Dose titration and patient selection increases the efficacy of GH replacement in severely GH deficient adults

Assessment of quality of life on 4-year growth hormone therapy in Japanese patients with adult growth hormone deficiency: A post-marketing, multicenter, observational study

OBJECTIVE

Improvement of quality of life (QOL) by growth hormone (GH) therapy was not demonstrated in Japanese adult growth hormone deficiency (AGHD) patients by either the QOL Assessment of Growth Hormone Deficiency in Adults or the Questions on Life Satisfaction-Hypopituitarism, which are widely used to evaluate QOL in Western AGHD patients. We therefore evaluated QOL in Japanese AGHD patients receiving recombinant GH, Norditropin® (Novo Nordisk A/S, Denmark), using the newly developed Adult Hypopituitarism Questionnaire (AHQ).

DESIGN

This multicenter, non-interventional, observational study in Japanese patients with severe AGHD was conducted from 1 October 2009 to 30 September 2014. Patients with severe AGHD already receiving somatropin and somatropin-naïve patients were included. GH therapy (Norditropin®) was initiated as injections of 0.021mg/kg/week divided into 6-7 doses/week, and was adjusted according to clinical responses. Demographic/clinical data were obtained from medical records or by patient recall. QOL was assessed using the AHQ at baseline; 3, 6, and 12months; and annually up to 4years.

RESULTS

Of 387 registered patients, 161 were eligible for QOL analysis. AHQ scores significantly improved after 3months of treatment. Improvements in the psycho-social and physical domains were statistically significant throughout the 4-year study period. Although the GH dose was increased in females such that insulin-like growth factor-1 levels reached those of males, QOL improvements in females did not reach those of males. Despite the greater GH dose in child-onset patients, limited QOL improvements were observed in child-onset vs adult-onset cases.

CONCLUSIONS

Four-year GH treatment in Japanese AGHD patients elicits sustained improvement in QOL as assessed by AHQ scores.

Gender differences in GH response to GHRH+ARG in lipodystrophic patients with HIV: a key role for body fat distribution

OBJECTIVE

Gender influence on GH secretion in human immunodeficiency virus (HIV)-infected patients is poorly known.

DESIGN AND METHODS

To determine the effect of gender, we compared GH response to GH-releasing hormone plus arginine (GHRH+Arg), and body composition in 103 men and 97 women with HIV and lipodystrophy. The main outcomes were IGF1, basal GH, GH peak and area under the curve (AUC) after GHRH+Arg, body composition, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).

RESULTS

Men had lower GH peak and AUC than women (P<0.001). Of the study population, 21% of women and 37% of men had biochemical GH deficiency (GHD; GH peak <7.5 μg/l). VAT-to-SAT ratio was higher in men than in women with GHD (P<0.05). Unlike women, VAT, SAT, and trunk fat were greater in men with GHD than in men without GHD. IGF1 was significantly lower in women with GHD than in women without GHD, but not in men. At univariate analysis, BMI, trunk fat mass, VAT, and total adipose tissue were associated with GH peak and AUC in both sexes (P<0.05). BMI was the most significant predictive factor of GH peak, and AUC at multiregression analysis. Overall, abdominal fat had a less pronounced effect on GH in females than in males.

CONCLUSIONS

These data demonstrate that GH response to GHRH+Arg is significantly lower in HIV-infected males than females, resulting in a higher percentage of GHD in men. Adipose tissue distribution more than fat mass per se seems to account for GH gender differences and for the alteration of GH-IGF1 status in these patients.

Understanding the growth hormone therapy adherence paradigm: a systematic review

INTRODUCTION

Growth hormone (GH) therapy is used to treat a variety of growth disorders in childhood/adolescence. Its efficacy is thought to be dependent on patients' adherence to their treatment regimen.

METHODS

PubMed was searched using the keywords 'growth hormone', 'child'[Mesh], 'adolescent'[Mesh], and 'patient compliance'[Mesh].

RESULTS

Most studies of adherence to paediatric GH therapy have used either issued/encashed GH prescriptions or questionnaires. Estimates of prevalence of non-adherence vary from 5-82%, depending on the methods and definitions used. Different studies have variously demonstrated an association (or lack thereof) between adherence and age, socioeconomic status, treatment duration, injection device used and injection-giver. A number of interventions have been proposed to improve adherence, including offering a choice of injection device, but none are supported by trials. Poor adherence is associated with reduced height velocity and likely increased economic costs; evidence for other effects is circumstantial.

CONCLUSION

Adherence to paediatric GH therapy is suboptimal, which may partially explain why the mean final height attained is below that of the general population. Analysis of the causes of non-adherence is complicated by conflicting evidence from different studies. Multifactorial interventions are most likely to be successful in improving adherence. We make recommendations for further research.

Extensive expertise in endocrinology: UK stance on adult GH replacement: the economist vs the endocrinologist

In the UK, through the use of a forced economic model, endocrinologists are in the curious position of offering GH replacement to some patients with severe GH deficiency (GHD) but withholding it from other patients with even more severe GHD. This approach is counter-intuitive to endocrine practice in treating endocrine deficiency states. For all other endocrine deficiencies, one would opt for treating those with the most severe biochemical evidence of deficiency first. If this endocrine approach was applied to adult GH replacement in an era of rationing, one would start with the GHD patients with a pathologically low IGF1 level. Given that the prevalence of subnormal IGF1 levels in a GHD population is age-dependent, this would result in GH replacement being offered to more young adult onset (AO) GHD and childhood onset GHD adults, and less often to middle-aged and elderly AO GHD adults. This in itself has the added advantage that the skeletal benefits appear more real in the former cohort of patients.

GH therapy in adult GH deficiency: a review of treatment schedules and the evidence for low starting doses

Recombinant human GH has been licensed for use in adult patients with GH deficiency (GHD) for over 15 years. Early weight- and surface area-based dosing regimens were effective but resulted in supraphysiological levels of IGF1 and increased incidence of side effects. Current practice has moved towards individualised regimens, starting with low GH doses and gradually titrating the dose according to the level of serum IGF1 to achieve an optimal dose. Here we present the evidence supporting the dosing recommendations of current guidelines and consider factors affecting dose responsiveness and parameters of treatment response. The published data discussed here lend support for the use of low GH dosing regimens in adult GHD. The range of doses defined as 'low dose' in the studies discussed here (∼1-4  mg/week) is in accordance with those recommended in current guidelines and encompasses the dose range recommended by product labels.

IGF-I bioactivity might reflect different aspects of quality of life than total IGF-I in GH-deficient patients during GH treatment

CONTEXT

No relationship has been found between improvement in quality of life (QOL) and total IGF-I during GH therapy.

AIM

Our aim was to investigate the relationship between IGF-I bioactivity and QOL in GH-deficient (GHD) patients receiving GH for 12 months.

METHODS

Of 106 GHD patients, 84 on GH treatment discontinued therapy 4 weeks before establishing baseline values and 22 were GH-naive. IGF-I bioactivity was determined by IGF-I kinase receptor activation assay, total IGF-I by immunoassay (Immulite), and QOL by the disease-specific Question on Life Satisfaction Hypopituitarism (QLS-H) module and by the general SF-36 questionnaire (SF-36Q).

RESULTS

IGF-I bioactivity increased after 6 months (-2.5 vs -1.9 SD, P < .001) and did not further increase after 12 months (-1.8 SD, P = .23); total IGF-I increased from -2.3 to -0.9 SD (P < .001) and to -0.6 SD (P = .005), respectively. QLS-H did not change over 12 months (-0.66 ± 0.16 to -0.56 ± 0.17 SD [P = .42] to -0.68 ± 0.17 SD [P = .22]). The mental component summary of the SF-36Q increased from 47.4 (38.7-52.8) to 50.2 (43.1-55.3) (P = .001) and did not further improve (49.4 [42.1-54.1], P = .19); the physical component summary did not change (47.5 [42.0-54.2] vs 47.0 [41.9-55.3], P = .91, vs 48.3 [39.9-55.4], P = .66). After 12 months, IGF-I bioactivity was related to QLS-H (r = 0.28, P = .01); total IGF-I was not (r = 0.10, P = .37). IGF-I bioactivity and total IGF-I were related to PCS (r = 0.35, P = .001; and r = 0.31, P = .003).

CONCLUSION

IGF-I bioactivity remained subnormal after GH treatment and was positively related to QLS-H, whereas total IGF-I was not. This suggests that IGF-I bioactivity reflects different aspects of QOL than total IGF-I in GHD patients during GH treatment.

Effects of growth hormone replacement therapy on bone mineral density in growth hormone deficient adults: a meta-analysis

Objectives. Growth hormone deficiency patients exhibited reduced bone mineral density compared with healthy controls, but previous researches demonstrated uncertainty about the effect of growth hormone replacement therapy on bone in growth hormone deficient adults. The aim of this study was to determine whether the growth hormone replacement therapy could elevate bone mineral density in growth hormone deficient adults. Methods. In this meta-analysis, searches of Medline, Embase, and The Cochrane Library were undertaken to identify studies in humans of the association between growth hormone treatment and bone mineral density in growth hormone deficient adults. Random effects model was used for this meta-analysis. Results. A total of 20 studies (including one outlier study) with 936 subjects were included in our research. We detected significant overall association of growth hormone treatment with increased bone mineral density of spine, femoral neck, and total body, but some results of subgroup analyses were not consistent with the overall analyses. Conclusions. Our meta-analysis suggested that growth hormone replacement therapy could have beneficial influence on bone mineral density in growth hormone deficient adults, but, in some subject populations, the influence was not evident.

Body composition and quality of life in adults treated with GH therapy: a systematic review and meta-analysis

OBJECTIVE

To summarise the evidence about the efficacy and safety of using GH in adults with GH deficiency focusing on quality of life and body composition.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science and Scopus through April 2011. We also reviewed reference lists and contacted experts to identify candidate studies.

STUDY SELECTION

Reviewers, working independently and in duplicate, selected randomised controlled trials (RCTs) that compared GH to placebo.

DATA SYNTHESIS

We pooled the relative risk (RR) and weighted mean difference (WMD) by the random effects model and assessed heterogeneity using the I(2) statistic.

RESULTS

Fifty-four RCTs were included enrolling over 3400 patients. The quality of the included trials was fair. GH use was associated with statistically significant reduction in weight (WMD, 95% confidence interval (95% CI): -2.31 kg, -2.66 and -1.96) and body fat content (WMD, 95% CI: -2.56 kg, -2.97 and -2.16); increase in lean body mass (WMD, 95% CI: 1.38, 1.10 and 1.65), the risk of oedema (RR, 95% CI: 6.07, 4.34 and 8.48) and joint stiffness (RR, 95% CI: 4.17, 1.4 and 12.38); without significant changes in body mass index, bone mineral density or other adverse effects. Quality of life measures improved in 11 of the 16 trials although meta-analysis was not feasible.

RESULTS

GH therapy in adults with confirmed GH deficiency reduces weight and body fat, increases lean body mass and increases oedema and joint stiffness. Most trials demonstrated improvement in quality of life measures.

Observations of nonadherence to recombinant human growth hormone therapy in clinical practice

BACKGROUND

The effectiveness of all prescribed treatments is contingent on patient adherence. The reported levels of adherence to recombinant human growth hormone (r-hGH) therapy are highly variable, but it has been suggested that nonadherence might be as high as 36% to 49%.

OBJECTIVES

This commentary discusses the factors that affect long-term adherence to injection treatment, of which r-hGH therapy is a particular challenge. It also explores potential strategies to improve adherence to injection treatments in clinical practice.

METHODS

The opinion of the authors was validated and supported by published literature. A PubMed literature search was conducted in November 2006, identifying English-language articles containing key terms growth hormone, adherence, and compliance.

RESULTS

This study found that factors associated with poor adherence to injection treatments include patients' lack of understanding of their disease, patient age, chronicity of the disease, complex treatment regimens, and insufficient information on the implications of nonadherence. Strengthening the patient-physician relationship by providing the patient with a clear understanding of his/her disease and the benefits of adherence, making improvements in injection devices, and eliminating subjective illness concepts, might increase adherence to SC injection treatments, thereby reducing increasing health care costs associated with nonadherence.

CONCLUSIONS

Poor adherence to r-hGH therapy has a dual effect, in that it leads to reduced efficacy out-comes and increased health care costs. Implementing strategies to improve adherence with injection treatment might be of particular clinical benefit to patients undergoing r-hGH therapy.

Positive effects of short-term growth hormone treatment on lean body mass and BMC after a hip fractureA double-blind placebo-controlled pilot study in 20 patients

BACKGROUND

A catabolic state develops after a hip fracture, with loss of muscle and bone tissue. Growth hormone (GH) treatment has been shown to exert anabolic effects during other catabolic states. We investigated whether GH given postoperatively to elderly hip fracture patients could increase serum insulin-like growth factor-I (IGF-I) and reduce the loss of lean body mass and bone mineral content (BMC) without considerable side effects.

PATIENTS AND METHODS

We randomized 20 patients operated on for a hip fracture to a double-blind placebo-controlled 4-week study with daily subcutaneous injections of GH or placebo. The patients were followed for another 2 months after termination of GH treatment.

RESULTS

Serum IGF-I and the IGF-I binding protein 1 (IGFBP-1) were measured by specific radioimmunoassay (RIA) technique. BMC and lean body mass were assessed by dual-energy X-ray absorptiometry and quantitative computed tomography. Serum IGF-I increased significantly during GH treatment, which also preserved lean body mass and BMC without serious adverse events.

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.

Cardiovascular risk in patients with growth hormone deficiency: effects of growth hormone substitution

OBJECTIVE

To review the literature on the increased cardiovascular risk in patients with growth hormone (GH) deficiency and the positive effects of GH replacement.

METHODS

We analyze the factors that contribute to cardiovascular risk in GH deficiency, including body composition and lipid profile, and summarize GH treatment strategies and results described in the literature.

RESULTS

The prominent clinical finding in patients with GH deficiency is the increased abdominal fat, even in patients with normal weight. Cardiac ejection volume tends to be decreased, and arterial distensibility is diminished. The lipid status is also worsened, accompanied by increased inflammatory markers, such as highly sensitive C-reactive protein. Typically, GH treatment reduces visceral fat and increases muscle mass, changes that diminish cardiovascular risk. Because of direct effects as well as increased hemodynamic performance and increased blood volume, cardiac performance is improved. With GH therapy, total cholesterol and low-density lipoprotein levels decrease by 10% to 20%, and inflammatory markers such as C-reactive protein decline. Carbohydrate metabolism during moderate to long-term treatment is minimally affected, although obese patients with GH deficiency on rare occasion may have hyperglycemia or even diabetes.

CONCLUSION

The relevance of the beneficial effects of GH on the cardiovascular system is strongly suggested but not fully proved. The results in a large cohort of GH-treated patients (the KIMS or Pharmacia and Upjohn International Metabolic Surveillance database) demonstrated no difference in cardiovascular risk in comparison with that in a control population after a mean of 3 years of treatment.

The influence of growth hormone status on physical impairments, functional limitations, and health-related quality of life in adults

The availability of recombinant human GH and somatostatin analogs has resulted in widespread treatment for adults with GH deficiency (GHD) and those with GH excess (acromegaly). Despite being at opposite ends of the spectrum in terms of their GH/IGF-I axis, both of these populations experience overlapping somatic impairments. Adults with untreated GHD have low circulating levels of IGF-I that manifest as altered body composition with increased fat and reduced lean body and skeletal muscle mass. At the other end of the spectrum, adults with GH excess, who have elevated levels of IGF-I, also have altered body composition. Impairments that result from disorders of either GHD or GH excess are both associated with increased functional limitations, such as reduced ability to walk quickly for prolonged periods, and poorer health-related quality of life (HR-QoL). Adults with untreated GHD and GH excess both commonly complain of excessive fatigue that seems to be associated more with impaired aerobic than muscular performance. Several studies have documented that administration of GH or somatostatin analogs to adults with GHD or GH excess, respectively, ameliorates abnormal biochemical profile and the associated somatic impairments. However, whether these improvements translate into improved physical function in adults with GHD or GH excess remains largely unknown, and their impact on HR-QoL controversial. Review of placebo-controlled trials to date suggests that GH and somatostatin analogs have greater effects on gas exchange and aerobic performance than as anabolic agents on skeletal muscle mass and function. Future investigations should include dose-response studies to establish the optimal combination of pharmacological agents plus exercise required to improve not only biochemical markers but also physical function and HR-QoL in adults with GHD or GH excess.

The Phenotype of Adults with Partial Growth Hormone Deficiency

The concept of partial growth hormone (GH) deficiency (GHD) is well established within the paediatric setting having been validated against height velocity. In hypopituitary adults, GHD is defined by a peak GH response <3 microg/l to stimulation. This cut-off is arbitrary due to the lack of a biological marker equivalent of height velocity. The majority of normal adults achieve peak GH levels several fold higher than this cut off during stimulation. It can be argued, therefore, that there is a cohort of hypopituitary adults with intermediate peak GH values (3-7 microg/l), who have relatively impaired GH secretion, and for whom the impact of this partial GHD (GH insufficiency, GHI) on biological endpoints is not known. Studies of GHI adults have demonstrated an abnormal body composition, adverse lipid profile, impaired cardiac performance, reduced exercise tolerance and insulin resistance. The severity of these abnormalities lies between GHD adults and normal subjects. Whether these anomalies translate into increased mortality, as observed in GHD hypopituitary adults, is not yet known. Given the presence of similar sequelae in GHI and GHD adults, and the improvements during GH replacement in GHD adults, a randomized placebo-controlled study of GH replacement in GHI patients is warranted.

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.

Liver-derived IGF-I regulates exploratory activity in old mice

Growth hormone (GH) replacement in hypopituitary patients improves well-being and initiative. Experimental studies indicate that these psychic effects may be reflected in enhanced locomotor activity in mice. It is unknown whether these phenomena are mediated directly by GH or by circulating IGF-I. IGF-I production in the liver was inactivated at 6-10 wk of age (LI-IGF-I-/- mice), resulting in an 80-85% reduction of circulating IGF-I, and, secondary to this, increased GH secretion. Using activity boxes on three different occasions during 1 wk, 6-mo-old LI-IGF-I-/- mice had similar activity levels, and 14-mo-old mice had a moderate but significant decrease in activity level, compared with control mice. At 20 mo of age, the LI-IGF-I-/- mice displayed a more prominent decrease in activity level with decreased horizontal activity throughout the test period, and at day 1, there were several signs of an altered habituation process with different time patterns of locomotor activity and horizontal activity compared with the control mice. At days 3 and 5, rearing activity was lower in the 20-mo-old LI-IGF-I-/- mice. Anxiety level was unaffected in all age groups, as measured using the Montgomery's elevated plus-maze. In conclusion, old LI-IGF-I-/- mice displayed a decrease in both horizontal and rearing (exploratory) activity level and an altered habituation process. These results indicate that liver-derived IGF-I mediates at least part of the effects of GH on exploratory activity in mice.

Impact of growth hormone status on body composition and the skeleton

Severe growth hormone (GH) deficiency (GHD) induces a well-defined clinical entity encompassing, amongst the most reported features, abnormalities of body composition, in particular increased fat mass, especially truncal, and reduced lean body mass. The results from virtually all treatment studies are in agreement that GH replacement improves the body composition profile of GHD patients by increasing lean body mass and reducing fat mass. More recently, the observations have been extended to adults with partial GHD, defined by a peak GH response to insulin-induced hypoglycaemia of 3-7 microg/l. These patients exhibit abnormalities of body composition similar in nature to those described in adults with severe GHD; these include an increase in total fat mass of around 3.5 kg and a reduction of lean body mass of around 5.5 kg. The increase in fat mass is predominantly distributed within the trunk. The degree of abnormality of body composition is intermediate between that of healthy subjects and that of adults with GHD. The impact of GH replacement on body composition in adults with GH insufficiency, although predictable, has not been formally documented. The skeleton is another biological endpoint affected by GH status: in adults with severe GHD, low bone mass has been reported using dual energy x-ray absorptiometry (DEXA) and other quantitative methodologies. The importance of low bone mass, in any clinical setting, is as a surrogate marker for the future risk of fracture. Several retrospective studies have documented an increased prevalence of fractures in untreated GHD adults. Hypopituitary adults with severe GHD have reduced markers of bone turnover which normalize with GH replacement, indicating that GH, directly or via induction of insulin-like growth factor-I, is intimately involved in skeletal modelling. Whilst the evidence that GH plays an important role in the acquisition of bone mass during adolescence and early adult life is impressive, the impact of GHD acquired later in adulthood is less clear. Recently we examined the relationship between bone mineral density (BMD) and age in 125 untreated adults with severe GHD using DEXA. A significant positive correlation was observed between BMD (z-scores) and age at all skeletal sites studied. Overall, few patients, except those aged less than 30 years, had significantly reduced bone mass (i.e. a BMD z-score of less than -2); correction of BMD to provide a pseudo-volumetric measure of BMD suggested that reduced stature of the younger patients may explain, at least in part, this higher frequency of subnormal BMD z-scores. Despite normal BMD, however, an increase in fracture prevalence may still be observed in elderly GHD adults as a consequence of increased falls related to muscle weakness and visual field defects.

Quality of life (QOL) in patients with acromegaly is severely impaired: use of a novel measure of QOL: acromegaly quality of life questionnaire

Acromegaly Quality of Life Questionnaire (AcroQoL) is a new disease-generated quality of life (QOL) questionnaire comprising 22 questions covering physical and psychological aspects of acromegaly and subdivided into "appearance" and "personal relations" categories. We have performed a cross-sectional study of QOL in 80 patients [43 male (mean age, 54.2 yr; range, 20-84); median GH, 0.93ng/ml (range, <0.3 to 23.7); IGF-I, 333.1 ng/ml (range, 47.7-899)] with acromegaly. In addition to AcroQoL, patients completed three generic QOL questionnaires: Psychological General Well-Being Schedule (PGWBS), EuroQol, and a signs and symptoms score (SSS). All three generic questionnaires confirmed impairment in QOL [mean scores: PGWBS, 69.6; EuroQol, visual analog scale, 66.4 (range, 20-100) and utility index, 0.7 (range, -0.07 to 0.92); and SSS, 12 (range, 0-27)]. There was no correlation between biochemical control and any measure of QOL. AcroQoL (57.3%; range, 18.2-93.2) correlated with PGWBS (r = 0.73; P < 0.0001); and in patients with active disease, AcroQoL-physical dimension correlated with SSS (r = -0.67; P < 0.0003). In all questionnaires, prior radiotherapy was associated with impaired QOL. In conclusion, these data underline the marked impact that acromegaly has on patients' QOL and provide the first evidence validating AcroQoL against well-authenticated measures of QOL. This indicates the potential of AcroQoL as a patient-friendly measure of disease activity.

Sheehan's syndrome: baseline characteristics and effect of 2 years of growth hormone replacement therapy in 91 patients in KIMS - Pfizer International Metabolic Database

OBJECTIVE

Sheehan's syndrome occurs as a result of ischaemic pituitary necrosis due to severe postpartum haemorrhage. It is one of the most important causes of hypopituitarism, and hence growth hormone deficiency (GHD), in developing countries. However, little is known about the effects of growth hormone (GH) replacement therapy in patients with Sheehan's syndrome.

DESIGN

The demographic background characteristics of 91 GH-deficient patients with Sheehan's syndrome (mean age +/- s.d., 46.3 +/- 9.4 years) were compared with those of a group of 156 GH-deficient women (mean age +/- s.d., 51.5 +/- 13.1 years) with a non-functional pituitary adenoma (NFPA). The baseline characteristics and the effects of 2 years of GH replacement therapy were also studied in the 91 patients with Sheehan's syndrome and an age-matched group of 100 women with NFPA (mean age +/- s.d. 44.5 +/- 10.2 years).

RESULTS

All patients were enrolled in KIMS (Pfizer International Metabolic Database). Patients with Sheehan's syndrome were significantly younger at pituitary disorder onset, diagnosis of GHD and at entry into KIMS than patients with NFPA (P < 0.01), and had significantly lower insulin-like growth factor I levels (P < 0.001). At baseline, quality of life (QoL) was significantly (P < 0.05) reduced in patients with Sheehan's syndrome compared with those with NFPA (P < 0.001). With regard to treatment effects, lean body mass increased significantly (P < 0.05), QoL improved significantly (P < 0.05) and total and low-density lipoprotein-cholesterol decreased significantly (P < 0.05) in patients with Sheehan's syndrome after 1 year of GH replacement therapy. Similar significant changes in QoL and lipid profiles occurred in patients with NFPA after 2 years of GH replacement. Blood pressure remained unchanged in patients with Sheehan's syndrome, but decreased significantly (P < 0.01) in the group with NFPA after 1 year, before returning to pretreatment levels at 2 years.

CONCLUSIONS

In conclusion, patients with Sheehan's syndrome have more severe GHD compared with individuals with NFPA. GH replacement therapy in patients with Sheehan's syndrome may have beneficial effects on QoL, body composition and lipid profile.

Insulin sensitivity is impaired in adults with varying degrees of GH deficiency

BACKGROUND

Severe GH deficiency (GHD) is arbitrarily defined by a peak GH (pGH) response to provocative tests of less than 3 microg/l. The impact of lesser degrees of GHD (pGH of 3-7 microg/l) in the adult is less well defined. Hypopituitary adults with severe GHD are insulin resistant as defined by the short insulin tolerance test (ITT), homeostatic model assessment (HOMA) or the hyperinsulinaemic euglycaemic clamp. Whether insulin action is impaired in the presence of lesser degrees of GHD (GH insufficiency, GHI) is not known.

PATIENTS AND METHODS

We studied 30 patients with GHD (median pGH 0.5 microg/l; 0.3-1.3 microg/l), 24 with GHI (median pGH 4.0 microg/l; 3.6-4.9 microg/l), and 30 age-, sex- and body mass index (BMI)-matched controls. A short ITT was performed in a subset of 20 patients from each group and the rate constant for glucose disappearance (K(ITT)) calculated.

RESULTS

Both GHD and GHI hypopituitary adults were found to be insulin resistant from the K(ITT) values compared with the control group [analysis of variance (anova) on ranks, -0.0210 vs. -0.0223 vs. -0.0261, P < 0.05]. No difference in K(ITT) values was detected between the GHD and GHI groups. Calculation of insulin resistance using the HOMA did not detect a significant difference between groups (anova on ranks, 2.04 vs. 1.54 vs. 1.34, P = 0.40). No significant difference in the fasting glucose, insulin or IGFBP-I levels between groups was detected. Insulin resistance estimated from the K(ITT) correlated with the serum IGF-I (r = -0.30, P = 0.01), and pGH level to the ITT (r = -0.31, P = 0.03). K(ITT) also correlated with total body percentage fat mass (r = -0.28, P = 0.03). Multivariate analysis found K(ITT) to be dependent on percentage fat mass, gender and age (r = 0.53, P = 0.0002). Insulin resistance increased in concert with percentage fat mass, age and male gender.

CONCLUSIONS

Although not detected under basal conditions, hypopituitary adults with both severe GHD and GHI are insulin resistant under conditions of insulin stimulation. This finding may be explained by the concomitant adverse changes in body composition observed in both these states of varying degrees of GHD. Insulin resistance is associated with a number of adverse cardiovascular risk factors that may place patients with GHI at risk of premature cardiovascular disease.

One year of GH replacement therapy with a fixed low-dose regimen improves body composition, bone mineral density and lipid profile of GH-deficient adults

OBJECTIVE

We have studied the effects on body composition and metabolism of a fixed low dose of growth hormone (GH), 0.6 IU (0.2 mg)/day, administered for 12 months to GH-deficient (GHD) adults.

DESIGN AND METHODS

Prospective open-label study, using 18 GHD patients (11 women, 7 men; aged 21-58 years). All investigations were performed at baseline and after 12 months. Body composition was determined by dual energy X-ray absorptiometry.

RESULTS

Total body fat decreased (-1.74+/-2.87%) and lean body mass (LBM) increased (1.27+/-2.08 kg) after therapy (P < 0.05). Changes in truncal fat did not reach statistical significance, but a decrease varying from 0.72 to 2.78kg (1 to 8.7%) was observed in 13 (72%) patients. Bone mineral density (BMD) increased at lumbar spine, total femur and femoral neck (P < 0.05). Levels of total and low-density lipoprotein (LDL)-cholesterol were lower after therapy (P < 0.05), and their changes were directly associated with values at baseline. Insulin levels increased and the insulin resistance index worsened at 12 months (P < 0.05). Median IGF-I s.d. score was -4.30 (range, -11.03 to -0.11) at baseline and -1.73 (range, -9.80 to 2.26) at 12 months. Normal age-adjusted IGF-I levels were obtained with therapy in 5 of 11 patients who had low IGF-I levels at baseline. Changes in IGF-I levels were not correlated with any biological end point, except changes in LBM (r = 0.53, P = 0.02). Side effects were mild and disappeared spontaneously.

CONCLUSIONS

One-year of a fixed low-dose GH regimen in GHD adults resulted in a significant reduction in body fat, total cholesterol and LDL-cholesterol, and a significant increase in LBM and BMD at lumbar spine and femur, regardless of normalization of IGF-I levels. This regimen led to an elevation of insulin levels and a worsening of the insulin resistance index.

Three-years of growth hormone (GH) replacement therapy in GH-deficient adults: effects on quality of life, patient-reported outcomes and healthcare consumption

OBJECTIVE

The objective was to investigate the effects of 3 years of growth hormone (GH) replacement therapy in GH deficient (GHD) patients in Sweden.

DESIGN AND PATIENTS

An open label study in 237 adults with GHD (116 men and 121 women), consecutively enrolled in KIMS (Pfizer's international metabolic database) in Sweden.

MEASUREMENTS

QoL and healthcare consumption were determined using questionnaires [QoL-assessment of GHD in Adults (QoL-AGHDA), the psychological general well-being (PGWB) index and the patient life situation form (PLSF)].

RESULTS

The mean starting dose of GH was 0.13 mg/day and the mean maintenance dose was 0.37 mg/day. The mean insulin-like growth factor I (IGF-I) SD score increased from -1.92 at baseline to 0.38 after 3 years. There was a sustained increase in QoL as measured by the QoL-AGHDA and PGWB questionnaires. The number of doctor visits and the number of days in hospital were reduced after 3 years of GH replacement. The number of days of sickleave decreased during the first 2 years of treatment, but returned towards baseline values after 3 years. Leisure-time physical activity and satisfaction with physical activity increased.

CONCLUSION

Three years of GH replacement therapy induced a sustained improvement in QoL. Healthcare consumption was reduced, although the reduction in the number of days of sickleave was not statistically significant after 3 years of treatment.

[Growth hormone deficiency in adults: effects of replacement therapy on body composition and health-related quality of life]

BACKGROUND AND OBJECTIVE

Deficiency of growth hormone (GH) in the adult is accompanied by changes in the body composition and a diminished health-related quality of life (HR-QoL). The aim of the study was to assess the biochemical response to GH replacement therapy and its safety as well as the resulting body composition and HR-QoL.

PATIENTS AND METHODS

One hundred sixty-five patients with hypopituitarism and GH deficiency were studied. A double-blind,randomized, placebo-controlled, 6-months study was first designed,then followed by a further 6-months period in which all patients received GH. The initial GH dose was 0.125 IU/Kg/week followed by 0.250 IU/Kg/week. The body composition was determined by bioelectric impedanciometry and the HR-QoL was evaluated by the Nottingham Health Profile (NHP) and the QoL-AGHDA questionnaire.

RESULTS

A significant increase in fat-free mass was observed during treatment with GH, which was accompanied with a simultaneous decrease in fat mass. Total body water increased during GH treatment. Energy and emotional reaction areas evaluated by the NHP showed changes at 6 months; no changes were observed in the remaining dimensions. A progressive improvement was observed in the QoL-AGHDA score in the treated group but not in the placebo group. Adverse events mainly consisted of fluid retention which resolved upon decrease of the dose.

CONCLUSIONS

GH treatment in GH-deficient adults is in general well tolerated and leads to beneficial effects on body composition and HR-QoL.

Long-Term Efficacy and Safety of Somatropin for Adult Growth Hormone Deficiency

The beneficial effects of somatropin (growth hormone [GH] replacement therapy) in adults are now established. Long-term somatropin administration in GH-deficient adults improves body composition, muscle strength, quality of life, bone mass and density, and lipoprotein pattern. The extent to which somatropin therapy can also reduce cardiovascular morbidity and mortality in GH-deficient adults remains to be determined. By starting with a low dose of somatropin, which is gradually increased based on clinical response (body composition, well-being, and serum insulin-like growth factor-1 concentration), effective treatment can be achieved with a minimum of fluid-related adverse effects. Thorough long-term monitoring of glucose metabolism, cardiovascular measurements, and underlying pituitary disease, is, however, mandatory.

IGFs and IGFBPs: role in health and disease

The insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP proteases are the main regulators of somatic growth and cellular proliferation. IGFs are involved in growth pre-natally and post-natally. Dysregulation of the IGF axis can lead to growth disorders such as growth hormone deficiency and acromegaly. Pre-natally, this dysregulation can lead to IUGR or macrosomia. IGFs also have an important mitogenic action and play a role in tumorigenesis and cancer. These actions are regulated by co-interactions with IGFBPs, especially IGFBP-3. In addition to somatic growth and mitogenic activity, IGFs have hypoglycaemic and insulin sensitizing actions, and their dysregulation is involved in diabetes and its complications. In this chapter, we examine the role of IGFs and IGFBPs in growth, tumorigenesis and diabetes, and discuss treatment modalities for each disease involving the GH-IGF-IGFBP axis, including discussion of current in vitro and in vivo investigations in this field.

The effect of long-term untreated growth hormone deficiency (GHD) and 9 years of GH replacement on the quality of life (QoL) of GH-deficient adults

BACKGROUND

Quality of life (QoL) is reduced in GH-deficient adults compared with the normal population. Further support for the role of GH in the maintenance of QoL is derived from short-term studies of GH replacement in severely GH-deficient adults; these have predominantly reported beneficial effects, although the degree of improvement has often been modest. To date, however, there are few data to demonstrate whether this beneficial effect on QoL is maintained in the long term.

PATIENTS AND METHODS

This study consisted of the follow-up of 85 GH-deficient adults who completed the Nottingham Health Profile (NHP) and the Psychological General Well-Being Schedule (PGWB) self-rating questionnaires in 1992, as part of a 12-month double-blind randomized study of GH replacement. In 2001 we attempted to contact all 85 patients and asked them to complete the two questionnaires again. Follow-up data were obtained in 61 patients. The findings were analysed according to whether the individual had received GH continuously since completion of the initial study, received no further GH replacement, or received GH replacement for only part of the intervening time. Both the NHP and the PGWB give a total score and subsection scores for six specific areas of QoL. A high score correlates with increased morbidity in the NHP, and with reduced morbidity in the PGWB.

RESULTS

Fifty-nine patients completed the NHP at both time points. The patients who continued GH (n = 17) had significantly greater morbidity at baseline than patients who opted to discontinue therapy (n = 27), as reflected by the higher scores overall (5.7 +/- 4.0 vs. 2.8 +/- 3.5; P = 0.01) and in the energy subsection (47.0 +/- 34.7 vs. 13.2 +/- 28.6; P < 0.001). Over the study period energy levels improved in the patients who remained on GH therapy (47.0 +/- 34.7 vs. 25.7 +/- 31.0; P = 0.04). By contrast, a deterioration in the physical mobility subsection (2.4 +/- 5.4 vs. 8.2 +/- 16.7; P = 0.04) occurred in the patients who did not continue GH therapy, and no change occurred in the energy subsection. In the 36 patients who completed the PGWB significant differences were observed at baseline between patients who received GH replacement continuously (n = 10) and those who discontinued therapy (n = 21) in the overall score (67.2 +/- 14.1 vs. 86.8 +/- 14.7; P = 0.001); and in the subsections for anxiety (P = 0.04), depression (P = 0.04), well-being (P = 0.001), self-control (P = 0.04) and vitality (P < 0.001); the greater morbidity at baseline being observed in the patients who continued GH replacement. In the patients receiving GH continuously for 9 years the vitality subsection score improved significantly (7.7 +/- 2.4 vs. 12.5 +/- 3.2; P = 0.003), whereas no change in vitality score occurred in patients who did not continue GH therapy. The change in the energy subsection of the NHP and vitality subsection of the PGWB over the 9 years of the study were significantly different between the patients who opted to continue GH replacement and those who discontinued therapy (P = 0.008 and P < 0.001, respectively).

CONCLUSION

During this 9-year study, small but significant declines in health were observed in GH-deficient adults who remained untreated. By contrast, the patients who received GH continuously experienced improvements in energy levels while all other areas of QoL were maintained. The beneficial effects of GH on QoL are therefore maintained with long-term GH replacement and obviate the reduction in QoL seen over time in untreated GH-deficient adults.

Growth hormone therapy and its relationship to insulin resistance, glucose intolerance and diabetes mellitus: a review of recent evidence

It is widely recommended that consideration should be given to the therapeutic use of growth hormone (GH) in adults with GH deficiency, whether the condition is of childhood or adult onset. One reason for this recommendation is the possibility that such treatment may reduce the excess cardiovascular risk which is associated with hypopituitarism. This excess risk has been well documented, with mortality ratios of 1.7 to 2.2 being quoted in different studies, and may be a result of the insulin resistance which occurs in hypopituitarism. However, it has also been suggested that this insulin resistance may itself be the result of GH deficiency, especially as GH deficiency is accompanied by suggestive morphological features such as central adiposity. There is, however, no direct evidence that the increase in cardiovascular risk in hypopituitarism is the result of GH deficiency, and the only prospective study designed to examine the relationship failed to find a statistically significant correlation between the two. Since GH administration may also have an independent adverse effect on insulin sensitivity and could thus cause a theoretical worsening of cardiovascular risk, it is important to review the observed effects of GH administration on carbohydrate metabolism in practice. Interpretation of the literature is made difficult by many confounding factors, including differences in study duration, biochemical tools adopted, the use of selected populations and the dose-dependent effect of GH on synthesis of insulin- like growth factor-1. One of the most sensitive markers of a deterioration in insulin sensitivity is the serum insulin level. A rise in serum insulin (fasting, or post-glucose load) was reported in all studies in which it was measured. The majority of studies have also reported a rise in fasting blood glucose. A smaller proportion of reports noted an associated increase in postprandial glucose and in glycosylated haemoglobin (HbA(1c)) while a few reported new cases of either impaired glucose tolerance or frank diabetes mellitus. In general, however, the observed deterioration in insulin sensitivity was small and increases which occurred in blood glucose were small. Nevertheless, these data indicate that rather than lead to an improvement in insulin resistance in hypopituitarism, GH treatment may actually make it worse. As it is also known that even minor reductions in insulin sensitivity may be associated with a clinically significant increase in cardiovascular risk, further large-scale controlled trials are required before the efficacy and safety of GH treatment of adults can be established.

Childhood-onset growth hormone (GH) deficiency in adult life

Over the last decade GH replacement therapy for adults has progressed in status from research study to a mainstream clinical indication. An area ripe for further research, however, is the difference between adults who developed GHD before and after completion of growth and puberty. That differences exist, not only in aetiology, but also in phenotype and response to GH therapy is clear. However, whether these differences are intrinsic to the timing of onset of GHD, or related to secondary factors including the method of assessment or dose of GH employed is uncertain. This chapter discusses the current state of knowledge in this area and poses further questions, not only for the researcher attempting to understand the mechanisms underlying these differences, but also for the physician seeking to ameliorate the impact of GHD in patients who acquired GHD in childhood.

Spinal irradiation impairs the osteo-anabolic effects of low-dose GH replacement in adults with childhood-onset GH deficiency

BACKGROUND AND OBJECTIVE

Both adult- and childhood-onset GH-deficient adults are prone to osteopenia. Studies of GH replacement have, for the most part, demonstrated increases in bone mineral density (BMD). Previous studies have, however, used GH doses in excess of those currently used in low-dose titration regimens aimed at normalizing the serum IGF-I level. Furthermore, the effect of GH on the lumbar spine that has been irradiated during treatment of childhood cancer is unknown.

PATIENTS

Thirty-two adult patients with childhood-onset GH deficiency were subdivided according to whether or not they had received spinal irradiation in childhood. The cohort in whom the spine had not been irradiated was comprised of 17 patients (seven male, 10 female), median age 29.8 years (range 20.6--40.8), the median age at primary pathological diagnosis being 9 years (range 4--16). The cohort who received spinal irradiation was composed of 15 patients (seven male, eight female), median age 22.9 years (range 16.5--40.3), with a median age at craniospinal irradiation of 9 years (range 2--16).

MEASUREMENTS

At baseline, BMD was assessed at the lumbar spine and femoral neck by DXA, and at the ultradistal and distal radius by SXA. The patients were then commenced on GH replacement, titrating the dose at 4--6-weekly intervals to normalize the serum IGF-I level. BMD scans were reassessed following at least 1 year of GH replacement therapy. The mean duration of GH therapy was 1.68 plus minus 0.52 years.

RESULTS

BMD was significantly reduced, compared to the reference data, at all four sites measured in both the spinally irradiated and unirradiated groups. No significant difference was observed between the subgroups with respect to lumbar spine BMD (P = 0.64). In the cohort who did not receive spinal irradiation, an increase in BMD of 3.5% above baseline was observed at the lumbar spine (P = 0.018), 13/17 patients showing a positive increment in lumbar spine BMD. No significant changes in BMD were observed at any other site within this cohort, or at any site in the patients who received spinal irradiation. A significantly greater change in lumbar spine BMD was observed in the unirradiated spine cohort compared with the spinally irradiated cohort (P = 0.018). No differences in response were demonstrated at the other sites studied between the two subgroups.

CONCLUSIONS

We have demonstrated an increase in lumbar spine BMD with long-term (mean 1.78 +/- 0.55 years) GH therapy in adults with childhood-onset GH deficiency, who have not received spinal irradiation, when GH was administered by a titration regimen aimed at normalizing the serum IGF-I level. No improvements were observed at the femoral neck, ultradistal or distal radius. Patients who had received spinal irradiation during childhood did not present with a reduction in spinal BMD in excess of that observed in the nonirradiated cohort. The spinally irradiated group were, however, resistant to the osteo-anabolic effects of GH, which we propose reflects the capacity of radiation-induced damage to suppress the skeletal response.

Hypothalamo-pituitary surveillance imaging in hypopituitary patients receiving long-term GH replacement therapy

Most cases of adult-onset (AO) GH deficiency (GHD) result from the presence of hypothalamo-pituitary tumors or their treatment. GH replacement is now widely used in adults with hypopituitarism, but its effect on hypothalamo-pituitary tumor growth or recurrence is unknown. Anecdotal evidence from early experience of GH replacement in adults documented occasional tumor recurrence, but any relationship of this to the use of GH was unclear. We have now prospectively imaged the pituitary glands of 100 consecutive patients (60 females, 40 males; mean age, 46 yr; range, 18-69 yr) who had AO-GHD after appropriate treatment for a pituitary or peripituitary tumor. External radiotherapy had been given to 91 patients. All patients were treated with a dose titration regimen to maintain serum IGF-I between the median and upper end of the age-related reference range. Pituitary imaging was performed before the commencement of GH and after 6 and 12 months of treatment in all patients, again at 2 yr in 92 patients, at 3 yr in 63 patients, and after 4 yr in 23 patients. In only one patient was there evidence of slight intrasellar tissue enlargement at 6 months; GH replacement was continued, and there was no further change between 6 and 12 months. In all other patients, either the appearances were unchanged or the amount of tissue was reduced during long-term follow-up on GH. We have shown that hypothalamo-pituitary tumor recurrence was thus very rare over this time period in this group of GH-treated patients, and this is reassuring. Similar prospective longitudinal observation of patients who have not received postoperative irradiation and comparison with rates of tumor recurrence in control series are desirable.

Commencing growth hormone replacement in adults with a fixed low dose. Effects on serum lipoproteins, glucose metabolism, body composition, and cardiovascular function

The safety and effects of a fixed low dose of growth hormone (GH), 0.17 mg/day was evaluated for 3 months, on glucose metabolism, serum lipids, body composition and cardiac function in 53 GH deficient adults aged 18-78 years. Body composition was determined by dual energy X-ray absorptiometry and total body water was determined by bioelectrical impedance. Echocardiography was used to assess cardiac function and bicycle ergonometry was used to determine exercise capacity. All investigations were performed at baseline and after 3 months. At 3 months, serum levels of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3 and lipoprotein (a) and lean body mass were increased (P<0.05). Total and low density lipoprotein cholesterol levels and fat mass were reduced (P<0.05). There was an increase in the serum glucose value at 120 min after an oral glucose tolerance test performed at 3 months (P<0.05), no other changes in glucose metabolism or in cardiac function were noted. Side-effects were few and mild. This fixed low-dose regime resulted in improvements in body composition and lipid profile, without causing serious side effects. This is therefore a valid method to institute GH replacement in adults.

Diagnosis and management of growth hormone deficiency in adults

In adults, GHD is a clinical syndrome that occurs in patients with pituitary or hypothalamic disease. It may be asymptomatic or present with relatively nonspecific constitutional symptoms. Most patients have abnormal body composition, consisting of increased fat mass and decreased lean mass. Life expectancy is significantly decreased in hypopituitary patients with GHD, with cardiovascular disease a common cause of death. Treatment with growth hormone reverses abnormalities in body composition and may reduce cardiovascular risk factors; however, the long-term treatment outcomes regarding mortality, the incidence of cardiovascular disease, bone fractures, tumor development, and recurrence are not known. Longer prospective clinical studies are needed. The major manufacturers of growth hormone have initiated postmarketing surveillance databases to monitor the safety of growth hormone treatment.

Optimizing gh therapy in adults and children

Until the advent of modern neuroradiological imaging techniques in 1989, a diagnosis of GH deficiency in adults carried little significance other than as a marker of hypothalamo-pituitary disease. The relatively recent recognition of a characteristic clinical syndrome associated with failure of spontaneous GH secretion and the potential reversal of many of its features with recombinant human GH has prompted a closer examination of the physiological role of GH after linear growth is complete. The safe clinical practice of GH replacement demands a method of judging overall GH status, but there is no biological marker in adults that is the equivalent of linear growth in a child by which to judge the efficacy of GH replacement. Assessment of optimal GH replacement is made difficult by the apparent diverse actions of GH in health, concern about the avoidance of iatrogenic acromegaly, and the growing realization that an individual's risk of developing certain cancers may, at least in part, be influenced by cumulative exposure to the chief mediator of GH action, IGF-I. As in all areas of clinical practice, strategies and protocols vary between centers, but most physicians experienced in the management of pituitary disease agree that GH is most appropriately begun at low doses, building up slowly to the final maintenance dose. This, in turn, is best determined by a combination of clinical response and measurement of serum IGF-I, avoiding supraphysiological levels of this GH-dependent peptide. Numerous studies have helped define the optimum management of GH replacement during childhood. The recent requirement to measure and monitor GH status in adult life has called into question the appropriateness of simplistic weight- and surface area-based dosing regimens for the management of GH deficiency in childhood, with reliance on linear growth as the sole marker of GH action. It is clear that the monitoring of parameters other than linear growth to help refine GH therapy should now be incorporated into childhood GH treatment protocols. Further research will be required to define the optimal management of the transition from pediatric to adult GH replacement; this transition will only be possible once the benefits of GH in mature adults are defined and accepted by pediatric and adult endocrinologists alike.

Growth hormone therapy in adults

The importance of growth hormone (GH) deficiency in adults became evident 10 to 15 years ago, when the first clinical studies on GH replacement therapy in adults were published. Since then, a number of studies have been reported showing that GH replacement therapy can improve this condition. Adult GH deficiency (GHD) is now recognized as a specific clinical syndrome and the first reports of long-term use of GH (up to 10 years) are now being published. The aim of this paper was to review the accumulated data on the various clinical aspects of adult GHD.

Body composition and quality of life in adults with growth hormone deficiency; effects of low-dose growth hormone replacement

OBJECTIVE

Adult growth hormone deficiency (AGHD) is characterized by abnormalities in body composition and a poor perceived quality of life (QoL). Weight-based high-dose growth hormone replacement (GHR) results in improvements in body composition and QoL in AGHD. However, a high patient percentage reported side-effects on high-dose GHR resulting in a high rate of patient withdrawal from growth hormone (GH) treatment. High-dose GH therapy also leads to supraphysiological serum insulin-like growth factor-I (IGF-I) concentrations that have been associated with breast and prostate cancer, raising major concerns over the use of such high-dose GH regimen in AGHD. The aim of this study was to assess the effects of low-dose growth hormone replacement (GHR) on body composition and QoL as early as 1 and 3 months.

STUDY DESIGN

A prospective, open treatment design study to determine the early effects of low-dose GH administration on body composition and QoL. GH was initiated at a daily dose of 0.4-0.5 IU, and titrated up to achieve and maintain IGF-I standard deviation score (IGF-I SDS) between the median and upper end of the age-related reference range.

PATIENTS

Forty-six, post-pituitary surgery, severe AGHD patients (22 women), defined as peak GH response < 9 mU/l to provocative testing. The mean age was 50.4 years (range 26-72). Forty-three patients required additional pituitary replacement hormones following pituitary surgery and were on optimal doses at recruitment.

MEASUREMENTS

Body composition and QoL were assessed prior to GHR and subsequently at 1 and 3 months after initiating GHR. Body mass index (BMI) and waist hip ratio (WHR) were calculated from measurements of height, weight, and waist and hip circumference, respectively. Bioelectrical impedance analysis (BIA) was used to determine body fat and lean body mass. QoL was assessed using the disease-specific 'QoL-assessment of growth hormone deficiency in adults (QoL-AGHDA)' questionnaire. Serum IGF-I was measured at each visit to assess the adequacy of GHR.

RESULTS

IGF-I and IGF-I SDS increased significantly at 1 and 3 months (P < 0.001) after commencing GHR. The increase in IGF-I (P < 0.05) and IGF-I SDS (P < 0.01) was significant between 1 and 3 months in the absence of any significant increase in GH dose (P = ns) during this period. Eighty-five per cent of patients achieved IGF-I SDS levels between median and upper end of the age-related reference range after 3 months of GHR, and no side-effects were reported during this period. There was a significant reduction in body fat percentage (BFP) from 36.1 +/- 9.1% at baseline to 34.9 +/- 9.3% (P < 0.01) at 1 month and 34.1 +/- 9.2% (P < 0.001) at 3 months. Body fat mass (BFM) reduced from 32.8 +/- 13.6 kg at baseline to 31.9 +/- 13.9 kg at 1 month (P < 0.05) and 31.1 +/- 13.6 kg at 3 months (P < 0.001). These changes in BFP and BFM occurred in the absence of any significant change in BMI and WHR (P = ns). Lean body mass (LBM) was 55.9 +/- 11.1 kg at baseline and increased to 57.1 +/- 11.3 kg after 1 month (P < 0.01) and to 57.6 +/- 11.5 kg (P < 0.001) after 3 months of GHR. Significant improvement was observed in the perceived QoL with the AGHD assessment scores reducing from 13.3 +/- 6.4 to 11.5 +/- 6.6 within 1 month (P < 0.01) and 10.0 +/- 6.6 at 3 months (P < 0.001). There was no significant correlation between improvement in QoL and changes in body fat percentage (r = 0.01 at 1 month and r = 0.12 at 3 months, P = ns) or IGF-I levels (r = 0.04 and r = 0.003, P = ns at 1 and 3 months, respectively). The improvement in body composition and QoL was significant between 1 and 3 months.

CONCLUSIONS

Low-dose GHR improves body composition and QoL as early as 1 month after commencement and the beneficial effects continue at 3 months. Most importantly, these changes occur in the absence of side-effects. We therefore suggest the use of low-dose GH therapy, maintaining IGF-I between the median and upper end of the age-related reference range, for the treatment of AGHD.

Hypopituitarism following traumatic brain injury and aneurysmal subarachnoid hemorrhage: a preliminary report

OBJECT

Recognition of pituitary hormonal insufficiencies after head injury and aneurysmal subarachnoid hemorrhage (SAH) may be important, especially given that hypopituitarism-related neurobehavioral problems are typically alleviated by hormone replacement. In this prospective study the authors sought to determine the rate and risk factors of pituitary dysfunction after head injury and SAH in patients at least 3 months after insult.

METHODS

Patients underwent dynamic anterior and posterior pituitary function testing. Results of the tests were compared with those of 18 age-, sex-, and body mass index-matched healthy volunteers. The 22 head-injured patients included 18 men and four women (mean age 28+/-10 years at the time of injury) with initial Glasgow Coma Scale (GCS) scores of 3 to 15. Eight patients (36.4%) had a subnormal response in at least one hormonal axis. Four were growth hormone (GH) deficient. Five patients (four men, all with normal testosterone levels, and one woman with a low estradiol level) exhibited an inadequate gonadotroph response. One patient had both GH and thyrotroph deficiency and another had both GH deficiency and borderline cortisol deficiency. At the time of injury, all eight patients with pituitary dysfunction had an initial GCS score of 10 or less and, compared with the 14 patients without dysfunction, were more likely to have had diffuse swelling, seen on initial computerized tomography scans (p < 0.05), and to have sustained a hypotensive or hypoxic insult (p = 0.07). Of two patients with SAH who were studied (Hunt and Hess Grade IV) both had GH deficiency.

CONCLUSIONS

From this preliminary study, some degree of hypopituitarism appears to occur in approximately 40% of patients with moderate or severe head injury, with GH and gonadotroph deficiencies being most common. A high degree of injury severity and secondary cerebral insults are likely risk factors for hypopituitarism. Pituitary dysfunction also occurs in patients with poor-grade aneurysms. Postacute pituitary function testing may be warranted in most patients with moderate or severe head injury, particularly those with diffuse brain swelling and those sustaining hypotensive or hypoxic insults. The neurobehavioral effects of GH replacement in patients suffering from head injury or SAH warrant further study.

Should we start and continue growth hormone (GH) replacement therapy in adults with GH deficiency?

During the last decade, growth hormone deficiency (GHD) in adults has been described as a clinical syndrome. Central features of this entity include increased fat mass, reduced muscle and bone mass, as well as impaired exercise capacity and quality of life. GH replacement therapy has been initiated on a wide scale, but patients do not profit equally from this expensive therapy. The decision to start and continue GH replacement should be made individually for each patient. An eligible patient should have a clear diagnosis of GHD. In addition, GH replacement therapy should be efficacious. Especially, the unique and valuable effects of GH replacement on exercise performance and quality of life are strong arguments in favour of continuation of therapy. In osteopenic patients, GH replacement increases bone mass. Also, GH induces improvements in the cardiovascular risk profile. However, it has not yet been proved whether GH replacement reduces the incidence of bone fractures and cardiovascular mortality and improves life expectancy. Thus far, long-term physiological GH replacement does not appear to be complicated by adverse effects. Therefore, available evidence warrants continuation of long-term GH replacement therapy in patients with a clear-cut diagnosis of GHD who demonstrate beneficial effects of this therapy, especially with regard to exercise performance and quality of life.

Monitoring serum insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and leptin during growth hormone treatment for disordered growth

OBJECTIVE

Serum IGF-I levels are monitored during GH replacement treatment in adults with GH deficiency (GHD) to guide GH dose adjustment and to minimize occurrence of GH-related side-effects. This is not routine practice in children treated with GH. The aim of this study was to evaluate changes in (1) serum IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio, and (2) serum leptin, an indirect marker of GH response, during the first year of GH treatment in children with disordered growth.

DESIGN

An observational prospective longitudinal study with serial measurements at five time points during the first year of GH treatment was carried out. Each patient served as his/her own control.

PATIENTS

The study included 31 patients, grouped as (1) GHD (n = 20) and (2) non-GHD (Turner syndrome n = 7; Noonan syndrome n = 4), who had not previously received GH treatment.

MEASUREMENTS

Serum IGF-I, IGFBP-3 and leptin levels were measured before treatment and after 6 weeks, 3 months, 6 months and 12 months of GH treatment, with a mean dose of 0.5 IU/kg/wk in GHD and 0.7 IU/kg/wk in non-GHD groups. IGF-I, IGFBP-3 and the calculated IGF-I/IGFBP-3 molar ratio were expressed as SD scores using reference values from the local population.

RESULTS

In the GHD group, IGF-I SDS before treatment was lower compared with the non-GHD (-5.4+/-2.5 vs. -1.8+/-1.0; P<0.001). IGF-I (-1.8 SDS +/- 2.2) and IGFBP-3 (-1.1 SDS +/- 0.6) levels and their molar ratios were highest at 6 weeks and remained relatively constant thereafter. In the non-GHD group, IGF-I levels increased throughout the year and were maximum at 12 months (0.3 SDS +/- 1.4) while IGFBP-3 (1.1 SDS +/- 0.9) and IGF-I/IGFBP-3 molar ratio peaked at 6 months. In both groups, IGF-I SDS and IGF-I/IGFBP-3 during treatment correlated with the dose of GH expressed as IU/m2/week (r-values 0. 77 to 0.89; P = 0.005) but not as IU/kg/week. Serum leptin levels decreased significantly during GH treatment in the GHD (median before treatment 4.0 microg/l; median after 12 months treatment 2.4 microg/l; P = 0.02) but not the non-GHD (median before treatment 3.0 microg/l; median after 12 months treatment 2.6 microg/l). In the GHD group, serum leptin before treatment correlated with 12 month change in height SDS (r = 0.70, P = 0.02).

CONCLUSIONS

The pattern of IGF-I, IGFBP-3 and their molar ratio during the first year of GH treatment differed between the GHD and non-GHD groups. Calculation of GH dose by surface area may be preferable to calculating by body weight. As a GH dose-dependent increase in serum IGF-I and IGF-I/IGFBP-3 may be associated with adverse effects, serum IGF-I and IGFBP-3 should be monitored routinely during long-term GH treatment. Serum leptin was the only variable that correlated with first year growth response in GHD.

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.

Growth hormone therapy for hypopituitary adults: time for re-appraisal

The advent of the production of large quantities of recombinant growth hormone (GH) has made it possible to have sufficient material to assess its efficacy in adult growth hormone deficiency (GHD). Although some studies have shown that patients who are severely deficient benefit from GH therapy, the spectrum of GHD is broad, and the degree of deficiency at times is very difficult to define. In some cases, benefit is not easily quantified, and some studies have claimed benefits that, although statistically significant, are either not clinically important or are so marginal as to be questionable in terms of cost, difficulty of administration and potential risks. The purpose here is to identify the current problems in the diagnosis of GHD, to discuss the rationale for GH therapy and to assess the potential effects of GHD as well as the benefits of GH therapy in GHD adults. We will include a commentary as to which effects appear more robust than others and which are likely to result in the greatest patient benefit. Finally, some attention will be paid to long-term safety issues that should be monitored to ensure that this medication is safe even for the patients with the greatest need.

Growth hormone: current and future therapeutic applications

The increased availability of growth hormone (GH) in the mid-1980s, as a result of advances in recombinant DNA techniques, has allowed research into the use of this hormone at physiological dosage, as replacement therapy for adults with GH deficiency (GHD) and at pharmacological dosages as a possible therapeutic agent, for a number of disease states. GHD adults have increased body fat and reduced muscle mass and consequently, reduced strength and exercise tolerance. In addition, they are osteopenic, have unfavourable cardiac risk factors and impaired quality of life. In these individuals, replacing GH reverses these anomalies, although it may not alter the reduced insulin-sensitivity. A proportion of adults with GHD perceive a dramatic improvement in their well-being, energy levels and mood following replacement. GH has protein and osteoanabolic, lipolytic and antinatriuretic properties. GH has been considered for the therapeutic treatment of frailty associated with ageing, osteoporosis, morbid obesity, cardiac failure, major thermal injury and various acute and chronic catabolic conditions. Initial small, uncontrolled studies for many of these clinical problems suggested a beneficial effect of GH, although, later placebo-controlled studies have not observed such dramatic effects. Furthermore, with a recent publication demonstrating an approximate 2-fold increase in mortality in critically ill patients receiving large doses of GH, the use of GH should remain in the realms of replacement therapy and research, until there are significant advances in our understanding.

Pre-treatment IGF-I level is the major determinant of GH dosage in adult GH deficiency

OBJECTIVE

Severe GH deficiency in adults is a definite clinical entity, the effects of which can be reversed by administration of subcutaneous recombinant GH. The ideal dosing regimen and determinants of the maintenance dose have, however, yet to be elucidated.

PATIENTS

In an open study of GH replacement we treated 65 GH-deficient adults of mixed adult- and childhood-onset, of mean age 35.5 (range 17-72) years, and comprising 38 females and 27 males, using an individualized low-dose titration regimen aimed at normalization of the serum IGF-I and induction of clinical improvement.

RESULTS

Before initiation of GH therapy, median IGF-I SD was significantly lower in female than male patients (- 3.3 vs. - 1.9, P = 0.007) and in childhood-onset compared with adult-onset patients (- 3.9 vs. - 2.0, P < 0.001). Once maintenance dosage had been achieved, the median GH requirement was significantly greater in female than male patients (1.6 vs. 0.8 IU/day, P = 0.013) and childhood-onset compared with adult-onset patients (1.6 vs. 0.8 IU/day, P = 0.019). The median maintenance GH dose for the cohort overall was 1.2 (range 0.4-2.4) IU/day. By univariate analysis a significant negative correlation was observed between the maintenance GH dose and baseline IGF-I SD (r = - 0.63, P < 0.001). No significant correlation was demonstrated between maintenance GH dose and either age or weight. Multiple linear regression analysis using age, gender, weight, time of onset of GH deficiency, peak GH to the insulin tolerance test (ITT) and baseline IGF-I SD as independent variables demonstrated baseline IGF-I SD to account for 51% of the variation in GH dose required to normalize the IGF-I SD (P < 0.001). Those patients with the lower IGF-I SD at initiation of GH therapy required the greater GH dose. None of the other variables studied significantly influenced the maintenance dose.

CONCLUSION

We have demonstrated that the GH dose required in an individual is dependent on the serum IGF-I SD before commencement of replacement. In contrast, the severity of GH deficiency as judged by the peak GH response to an ITT was unrelated to the maintenance GH requirement. The effect of age, gender and age at onset of GH deficiency on the final GH dose are accounted for by the lower pretreatment IGF-I SD in young, female and childhood-onset patients relative to older, male and adult-onset patients, respectively.

Survivors of childhood cancer: long-term endocrine and metabolic problems dwarf the growth disturbance

The long-term effects of radiotherapy and chemotherapy are becoming increasingly recognized as the cure rates of certain childhood malignancies improve. The endocrine system is particularly sensitive to cancer therapies. Long-term survivors of childhood cancer who received cranial irradiation have been shown to have lower than predicted height, an increased prevalence of obesity and reductions in strength, exercise tolerance, bone mineral density, quality of life and academic achievement. Growth hormone deficiency (GHD) is the most frequent endocrine deficiency observed following cranial irradiation. Adults with GHD resulting from primary hypothalamic-pituitary disease during childhood have been shown to exhibit a clinical picture similar to that described in long-term survivors of childhood cancer: increased fat mass and reduced lean mass, strength, exercise tolerance, bone mineral density and quality of life. This review considers the possible contribution of GHD to the adverse sequelae observed in long-term survivors of childhood malignancy and includes our preliminary experience in treating 14 adults with GHD resulting from the treatment of childhood malignancies.

Influences on quality of life in GH deficient adults and their effect on response to treatment

OBJECTIVE

Studies of the effect of GH on quality of life (QOL) in growth hormone deficient (GHD) adults have reported conflicting results. Recently, however, we have demonstrated that by selecting only those patients with impaired QOL the efficacy of GH replacement on QOL can be greatly improved. The improvement in QOL was observed to correlate significantly with that recorded before commencing GH therapy. This study aims to assess if demographic variables affect QOL in untreated GHD adults or the improvement in QOL following GH therapy.

DESIGN

An open study of GH replacement, initiating treatment with a dose of 0.8 IU/day and titrating the dose by 0.4 IU increments to normalize the IGF-I SDS between - 2.0 and + 2.0 SD of the age related normal range.

PATIENTS

65 severely GHD patients (peak GH < 9 mU/l to provocative testing), mean age 38.7 (range 17-72) years. Inclusion criterion was that of subjectively poor quality of life on clinical interview.

MEASUREMENTS

Blood was taken for insulin-like growth factor 1 (IGF-I). The Psychological General Well-Being Schedule (PGWB) and Adult Growth Hormone Deficiency Assessment (AGHDA) self-rating questionnaires were used to assess quality of life at baseline, three and eight months after commencing GH.

RESULTS

The patients were subgrouped on the basis of gender, age of onset of GHD, pathology and presence of additional pituitary hormone deficits. The cohort consisted of 40 females and 25 males, 45 of adult-onset (AO) and 20 of childhood-onset (CO). GH deficiency resulted from a hypothalamo-pituitary pathology, or treatment thereof, in 36 patients and as a result of cranial irradiation for a primary brain tumour or prophylaxis in acute lymphoblastic leukaemia in 29 patients. Isolated GH deficiency (IGHD) was present in 25 patients, and 32 patients were demonstrated to have at least two additional pituitary hormone deficits (MPHD). No significant difference was detected between baseline PGWB scores of the subgroups. Multiple linear regression analysis revealed the age of onset of GHD to be a significant determinant of both the baseline PGWB (P = 0.05) and AGHDA (P = 0.025) scores, AO patients perceiving the greater distress. A significant improvement, from baseline, in both QOL scores was observed in all subgroups at three months, and in all subgroups at eight months except IGHD, where a trend towards improvement in the AGHDA score was observed but failed to reach significance. The mean improvement in the PGWB following GH therapy was not significantly different between subgroups. Multiple linear regression analysis confirmed baseline PGWB and AGHDA scores to be the most important variable in prediction of the level of improvement in respective scores following GH therapy. Age of onset was also observed to be a significant determinant of the PGWB scores following GH therapy (P = 0.02), the CO cohort experiencing the greater improvement. A similar relationship between age of onset and AGHDA scores was not observed (P = 0.22).

CONCLUSIONS

Baseline QOL as assessed by self-rating questionnaires is influenced by the age of onset of the GH deficiency, adult onset patients expressing the greater distress. Improvements in QOL scores are influenced by both baseline score and to a lesser extent the age of onset of GHD, the greater improvement being observed in childhood onset patients. The degree of improvement was observed to be independent of gender, pathology and number of pituitary hormone deficits. In a cohort selected by subjectively impaired QOL, we have demonstrated childhood onset GHD patients perceive themselves to have less impairment of QOL pretreatment. In contrast to previous data in unselected cohorts, however, we have shown that those childhood onset GHD patients in whom QOL is significantly reduced, show a capacity for improvement that is equal to, if not greater, than that seen in adult onset-GHD patients.