Night sleep EEG and daytime sleep propensity in adult hypopituitary patients with growth hormone deficiency before and after six months of growth hormone replacement

Adult growth hormone deficiency: clinical advances and approaches to improve adherence

Introduction: There have been significant clinical advances in the understanding of the diagnosis and benefits of long-term recombinant human growth hormone (rhGH) replacement in adults with GH deficiency (GHD) since its approval in 1996 by the United States Food and Drug Administration.Areas covered: We searched PubMed, Medline, CINAHL, EMBASE and PsychInfo databases between January 2000 and June 2019 for published studies evaluating adults with GHD. We reviewed the data of the oral macimorelin test compared to the GHRH plus arginine and the insulin tolerance tests that led to its approval by the United States FDA and European Medicines Agency for adult diagnostic testing. We summarize the clinical advances of long-term benefits of rhGH therapy and the potential effects of GH receptor polymorphisms on individual treatment responsiveness. We identify that non-adherence and discontinuation rates are high and recommend strategies to support patients to improve adherence. We also provide an overview of several long-acting GH (LAGH) preparations currently under development and their potential role in improving treatment adherence.Expert opinion: This article summarizes recent clinical advances in rhGH replacement therapy, the biological and molecular aspects that may influence rhGH action, and offers practical strategies to enhance adherence in adults with GHD.

Growth Hormone Deficiency and Excessive Sleepiness: A Case Report and Review of the Literature

The somatotropic axis is intricately involved in normal sleep, as evidenced by the fact that hypothalamic growth hormone-releasing hormone (GHRH) has sleep promoting effects and pituitary growth hormone (GH) release is strongly associated with slow-wave sleep (SWS). Abnormalities in the somatotropic axis, such as GH deficiency of hypothalamic or pituitary origin, result in an alteration of normal sleep patterns which may explain the fatigue reported in these individuals. Sleep disorders such as narcolepsy, in which individuals abnormally enter rapid eye movement (REM) sleep at sleep onset are also associated with an altered GHRH circadian rhythm and abnormal GH secretion. While few studies are available, this review explores what is known about sleep abnormalities in GH deficiency, the effect of treatment on sleep in patients with GH deficiency, and GH secretion in narcolepsy. Emerging evidence suggests a hypothalamic link between narcolepsy and GH secretion. We also describe the unique constellation of isolated idiopathic GH deficiency and severe excessive sleepiness in adopted Nicaraguan siblings, one of which has narcolepsy and the other idiopathic hypersomnia.

Pituitary diseases and sleep disorders

PURPOSE OF REVIEW

Patients with pituitary diseases have decreased quality of life. Sleep disorders are prevalent among patients with pituitary diseases and contribute to decreased quality of life.

RECENT FINDINGS

Patients previously treated for compression of the optic chiasm by surgery, and in some cases postoperative radiotherapy, suffer from sleep disorders. These are characterized by decreased sleep quality, delayed onset of sleep, and daytime sleepiness. Circumstantial evidence suggests that this may be caused by hypothalamic dysfunction. A challenging speculation is that previous compression of the optic chiasm compromised the function of the retinohypothalamic tract. Through this tract the eyes convey information on day-night cycles to the hypothalamic nuclei. Patients with acromegaly, even despite biochemical control, suffer frequently from obstructive sleep apnea. Patients with Cushing's disease suffer from fragmented sleep, sleep apnea, and snoring. Prolactinomas do not seem to affect sleep characteristics. The association between appropriately substituted pituitary insufficiency and sleep disorders is less clear. The effects of recombinant human growth hormone on sleep characteristics in adults are inconsistent.

SUMMARY

Pituitary disorders are associated with different sleep disorders. Different studies point to irreversible changes in sleep-wake rhythmicity in patients treated previously for pituitary tumors with chiasm compression. VIDEO ABSTRACT.

Neuroendocrine Regulation of Growth Hormone Secretion

This article reviews the main findings that emerged in the intervening years since the previous volume on hormonal control of growth in the section on the endocrine system of the Handbook of Physiology concerning the intra- and extrahypothalamic neuronal networks connecting growth hormone releasing hormone (GHRH) and somatostatin hypophysiotropic neurons and the integration between regulators of food intake/metabolism and GH release. Among these findings, the discovery of ghrelin still raises many unanswered questions. One important event was the application of deconvolution analysis to the pulsatile patterns of GH secretion in different mammalian species, including Man, according to gender, hormonal environment and ageing. Concerning this last phenomenon, a great body of evidence now supports the role of an attenuation of the GHRH/GH/Insulin-like growth factor-1 (IGF-1) axis in the control of mammalian aging.

The impact of sleep on age-related sarcopenia: Possible connections and clinical implications

Sarcopenia is a geriatric condition that comprises declined skeletal muscle mass, strength and function, leading to the risk of multiple adverse outcomes, including death. Its pathophysiology involves neuroendocrine and inflammatory factors, unfavorable nutritional habits and low physical activity. Sleep may play a role in muscle protein metabolism, although this hypothesis has not been studied extensively. Reductions in duration and quality of sleep and increases in prevalence of circadian rhythm and sleep disorders with age favor proteolysis, modify body composition and increase the risk of insulin resistance, all of which have been associated with sarcopenia. Data on the effects of age-related slow-wave sleep decline, circadian rhythm disruptions and obstructive sleep apnea (OSA) on hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG), somatotropic axes, and glucose metabolism indicate that sleep disorder interventions may affect muscle loss. Recent research associating OSA with the risk of conditions closely related to the sarcopenia process, such as frailty and sleep quality impairment, indirectly suggest that sleep can influence skeletal muscle decline in the elderly. Several protein synthesis and degradation pathways are mediated by growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol and insulin, which act on the cellular and molecular levels to increase or reestablish muscle fiber, strength and function. Age-related sleep problems potentially interfere intracellularly by inhibiting anabolic hormone cascades and enhancing catabolic pathways in the skeletal muscle. Specific physical exercises combined or not with nutritional recommendations are the current treatment options for sarcopenia. Clinical studies testing exogenous administration of anabolic hormones have not yielded adequate safety profiles. Therapeutic approaches targeting sleep disturbances to normalize circadian rhythms and sleep homeostasis may represent a novel strategy to preserve or recover muscle health in older adults. Promising research results regarding the associations between sleep variables and sarcopenia biomarkers and clinical parameters are required to confirm this hypothesis.

Unusual effects of GH deficiency in adults: a review about the effects of GH on skin, sleep, and coagulation

Based on the literature data in the last two decades, growth hormone deficiency (GHD) in adults has been accepted as a clinical entity. Due to the presence of GH and IGF-I receptors throughout the body, the physiological effects of the GH-IGF-I axis are still under investigation. The effects of GH on skin, sleep, and coagulation parameters in adults have only been investigated in detail only in the recent years. In this review, our aim was to summarize the literature regarding the effects of GHD and GH replacement treatment on the skin, sleep, and coagulation parameters in adults.

Impact of GH replacement therapy on sleep in adult patients with GH deficiency of pituitary origin

OBJECTIVES

We previously reported that adult patients with GH deficiency (GHD) due to a confirmed or likely pituitary defect, compared with healthy controls individually matched for age, gender, and BMI, have more slow-wave sleep (SWS) and higher delta activity (a marker of SWS intensity). Here, we examined the impact of recombinant human GH (rhGH) therapy, compared with placebo, on objective sleep quality in a subset of patients from the same cohort.

DESIGN

Single-blind, randomized, crossover design study.

METHODS

Fourteen patients with untreated GHD of confirmed or likely pituitary origin, aged 22-74 years, participated in the study. Patients with associated hormonal deficiencies were on appropriate replacement therapy. Polygraphic sleep recordings, with bedtimes individually tailored to habitual sleep times, were performed after 4 months on rhGH or placebo.

RESULTS

Valid data were obtained in 13 patients. At the end of the rhGH treatment period, patients had a shorter sleep period time than at the end of the placebo period (479±11 vs 431±19 min respectively; P=0.005), primarily due to an earlier wake-up time, and a decrease in the intensity of SWS (delta activity) (559±125 vs 794±219 μV(2) respectively; P=0.048).

CONCLUSIONS

Four months of rhGH replacement therapy partly reversed sleep disturbances previously observed in untreated patients. The decrease in delta activity associated with rhGH treatment adds further evidence to the hypothesis that the excess of high-intensity SWS observed in untreated pituitary GHD patients is likely to result from overactivity of the hypothalamic GHRH system due to the lack of negative feedback inhibition by GH.

Effects of replacement therapy on sleep architecture in children with growth hormone deficiency

OBJECTIVE

Children with GH deficiency (GHD) show a general decrease in electroencephalographic (EEG) arousability represented by a significant global decrease in Cyclic Alternating Pattern (CAP). The aim of the present study was to evaluate if sleep structure is influenced by GH substitutive therapy by analyzing the classical sleep architecture parameters and sleep microstructure by means of CAP.

SUBJECTS AND METHODS

Laboratory polysomnographic sleep recordings were obtained from five children affected by GHD (two girls and three boys; mean age: 4.6 ± 3.1 years), at baseline and after GH therapy, and from 10 normal healthy children (four girls and six boys, mean age: 5.6 ± 2.2 years).

RESULTS

Compared to controls, GHD subjects showed a reduced total sleep time with increased wakefulness and a consequent decrease in sleep efficiency; GH therapy was associated with an increase of the awakenings/hour and a large effect size was evident for sleep latency, sleep efficiency, and stage N3, which were decreased, and for stage W, which was increased. CAP appeared to be globally reduced and all phase A subtypes and CAP cycle showed a longer duration in GHD children vs. controls. GH substitutive treatment was followed by an increase in CAP rate (total, in N2, and in N3); additionally, A1 index was also significantly increased, especially during stage N3, with a very large effect size. On the other hand, A2 and A3 index and CAP cycle mean duration were reduced.

CONCLUSION

Sleep stage architecture seems to be influenced by the GH status, but the analysis of sleep microstructure by means of CAP reveals an enhancement of EEG slow oscillations in GHD patients (demonstrated by an increase in CAP rate and A1 index during N3) after the start of GH replacement therapy. These findings deserve to be verified in a larger trial.

Somnolence in adult craniopharyngioma patients is a common, heterogeneous condition that is potentially treatable

CONTEXT AND OBJECTIVE

Somnolence and obesity are prevalent in craniopharyngioma patients. We hypothesized that somnolence was because of obstructive sleep apnoea in craniopharyngioma patients.

DESIGN, PATIENTS AND MEASUREMENTS

We assessed prevalence of somnolence and sleep apnoea in 28 craniopharyngioma and 23 obese controls attending a tertiary referral centre, by means of the Epworth Sleepiness Score (ESS) and polysomnography. All subjects with sleep apnoea were offered continuous positive airway pressure therapy (CPAP) or modafinil. All craniopharyngioma patients, with unexplained somnolence, were offered modafinil.

RESULTS

Somnolence was reported by 20/28 (71·5%) craniopharyngioma patients and 4/23 (17%) obese subjects (P < 0·001). Median ESS was 7·5 (IQR 6, 10·7) in craniopharyngioma patients and 4·0 (4,8) in controls, P < 0·01. Eleven somnolent craniopharyngioma patients had obstructive sleep apnoea, in whom treatment led to a reduction in ESS by 6·4 ± 1·4, P = 0·01. Among the remaining nine patients, five were offered modafinil therapy, of whom four had benefit, three were not compliant with hormone replacement, and one died before intervention. There was no difference in the prevalence of obstructive sleep apnoea between craniopharyngioma (n = 13, 46%) and obese subjects (n = 14, 61%, P = 0·4). Body mass index (BMI) does not correlate with apnoea hypopnoea index [apnoea - hypopnoea index (AHI), r = 0·25, P = 0·08], which suggests that obesity alone does not explain the prevalence of sleep apnoea in craniopharyngioma patients.

CONCLUSIONS

Somnolence is common in craniopharyngioma patients and in the majority is because of obstructive sleep apnoea. An additional group of somnolent craniopharyngioma patients benefits from modafinil.

Sleep characteristics in children with growth hormone deficiency

BACKGROUND/AIMS

Growth hormone (GH) is preferentially secreted during slow wave sleep and the interactions between human sleep and the somatotropic system are well documented, although only few studies have investigated the sleep EEG in children with GH deficiency (GHD). The aim of this study was to evaluate the sleep structure of children with dysregulation of the GH/insulin-like growth factor axis.

METHODS

Laboratory polysomnographic sleep recordings were obtained from 10 GHD children and 20 normal healthy age-matched children. The classical sleep parameters were evaluated together with sleep microstructure, by means of the cyclic alternating pattern (CAP), in GHD patients and compared to the control group.

RESULTS

GHD children showed a significant decrease in total sleep time, sleep efficiency, movement time and in non-rapid eye movement sleep stage 2. Although some indicators of sleep fragmentation were increased in GHD children, we found a general decrease in EEG arousability represented by a significant global decrease in the CAP rate, involving all CAP A phase subtypes.

CONCLUSIONS

The analysis of sleep microstructure by means of CAP, in children with GHD, showed a reduction of transient EEG amplitude oscillations. Further studies are needed in order to better clarify whether GH therapy is able to modify sleep microstructure in GHD children, and the relationships between sleep microstructure, hormonal secretion and neurocognitive function in these patients.

Sleep disturbances, daytime sleepiness, and quality of life in adults with growth hormone deficiency

CONTEXT

Low energy and fatigue are frequent complaints in subjects with GH deficiency (GHD). Because interrelations between sleep and GH regulation are well documented, these complaints could partly reflect alterations of sleep quality.

OBJECTIVE

The objective of the study was to determine objective and subjective sleep quality and daytime sleepiness in adult GHD patients.

SUBJECTS

Thirty patients, aged 19-74 yr, with untreated GHD (primary pituitary defects confirmed or likely in 26 patients, hypothalamic origin in four patients), and 30 healthy controls individually matched for gender, age, and body mass index participated in the study. Patients with associated pituitary deficiencies (n = 28) were on hormonal replacement therapy.

METHODS

Polygraphic sleep recordings, assessment of Pittsburgh Sleep Quality Index, and Quality of Life Assessment for GHD in Adults were measured.

RESULTS

Irrespective of etiology, GHD patients had a Pittsburgh Sleep Quality Index score above the clinical cutoff for poor sleep and lower Quality of Life Assessment for GHD in Adults scores than controls, with tiredness being the most affected domain. Patients with pituitary GHD spent more time in slow-wave sleep (SWS) and had a higher intensity of SWS than their controls. Among these patients, older individuals obtained less total sleep than controls, and their late sleep was more fragmented. Contrasting with pituitary GHD, the four patients with hypothalamic GHD had lower intensity of SWS than their controls.

CONCLUSIONS

GHD is associated with sleep disorders that may be caused by specific hormonal alterations as well as with poor subjective sleep quality and daytime sleepiness. Disturbed sleep is likely to be partly responsible for increased tiredness, a major component of quality of life in GHD.

Effects of poly-gamma-glutamic acid on serum and brain concentrations of glutamate and GABA in diet-induced obese rats

Poly-gamma-glutamic acid (gamma-PGA) is a mucilaginous and biodegradable compound produced by Bacillus subtilis from fermented soybeans, and is found in the traditional Korean soy product, cheongkukjang. This study was carried out to evaluate the effects of gamma-PGA from a food source on the concentration of the neurotransmitter GABA and its metabolic precursor glutamate in diet-induced obese rats. Eight-week old male Sprague-Dawley rats (n=60) were used. The rats were divided into two groups and obesity was induced by providing either a 10% control fat or 45% high fat diet for 5 weeks. The rats were then blocked into 6 groups and supplemented with a 0.1% gamma-PGA diet for 4 weeks. After sacrifice, brain and serum GABA and glutamate concentrations were analyzed by high performance liquid chromatography with fluorometric detection. The rats fed the high fat diet had significantly increased body weights. gamma-PGA supplementation significantly increased serum concentrations of glutamate and GABA in the control fat diet groups while this effect was not found in the high fat groups. In the brain, glutamate concentrations were significantly higher in the gamma-PGA supplemented groups both in rats fed the normal and high fat diets than in the no gamma-PGA controls. GABA concentrations showed the same tendency. The results indicated that gamma-PGA intake increased GABA concentrations in the serum and brain. However, the effects were not shown in obese rats.

Sleep architecture in Sheehan's syndrome before and 6 months after growth hormone replacement therapy

OBJECTIVE

To characterize the sleep parameters in patients with growth hormone (GH) deficiency in Sheehan's syndrome adults and to assess the effects of 6-month GH replacement therapy (GHRT).

METHODS

Twenty-two women with Sheehan's syndrome, (mean age; 49.1+/-2.2 years), and 12 women with similar age (mean age; 51.3+/-3.8 years) and body mass index as control subjects were included in the study. Under baseline conditions, women received adequate hormone replacement therapy for all hormonal deficiencies other than GH. Twelve patients received recombinant GH (Genotropin; Pfizer Stockholm, Sweden) (treatment group) and eight patients received placebo (placebo group) for 6 months. Two patients had only baseline evaluation and were not followed up prospectively. Two polysomnography (PSG) recordings were performed on the patients group, one in the baseline period and the other at the sixth month of treatment (either GH or placebo). Control group had only baseline PSG.

RESULTS

GH deficient females with Sheehan's syndrome have more NREM (95.9+/-1.5% and 88.6+/-0.9%, respectively; p<0.05), particularly in stage 4 sleep (11.4+/-1.9% and 4.9+/-1.6, respectively; p<0.05), less REM sleep (4.2+/-1.5% and 11.4+/-0.9, respectively; p<0.05) and also less sleep efficiency (69.7+/-3.4% and 81.1+/-2.8%, respectively; p<0.05) when compared to healthy controls. After 6 months of GHRT there was no significant difference in sleep parameters.

CONCLUSION

GH deficiency has sleep disturbing effects on Sheehan's syndrome patients under baseline conditions.

Neurochemical regulation of sleep

This review summarizes recent developments in the field of sleep regulation, particularly in the role of hormones, and of synthetic GABA(A) receptor agonists. Certain hormones play a specific role in sleep regulation. A reciprocal interaction of the neuropeptides growth hormone (GH)-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) plays a key role in sleep regulation. At least in males GHRH is a common stimulus of non-rapid-eye-movement sleep (NREMS) and GH and inhibits the hypothalamo-pituitary adrenocortical (HPA) hormones, whereas CRH exerts opposite effects. Furthermore CRH may enhance rapid-eye-movement sleep (REMS). Changes in the GHRH:CRH ratio in favor of CRH appear to contribute to sleep EEG and endocrine changes during depression and normal ageing. In women, however, CRH-like effects of GHRH were found. Besides CRH somatostatin impairs sleep, whereas ghrelin, galanin and neuropeptide Y promote sleep. Vasoactive intestinal polypeptide appears to be involved in the temporal organization of human sleep. Beside of peptides, steroids participate in sleep regulation. Cortisol appears to promote REMS. Various neuroactive steroids exert specific effects on sleep. The beneficial effect of estrogen replacement therapy in menopausal women suggests a role of estrogen in sleep regulation. The GABA(A) receptor or GABAergic neurons are involved in the action of many of these hormones. Recently synthetic GABA(A) agonists, particularly gaboxadol and the GABA reuptake inhibitor tiagabine were shown to differ distinctly in their action from allosteric modulators of the GABA(A) receptor like benzodiazepines as they promote slow-wave sleep, decrease wakefulness and do not affect REMS.

Roles of peptides and steroids in sleep disorders

A bidirectional interaction exists between the electrophysiological and neuroendocrine components of sleep. The first is represented by the nonrapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS) cycles, the latter by distinct patterns of the secretion of various hormones. Certain hormones (neuropeptides and steroids) play a specific role in sleep regulation. Changes in their activity contribute to the pathophysiology of sleep disorders. A reciprocal interaction of the peptides growth hormone-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) plays a key role in sleep regulation. GHRH promotes growth hormone secretion and, at least in males, NREMS, whereas CRH impairs NREMS, promotes REMS and stimulates the secretion of adrenocorticotropic hormone and cortisol. Changes in the CRH:GHRH ratio in favor of CRH contribute to impaired sleep, elevated cortisol secretion and blunted GH levels during depression and normal aging. However, in women, GHRH exerts CRH-like effects. Galanin, ghrelin and neuropeptide Y are other sleep-promoting peptides, whereas somatostatin impairs sleep. A decline of orexin activity causes narcolepsy. In addition to CRH overactivity, hypercortisolism appears to be involved in the pathophysiology of sleep- electroencephalogram (EEG) changes in depression. Various neuroactive steroids exert specific effects on sleep. The changes of sleep EEG in women after the menopause are related to the decline of estrogen and progesterone. Furthermore, sleep-EEG changes in dwarfism, acromegaly, Addison's disease, Cushing's disease, brain injury, sleep apnea syndrome, primary insomnia, prolactinoma and dementia appear to be related to changes in the activity of peptides and steroids.

Sleep apnoea and quality of life in growth hormone (GH)-deficient adults before and after 6 months of GH replacement therapy

OBJECTIVE

To investigate the sleep architecture and breathing as well as quality of life (QoL) in adults with GH deficiency (GHD) before and 6 months after GH replacement therapy.

DESIGN

A prospective observational study.

PATIENTS

Nineteen consecutive adults with GHD (11 men, eight women; mean age 53, range 21-73 years) were studied.

MEASUREMENTS

An overnight sleep study was performed and the Minor Symptom Evaluation Profile (MSEP), Functional Outcome of Sleep Questionnaire (FOSQ), Short Form 36 (SF-36) and Epworth Sleepiness Scale (ESS) questionnaires were applied at baseline and after the treatment period.

RESULTS

For the whole group, there were no significant changes in mean total sleep time (TST; 370 min vs. 374 min), proportion of slow-wave sleep (SWS; 17.8%vs. 18.4%) and rapid eye movement (REM) sleep (12.1%vs. 13.9%) on GH replacement. Mean apnoea-hypopnoea index (AHI) was high and remained unchanged (28.2/h before vs. 28.0/h following GH replacement). Twelve patients (63%) were found to have obstructive sleep apnoea (OSA; AHI >or= 10/h) at baseline. Compared with GH-deficient patients without OSA (AHI 3.9/h), the OSA patients (AHI 42.4/h) had less SWS (11.4%vs. 28.6%, P = 0.010) and REM sleep (10.1%vs. 15.5%, P = 0.036). A marginal increase was observed in REM sleep time (10.1% before vs. 12.7% after GH; P = 0.048) while SWS was unchanged in this group. Moreover, MSEP for General Well-being and Responsiveness, FOSQ scores for General Productivity, Activity Level and Vigilance as well as SF-36 domains for Vitality and Mental Health were improved.

CONCLUSIONS

Contrary to some previous observations in a smaller group of patients, our data suggest that GH therapy does not induce or aggravate OSA in GH-deficient adults. Moreover, GH therapy may improve some of the QoL dimensions in these patients.