Reactivity to stress and psychological adjustment in adults with pituitary insufficiency

The effects of repeat traumatic brain injury on the pituitary in adolescent rats

Adolescents are one of the highest groups at risk for sustaining both traumatic brain injury (TBI) and repeat TBI (RTBI). Consequences of endocrine dysfunction following TBI have been routinely explored in adults, but studies in adolescents are limited, and show an incidence rate of endocrine dysfunction in 16-61% in patients, 1-5 years after injury. Similar to in adults, the most commonly affected axis is growth hormone (GH) and insulin-like growth hormone 1 (IGF-1). Despite TBI being the primary cause of morbidity and mortality among the pediatric population, there are currently no experimental studies specifically addressing the occurrence of pituitary dysfunction in adolescents. The present study investigated whether a sham, single injury or four repeat injuries (24 h interval) delivered to adolescent rats resulted in disruption of the GH/IGF-1 axis. Circulating levels of basal GH and IGF-1 were measured at baseline, 24 h, 72 h, 1 week, and 1 month after injury, and vascular permeability of the pituitary gland was quantified via Evans Blue dye extravasation. Changes in weight and length of animals were measured as a potential consequence of GH and IGF-1 disruption. The results from the current study demonstrate that RTBI results in significant acute and chronic decreases in circulation of GH and IGF-1, reduction in weight gain and growth, and an increase in Evans Blue dye extravasation in the pituitary compared with sham and single injury animals. RTBI causes significant disruption of the GH/IGF-1 axis that may ultimately affect normal cognitive and physical development during adolescence.

Growth hormone replacement therapy in patients with traumatic brain injury

In patients with severe traumatic brain injury (TBI), a growth hormone deficiency (GHD) is frequent and may contribute to the cognitive sequelae and reduction in quality of life (QoL). Recent studies have suggested that GH replacement therapy (GHRT) can improve processing speed and memory. The aim of the study was to analyze the efficacy of GHRT on cognition, activities of daily living (ADL), and QoL and the factors that predicted and contributed to these effects. We included patients at least 1 year after their TBI and assessed pituitary functions (with stimulation tests), cognition (attention, memory, and executive function), participation in ADL and QoL. GHD was treated for at least 1 year in 23 patients, who were compared with 27 non-treated patients. Other deficiencies were also treated. Measurements were performed at baseline and 1 year later. An analysis of variance of the factors group and session (p ≤ 0.05) showed that most cognitive parameters had improved at 1 year (evidencing a session effect). A stronger effect of GHRT (i.e. a group x session interaction) was found for Rey Osterrieth complex figure recall and 2/6 domains in the QoL questionnaire ("personal" and "functional"). Trends (p ≤ 0.07) were also found for spatial orientation and immediate recall in the verbal memory test. Greatest improvements were associated with lower performance before treatment. The magnitude of the improvements in ADL and QoL was moderately correlated with the improvement in cognition. In conclusion, replacement therapy can improve cognition and QoL in patients with TBI who have GHD, especially in those with severe disabilities.

Lasting pituitary hormone deficiency after traumatic brain injury

Pituitary deficiencies have been reported after traumatic brain injury (TBI) and may contribute to lasting cognitive disorders in this context. In a population of TBI patients with persistent cognitive and/or behavioral disorders, we sought to determine the prevalence of lasting pituitary deficiency and relationships with TBI severity, cognitive disorders, and impairments in activities of daily living (ADL). Fifty-five patients were included (mean age 36.1 years; 46 men) at least 1 year after TBI. They underwent a comprehensive evaluation of pituitary function (basic tests and stimulation), initial TBI severity, and long-term outcomes (cognitive performance, Glasgow Outcome Scale score, impact on ADL, and quality of life [QoL]). We used chi-squared and Mann-Whitney tests to probe for significant (p≤0.05) relationships between pituitary disorders and other parameters. Thirty-eight (69%) patients had at least one pituitary hormone deficiency. Growth hormone deficiency was more prevalent (severe: 40.0%; partial: 23.6%) than corticotropin (27.3%) or thyrotropin (21.8%) deficiencies. Other deficiencies were rare. Growth hormone deficiency was associated with attention and verbal memory disorders and reduced involvement in ADL. We did not find any relationship between pituitary deficiency and the TBI's initial severity. In a multivariate analysis, the TBI severity was introduced as a first factor, and pituitary deficits as a secondary factor for explaining the late outcome (ADL and QoL). In conclusion, TBI patients with cognitive sequelae must undergo pituitary screening because growth hormone, corticotropin, and thyrotropin deficits are particularly common and can adversely affect ADL and reduce QoL.

Changes in insulin levels following 6-month treatment with recombinant human growth hormone in growth hormone-deficient adults

INTRODUCTION

Eighty-six adult patients with GH deficiency (GHD) of adult or childhood onset were treated for 6 months, with recombinant human growth hormone (rhGH) at a low (LD) or conventional dose (CD). The treatment effect on insulin levels was investigated.

METHODS

This manuscript refers to the Italian addendum to an International Study (B9R-EW-GDED) in which patients with GHD were randomized to receive r-hGH replacement therapy at a dose of either 3 microg/kg/day or 6 microg/kg/day for the 3 months. The dose was then doubled for the next 3 months.

RESULTS

After 6 months of r-hGH treatment, insulin levels increased with both GH dosages, with a greater increase achieved in the low-dose subgroup. Insulin levels also increased significantly in the childhood-onset, while even decreased in the adult-onset subgroup. On the whole, in more than 50% of patients, insulin values rose by >13%. Moreover, mean levels of IGF-I increased 2-3 fold (p<0.001 vs baseline) in both the LD and CD groups. Significant and similar increases in IGF binding protein-3 levels were seen in both the LD and CD groups over the treatment period, regardless the time of onset of GHD.

CONCLUSION

Insulin increased with both GH dosages and more than half of patients presented an important increase in insulin plasma levels. It would be of interest to assess if there is a correlation between the changes in insulin levels and other cardiovascular risk factors such as hemostatic parameters.

Potential benefits of recombinant human growth hormone (rhGH) to athletes

Athletes have enjoyed almost a thirty year amnesty of rhGH abuse, which they consider has contributed to the winning of medals and the breaking of world records. Such a reprieve is almost at an end, since WADA have identified a method to detect rhGH abuse. Or have they? The anecdotal word "on the street" is that rhGH is still undetectable and athletes believe that the benefits, at the dosages they administer, far outweigh the risks! Scientists are aware that in a hormone deficiency condition, replacement can halt and in certain situations reverse some of the adverse effects. Growth hormone deficiency can lead to a loss of skeletal muscle mass and an increase in abdomino-visceral obesity, which is reversed on replacement with rhGH. Since the availability of GH, athletes have been trying to extrapolate these effects from the deficiency state to the healthy corpus and increase their sporting prowess. Past confessions from athletes, such as Ben Johnson, Kelly White, Tim Montgomery, Marion Jones and currently Dwain Chambers have demonstrated that they are prepared to tread the very fine lines that separate the "men from the boys". Rewards are so great, that anonymous surveys have identified that athletes will risk ill health, if they believe they can cheat, win and not get caught. The question that still needs to be answered is, "does growth hormone enhance performance"? Recent research suggests that it could. There is also a suspicion that in "cycled" low supraphysiological doses, it is no where near as harmful as WADA claim it to be.

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.

AAS, growth hormone, and insulin abuse: psychological and neuroendocrine effects

The nontherapeutic use of prescription medicines by individuals involved in sport is increasing. Anabolic-androgenic steroids (AAS) are the most widely abused drug. Much of our knowledge of the psychological and physiological effects of human growth hormone (hGH) and insulin has been learned from deficiency states. As a consequence of the Internet revolution, previously unobtainable and expensive designer drugs, particularly recombinant human growth hormone (rhGH) and insulin, have become freely available at ridiculously discounted prices from countries such as China and are being abused. These drugs have various physiological and psychological effects and medical personnel must become aware that such prescription medicine abuse appears to be used not only for performance and cosmetic reasons, but as a consequence of psychological pre-morbidity.

The incidence of Sheehan's syndrome after obstetric hemorrhage

OBJECTIVE

To estimate the incidence of Sheehan's syndrome in a well-described cohort of patients with obstetric hemorrhage.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care center.

PATIENT(S)

Two hundred patients.

INTERVENTION(S)

Questionnaires were sent to study and comparison patients asking about menstrual dysfunction, lactation difficulty, cold intolerance, fatigue, axillary and pubic hair loss, and secondary infertility.

MAIN OUTCOME MEASURE(S)

Women who experienced two or more symptoms were referred for hormone testing of insulin-like growth factor 1 (IGF-1), T4, PRL, and early morning cortisol (F) levels.

RESULT(S)

A total of 109 patients responded to the survey, a 55% response rate. Fourteen of 55 (25%) patients in the hemorrhage group identified themselves as suffering from two or more symptoms on the questionnaire. Eight of the 14 patients were tested, but none had hormonal evidence of hypopituitarism. Four of 54 (7%) comparison patients also identified themselves as suffering from two or more symptoms, but neither of the two tested had hormonal evidence of hypopituitarism.

CONCLUSION(S)

Among women with postpartum hemorrhage, subsequent development of clinical symptoms does not correlate well with laboratory evidence of hypopituitarism. Clinically significant Sheehan syndrome is an uncommon consequence of obstetric hemorrhage in today's environment.

Long-Term Challenges in Growth Hormone Treatment

Growth hormone deficiency (GHD) is defined biochemically as a response to hypoglycaemia with a peak GH concentration of less than 5 microg/l. The 'GHD syndrome' is a range of psychological and physical symptoms that are associated with GHD, which include increased central adiposity, decreased bone mineral density, abnormal lipid profiles, decreased cardiovascular performance, reduced lean body mass (LBM), social isolation, depressed mood and increased anxiety. Importantly, the combination of physical and psychological problems can often result in a reduced quality of life. A number of trials have shown that GH replacement therapy can lead to a substantial improvement in GHD associated symptoms. Following up to 12 months of treatment with GH, LBM increased, left ventricular systolic function improved and the mean volume of adipose tissue fell. After only 4 months of treatment, a rise in exercise capacity was recorded, and after 2 years' treatment, isokinetic and isometric muscle strength had normalized in proximal muscle groups. Feelings of well-being and vitality also improved significantly. However, studies on the effects of treatment on insulin sensitivity in GH-deficient patients have had conflicting results. In this paper, we will discuss the long-term consequences of GHD and the effects of GH replacement therapy.

Short normal stature and psychosocial disadvantage: a critical review of the evidence

Physicians and parents alike are under increasing pressure to identify and to treat short stature, but intervention implies the presence of some pathology, physical or psychological, that can be corrected. Where there is true GH deficiency, the argument for replacement is uncontroversial. It is less compelling where GH 'insufficiency' is diagnosed. In the case of the short, but otherwise normal, child the indications for therapy are even less clear. Short stature, per se, is clearly not a disease, in spite of the perception by some practitioners that the rate of growth of such children is abnormal. Short stature is, however, commonly perceived to be associated with social and psychological disadvantage, yet many of these misperceptions about short stature can be challenged. A critical review of the literature pertaining to the psychosocial correlates of short stature uncovers much flawed evidence. Most importantly, the belief, widely held by paediatricians, that short children are likely to be significantly disadvantaged, has been founded largely on data from clinic-referred samples. In such studies, children with real (or perceived) behavioural or academic problems are likely to be overly represented. Publications arising from such studies, however, inevitably lead to an increase in the demand for treatment both from and for those who previously had no such concern. In contrast, data from a well controlled, prospective population-based study suggest the essential normality of the short normal child. Parents and children alike should be reassured by these findings. In the absence of clear pathology, physical or psychological, GH therapy for short but otherwise normal children must therefore, in most cases, be deemed cosmetic, raising issues as to the ethics of so-called "plastic endocrinology".

Growth hormone replacement in adults with growth hormone deficiency: assessment of current knowledge

The recent availability of recombinant human growth hormone (GH) has led to intense investigation of the consequences of adult GH deficiency (GHD) and the effects of GH replacement. These studies have led to the identification of a characteristic syndrome of GHD consisting of decreased mood and well-being, with alterations in body composition and substrate metabolism. In both placebo-controlled and open studies, GH replacement therapy has consistently been shown to reverse or correct these features. Whether long-term GH replacement will result in a reduction of osteoporotic fractures, cardiovascular morbidity and mortality is not yet known. To date, no permanent serious adverse effects have been associated with GH replacement in GHD, and although currently expensive, it is anticipated that GH replacement will become routine in the treatment of the severely hypopituitary adult.

Behavior change after growth hormone treatment of children with short stature

OBJECTIVES

To measure the prevalence of behavioral and learning problems among children with short stature and to assess the effect of growth hormone (GH) treatment on such problems.

STUDY DESIGN

A total of 195 children with short stature (age range 5 to 16 years, mean age 11.2 years) were tested for intelligence, academic achievement, social competence, and behavior problems before beginning GH therapy and yearly during 3 years of treatment. Children were classified as having growth hormone deficiency (GHD) when GH responses to provocative stimuli were <10 ng/mL (n = 109) and as having idiopathic short stature (ISS) when >10 ng/mL (n = 86). A normal-statured matched comparison group was tested at the baseline only.

RESULTS

Seventy-two children in the GHD group and 59 children in the ISS group completed 3 years of GH therapy and psychometric testing. Mean IQs of the children with short stature were near average. IQs and achievement scores did not change with GH therapy. Child Behavior Checklist scores for total behavior problems were higher (P < .001) in the children with short stature than in the normal-statured children. After 3 years of GH therapy these scores were improved in patients with GHD (P < .001) and ISS (P < .003). Also, there was improvement in the scores of children in the GHD group in the internalizing subscales (withdrawn: P < .007; somatic complications, P < .001; anxious/depressed, P < .001) and on the 3 components of the ungrouped subscales (attention, social problems, and thought problems, each P = .001). Larger effects were observed in the GHD group than in the ISS group.

CONCLUSIONS

Many referred children with short stature have problems in behavior, some of which ameliorate during treatment with GH.

Effects of physiological growth hormone (GH) therapy on cognition and quality of life in patients with adult-onset GH deficiency

GH replacement of adults with acquired GH deficiency (GHD) results in body composition changes including increases in lean mass and bone mineral density. However, the effects of long-term GH therapy on cognitive function are largely unknown, and there are conflicting data regarding quality of life. We performed a randomized, double-blind, placebo-controlled study of GH replacement in adults with GHD and measured cognition and sense of well-being using standardized psychometric tests before and after therapy. Forty men (median age 51 yr, range 24-64 yr) with a history of pituitary disease were randomized to GH therapy (starting dose, 10 +/- 0.3 micrograms/kg per day: mean treatment dose, 4 +/- 2 micrograms/kg per day) vs. placebo for 18 months, and GH doses were adjusted according to serum insulin growth factor-I levels. At baseline, the patients displayed a full-scale intelligence quotient (IQ) score nearly 1 SD above the normal mean. Mean scores on all cognitive tests fell within normal limits, and on many tests, fell above the mean. On tests of verbal learning and delayed visual memory, mean test scores fell below the mean (although within normal limits), suggestive of a relative compromise in the area of memory performance. Following 18 months of GH replacement therapy, there were no significant changes in cognitive function or quality of life. We conclude that acquired GHD in adult men is not associated with significant alterations in cognitive function as assessed by standardized tests, and chronic low-dose GH replacement therapy does not result in significant beneficial effects on cognitive function or quality of life. Although previous studies have suggested that GH replacement in adults with acquired GHD may improve quality of life, our data do not support the use of physiological GH replacement in GHD men for this indication.

Recombinant human growth hormone: old and novel uses

Recent studies of the growth hormone insulinlike growth factor I (IGFI) axis suggest that these hormones are involved in several physiologic processes, in addition to growth. Thus, several lines of evidence indicate an increasingly important role for recombinant human growth hormone as a part of the modern therapeutic armamentarium. In addition to the treatment of children with growth hormone deficiency, administration of growth hormone appears to be of considerable benefit to girls with Turner syndrome, children with chronic renal failure, and adults with growth hormone deficiency or human immunodeficiency virus (HIV) wasting syndrome. Moreover, its therapeutic use is being investigated in other conditions, such as children with idiopathic short stature, the healthy elderly, and the critically ill. However, long-term surveillance among growth hormone recipients is needed to fully evaluate its risk-benefit profile.

Cognitive changes during growth hormone replacement in adult men

The present study evaluates the effects of 2 years of growth hormone (GH) replacement therapy on psychological well-being and cognitive performance in adults with childhood-onset growth hormone deficiency (CO-GHD). A total of 48 GHD adult men (mean age: 27 years) were randomly assigned to one of four treatment groups: placebo treatment, or GH replacement in a dose of 1, 2, or 3 IU/m2, respectively. Placebo treatment was given for 6 months. Psychological assessments were made every 6 months. Assessments included somatic and psychological complaints, depression, fatigue, vigor, tension, state/trait anxiety, iconic memory, short-term memory, long-term memory and perceptual-motor skill. GH treatment was considered physiological if the observed insulin-like growth factor-I (IGF-I) levels were within the normal range. It was considered supraphysiological if serum IGF-I rose to a value exceeding the upper normal limit. During the placebo-controlled phase of the study the changes in memory performance were positively correlated to the GH induced changes in serum IGF-I concentration and, more weakly, to the daily GH substitution dose. At 6 months memory only had improved in the group receiving supraphysiological GH treatment, but not in the group of patients who had a normalization of serum IGF-I. However, after 1 year of treatment a normalization of memory functioning was found in both groups of patients and this was preserved during the 2nd year of treatment. No changes were observed in psychological well-being and perceptual-motor skill. We conclude that GH replacement improves memory function in adults with CO-GHD. It has no effect on psychological well-being or perceptual-motor skill. Supraphysiological treatment accelerates the recovery of memory performance. However, the long-term effects are not different from those achieved with physiological GH replacement.