Efficacy and safety of growth hormone (GH) in the treatment of adult Japanese patients with GH deficiency: a randomised, placebo-controlled study

Growth hormone therapy in adults with growth hormone deficiency: a critical assessment of the literature

PURPOSE

Growth hormone (GH) therapy has been studied as treatment for clinical manifestations of adult-onset growth hormone deficiency (AO-GHD), including cardiovascular risk, bone health, and quality of life. Patients with AO-GHD typically also have significant history of pituitary pathology and hypopituitarism, which raises the question of what proportion of their clinical presentation can be attributed to GHD alone. Currently, much of the existing data for GH therapy in AO-GHD come from uncontrolled retrospective studies and observational protocols. These considerations require careful reassessment of the role of GH as a therapeutic agent in adult patients with hypopituitarism.

METHODS

We contrast results from placebo-controlled trials with those from uncontrolled and retrospective studies for GH replacement in patients with hypopituitarism. We also examine the evidence for the manifestations of AO-GHD being attributed to GHD alone, as well as the data on adults with congenital, life-long untreated isolated GHD.

RESULTS

The evidence for increased morbidity and mortality in hypopituitary patients with GHD, and for the benefits of GH therapy, are conflicting. There remains the possibility that the described clinical manifestations of AO-GHD may not be due to GHD alone, but may also be related to underlying pituitary pathology, treatment history and suboptimal hormone replacement.

CONCLUSIONS

In the setting of inconsistent data on the benefits of GH therapy, treatment of AO-GHD remains an individualized decision. There is a need for more randomized, placebo-controlled studies to evaluate the long-term outcomes of GH therapy in adults with hypopituitarism.

Decreased quality of life (QoL) in hypopituitary patients: involvement of glucocorticoid replacement and radiation therapy

PURPOSE

Hypopituitary patients are assumed to have decreased QoL due to GHD. However, in placebo controlled trials, the effects of GH replacement are no different from placebo. Hydrocortisone dose > 20 mg/day and pituitary radiation are independently associated with poorer QoL. We assessed QoL in panhypopituitary GH- deficient patients never treated with GH.

METHODS

Study group was divided into: (a) surgery followed by radiation (n = 21) and (b) surgery alone (n = 32). Mean duration of GHD was 71.4 ± 7.8 months and mean daily hydrocortisone dose was 15 ± 0.7 mg. Control group had transnasal surgery for benign sinus conditions (n = 54).

RESULTS

AGHDA scores were significantly worse in the entire study group compared to controls (8.1 ± 1.0 vs. 5.1 ± 0.9, p = 0.03). In patients with history of radiation therapy AGHDA scores were significantly worse than in controls (9.1 ± 1.5, p = 0.02) and SNOT-22 (Sino-Nasal Outcome Test) scores were also significantly worse (15.8 ± 2.0 vs. 23.2 ± 3.5, p = 0.04). However, AGHDA scores in patients without history of radiation and on "physiological" dose of hydrocortisone were similar to those in controls (5.1 ± 0.9 vs. 7.3 ± 1.3, p = 0.17).

CONCLUSIONS

Replacement with hydrocortisone doses not exceeding 20 mg/day and avoidance of radiation therapy was accompanied by normal QoL in patients not replaced with GH. Thus, we suggest that the decreased QoL in hypopituitary patients may not be due to GH deficiency per se, but rather to high hydrocortisone doses and to aftereffects of cranial radiation.

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.

Safety and effectiveness of long-term growth hormone therapy in Japanese patients with adult growth hormone deficiency: a postmarketing, multicenter, observational study

We aimed to evaluate the long-term safety and effectiveness of growth hormone (GH) therapy in Japanese patients with adult growth hormone deficiency (AGHD). In this observational, multicenter study, Norditropin^® (Novo Nordisk A/S, Bagsvaerd, Denmark) was administered as injections of 0.021 mg/kg/week as a starting dose divided into 6-7 doses/week. The dose was increased according to clinical response. Patients' data were obtained from medical records. Measurements (lipids, glucose metabolism, and body composition) taken at baseline; 3, 6, and 12 months; and yearly until the end of the study were collected. Adverse drug reactions (ADRs), serious ADRs, and serious adverse events (SAEs) were evaluated. Of 387 registered patients, 334 were eligible for safety. After GH treatment initiation, a marked decrease in total cholesterol was observed earlier in the child-onset group than in the adult-onset group. LDL-cholesterol also decreased, but no significant differences in changes in LDL-cholesterol between adult-onset and child-onset groups were found. A significant increase in HDL-cholesterol starting 1 year after GH treatment initiation was found in the adult-onset group. There was no effect of GH treatment on glucose metabolism. Because of the small number of dual-energy X-ray absorptiometry data, the overall assessment of changes of body composition was difficult. Fifty-six (16.8%), 12 (3.6%), and 35 (10.5%) patients experienced ADRs, serious ADRs, and SAEs, respectively. This study demonstrated a favorable long-term safety and effectiveness profile of GH therapy in AGHD patients in the real-life Japanese clinical practice setting.

Endocrine status of patients with septo-optic dysplasia: fourteen Japanese cases

A clinical diagnosis of septo-optic dysplasia (SOD) is made when two or more of the classical triad of optic nerve hypoplasia, pituitary hormone abnormalities or midline brain defects. To date, a clinical study of SOD, regarding its endocrinological features in particular, has not been undertaken in Japan. We retrospectively evaluated 14 SOD patients at our institution. Hormonal dysfunction was present in 78% of cases: ten cases presented combined hypopituitarism and one case presented precocious puberty. GHD and hypothyroidism were the most common endocrinopathies. A thin pituitary stalk and a gradual decrease in hormone secretion were the main characteristics. SOD patients usually visited ophthalmologists during early infancy because of eye problems; however, the medical examination did not always lead to endocrine assessments being made. Consequently, children who have eye problems with optic nerve hypoplasia should undergo head MRI imaging. If diagnosed with SOD, it is very important to evaluate pituitary functions. Their endocrinological status should be followed for a long time, even if they do not exhibit any endocrinological problems at evaluation.

A Randomized Safety and Efficacy Study of Somavaratan (VRS-317), a Long-Acting rhGH, in Pediatric Growth Hormone Deficiency

CONTEXT

Somavaratan (VRS-317) is a long-acting form of recombinant human GH under development for children and adults with GH deficiency (GHD).

OBJECTIVES

To determine the optimal somavaratan dose regimen to normalize IGF-1 in pediatric GHD and to evaluate safety and efficacy of somavaratan over 6 months.

DESIGN

Open-label, multicenter, single ascending dose study followed by 6-month randomized comparison of 3 dosing regimens.

SETTING

Twenty-five United States pediatric endocrinology centers.

PATIENTS

Naive-to-treatment, prepubertal children with GHD (n = 68).

INTERVENTION(S)

Patients received single sc doses of somavaratan (0.8, 1.2, 1.8, 2.7, 4.0, or 6.0 mg/kg) during the 30-day dose-finding phase, then were randomized to somavaratan 1.15 mg/kg weekly, 2.5 mg/kg twice monthly, or 5.0 mg/kg monthly for 6 months.

MAIN OUTCOME MEASURES

Safety, pharmacokinetics, pharmacodynamics, 6-month height velocity (HV).

RESULTS

Somavaratan pharmacokinetics was linearly proportional to dose; dose-dependent increases in the magnitude and duration of IGF-1 responses enabled weekly, twice-monthly or monthly dosing. A single dose of somavaratan sustained IGF-1 responses for up to 1 month. No somavaratan or IGF-1 accumulation occurred with repeat dosing. Mean annualized HVs for somavaratan administered monthly, twice monthly, or weekly (7.86 ± 2.5, 8.61 ± 2.7, and 7.58 ± 2.5 cm/y, respectively) were similar between groups. Adverse events were mostly mild and transient.

CONCLUSIONS

Somavaratan demonstrated clinically meaningful improvements in HV and IGF-1 in prepubertal children with GHD, with no significant differences between monthly, twice-monthly, or weekly dosing.

Reviewing the safety of GH replacement therapy in adults

CONTEXT

Systematic data on safety of growth hormone (GH) replacement therapy in adult GH deficiency is lacking.

OBJECTIVE

To systematically describe safety of adult GH replacement therapy on glucose metabolism and long term safety.

DESIGN

A systematic web-based search of PubMed was performed guided by the Standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

OUTCOME

Randomised controlled trials of ≥3 months and open trials for ≥12 months with more than 50 adult patients (50 patient years, prospective and retrospective) including adverse event reporting as well as articles on mortality primarily on adult onset patients, reporting mortality ratios on GH treated patients, were included for the review.

RESULTS

Based on the defined selection criteria 94 studies were included. The short-term early placebo controlled trials did not demonstrate an increased frequency of diabetes mellitus (DM) and the long-term open studies did not consistently show an increased incidence of DM during GH replacement. The concern that long-term GH replacement might increase the risk of primary cancer, secondary neoplasia after tumour treatment and recurrence of previous tumours was not evident in the study data.

CONCLUSION

Based on available data, short- and long-term adult GH replacement in patients with severe GH deficiency and hypopituitarism is safe. However, the small number of subjects, limitation of long-term of GH treatment data and absence of an adequate control population is still a limitation for the interpretation of these data.

Adult growth hormone deficiency: current concepts

The clinical syndrome of adult growth hormone deficiency (AGHD) was widely recognized in the 1980s. In this review, we first describe the clinical features and diagnosis of AGHD and then state the effects of growth hormone (GH) therapy for these patients. The main characteristics of AGHD are abnormal body composition, dyslipidemia, insulin resistance, and an impaired quality of life (QoL) due to decreased psychological well-being. For diagnosing AGHD, the international consensus guidelines have suggested that an insulin tolerance test (ITT) is the gold standard, but in Japan, the growth hormone releasing peptide-2 (GHRP-2) test is available and is recommended as a convenient and safe GH stimulating test. The cut-off for diagnosing severe AGHD is a peak GH concentration of 9 g/L during the GHRP-2 test. Since 2006, GH therapy has been approved for Japanese patients with severe AGHD. For adults, GH replacement therapy should be initiated at a low dose (3 g/kg body weight/day), followed by individualized dose titration while monitoring patients' clinical status and serum insulin-like growth factor-I (IGF-I) concentrations. A variety of favorable effects of GH replacement have been indicated; however, it has not yet been established fully whether there is a direct effect of GH treatment on reducing mortality.

Efficacy and safety of growth hormone replacement therapy in Japanese adults with growth hormone deficiency: a post-marketing observational study

This large-scale observational study examined the long-term effectiveness and safety of growth hormone (GH) replacement therapy for adult GH deficiency (GHD) in Japanese clinical practice using the Hypopituitary Control and Complications Study database. The study included 402 GHD patients for safety analyses and a subset of 209 patients (149 adult-onset and 60 childhood-onset GHD patients) who had not previously received GH replacement therapy for the efficacy analyses. Data on clinical, metabolic, quality of life (QoL) characteristics, and all adverse events (AEs) were collected at baseline (start of GH treatment), 6 months, 1 year and 2 years. Over the observation period, there were improvements from baseline in insulin-like growth factor-I standard deviation scores (P<0.001), although the changes in metabolic parameters were minimal. QoL (Short Form-36) Z-scores significantly increased from baseline in both onset-type groups for several subscale domains (P<0.05). A total of 145 (36.1%) patients experienced ≥1 AE. Common AEs were hyperlipidaemia (2.7%) and hyperinsulinaemia (2.2%). Some patients experienced recurrent hypothalamic/pituitary tumour (events per 1000 patient-years: 2.78), new benign (0.93), malignant tumour (10.28) or other new tumour (0.93), new diabetes mellitus (7.45), and new stroke (3.71). Seven patients died during the observation period. Our safety findings are inconclusive about the associations between GH replacement and AEs, although the incidence of diabetes mellitus and cardiovascular events are similar to those reported in the Japanese general population. In conclusion, the key beneficial effects of GH replacement therapy for GHD are observed in routine clinical practice in Japan.

Development and validation of a new questionnaire assessing quality of life in adults with hypopituitarism: Adult Hypopituitarism Questionnaire (AHQ)

Objective

To develop and validate the Adult Hypopituitarism Questionnaire (AHQ) as a disease-specific, self-administered questionnaire for evaluation of quality of life (QOL) in adult patients with hypopituitarism.

Methods

We developed and validated this new questionnaire, using a standardized procedure which included item development, pilot-testing and psychometric validation. Of the patients who participated in psychometric validation, those whose clinical conditions were judged to be stable were asked to answer the survey questionnaire twice, in order to assess test-retest reliability.

Results

Content validity of the initial questionnaire was evaluated via two pilot tests. After these tests, we made minor revisions and finalized the initial version of the questionnaire. The questionnaire was constructed with two domains, one psycho-social and the other physical. For psychometric assessment, analyses were performed on the responses of 192 adult patients with various types of hypopituitarism. The intraclass correlations of the respective domains were 0.91 and 0.95, and the Cronbach’s alpha coefficients were 0.96 and 0.95, indicating adequate test-retest reliability and internal consistency for each domain. For known-group validity, patients with hypopituitarism due to hypothalamic disorder showed significantly lower scores in 11 out of 13 sub-domains compared to those who had hypopituitarism due to pituitary disorder. Regarding construct validity, the domain structure was found to be almost the same as that initially hypothesized. Exploratory factor analysis (n = 228) demonstrated that each domain consisted of six and seven sub-domains.

Conclusion

The AHQ showed good reliability and validity for evaluating QOL in adult patients with hypopituitarism.

Growth hormone treatment in boys with Duchenne muscular dystrophy and glucocorticoid-induced growth failure

This study evaluated efficacy and safety of growth hormone treatment in Duchenne muscular dystrophy boys with glucocorticoid-induced growth failure. We reviewed 39 consecutive boys (average age 11.5 years; 32 ambulatory) treated with growth hormone for 1 year during a four-year period. Boys were on long-term daily deflazacort or prednisone (mean duration 5 ± 2.2 years; dosing regimen prednisone 0.75 mg/kg/day equivalent). Primary outcomes were growth velocity and height-for-age z-scores (height SD) at 1 year. Height velocity increased from 1.3 ± 0.2 to 5.2 ± 0.4 cm/year on growth hormone (p<0.0001). Pre-growth hormone decline in height SD (-0.5 ± 0.2SD/year) stabilized at height SD -2.9 ± 0.2 on growth hormone (p<0.0001). The rate of weight gain was unchanged, at 2.8 ± 0.6 kg/year pre-growth hormone and 2.6 ± 0.7 kg/year at 1 year. Motor function decline was similar pre-growth hormone and at 1 year. Cardiopulmonary function was unchanged. Three experienced side effects. In this first comprehensive report of growth hormone in Duchenne muscular dystrophy, growth hormone improved growth at 1 year, without detrimental effects observed on neuromuscular and cardiopulmonary function.

Favorable Impacts of Growth Hormone (GH) Replacement Therapy on Atherogenic Risks in Japanese Children with GH Deficiency

Growth hormone (GH) affects body composition and atherogenic risk factors. Severe hyperlipidemia may develop in GH-deficient adults as a consequence of continuous GH deficiency. We investigated changes in lipid profiles in 158 Japanese children (103 boys and 55 girls) with GH deficiency who had been enrolled in the Pfizer International Growth Database Japan during 3 yr of GH replacement therapy to evaluate whether GH treatment has beneficial effects on atherogenic risk factors. Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and atherogenic index were evaluated before treatment and then once a year during treatment. The mean baseline TC was within the normal range in both boys and girls. Seventeen (16.5%) of the 103 boys and 18 (32.7%) of the 55 girls, however, had a TC level over 200 mg/dl before treatment. The mean TC level showed a significant decrease in girls. In a separate analysis, patients of both sexes with a TC level > 200 mg/dl showed significantly decreased TC. LDLC decreased significantly only in girls, while HDLC showed no change in either sex. The atherogenic index decreased significantly in girls. GH replacement therapy in children with GH deficiency had beneficial effects on lipid metabolism and atherogenic risk in both sexes. Early GH treatment would produce lipid metabolism benefits in these patients.

Standardized centile curves and reference intervals of serum insulin-like growth factor-I (IGF-I) levels in a normal Japanese population using the LMS method

Measurements of insulin-like growth factor-I (IGF-I) are useful not only for diagnosis and management of patients with growth hormone (GH)-related disorders but also for assessing nutritional status. We reported population-based references of serum IGF-I in 1996. However, they did not properly reflect data in the transition period from puberty to maturity. The aim of the present study was to re-establish a set of normative data for IGF-I for the Japanese population. The study included 1,685 healthy Japanese subjects (845 males, 840 females) from 0 to 83 years old. Subjects suffering from diseases that could affect IGF-I levels were excluded. Obese or extremely thin adult subjects were also excluded. IGF-I concentrations were determined by commercially available immunoradiometric assays. The reference intervals were calculated using the LMS method. Median IGF-I levels reached 310 ng/mL in males at the age of 14 years and 349 ng/mL in females at the age of 13 years, falling to 124 ng/mL and 103 ng/mL, respectively, by the age of 70 years. The mean pretreatment IGF-1 SD scores in patients with severe GH deficiency (GHD) obtained from the database of the Foundation for Growth Science and from clinical studies for adult GHD were -2.1±1.6 and -4.9±2.5, respectively. The present study established age- and gender-specific normative IGF-I data for the Japanese population and showed the utility of these references for screening patients with severe GHD.

Clinical characteristics of Japanese adults with growth hormone deficiency: a HypoCCS database study

The clinical characteristics of Caucasian adults with growth hormone (GH) deficiency (GHD) have been well defined. However, no large-scale clinical practice study has examined the clinical characteristics of Japanese adults with GHD. The aim of our study was to describe the clinical characteristics of Japanese adults with GHD by reviewing the records of participants who were GH-naive at the time of enrollment in the Hypopituitary Control and Complications Study (N = 349). The majority of participants (280 of 349; 80.2%) had adult-onset rather than childhood-onset GHD. Hypothalamo-pituitary tumors were the most common cause of GHD in Japanese adults (247 of 349; 70.8%); these tumors were primarily pituitary adenomas in participants with adult-onset GHD (156 of 243; 64.2%), and germ cell tumors (19 of 40; 47.5%) and craniopharyngiomas (18 of 40; 45.0%) in participants with childhood-onset GHD. Most participants (310 of 349; 88.8%) had multiple pituitary hormone deficiencies. Dyslipidemia (195 of 349; 55.9%), visual field loss (67 of 349; 19.2%), hypertension (59 of 349; 16.9%), and liver disease (54 of 349; 15.5%) were the most common pre-existing conditions in Japanese adults with GHD. Quality of life was decreased in seven of the eight short form-36 domains in participants with GHD compared with age- and sex-matched healthy Japanese individuals. Our findings confirm that the clinical characteristics of Japanese adults with GHD are similar to those of Caucasian adults with GHD. Confirmation of these clinical characteristics will enhance the ability of clinicians to identify and treat Japanese adults with GHD.

Assessment of quality of life in adult patients with GH deficiency: KIMS contribution to clinical practice and pharmacoeconomic evaluations

Quality of life (QoL) has emerged as an important construct that has found numerous applications across healthcare-related fields, ranging from research and clinical evaluation of treatment effects to pharmacoeconomic evaluations and global healthcare policy. Impairment of QoL is one of the key clinical characteristics in adult GHD and has been extensively studied in the Pfizer International Metabolic Database (KIMS). We provide summarized evidence on GH treatment effects for both clinical and health economic applications based on the KIMS data. The primary focus is on those aspects of QoL research that cannot be investigated in the traditional clinical trial setting, such as specific patient subgroups, cross-country comparisons and long-term follow-up. First, the impact of age, gender, disease onset, primary aetiology, extent of hypopituitarism, previous radiotherapy and obesity on QoL before and during long-term GH replacement is discussed. Secondly, the studies on QoL in relation to country-specific normative values are reviewed. Finally, health economic data derived from KIMS including both burden of disease and utility assessment are evaluated. We conclude that the wide spectrum of analyses performed on the KIMS data allows for practical application of the results not only to research and clinical practice but also to health policy and global medical decision making.

Safety and efficacy of growth hormone (GH) during extended treatment of adult Japanese patients with GH deficiency (GHD)

OBJECTIVES

To assess the effects of a growth hormone (GH) replacement therapy using a GH dose regimen based on serum insulin-like growth factor (IGF-I) concentrations in Japanese adults with GH deficiency (GHD).

DESIGN

In this multicentre, uncontrolled, open-label study, Japanese adults with GHD who had received either GH replacement therapy (GH-GH group, n=35) or placebo (Placebo-GH group, n=36) in a previous randomised, double-blind, placebo-controlled trial were treated with GH replacement therapy for 48 weeks. GH treatment was started at a dose of 0.003 mg/kg/day administered by subcutaneous injection for the first 8 weeks, after which the dose was adjusted to maintain patients' serum IGF-I levels within the reference range adjusted for age and gender. Body composition, serum lipids, serum IGF-I and IGF binding protein-3 (IGFBP-3) levels were measured throughout study. Symptom and quality of life scores were also determined.

RESULTS

Lean body mass (LBM) was increased compared with baseline (the end of the preceding double-blind trial) at 24 and 48 weeks, with a mean (+/-SD) increase of 1.3% (+/-4.2%) at week 48 in the GH-GH group (an increase of 6.6% [+/-6.0%] from the start of the preceding double-blind trial) and a larger increase of 4.7% (+/-5.9%) in the Placebo-GH group. Body fat mass (BFM) increased slightly from baseline in the GH-GH group with a mean increase of 2.9+/-10.6% at week 48 (a decrease from the start of the preceding double-blind trial at 48 weeks of 7.8% [+/-15.0%]) but decreased by 6.5% (+/-11.7%) at week 48 in the Placebo-GH group. Serum lipids were unchanged or slightly increased from baseline in the GH-GH group but patients' lipid profiles improved in the Placebo-GH group. In patients who received placebo during the double-blind study, individualised GH therapy in this open-label study increased mean LBM at 48 weeks by 6.2+/-6.8% in patients with CO GHD and by 3.0+/-4.4% in patients with AO GHD. Changes in mean LBM and mean BFM at week 48 were +4.1+/-4.5% and -2.4+/-10.5%, respectively, in females and +5.0+/-6.7% and -8.9+/-11.8%, respectively, in males. In patients who received GH treatment during the double-blind study, overall changes in LBM, BFM and IGF-I SD score after 24 weeks and 48 weeks were small, with no significant differences between subgroups. While the overall incidence of adverse events was broadly similar in the GH-GH and Placebo-GH groups (97% and 89%, respectively), the incidence of treatment-related events was higher in the GH-GH group (83% vs 42% in the Placebo-GH group). Most adverse events in both treatment groups were of mild or moderate severity and not clinically significant. The incidences of oedema and cases of high IGF-I during the IGF-I level-adjusted treatment regimen were lower than those during the preceding fixed dose titration.

CONCLUSION

Long-term GH replacement therapy was well tolerated in Japanese adults with GHD. GH treatment maintained the improvements in body composition and lipid profiles in the patients previously treated in the double-blind study (GH-GH group) and improved these parameters in previously untreated patients (Placebo-GH group). Individualised GH administration based on IGF-I levels was well-tolerated and effective.

Fasting inhibits the growth and reproductive axes via distinct Y2 and Y4 receptor-mediated pathways

Neuropeptide Y, a neuropeptide abundantly expressed in the brain, has been implicated in the regulation of the hypothalamo-pituitary-somatotropic axis and the hypothalamo-pituitary-gonadotropic axis. Elevated hypothalamic neuropeptide Y expression, such as that occurs during fasting, is known to inhibit both of these axes. However, it is not known which Y receptor(s) mediate these effects. Here we demonstrate, using Y receptor knockout mice, that Y2 and Y4 receptors are separately involved in the regulation of these axes. Fasting-induced inhibition of hypothalamic GHRH mRNA expression and reduction of circulating IGF-I levels were observed in wild-type and Y4(-/-) mice but not Y2(-/-) or Y2(-/-)Y4(-/-) mice. In contrast, fasting-induced reduction of GnRH expression in the medial preoptic area and testis testosterone content were abolished in the absence of Y4 receptors. Colocalization of Y2 receptors and GHRH in the arcuate nucleus (Arc) suggests that GHRH mRNA expression in this region might be directly regulated by Y2 receptors. Indeed, hypothalamic-specific deletion of Y2 receptors in conditional knockout mice prevented the fasting-induced reduction in Arc GHRH mRNA expression. On the other hand, fasting-induced decrease in GnRH mRNA expression in the medial preoptic area is more likely indirectly influenced by Y4 receptors because no Y4 receptors could be detected on GnRH neurons in this region. Together these data show that fasting inhibits the somatotropic axis via direct action on Y2 receptors in the Arc and indirectly inhibits the gonadotropic axis via Y4 receptors.

Validation of the Japanese version of the Quality of Life-Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA)

OBJECTIVE

To evaluate validity and reliability of the Japanese version of the Quality of Life-Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA).

DESIGN

Observational study; cross-sectional, longitudinal.

METHODS

Seventy-five adults with growth hormone deficiency completed the SF-36 (a generic health-related QOL scale) and the QoL-AGHDA before growth hormone replacement therapy and approximately 3 weeks later (when the therapy began). A sample (n=1000) of controls from the general population was also studied. We computed rates of missing data, measured reproducibility and internal consistency reliability, and tested for known-groups validity, concurrent validity, unidimensionality (by principle component analysis), and content validity.

RESULTS

Rates of missing data were low (0-1.4%). The mean of QoL-AGHDA scores in the patients was 8.2 (SD, 6.4). The scores were reproducible (k=0.41-0.78), and internally consistent (alpha=0.91) and the scale was unidimensional. QoL-AGHDA scores were associated with SF-36 scores as hypothesized. Scores were significantly higher in the patients than in controls (8.1+/-0.7, and 5.6+/-0.2, P<0.001). Discrimination between patients and controls was slightly better using scores on the "General Health" and "Role Physical" subscale of the SF-36 as explanatory variables than using QoL-AGHDA scores.

CONCLUSIONS

The QoL-AGHDA's reliability, validity, and rates of missing data were satisfactory, and the scale was confirmed to be unidimensional. However, because some subscales of the SF-36 were better for discriminating patients from controls, the content validity of the QoL-AGHDA may need to be re-evaluated.

Effect of growth hormone treatment on trunk fat accumulation in adult GH-deficient Japanese patients: a randomised, placebo-controlled trial

OBJECTIVE

Patients with growth hormone deficiency (GHD), both Japanese and Caucasian, have an abnormal body composition with pronounced abdominal obesity. This study aimed to evaluate changes in trunk fat with GH treatment.

DESIGN

Double-blind, placebo-controlled study.

PATIENTS AND MEASUREMENTS

Sixty-one Japanese adult GH deficient patients (mean age 37 years) were randomised to either GH, titrated to 0.012 mg/kg/day, (n = 30) or placebo (n = 31) for 24 weeks. Body composition, by dual-energy X-ray absorptiometry (DXA), was evaluated at a central laboratory for trunk fat, total body fat and lean body mass. Serum lipid levels were also determined centrally.

RESULTS

At baseline, 26 (42.6%) patients had a body mass index (BMI) > or = 25 kg/m(2), the threshold for obesity-related complications for Japanese subjects. Median trunk fat mass (FM) was > or = 9.0 kg for each treatment and gender group, higher than the cut-off for increased age-adjusted risk for cardiovascular complications reported in the normal Japanese population. After 24 weeks of GH treatment, the change in percentage trunk FM was -3.4 +/- 0.6%, versus 0.4 +/- 0.6% with placebo (p < 0.001). Change in total body FM was -2.8 +/- 0.5% with GH and 0.0 +/- 0.5% with placebo, indicating that the decrease in trunk fat was more pronounced than for total body fat. Total and low density lipoprotein (LDL)-cholesterol were both significantly (p < 0.001) decreased compared with placebo. One patient discontinued due to a subdural haematoma and one had GH dose reduced due to hyperglycaemia.

CONCLUSIONS

Japanese patients with GHD have abnormal central fat accumulation, which is reduced by GH treatment over 24 weeks. This may reduce cardiovascular risk but the GH dose should be individualised to maintain IGF-I in the normal range.