2.3 (0.6-4.0) mg/L. Mean follow-up was 8 ± 2 years. The suPAR levels remained stable during follow-up, although individual increases were seen on occurrence or presence of co-morbidities. In contrast, levels of CRP decreased. In conclusion, the decrease in CRP and indirectly the absence of an expected increase in suPAR over time indicates a favourable effect of GH on low-grade inflammation.

Oxidative stress in adult growth hormone deficiency: different plasma antioxidant patterns in comparison with metabolic syndrome

BACKGROUND AND AIMS

Growth hormone deficiency (GHD) is a condition associated with increased cardiovascular risk and insulin-resistance. Oxidative stress (OS) could be a mechanism underlying both these phenomena. In order to investigate plasma antioxidant defenses in such condition, we evaluated adults with GHD, compared with controls and metabolic syndrome patients (MetS), studying plasma total antioxidant capacity (TAC) and coenzyme Q10 (CoQ10, lipophilic antioxidant) levels, both in its oxidized and reduced forms, correlating this data with metabolic and hormonal pattern.

MATERIALS AND METHODS

In this case-control study, 51 GHD, 36 controls, and 35 MetS were enrolled. An evaluation of hormonal and metabolic parameters was performed. TAC was measured using the system metmyoglobin -H₂0₂ and the chromogen ABTS, whose radical form is spectroscopically revealed; latency time (LAG) in the appearance of ABTS^● is proportional to antioxidant in sample. CoQ10 was assayed by electrochemical method.

RESULTS

Despite HOMA index was higher in both GHD and MetS (2.2 ± 0.3 and 3.1 ± 0.3 vs. 1.2 ± 0.2 in controls), only in MetS we observed lower LAG levels (64.5 ± 3.1 s vs. 82.8 ± 5.8 in GHD and 80.6 ± 6.6 in controls), suggesting an increased consumption of antioxidants. LAG significantly correlated with uric acid only in MetS (r ² = 0.65, p < 0.001), suggesting a different pattern of antioxidants. CoQ10 exhibited a trend toward lower levels in GHD, although not significant.

CONCLUSIONS

Our data indicate that GHD, although sharing with MetS various metabolic features, including increased HOMA levels, showed a different pattern of plasma antioxidants, suggesting inadequate reactivity toward radical production rather than an antioxidants consumption as in MetS.

Controversies in the risk of neoplasia in GH deficiency

Growth hormone (GH) replacement in GH deficient (GHD) children secures normal linear growth, while in GHD adults it improves metabolic status, body composition and quality of life. Safety of GH treatment is an important issue in particular concerning the controversy of potential cancer risk. Unlike in congenital IGF-1 deficiency, there is no complete protection against cancer in GHD patients. Important modifiable risk factors in GHD patients are obesity, insulin resistance, sedentary behavior, circadian rhythm disruption, chronic low grade inflammation and concomitant sex hormone replacement. Age, family history, hereditary cancer predisposition syndromes or cranial irradiation may present non-modifiable risk factors. Quantifying the risk of cancer in relation to GH therapy in adult GHD patients is complex. There is evidence that links GH to cancer occurrence or promotion, but the evidence is progressively weaker when moving from in vitro studies to in vivo animal studies to epidemiological studies and finally to studies on GH treated patients. GH-IGF inhibition in experimental animals leads to decreased cancer incidence and progression. Epidemiological studies suggest an association of high normal circulating IGF-1 or GH to cancer incidence in general population. Data regarding cancer incidence in acromegaly are inconsistent but thyroid and colorectal neoplasias are the main source of concern. Replacement therapy with rhGH for GHD is generally safe. Overall the rate of de novo cancers was not increased in studies of GH-treated GHD patients. Additional caution is mandated in patients with history of cancer, strong family history of cancer and with advancing age. Childhood cancer survivors may be at increased risk for secondary neoplasms compared with general population. In this subgroup GH therapy should be used cautiously and with respect to other risk factors (cranial irradiation etc). We believe that the benefits of GH therapy against the morbidity of untreated GH deficiency outweigh the theoretical cancer risk. Proper monitoring of GH treatment with diligent cancer surveillance remains essential.

Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy

Growth hormone deficiency (GHD) in adulthood is associated with an increased risk of developing adverse cardiovascular events and with reduced life expectancy. Cardiovascular and metabolic abnormalities have so far been evaluated only in a small number of children with GHD and adolescents. In this article we review these abnormalities and their underlying mechanisms and discuss the beneficial effect of growth hormone treatment in subjects with GHD.

Periodontal disease in adults with untreated congenital growth hormone deficiency: a case-control study

AIM

The aim of this study was to investigate the possible associations between isolated growth hormone deficiency (IGHD) and periodontal attachment loss (PAL) in adults affected by congenital IGHD.

MATERIALS AND METHODS

Forty-five previously identified IGHD subjects were eligible for this study. The final study sample comprised 32 cases (gender:20M/12F; age:44.8 ± 17.5) matched for age, gender, diabetes, smoking status and income to 32 controls (non-IGHD subjects). Participants were submitted to a full-mouth clinical examination of six sites per tooth and were interviewed using a structured, written questionnaire. Periodontitis was defined as proximal PAL≥5 mm affecting ≥30% of teeth.

RESULTS

No significant differences were observed in the percentage of sites with visible plaque between IGHD and non-IGHD subjects (59.4% versus 46.9%, p=0.32). IGHD subjects had significant less supragingival calculus (31.3% versus 59.4%, p=0.02) and more bleeding on probing (71.9% versus 18.8%, p<0.01) than controls. PAL≥5 mm was significantly more prevalent (100% versus 71.9%, p<0.01) and affected more teeth (30.5% versus 6.7%, p<0.01) in cases than in controls. After adjusting for supragingival calculus, IGHD cases had a higher likelihood of having periodontitis than controls (OR=17.4-17.8, 95% CI=2.3-134.9, p=0.004-0.005).

CONCLUSION

Congenital IGHD subjects have a greater chance of having PAL.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

The influence of growth hormone replacement on peripheral inflammatory and cardiovascular risk markers in adults with severe growth hormone deficiency

BACKGROUND

Adult GHD syndrome is associated with clustering of adverse cardiovascular (CV) risk factors such as abnormal body composition, dyslipidemia, insulin resistance and abnormal haemostatic factors. There is a wealth of evidence linking CV events with elevated levels of inflammatory markers (hs-CRP and IL-6) in the general population; however data on their abnormalities in GHD and specially the effects of GH replacement (GHR) on these inflammatory markers are limited.

OBJECTIVE

To study the effects of GHR on inflammatory markers, glucose homeostasis and body composition in a cohort of adults with recently diagnosed severe GHD due to hypothalamic pituitary disease.

DESIGN

Fifteen hypopituitary adults (11 males, mean age 48.5 years) with recently diagnosed, severe GHD were recruited. Patients received GHR (in addition to other pituitary hormone replacements) titrated to clinical response and to normalize age and gender adjusted IGF-1 levels. Weight, waist hip ratio (WHR), body composition, fasting plasma glucose and insulin, insulin resistance index (HOMA-IR), fasting serum lipid levels, hs-CRP, IL-6 and TNF-alpha were measured at baseline and following a minimum 6 months of stable maintenance GHR.

RESULTS

GHR resulted in a physiological increase in IGF-1 SDS [median -0.6 to +0.39, P<0.0001], improved quality of life (mean pre-treatment AGHDA score 16 vs. post-treatment score 7, P<0.0001) and reduction in WHR (0.94 vs. 0.92, P=0.01). There were no significant changes in body weight and composition. Levels of hs-CRP (log transformed, mean (SD)) were significantly reduced following GHR (pre 1.21 (0.9) vs. post 0.27 (0.9), P<0.0001) but TNF-alpha and IL-6 levels remained unchanged. Fasting glucose (mmol/L) [4.6 (0.1) vs. 5.1 (0.1), P=0.003], fasting insulin (muU/mL) [9.4 (8.1) vs. 12.1 (9.2), P=0.03] and HOMA-IR [1.2 (1.0) vs. 1.5 (1.1) P=0.02] (all pre-GHR vs. post-GHR and mean (SD)) significantly increased following GHR indicating increased insulin resistance. Significant improvements were noted in fasting LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) levels following GHR [3.4 (0.9) vs. 2.9 (0.7), P=0.03 and 1.2 (0.2) vs. 1.3 (0.2), P=0.02, respectively] (all pre-GHR vs. post-GHR and mean (SD)). Levels of total cholesterol and triglycerides did not change following GHR.

CONCLUSIONS

Physiological GHR for at least 6 months in hypopituitary adults with recently diagnosed severe GHD resulted in favourable changes in hs-CRP, WHR, fasting LDL-C and HDL-C levels all of which are recognised CV risk markers. However, there remains a high prevalence of obesity in this population and given the worsening of insulin sensitivity in the short term with GHR, monitoring and aggressive treatment of established CV risk factors is essential to reduce premature atherosclerotic CVD in this patient population.

Changes in endothelial dysfunction and associated cardiovascular disease morbidity markers in GH-IGF axis pathology

Arterial endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and predisposes individuals to the deposition of unstable atherosclerotic plaques. It can also lead to increased arterial stiffness, which is an accepted cause of increased arterial pulse wave velocity (APWV). Endothelial dysfunction is reversed by recombinant human growth hormone (rhGH) therapy in patients with growth hormone (GH) deficiency (GHD), favorably influencing the risk for atherogenesis. Endogenous human growth hormone (hGH), secreted by the anterior pituitary, and levels of insulin-like growth factor-I (IGF-I), produced in response to hGH stimulation of the liver, peak during early adulthood, but decline throughout adulthood. It is suspected that low-grade inflammatory cardiovascular pathophysiologic markers such as homocysteine, nitric oxide, C-reactive protein (CRP), and fibrinogen and plasminogen activator inhibitor along with changes in lipid and glucose metabolism may all contribute to GHD-associated metabolic and cardiovascular complications. These effects are associated with increased APWV, but are attenuated by rhGH therapy in GHD. GH replacement increases IGF-I levels and reduces CRP and large-artery stiffness. Reviews of rhGH in the somatopause have not been overtly favorable. Whereas reviews of rhGH/rhIGF-I combinations in GH resistance are more positive than those for rhGH alone, their combined use in the somatopause is limited. Senescent individuals may benefit from such a combination.

Cardiovascular risk factors in hypopituitary GH-deficient adults

Design Data on lipids, body composition, and blood pressure (BP) from all published KIMS papers are summarized and compared with a literature review. Results KIMS data confirm and extend previous research showing that adults with GH deficiency (GHD) have an adverse cardiovascular risk profile. GHD patients have high levels of dyslipidemia, elevated body mass index, unfavorable waist-to-hip ratio and body composition, and a high risk of hypertension. These abnormalities are likely to explain the increased cardiovascular mortality observed in patients with hypopituitarism. When given GH replacement therapy, an improvement is seen in KIMS as well as earlier studies for lipid profile, body composition, and BP. The added value of the different KIMS papers over previous research is that KIMS involves a much larger number of patients, that lipid concentrations and IGF1 are measured in a single central laboratory, and that the effects of GH replacement therapy can be followed longer than the duration of earlier trials. By the large number of patients, KIMS gives insight into the effects of GH in different patients' subgroups such as elderly patients, patients with idiopathic GHD, patients with craniopharyngioma, patients after irradiation, and so on. In addition, KIMS has made it possible to calculate more exactly the influence of baseline parameters on these cardiovascular risk parameters and their response to GH. Conclusions Taken together, data from KIMS confirm earlier knowledge about the important benefits of GH replacement therapy, but also on the use of GH in specific subgroups such as isolated GHD, patients above 65 years, and patients after irradiation. No subgroup yet has been identified as not responding well to GH.

Arterial pulse wave velocity, inflammatory markers, pathological GH and IGF states, cardiovascular and cerebrovascular disease

Blood pressure (BP) measurements provide information regarding risk factors associated with cardiovascular disease, but only in a specific artery. Arterial stiffness (AS) can be determined by measurement of arterial pulse wave velocity (APWV). Separate from any role as a surrogate marker, AS is an important determinant of pulse pressure, left ventricular function and coronary artery perfusion pressure. Proximal elastic arteries and peripheral muscular arteries respond differently to aging and to medication. Endogenous human growth hormone (hGH), secreted by the anterior pituitary, peaks during early adulthood, declining at 14% per decade. Levels of insulin-like growth factor-I (IGF-I) are at their peak during late adolescence and decline throughout adulthood, mirror imaging GH. Arterial endothelial dysfunction, an accepted cause of increased APWV in GH deficiency (GHD) is reversed by recombinant human (rh) GH therapy, favorably influencing the risk for atherogenesis. APWV is a noninvasive method for measuring atherosclerotic and hypertensive vascular changes increases with age and atherosclerosis leading to increased systolic blood pressure and increased left ventricular hypertrophy. Aerobic exercise training increases arterial compliance and reduces systolic blood pressure. Whole body arterial compliance is lowered in strength-trained individuals. Homocysteine and C-reactive protein are two inflammatory markers directly linked with arterial endothelial dysfunction. Reviews of GH in the somatopause have not been favorable and side effects of treatment have marred its use except in classical GHD. Is it possible that we should be assessing the combined effects of therapy with rhGH and rhIGF-I? Only multiple intervention studies will provide the answer.

IGF1 as predictor of all cause mortality and cardiovascular disease in an elderly population

BACKGROUND

IGF1 is believed to influence ageing and development of cardiovascular disease (CVD) through complex mechanisms. Reduced IGF1 levels might be causally associated with conditions accompanying ageing including development of CVD. However, in animal models reduced GH-IGF1 signalling increases lifespan. Reduced IGF1 activity might also be associated with longevity in humans.

OBJECTIVE

The objective was to investigate if plasma IGF1 levels were associated with all cause mortality, and the development of chronic heart failure (CHF) and a major CV event.

PATIENTS AND DESIGN

A population based study of 642 individuals, aged 50-89 years. Development of CHF was evaluated in 576 individuals with normal systolic function assessed by echocardiography and without the history of CHF or myocardial infarction. Development of the first major CV event was evaluated in 504 individuals with normal systolic function and without prevalent CVD. Outcomes were ascertained after 5 years using hospital discharge diagnoses.

RESULTS

Adjustment for risk factors IGF1 values in the fourth quartile versus values below the fourth quartile was associated with increased mortality (n=103), hazard ratio (HR) 1.52 (95% confidence interval (CI) 1.01-2.28; P=0.044). IGF1 in the fourth quartile was also independently associated with risk of development of CHF (n=19), HR 5.02 (95% CI 2.00-12.64; P=0.001) but showed no association with the overall incidence of major CV events (n=58), HR 1.05 (95% CI 0.59-1.90; P=0.861).

CONCLUSIONS

High IGF1 levels were independently associated with increased all cause mortality and risk of development of CHF, whereas no relation with the overall incidence of CVD was observed.

Adult-onset growth hormone deficiency: causes, complications and treatment options

PURPOSE OF REVIEW

Description of the progresses related to the complications and treatment of adult-onset growth hormone deficiency.

RECENT FINDINGS

Growth hormone deficiency in adults has gained attention as a clinical syndrome associated with increased morbidity and possibly mortality. Many studies have been conducted on the consequences of growth hormone deficiency and of its replacement, supporting its use in appropriate patients. Early studies were characterized by a high incidence of side effects due to a lack of pilot data to guide appropriate dosing. Given the wide variability in individual responsiveness to growth hormone therapy based on age, sex, and body composition, recent work has been dedicated to understanding which patients derive benefit from therapy, minimizing side effects, and ensuring cost-effectiveness.

SUMMARY

Long-term prospective trials have shown that growth hormone replacement therapy results in improvements in body composition, dyslipidemia, bone mineral density, and quality of life. The effects on endpoints such as cardiovascular morbidity and mortality and fractures are, however, not fully proven. Randomized trials that compare homogenous groups of growth hormone deficiency patients are still needed. Given the high cost of treatment, dynamic testing for growth hormone deficiency should only be performed in patients in whom there is high clinical suspicion, and therapy should be limited to those with biochemically proven growth hormone deficiency.

Hypopituitarism: clinical features, diagnosis, and management

Hypopituitarism is characterized by loss of function of the anterior pituitary gland. It is a rare condition that can present at any age and is caused by pathology of the hypothalamic-pituitary axis or one of many gene mutations. The symptoms and signs of hypopituitarism may evolve over several years and be nonspecific or related to the effects of the underlying disease process or to hormone deficiencies. Investigation of patients requires a combination of basal hormone levels and dynamic function tests; management requires regular monitoring. The goal of physicians managing patients who have hypopituitarism is to improve their health and long-term outcome.

Management of growth hormone deficiency in adults

Growth hormone (GH) deficiency in adults is a recognised clinical entity. There is still, however, an ongoing debate of the clinical need and the importance of replacing GH in adults with severe GH deficiency. This review will focus on the overall management of adults with GH deficiency and highlight published data on dose management and treatment goals for various age groups. The efficacy data on quality of life and well-being is discussed and available and growing experience on long-term effects of GH replacement in adults and safety in terms of diabetes mellitus, pituitary tumour recurrence/regrowth and malignancy risk will be reviewed.

Concentrations of the acute phase reactants high-sensitive C-reactive protein and YKL-40 and of interleukin-6 before and after treatment in patients with acromegaly and growth hormone deficiency

BACKGROUND

Acromegaly is accompanied by increased cardiovascular mortality and a cluster of proatherogenic risk factors. In the general population, ischaemic heart disease (IHD) is associated with elevated levels of inflammatory markers. The acute phase reactant (APR) C-reactive protein (CRP) has been reported to be reduced in acromegaly and increase after treatment, suggesting that excess of GH/IGF-I could have anti-inflammatory effects. This is in accordance with results obtained in patients with growth hormone deficiency (GHD), where increased levels of CRP have been reported.

OBJECTIVE

To investigate the hypothesis that the GH/IGF-I system is a suppressive regulator of inflammatory processes.

SUBJECTS AND METHODS

Twenty-one acromegalic patients and 19 GH-deficient patients were studied. The two APRs CRP and YKL-40 and the proinflammatory cytokine interleukin-6 (IL-6) were measured before and after treatment and in healthy matched controls.

RESULTS

In acromegalic patients, serum concentrations of high-sensitive CRP (hsCRP) and YKL-40 were reduced compared to controls (P < 0.001) and increased (P < 0.001) after treatment, together with IL-6 (P = 0.021), to levels comparable with controls. Pretreatment serum YKL-40 and IL-6 showed a significant inverse correlation with IGF-I and GH. In GH-deficient patients, hsCRP and YKL-40 were elevated compared to controls (P = 0.001 and P = 0.048). During treatment, levels of both APRs showed a trend towards a decrease (P = 0.087 and P = 0.060), and after treatment, levels of YKL-40 no longer differed from that of controls. Serum IL-6 was not different from controls and did not change during GH treatment.

CONCLUSION

The results point to the possibility of a relationship between GH disturbances and inflammatory processes.

Peripheral fibrinolytic markers, soluble adhesion molecules, inflammatory cytokines and endothelial function in hypopituitary adults with growth hormone deficiency

BACKGROUND

Increased mortality due to cardiovascular disease has been described in adult patients with untreated GH deficiency (GHD). GH replacement has been demonstrate to improve vascular reactivity and reverse early atherosclerotic changes in adults with GHD.

OBJECTIVE

Assessment of fibrinolytic markers, soluble adhesion molecules, inflammatory cytokines and endothelial function in hypopituitary adults with GHD at baseline and 1 year after GH replacement therapy.

METHODS

We studied 10 patients with GHD (five men and five women; aged 45.6 +/- 10.4 years) at baseline and 1 year after GH replacement therapy compared with a control group (nine men and 16 women) matched for age and body mass index (BMI). All subjects, patients and controls, were life-long nonsmokers, normotensive and nondiabetic. The following variables were recorded: anthropometric and body composition variables, serum concentrations of glucose, insulin and C-peptide; thrombin anti-thrombin (TAT) fragments and fibrin degradation product D-dimer, which were determined by an enzyme-linked immunosorbent assay (ELISA); IGF-I by radioimmunoassay (RIA); C-reactive protein (CRP) by highly sensitive immunonephelometry; E-selectin, P-selectin, soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) by ELISA. The assessment of endothelial function in vivo was measured with a Doppler device.

RESULTS

Patients with GHD without GH substitution had higher hip/waist ratio and body fat than controls. Insulin, C-peptide and triglyceride concentrations were also higher. Our results demonstrated no difference in fibrinogen and in TAT fragment concentrations among patients and controls. E-selectin concentrations were higher in patients than in controls (26.1 +/- 11 vs. 10.7 +/- 6.2 microg/l, P = 0.0001). P-selectin, sICAM-1, sVCAM-1, IL-6, MCP-1 and CRP were similar in the two groups. Vascular reactivity and carotid intima-media thickness (IMT) were also similar in patients and controls. After 1 year of GH treatment we found no changes in biochemical parameters, fibrinolytic markers, soluble adhesion molecules, inflammatory cytokines and endothelial function.

CONCLUSION

Adults with GHD show some subtle changes in soluble adhesion molecules but our data suggest no beneficial effects of GH over these markers in relationship to endothelial function. Factors other than GH treatment, such as differences in age, degree of obesity, the presence of diabetes mellitus and arterial hypertension or tobacco consumption, could explain the observed increase in markers of vascular risk in GH-deficient patients.

Increased carotid intima-media thickness and serum inflammatory markers in obstructive sleep apnea

Increased carotid intima-media thickness (IMT) and increased serum levels of inflammatory markers, such as C-reactive protein (CRP), interleukin (IL)-6, and IL-18, are associated with an increased risk of cardiovascular and cerebrovascular diseases. The aim of this study was to evaluate whether carotid IMT, a useful marker for early atherosclerosis, is associated with these inflammatory markers in patients with obstructive sleep apnea (OSA). Carotid IMT was investigated with ultrasonography in 36 patients with OSA and 16 obese control subjects. Serum levels of CRP, IL-6, and IL-18 were measured at 5:00 A.M. Carotid IMT (p < 0.001) and serum levels of CRP (p < 0.003), IL-6 (p < 0.005), and IL-18 (p < 0.03) of patients with OSA were significantly higher than those of obese control subjects. Carotid IMT was significantly correlated with serum levels of CRP (r = 0.61, p = 0.0001), IL-6 (r = 0.41, p = 0.01), and IL-18 (r = 0.45, p = 0.005), duration of OSA-related hypoxia (r = 0.60, p = 0.0001), and severity of OSA (r = 0.50, p = 0.002). In addition, the primary factor influencing carotid IMT was duration of hypoxia during total sleep time (p = 0.036). These results suggest that OSA-related hypoxia and systemic inflammation might be associated with the progression of atherosclerosis and thus might increase the risks of cardiovascular and cerebrovascular morbidity in patients with OSA.

Safety and efficacy of growth hormone replacement therapy in adults

Limitless supplies of recombinant human growth hormone (GH) have been available for the last 20 years. During that period, studies have characterised the effects of GH deficiency in adults and the benefits of GH replacement therapy. Areas of greatest impairment and benefit are quality of life, skeletal health and cardiovascular risk factors including the serum lipid profile and body composition. By optimising GH replacement therapy at various stages of adult life, it is hoped that it will prevent the development of osteoporosis and reduce the mortality and morbidity associated with hypopituitarism. However, the primary indication for GH therapy in adults in England and Wales is quality of life. The benefits of GH treatment are sustained over several years, and long-term surveillance of patients continues.

Endothelial function, carotid artery intima-media thickness, epicardial adipose tissue, and left ventricular mass and function in growth hormone-deficient adolescents: apparent effects of growth hormone treatment on these parameters

OBJECTIVE

The purpose of this study was to determine whether GH-deficient (GHD) adolescents have abnormalities of cardiac and vascular function detectable during the teenage years.

DESIGN/METHODS

Ten GHD children on GH treatment with a chronological age (CA) of 14.6 +/- 1.7 yr and 12 untreated GHD adolescents with a CA of 15.0 +/- 3.0 yr were studied. Cardiac mass and function, carotid artery intima-media thickness, flow-mediated endothelium-dependent vasodilation (percent change from baseline diameter during hyperemia), and hyperemia-induced blood flow increase of the brachial artery (percent change from baseline) and epicardial adipose tissue were evaluated by echocardiography. Fourteen healthy adolescents served as controls.

RESULTS

Untreated GHD adolescents present with a reduced left ventricular mass when compared with controls (P < 0.05) and a lower flow-mediated endothelium-dependent increase in the diameter of the brachial artery during hyperemia than both controls and treated GHD subjects (P < 0.02), whereas their epicardial adipose tissue is significantly higher than that of healthy controls (P < 0.02). Interventricular septum thickness, posterior wall thickness, left ventricular ejection fraction, and carotid artery intima-media thickness were similar in all three groups. Hyperemia-induced blood flow increase was greater in treated GHD adolescents than both untreated subjects and controls (P < 0.001). Body mass index correlated positively with epicardial adipose tissue in all three groups and with carotid intima-media thickness in treated and untreated GHD adolescents.

CONCLUSIONS

GHD adolescents have a reduced left ventricular mass and vascular abnormalities manifested by lower flow-mediated endothelium-dependent vasodilation. These findings together with an increase in epicardial adipose tissue, a good indicator of abdominal/visceral fat, may contribute to an increased cardiovascular risk in the long term. An improvement in endothelial function and a reduction in arterial stiffness appear to occur after GH replacement.

Determinants of endothelial dysfunction and carotid intima???media thickness in combined hyperlipidemia

BACKGROUND

Early functional and morphological changes in the course of the atherosclerotic process are manifested as endothelial dysfunction and increased intima-media thickness (IMT) of the arterial wall. These are both associated with various atherosclerotic risk factors. We investigated whether the same factors are associated with functional and morphological changes of the arterial wall in men with combined hyperlipidemia.

METHODS

Flow-mediated dilatation (FMD) of the brachial artery and carotid IMT were measured in 72 male patients aged 46+/-5 years with combined hyperlipidemia. Serum lipoproteins, fibrinolytic and coagulation parameters, blood glucose, proinflammatory cytokines and C-reactive protein were also measured.

RESULTS

Tumor necrosis factor-alpha, interleukin 6 and apolipoprotein (apo) B were found to be independent predictors of FMD, explaining 87% of FMD variability in multivariate analysis. On the other hand, total tissue factor pathway inhibitor and apo B were independent predictors of increased carotid IMT, explaining 82% of the variation in carotid IMT.

CONCLUSIONS

Apo B, which is a marker for the presence of the atherogenic lipoproteins, is associated with both functional and morphological changes of the artery wall. In addition, in asymptomatic overweight middle-aged men with combined hyperlipidemia, functional changes are associated with proinflammatory cytokines, while morphological changes are associated with coagulation parameters.

Adiponectin, leptin, and erythrocyte sodium/lithium countertransport activity, but not resistin, are related to glucose metabolism in growth hormone-deficient adults

In a randomized, placebo-controlled, crossover study under metabolic ward conditions, 10 GH-deficient adults received 1-wk GH replacement therapy (9.5 microg/kg.d). The effect of this treatment on the erythrocyte sodium/lithium countertransport (SLC) activity and on serum levels of adiponectin, resistin, leptin, IGF binding protein-1 (IGFBP-1) and IL-6 was determined. The 1-wk GH replacement impaired glucose homeostasis determined from an oral glucose tolerance test. The other measured variables in serum were unchanged by GH replacement. At baseline, serum adiponectin level was inversely correlated and serum leptin level was positively correlated with measures of glucose tolerance and insulin sensitivity. The changes in serum leptin level and erythrocyte SLC activity were positively correlated, and the change in serum IGFBP-1 level was negatively correlated, correlated with changes in measures of glucose metabolism. In conclusion, short-term GH treatment induced glucose intolerance but did not significantly change the erythrocyte SLC activity and the serum levels of adipokines, arguing against direct effects of GH on these measures. However, baseline values or changes in erythrocyte SLC activity, adiponectin, leptin, and IGFBP-1 correlated with glucose metabolism. This suggests that these factors are of importance for glucose homeostasis in GH-deficient adults, most likely through GH-independent mechanisms.

Growth hormone replacement reduces C-reactive protein and large-artery stiffness but does not alter endothelial function in patients with adult growth hormone deficiency

Hypopituitary patients have an increased risk of vascular mortality that may relate to growth hormone deficiency (GHD). We investigated the effects of 6 months of GH therapy on large- and small-artery function and high-sensitivity C-reactive protein (hsCRP) in a cohort of GH-deficient patients. Sixteen hypopituitary patients were randomized to 6 months of GH therapy or no treatment, then vice versa. hsCRP, 24-h blood pressure (BP) and pulse wave velocity (PWV) were measured and resistance arteries were used to construct concentration-response curves to endothelium-dependent and -independent agents. GH therapy increased IGF-1 from 60 +/- 7.2 to 167 +/- 16.2 microg/l [confidence interval (CI) 94.9, 138.8, P < 0.001]. hsCRP declined after 6 months of GH from 3.8 +/- 0.88 to 2.0 +/- 0.49 mg/l (CI 0.73, 3.57, P = 0.006). Mean arterial BP fell from 91.7 +/- 1.5 to 89.3 +/- 1.2 mmHg (CI 0.81, 4.07, P = 0.005), as did PWV (8.1 +/- 0.4 to 6.7 +/- 0.5 m/s). The decline in PWV correlated with the decline in hsCRP (r = 0.68, P = 0.01). Resistance artery function was unchanged after GH therapy. GH replacement may lead to differentially altered production of vasorelaxant agents from the endothelium of large and small arteries. Reduction in vascular inflammation may be associated with reduced vascular risk.

Peripheral inflammatory and fibrinolytic markers in adolescents with growth hormone deficiency: relation to postprandial dyslipidemia

OBJECTIVE

To determine whether peripheral inflammatory and fibrinolytic markers are elevated in growth hormone-deficient (GHD) adolescents and associated with increased postprandial lipoproteins.

STUDY DESIGN

Fifteen GHD children on GH treatment with a chronologic age of 12.7 +/- 2.5 years and 10 untreated GHD adolescents with a chronologic age of 13.0 +/- 2.6 years were studied. Triglycerides (TG), C-reactive protein (CRP), fibrinogen, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were measured in the fasting state and 4 hours after ingesting a high-fat meal; 15 healthy adolescents served as controls.

RESULTS

Fasting and postprandial TG of untreated GHD children were higher than those in treated subjects and healthy controls. Fasting TNF-alpha, CRP, and fibrinogen concentrations of untreated GHD adolescents were higher than those in healthy controls, but similar to those of GH-treated GHD adolescents. Although fibrinogen levels increased after a high-fat meal in GHD adolescents, CRP, TNF-alpha, and IL-6 concentrations did not increase further. Fasting and postprandial TG of untreated GHD adolescents were positively associated with fasting and postprandial CRP, and with postprandial TNF-alpha and IL-6 concentrations. Fasting TG also correlated positively with fasting fibrinogen concentrations in untreated and treated GHD adolescents.

CONCLUSIONS

The pronounced inflammatory response seen in GHD adolescents seems to be associated with the presence of elevated levels of fasting and postprandial TG, which may result in an increased susceptibility for premature atherosclerosis.