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

Comprehensive assessment of cardiovascular disease risk in children with short stature due to isolated growth hormone deficiency: a case-control study

OBJECTIVES

Growth hormone deficiency (GHD) in adults is associated with an increased risk of cardiovascular morbidity and mortality. Although children with GHD are also believed to have a similar cardiovascular disease (CVD) risk beginning at an early age, the available data in children is scarce. We aimed to determine the various CVD risk parameters in children with isolated GHD (IGHD).

METHODS

A cross-sectional case-control study was conducted at a tertiary care centre in North India comparing various auxological, biochemical, and echocardiographic parameters between 20 IGHD children aged 5-15 years and their age and sex-matched healthy controls.

RESULTS

The mean age of children with IGHD and controls was similar (10.5 ± 2.6 yr vs. 9.9 ± 2.7 yr, p=0.48). Children with IGHD had significantly higher waist-hip-ratio (p=0.01), total cholesterol (p=0.02), non-high-density lipoprotein-cholesterol (p=0.02), serum homocysteine (p<0.001), C-reactive protein (CRP) (p=0.01) and pro-brain natriuretic peptide (pro-BNP) (p=0.04) levels as compared to healthy controls. Left ventricular mass (LVM) and interventricular septal thickness were significantly lower (p=0.04; p=0.02) in IGHD children. Correlation analysis showed that pro-BNP and CRP levels had negative correlation (p<0.001, r=-0.70; and p=0.04, r=-0.44, respectively) and LVM had a positive correlation (p=0.02, r=0.53) with height SDS among IGHD children.

CONCLUSIONS

Children with IGHD showed abnormalities in several biochemical and cardiac parameters that may be associated with an increased CVD risk in later life. More extensive studies, including younger children with IGHD, are needed to determine the lower ages at which the CVD risk is detectable.

Adult growth hormone deficiency: diagnostic and treatment journeys from the patients’ perspective

Adult growth hormone deficiency (AGHD) is a rare and serious condition associated with significant morbidity, including reduced quality of life, and is underdiagnosed and often missed in patients. Although the onset of AGHD can occur in either childhood or adulthood, adult-onset AGHD is more difficult to identify as it lacks the auxologic signs caused by GHD during childhood, includes symptoms that tend to be nonspecific, and lacks reliable, simple biomarker testing options. A panel of 9 patients with AGHD (3 with childhood onset; 6 with adult onset) was assembled to share their first-hand experiences, to help reveal important areas of need, increase health literacy, and to raise awareness about GHD among patients, caregivers, and healthcare practitioners. Interviews with patients yielded valuable insights from the patient perspective to supplement prior knowledge about AGHD symptomatology, biomarker testing, and treatment outcomes. Some patients described a burdensome and ineffective screening process that sometimes included many visits to different specialists, repeated rounds of biomarker testing, and, in some cases, excessive delays in AGHD diagnosis. All patients expressed frustration with insurance companies that often resist and/or delay treatment authorization and reimbursement and frequently require additional testing to verify the diagnosis, often leading to treatment gaps. These findings emphasize the necessity of more efficient identification and screening of patients with possible AGHD, better recognition by clinicians and insurance providers of the importance of sustained GH replacement therapy during adulthood, and better patient support for accessing and maintaining uninterrupted GH replacement therapy for patients with documented AGHD.

Somatropin therapy in italian adults with growth hormone deficiency

BACKGROUND

In adult population, Growth Hormone Deficiency (GHD) is a complex clinical condition with heterogeneity of causes and duration. Growth Hormone (GH) replacement therapy has beneficial effects entailing a chronic and expensive use. Therefore, entity, appropriateness and standardization of GHD treatment need to be accurately analysed. In Italy, the epidemiological surveillance on somatropin therapy is entrusted to the National Register of Growth Hormone Therapy (Registro Nazionale degli Assuntori dell'Ormone della Crescita-RNAOC) by the Italian Regulation, in accordance of which the RNAOC-database is collecting the notifications of somatropin prescriptions.

METHODS

Aim of this study is to analyse data on somatropin-treated adult population communicated to the RNAOC by the specialist centres of 15 Italian regions and 2 autonomous provinces.

RESULTS

From 2011 to 2019, the somatropin-treated adults were 970 with 4061 examinations (1.21 ± 0.33 visits/year). The diagnoses were: hypopituitarism (n = 579); hypophysectomy (n = 383); and congenital GHD (n = 3). Five subjects were addressed with diagnoses not included in the regulation. The starting posology of somatropin was 0.320 (± 0.212) mg/day, 0.292 (± 0.167) mg/day in male and 0.360 (± 0.258) in female patients, with 7 administrations/week in 70.31% of the prescriptions. The differences in posology by gender persisted at 10th year of the follow-up. Starting dosage was higher in patients diagnosed with adult GHD before the age of 30 (0.420 ± 0.225 mg/day), with a progressive decrease of the dosage during the follow-up.

CONCLUSIONS

This is the first report on adult GH treatment, describing numbers, diagnoses, and pharmaceutical prescriptions associated to somatropin therapy in a large cohort of Italian GHD-adults.

Growth hormone deficiency and the transition from pediatric to adult care

OBJECTIVE

To discuss the approach to patients diagnosed with growth hormone deficiency (GHD) in childhood during the transition period from puberty to adulthood, focusing on the following: (1) physiology; (2) effects of recombinant human GH (rhGH) interruption/reinstitution after adult height achievement; (3) re-evaluation of somatrotropic axis; (4) management of rhGH reinstitution, when necessary.

SOURCE OF DATA

Narrative review of the literature published at PubMed/MEDLINE until September 2020 including original and review articles, systematic reviews and meta-analyses.

SYNTHESIS OF DATA

Growth hormone is crucial for the attainment of normal growth and for adequate somatic development, which does not end concomitantly with linear growth. Retesting adolescents who already meet the criteria that predict adult GHD with high specificity is not necessary. Patients with isolated GHD have a high likelihood of normal response to GH testing after puberty. Adolescents with confirmed GHD upon retesting should restart rhGH replacement and be monitored according to IGF-I levels, clinical parameters, and complementary exams.

CONCLUSION

Patients with isolated idiopathic GHD in childhood are a special group who must be reevaluated for GHD as many of them have normal GH provocative tests upon retesting after puberty. Patients who confirm the persistence of GHD in the transition period should maintain rhGH replacement in order to reach an ideal peak bone mass, satisfactory body composition, lipid and glucose profiles, and quality of life.

Pituitary Dysfunction as a Cause of Cardiovascular Disease

The hypothalamic-pituitary axis is responsible for the neuroendocrine control of several organ systems. The anterior pituitary directly affects the functions of the thyroid gland, the adrenal glands, and gonads, and regulates growth and milk production. The posterior hypophysis, through nerve connections with the hypothalamic nuclei, releases vasopressin and oxytocin responsible for water balance and social bonding, sexual reproduction and childbirth, respectively. Pituitary gland hormonal excess or deficiency results in dysregulation of metabolic pathways and mechanisms that are important for the homeostasis of the organism and are associated with increased morbidity and mortality. Cardiovascular (CV) disorders are common in pituitary disease and have a significant impact on survival. Hormonal imbalance is associated with CV complications either through direct effects on the heart structure and function and vasculature or indirectly by altering the metabolic profile. Optimal endocrine control can prevent or reverse CV defects and preserve survival and quality of life. In this review, we discuss the effects of pituitary hormone excess and deficiency on the CV system. Specifically, we assess the impact of Somatotroph, Corticotroph, Gonadotroph, and Lactotroph anterior pituitary axes on the CV system. The effect of posterior pituitary function on the CV system is also explored.

Association between triglyceride glucose index and peak growth hormone in children with short stature

Growth hormone (GH) secretion is related to many factors, such as weight and puberty, and the reproducibility of GH provocation tests is very poor. This study aimed to evaluate whether the triglyceride (TyG) index was associated with peak GH in children with short stature. This study included 1095 children with short stature divided into two groups based on peak GH level in GH provocation tests [GH deficiency (GHD) group = 733 children; non-GHD group = 362 children]. We found that the TyG index was significantly higher in the GHD group than in the non-GHD group (P < 0.001). A nonlinear relationship was detected between the TyG index and peak GH, whose point was 7.8. A significant negative association between the TyG index and peak GH was observed when the TyG index was greater than 7.8 (β − 2.61, 95% CI − 3.98, − 1.24; P < 0.001), whereas, the relationship between the TyG index and peak GH was not significant when the TyG index was lower than 7.8 (β 0.25, 95% CI − 1.68, 2.17; P = 0.799). There is a nonlinear relationship between the TyG index and peak GH, and a higher TyG index is associated with decreased peak GH in children with short stature.

Meta-analysis of metabolic changes in children with idiopathic growth hormone deficiency after recombinant human growth hormone replacement therapy

PURPOSES

We aimed to assess the effects of recombinant human growth hormone (rhGH) replacement therapy on metabolic changes by synthesizing data from clinical trials involving children with idiopathic growth hormone deficiency (IGHD).

METHODS

Two investigators independently completed literature search, quality assessment, and data extraction. Effect-size estimates are expressed as weighted mean difference (WMD) with 95% confidence interval (CI).

RESULTS

A total of 16 clinical trials involving 1319 children were eligible for analysis. Overall analyses showed that total cholesterol was significantly decreased after rhGH replacement therapy (WMD: -0.20 mmol/l; 95% CI: -0.30 to -0.10; p < 0.001), and high-density lipoprotein was significantly increased (WMD: 0.29 mmol/l; 95% CI: 0.24 to 0.33; p < 0.001). Marginal increase was noted for low-density lipoprotein (WMD: -0.22 mmol/l; 95% CI: -0.47 to 0.22; p = 0.092). Subsidiary and meta-regression analyses revealed that length of intervention and sample size were possible causes of heterogeneity. There was a low probability of publication bias.

CONCLUSIONS

Our findings indicate an obviously favorable role of rhGH replacement therapy in lipid metabolism in children with IGHD, and this role might be dependent on length of intervention.

Cardiovascular effects of growth hormone (GH) treatment on GH-deficient adults: a meta-analysis update

BACKGROUND

It is still unclear whether growth hormone (GH) replacement is able to improve cardiovascular parameters in adults with GH deficiency (AGHD) from the updated clinical trials reported to date.

METHODS AND RESULTS

We systematically reviewed clinical trials of GH treatment on AGHD patients in recent decade, and evaluated the effects of GH on cardiovascular parameters assessed by echocardiography. 11 clinical trials were identified in 3 bibliographic databases. We conducted a combined analysis of effects on four aspects: General indicators: baseline heart rate (BHR), peak heart rate (PHR), systolic blood pressure (SBP), diastolic blood pressure (DBP); Cardiac structure: left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), left ventricular interventricular septum (LVIS), left ventricular mass (LVM), left ventricular posterior wall (LVPW); Cardiovascular function: deceleration time of E wave (DT), E/A ratio (E/A), ejection fraction (EF), NT-BNP; Life quality: peak VO₂, VE/VCO₂ slope. Overall effect size was used to evaluate significance, and weighted mean difference after GH treatment was given to appreciate size of the effect. GH treatment was associated with a significant increase in BHR (3.03[2.00, 4.06]), LVIS (0.50[0.43, 0.57]), LVPW (0.50[0.43, 0.57]), and EF (2.12[1.34, 2.90]). Overall effect sizes were negative significant for DBP (- 1.19[- 2.33, - 0.05]), LVEDV (- 9.84[- 16.53, - 3.15]), NT-BNP (- 206.34[- 308.95, - 103.72]), and VE/VCO2 slope (- 2.31[- 2.92, - 1.71]).

CONCLUSIONS

As assessed by echocardiography, GH administration may improve the general vital signs and life quality of AGHD patients, based on the positive effect on BHR and negative effects on DBP and VE/VCO₂ slope. Also, GH treatment would influence the structure of heart with positive effects on LVIS, LVPW and negative effect on LVEDV, which together with the increase of EF and decrease of NT-BNP, then resulting in improving the systolic function of AGHD patients.

Analysis of characteristics and outcomes by growth hormone treatment duration in adult patients in the Italian cohort of the Hypopituitary Control and Complications Study (HypoCCS)

PURPOSE

To examine differences in effects according to growth hormone (GH) treatment duration in adult GH-deficient patients.

METHODS

In the Italian cohort of the observational Hypopituitary Control and Complications Study, GH-treated adults with GH deficiency (GHD) were grouped by duration of treatment; ≤ 2 years (n = 451), > 2 to ≤ 6 years (n = 387) and > 6 years (n = 395). Between-group differences in demographics, medical history, physical characteristics, insulin-like growth factor-I standard deviation score (IGF-I SDS) and lipid profile at baseline, last study visit and changes from baseline to last study visit were assessed overall, for adult- and childhood-onset GHD and by gender using ANOVA for continuous variables and Chi-squared test for categorical variables.

RESULTS

At baseline, treatment duration groups did not differ significantly for age, gender, body mass index, GHD onset, IGF-I SDS, lipid profile, and quality of life. Mean initial GH dose did not differ significantly according to treatment duration group in any subgroup, except female patients, with highest mean dose seen in the longest duration group. In the longest duration group for patients overall, adult-onset patients and male patients, there were significant decreases in GH dose from baseline to last visit, and in total and low-density lipoprotein (LDL)-cholesterol concentrations. IGF-I SDS increased, to a greater extent, in the longest duration group for patients overall and female patients.

CONCLUSIONS

The results show that long-term GH treatment is associated with decreasing GH dose, increased IGF-I, decreased LDL-cholesterol and the presence of surrogate markers that help to give confidence in a diagnosis of GHD.

Growth hormone replacement therapy reduces risk of cancer in adult with growth hormone deficiency: A meta-analysis

The risk of growth hormone on cancer in adult with growth hormone deficiency remains unclear. We carried out a meta-analysis to evaluate the risk of cancer in adult with and without growth hormone replacement therapy. We searched PubMed, Web of Science, China National Knowledge Infrastructure, and WanFang databases up to 31 July 2016 for eligible studies. Pooled risk ratio (RR) with 95% confidence interval (CI) was calculated using fixed-or random-effects models if appropriate. The Newcastle-Ottawa Scale was used to assess the study quality. Two retrospective and seven prospective studies with a total of 11191 participants were included in the final analysis. The results from fixed-effects model showed this therapy was associated with the deceased risk of cancer in adult with growth hormone deficiency (RR=0.69, 95%CI: 0.59-0.82), with low heterogeneity within studies (I2=39.0%, P=0.108). We performed sensitivity analyses by sequentially omitting one study each time, and the pooled RRs did not materially change, indicating that our results were statistically stable. Begger's and Egger's tests suggested that there was no publication bias (Z=-0.63, P=0.520; t=0.16, P=0.874). Our study suggests that growth hormone replacement therapy could reduce risk of cancer in adult with growth hormone deficiency.

Glucose Metabolism in Children With Growth Hormone Deficiency

BACKGROUND

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis has a fundamental impact on glucose metabolism. Therefore, both untreated GH deficiency (GHD) and GH treatment (GHT) may be associated with some metabolic alterations, although the abnormalities of glucose metabolism have been investigated by relatively few studies as main outcomes.

AIM

The present review summarizes the available data on glucose metabolism in children with GHD, providing an overview of the current state of the art in order to better clarify the real metabolic impact of GHD and GHT.

METHODS

Among all the existing studies, we evaluated all original studies that fulfilled our criteria for analysis reporting parameters of glucose metabolism as the primary or secondary objective.

RESULTS

The reported impact of GHD per se on glucose metabolism is quite homogeneous, with the majority of studies reporting no significant difference in metabolic parameters between GHD children and controls. Conversely, GHT proves to be more frequently associated with a subtle form of insulin resistance, while both fasting glucose and HbA1c levels remain almost always within the normal range.

CONCLUSION

The different methods to study glucose metabolism, the heterogeneity of the populations evaluated, the different doses of GH used together with the variable duration of follow-up may be responsible for discrepancy in the results. Long-term longitudinal studies having glucose homeostasis as their primary outcome are still needed in order better to clarify the real metabolic impact of GHD and GHT in children.

The Role of the Growth Hormone/Insulin-Like Growth Factor System in Visceral Adiposity

There is substantial evidence that the growth hormone (GH)/insulin-like growth factor (IGF) system is involved in the pathophysiology of obesity. Both GH and IGF-I have direct effects on adipocyte proliferation and differentiation, and this system is involved in the cross-talk between adipose tissue, liver, and pituitary. Transgenic animal models have been of importance in identifying mechanisms underlying these interactions. It emerges that this system has key roles in visceral adiposity, and there is a rationale for targeting this system in the treatment of visceral obesity associated with GH deficiency, metabolic syndrome, and lipodystrophies. This evidence is reviewed, gaps in knowledge are highlighted, and recommendations are made for future research.