Severe GH deficiency (GHD) in adults has been described as a clinical entity. However, some of the features associated with GHD could be due to unphysiological and inadequate replacement of other pituitary hormone deficiencies. This may be true for glucocorticoid replacement that lacks a biomarker making dose titration and monitoring difficult. Moreover, oral estrogen replacement therapy decreases IGF1 levels compared with the transdermal route, which attenuates the responsiveness to GH replacement therapy in women. In addition, in untreated female hypogonadism, oral estrogen may augment the features associated with GHD in adult women. Important interactions between the hormones used for replacing pituitary hormone deficiency occur. Introducing GH replacement may unmask both an incipient adrenal insufficiency and central hypothyroidism. Therefore, awareness and proper monitoring of these hormonal interactions are important in order to reach an optimal replacement therapy. This review will focus on the complex hormonal interactions between GH and other pituitary hormones in GHD and in GH replacement.
Helena Filipsson and Gudmundur Johannsson
Oskar Ragnarsson and Gudmundur Johannsson
One hundred years have passed since Harvey Williams Cushing presented the first patient with the syndrome that bears his name. In patients with Cushing's syndrome (CS), body composition and lipid, carbohydrate and protein metabolism are dramatically affected and psychopathology and cognitive dysfunction are frequently observed. Untreated patients with CS have a grave prognosis with an estimated 5-year survival of only 50%. Remission can be achieved by surgery, radiotherapy and sometimes with medical therapy. Recent data indicate that the adverse metabolic consequences of CS are present for years after successful treatment. In addition, recent studies have demonstrated that health-related quality of life and cognitive function are impaired in patients with CS in long-term remission. The focus of specialised care should therefore be not only on the diagnostic work-up and the early postoperative management but also on the long-term follow-up. In this paper, we review the long-term consequences in patients with CS in remission with focus on the neuropsychological effects and discuss the importance of these findings for long-term management. We also discuss three different phases in the postoperative management of surgically-treated patients with CS, each phase distinguished by specific challenges: the immediate postoperative phase, the glucocorticoid dose tapering phase and the long-term management. The focus of the long-term specialised care should be to identify cognitive impairments and psychiatric disorders, evaluate cardiovascular risk, follow pituitary function and detect possible recurrence of CS.
Helena Filipsson, Ernst Nyström and Gudmundur Johannsson
The diagnosis of central hypothyroidism (CH) is often difficult to establish as serum TSH levels may be low, normal, or slightly increased.
To explore the use of recombinant human TSH (rhTSH) in the diagnosis of CH.
Randomized single-blind clinical trial.
Outpatient clinic of a tertiary care referral center.
A single intramuscular injection of 0.1 and 0.9 mg rhTSH in random order with 1-week interval.
Eighteen adult patients with pituitary insufficiency and six healthy age-, sex-, and body mass index-matched controls. Six patients had untreated CH (newCH), six had treated CH (CH), and six patients were TSH sufficient (nonCH). Five weeks before TSH stimulation, levothyroxine was replaced with tri-iodothyronine (T3) for 4 weeks. One week before stimulation, treatment was withdrawn.
Main outcome measures
Thyroid hormones and thyroglobulin (Tg) before and 2, 3½, 7, 24, 48, and 72 h after each injection.
In the newCH group, basal free thyroxine (FT4) levels were lower than in controls (P<0.05). After 0.9 mg rhTSH, the increases in FT4 and reverse T3 (rT3) were less marked in the newCH group than in controls (FT4±s.e.m. 9.2±0.5 to 19.7±1.2 vs 11.3±0.5 to 27.8.2±2.4 pmol/l, P<0.05). The CH group exhibited reduced basal and stimulated FT4 compared with the TSH-sufficient groups. Tg increased similarly among all study groups after rhTSH injection.
In this pilot study, patients with untreated CH had lower response to 0.9 mg rhTSH in FT4 and rT3 than controls. An rhTSH test may be useful in the diagnosis of CH, but further studies are required.
Gudmundur Johannsson, Hans Lennernäs, Claudio Marelli, Kevin Rockich and Stanko Skrtic
Oral once-daily dual-release hydrocortisone (DR-HC) replacement therapy was developed to provide a cortisol exposure−time profile that closely resembles the physiological cortisol profile. This study aimed to characterize single-dose pharmacokinetics (PK) of DR-HC 5–20mg and assess intrasubject variability.
Thirty-one healthy Japanese or non-Hispanic Caucasian volunteers aged 20−55 years participated in this randomized, open-label, PK study. Single doses of DR-HC 5, 15 (3×5), and 20mg were administered orally after an overnight fast and suppression of endogenous cortisol secretion. After estimating the endogenous cortisol profile, PK of DR-HC over 24h were evaluated to assess dose proportionality and impact of ethnicity. Plasma cortisol concentrations were analyzed using liquid chromatography−tandem mass spectrometry. PK parameters were calculated from individual cortisol concentration−time profiles.
DR-HC 20mg provided higher than endogenous cortisol plasma concentrations 0−4h post-dose but similar concentrations later in the profile. Cortisol concentrations and PK exposure parameters increased with increasing doses. Mean maximal serum concentration (Cmax) was 82.0 and 178.1ng/mL, while mean area under the concentration−time curve (AUC)0−∞ was 562.8 and 1180.8h×ng/mL with DR-HC 5 and 20mg respectively. Within-subject PK variability was low (<15%) for DR-HC 20mg. All exposure PK parameters were less than dose proportional (slope <1). PK differences between ethnicities were explained by body weight differences.
DR-HC replacement resembles the daily normal cortisol profile. Within-subject day-to-day PK variability was low, underpinning the safety of DR-HC for replacement therapy. DR-HC PK were less than dose proportional – an important consideration when managing intercurrent illness in patients with adrenal insufficiency.
Ashley Grossman, Gudmundur Johannsson, Marcus Quinkler and Pierre Zelissen
Conventional glucocorticoid (GC) replacement for patients with adrenal insufficiency (AI) is inadequate. Patients with AI continue to have increased mortality and morbidity and compromised quality of life despite treatment and monitoring.
i) To review current management of AI and the unmet medical need based on literature and treatment experience and ii) to offer practical advice for managing AI in specific clinical situations.
The review considers the most urgent questions endocrinologists face in managing AI and presents generalised patient cases with suggested strategies for treatment.
Optimisation and individualisation of GC replacement remain a challenge because available therapies do not mimic physiological cortisol patterns. While increased mortality and morbidity appear related to inadequate GC replacement, there are no objective measures to guide dose selection and optimisation. Physicians must rely on experience to recognise the clinical signs, which are not unique to AI, of inadequate treatment. The increased demand for corticosteroids during periods of stress can result in a life-threatening adrenal crisis (AC) in a patient with AI. Education is paramount for patients and their caregivers to anticipate, recognise and provide proper early treatment to prevent or reduce the occurrence of ACs.
This review highlights and offers suggestions to address the challenges endocrinologists encounter in treating patients with AI. New preparations are being developed to better mimic normal physiological cortisol levels with convenient, once-daily dosing which may improve treatment outcomes.
Mariam Elbornsson, Alexandra Horvath, Galina Götherström, Bengt-Åke Bengtsson, Gudmundur Johannsson and Johan Svensson
Few studies have determined the effects of long-term growth hormone (GH) replacement on quality of life (QoL). This study investigated the effects of 7 years of GH replacement on QoL.
A prospective, single-center, open-label study of 95 adults (mean age 52.8 years; 46 men) with adult-onset GH deficiency (GHD).
QoL was measured using Quality of Life-Assessment for Growth Hormone Deficiency in Adults (QoL-AGHDA) and Psychological General Well-Being (PGWB) scores.
The GH dose was gradually increased from 0.13 mg/day to 0.42 mg/day. IGF-I SD score increased from −1.49 at baseline to 0.35 at study end. The GH replacement induced sustained improvements in total QoL-AGHDA and PGWB scores. GHD women had a more marked improvement in total QoL-AGHDA score than GHD men after 5 and 7 years. Most of the improvement in QoL was seen during the first year, but there was a small further improvement also after one year as measured using QoL-AGHDA. All QoL-AGHDA dimensions improved, but the improvement in memory and concentration as well as tenseness occurred later than that of other dimensions. Correlation analysis demonstrated that the patients with the lowest baseline QoL had the greatest improvement in QoL.
Seven years of GH replacement improved QoL with the most marked improvements in GHD women and in patients with low baseline QoL. Most, but not all, of the improvement in QoL was seen during the first year. Some QoL-AGHDA dimensions (memory and concentration, tenseness) responded at a slower rate than other dimensions.
Galina Götherström, Mariam Elbornsson, Katharina Stibrant-Sunnerhagen, Bengt-Åke Bengtsson, Gudmundur Johannsson and Johan Svensson
Only few studies have investigated the effects of GH replacement on muscle strength in elderly patients with GH deficiency (GHD).
Objective, design, and patients
In this prospective open-labeled study, the effects of 10 years of GH replacement on muscle strength and neuromuscular function were followed in 24 elderly GHD adults (mean age of 65.2 years; range 61–74 years). Muscle strength was compared with reference values obtained from the background population.
The mean initial GH dose of 0.72 mg/day was lowered to 0.37 mg/day. The mean IGF1 SDS increased from −1.10 at baseline to 1.17 at study end. GH replacement induced a sustained increase in lean body mass and a transient increase in isometric knee flexor strength. Isometric knee extensor strength was reduced after 10 years. However, after correction for age and gender, using observed/predicted value ratios, there was sustained and even progressive increase in most variables reflecting muscle strength. Measurements of neuromuscular function showed unchanged voluntary motor unit activation after 10 years.
Ten years of GH replacement therapy in elderly GHD adults resulted in a transient increase in isometric knee flexor strength, and provided protection from most of the normal age-related decline in muscle performance and neuromuscular function.
Harald J Schneider, Michael Buchfelder, Henri Wallaschofski, Anton Luger, Gudmundur Johannsson, Peter H Kann and Anders Mattsson
There is no single clinical marker to reliably assess the clinical response to growth hormone replacement therapy (GHRT) in adults with growth hormone deficiency (GHD). The objective of this study was to propose a clinical response score to GHRT in adult GHD and to establish clinical factors that predict clinical response.
This was a prospective observational cohort study from the international KIMS database (Pfizer International Metabolic Database).
We included 3612 adult patients with GHD for proposing the response score and 844 patients for assessing predictors of response. We propose a clinical response score based on changes in total cholesterol, waist circumference and QoL-AGHDA quality of life measurements after 2 years of GHRT. A score point was added for each quintile of change in each variable, resulting in a sum score ranging from 3 to 15. For clinical response at 2 years, we analysed predictors at baseline and after 6 months using logistic regression analyses.
In a baseline prediction model, IGF1, QoL-AGHDA, total cholesterol and waist circumference predicted response, with worse baseline parameters being associated with a favourable response (AUC 0.736). In a combined baseline and 6-month prediction model, baseline QoL-AGHDA, total cholesterol and waist circumference, and 6-month change in waist circumference were significant predictors of response (AUC 0.815).
A simple clinical response score might be helpful in evaluating the success of GHRT. The baseline prediction model may aid in the decision to initiate GHRT and the combined prediction model may be helpful in the decision to continue GHRT.
Gudmundur Johannsson, Ragnhildur Bergthorsdottir, Anna G Nilsson, Hans Lennernas, Thomas Hedner and Stanko Skrtic
Endogenous plasma cortisol levels have a well-defined circadian rhythm. The aim of this project is to develop a once daily oral dual-release formulation for cortisol replacement therapy that mimics the diurnal variation in the plasma cortisol profile.
To determine single-dose plasma pharmacokinetics and dose-proportionality of oral 5 and 20 mg dual-release hydrocortisone tablets in healthy volunteers. In addition, the effect of food intake was investigated for the 20 mg dose.
A randomised, controlled, two-way cross-over, double-blind, phase I study of oral hydrocortisone (modified (dual) release; 5 and 20 mg) with an open food-interaction arm.
The single dose pharmacokinetic studies were performed with betamethasone suppression. The two first study days were blinded and randomised between morning administration of 5 and 20 mg tablet in a fasting state. The third day was open with a 20 mg tablet taken 30 min after a high-calorie, high-fat meal. The plasma samples were assayed using both a validated LC–MS/MS and an immunoassay. The plasma pharmacokinetic variables were calculated using non-compartmental data analysis.
The time to reach a clinically significant plasma concentration of cortisol (>200 nmol/l) was within 20 min and a mean peak of 431 (s.d. 126) nmol/l was obtained within 50 min after administration of the 20 mg tablet. Plasma cortisol levels remained above 200 nmol/l for around 6 h thereafter and all plasma concentrations 18–24 h after intake were below 50 nmol/l. In the fed state the time to reach 200 nmol/l was delayed by 28 and 9 min based on LC–MS/MS and immunoassay, respectively. The 5 and 20 mg tablets produced an increase in plasma exposure of cortisol that was not fully dose proportional.
The dual release hydrocortisone tablet with once-daily administration produced a diurnal plasma cortisol profile mimicking the physiological serum cortisol profile.
Johan Svensson, Gudmundur Johannsson, Ali Iranmanesh, Kerstin Albertsson-Wikland, Johannes D Veldhuis and Bengt-Åke Bengtsson
Objective: Some adolescents who discontinue GH treatment due to GH deficiency (GHD) and short stature in childhood do not have classical GHD at retesting in adult life. It is unknown whether there is a neuroendocrine disturbance in the spontaneous pattern of GH release in these patients.
Design/patients/methods: Thirty-seven adolescents, who had received treatment with GH due to impaired longitudinal growth, were included. The adolescents were divided into two groups; one (GHD; n = 19) with classical GHD in adult life and another (GH sufficient (GHS); n = 18) without classical adult GHD. One year after GH discontinuation, 24-h GH profiles were performed with blood sampling every 30 min. Sixteen matched healthy controls were also studied. All blood samples were analysed using an ultrasensitive GH assay and then, approximate entropy (ApEn) and deconvolution analysis were performed.
Results: The GHD group had higher mean ApEn level than the healthy controls (P < 0.05). As measured by deconvolution analysis, they had lower basal GH secretion (P < 0.01), increased number of GH peaks (P < 0.001), but lower burst mass (P < 0.001), lower percentage pulsatile GH secretion (P < 0.001) and lower total GH secretion (P < 0.001), compared with control subjects. Adolescents in the GHS group had a pattern of 24-h GH release similar to that in healthy controls.
Conclusion: Young adults with childhood-onset severe GHD have a high-frequency, low-amplitude GH secretion with decreased orderliness. The adolescents without classical GHD in adult life maintain a pattern of spontaneous GH release that is not statistically different from that in the healthy controls.