Patrick Wilton

GH replacement in 1034 growth hormone deficient hypopituitary adults: demographic and clinical characteristics, dosing and safety.

Long‐term experience of growth hormone (GH) replacement therapy in a large population of hypopituitary adults with GH deficiency (GHD) is limited, and safety surveillance is clearly essential. KIMS, the Pharmacia & Upjohn International Metabolic Database, is a long‐term, open, outcomes research programme of hypopituitary adult patients with GHD who are treated in a conventional clinical setting.

The Influence of Growth Hormone Deficiency, Growth Hormone Replacement Therapy, and Other Aspects of Hypopituitarism on Fracture Rate and Bone Mineral Density

To assess the influence of factors affecting fracture risk and bone density in adult hypopituitary patients with growth hormone deficiency (GHD), data from a large‐scale pharmacoepidemiological survey (the Pharmacia & Upjohn International Metabolic Database [KIMS]) were analyzed and compared with data from a control population (the European Vertebral Osteoporosis Study [EVOS]). The KIMS group consisted of 2084 patients (1112 men and 972 women) with various types of pituitary disease and EVOS consisted of 1176 individuals (581 men and 595 women). Fracture and bone mineral density (BMD) data were available from 2024 patients from the KIMS group and 392 patients from EVOS. The prevalence of fractures in patients with hypopituitarism was 2.66 times that in the non‐GH‐deficient EVOS population. Adult‐onset hypopituitarism with GHD was associated with a higher fracture risk than childhood‐onset disease, and patients with isolated GHD had a similar prevalence of fractures to those with multiple pituitary hormone deficiencies. Hormonal replacement therapy with L‐thyroxine, glucocorticoids, and sex steroids did not affect the risk of fracture in KIMS patients. In addition, fracture rates in KIMS were independent of body mass index (BMI) and the country of origin. However, smoking was associated with a higher fracture rate in this group. In summary, this is the first large‐scale analysis to support the hypothesis of an increased fracture risk in adult patients with hypopituitarism and GHD. This increased risk appears to be attributable to GHD alone, rather than to other pituitary hormone deficiencies or to their replacement therapy.

Incidence of diabetes mellitus and impaired glucose tolerance in children and adolescents receiving growth-hormone treatment

BACKGROUND Growth hormone (GH) contributes to insulin resistance, but whether children treated with GH are at increased risk of diabetes has not been established. We undertook a retrospective analysis of data from an international pharmacoepidemiological survey of children treated with GH to find out the incidence of impaired glucose tolerance and types 1 and 2 diabetes mellitus. METHODS Reports to the survey of abnormal glucose metabolism were investigated and classified. The incidence and age-distribution of type 1 diabetes were compared with values from a model of reference data. The incidence of type 2 diabetes was compared with data from two reports of children not treated with GH. FINDINGS 85 (0.36%) of 23333 children were reported with abnormal glucose metabolism. After investigation, 43 had confirmed glucose disorders (11 with type 1 diabetes, 18 with type 2 diabetes, and 14 with impaired glucose tolerance). The incidence and age at diagnosis of type 1 diabetes in children treated with GH did not differ from expected values. The incidence of type 2 diabetes was 34.4 cases per 100000 years of GH treatment which was six-fold higher than reported in children not treated with GH. Type 2 diabetes did not resolve after GH therapy was stopped. INTERPRETATION GH treatment did not affect the incidence of type 1 diabetes mellitus in any age group. We postulate that the higher than expected incidence of type 2 diabetes mellitus with GH treatment may be an acceleration of the disorder in predisposed individuals.

Congenital idiopathic growth hormone deficiency associated with prenatal and early postnatal growth failure

To assess the role of growth hormone in fetal and infant growth, we analyzed the pretreatment data on 52 patients with a diagnosis of congenital growth hormone deficiency before 2 years of age, obtained from the Kabi Pharmacia International Growth Study. These infants had reduced birth-length standard deviation scores, an excess of birth weight relative to length, and progressive growth failure. We conclude that congenital growth hormone deficiency may cause impaired growth in utero and early infancy, and that growth hormone plays an important role in perinatal and infantile growth.

Improvement of diagnostic criteria in growth hormone insensitivity syndrome: solutions and pitfalls

A survey to identify children and adolescents with primary growth hormone insensitivity syndrome (GHIS) yielded 38 patients who were positively identified using a scoring system that included five criteria: height, basal growth hormone (GH), GH binding protein, basal insulin‐like growth factor 1 (1GF‐I) and the increase of IGF‐I after 4 days of GH administration (IGF generation test). Because of an overlap of the accepted and excluded groups with respect to points scored, an attempt was made to improve the scoring system. The new criteria were: height below –3 SDS, basal GH 4 mU/I or above, GH binding below 10%, basal IGF‐I and basal IGF binding protein‐3 (IGFBP‐3) below the 0.1 centile for age, an increase of IGF‐I in the IGF generation test less than 15 μg/1, and the increase of IGFBP‐3 less than 0.4 mg/1. With this scoring system, a clear separation between the accepted and the excluded groups was obtained. IGFBP‐3 was included to give the GH‐dependent parameters of the IGF system more weight and because the accuracy of IGFBP‐3 in the IGF generation tests was greater than the accuracy of IGF‐I, when the group of patients with GHIS was compared with a group of patients with GH deficiency. Unexpectedly, the IGF generation test was unable to segregate both cohorts completely. In the GHIS‐positive group, a significant correlation was found between basal IGF‐I or IGFBP‐3 levels corrected for age (SDS) and height SDS (r= 0.49, p < 0.002 and r= 0.61, p < 0.0001, respectively). There was also a significant correlation between the changes of IGF‐I or IGFBP‐3 in the IGF generation test and height SDS. That is, the patients with a slight response to GH were those with the least growth retardation, suggesting the existence of partial GH insensitivity.

Overall and cause-specific mortality in GH-deficient adults on GH replacement.

OBJECTIVE Hypopituitarism is associated with an increased mortality rate but the reasons underlying this have not been fully elucidated. The purpose of this study was to evaluate mortality and associated factors within a large GH-replaced population of hypopituitary patients. DESIGN In KIMS (Pfizer International Metabolic Database) 13,983 GH-deficient patients with 69,056 patient-years of follow-up were available. METHODS This study analysed standardised mortality ratios (SMRs) by Poisson regression. IGF1 SDS was used as an indicator of adequacy of GH replacement. Statistical significance was set to P<0.05. RESULTS All-cause mortality was 13% higher compared with normal population rates (SMR, 1.13; 95% confidence interval, 1.04-1.24). Significant associations were female gender, younger age at follow-up, underlying diagnosis of Cushings disease, craniopharyngioma and aggressive tumour and presence of diabetes insipidus. After controlling for confounding factors, there were statistically significant negative associations between IGF1 SDS after 1, 2 and 3 years of GH replacement and SMR. For cause-specific mortality there was a negative association between 1-year IGF1 SDS and SMR for deaths from cardiovascular diseases (P=0.017) and malignancies (P=0.044). CONCLUSIONS GH-replaced patients with hypopituitarism demonstrated a modest increase in mortality rate; this appears lower than that previously published in GH-deficient patients. Factors associated with increased mortality included female gender, younger attained age, aetiology and lower IGF1 SDS during therapy. These data indicate that GH replacement in hypopituitary adults with GH deficiency may be considered a safe treatment.

Growth hormone deficiency and replacement in elderly hypopituitary adults

Although elderly hypopituitary adults demonstrate an increase in total and central fat compared with age‐matched controls and are distinguishable from control subjects in terms of growth hormone (GH) responsiveness on dynamic testing, there are few data available on response to GH replacement. The objective of this study was to compare the baseline characteristics and longitudinal response to GH replacement in patients aged > 65 years with that observed in younger patients enrolled in KIMS (Pharmacia and Upjohn International Metabolic Database). KIMS is a physician‐managed, open, long‐term surveillance study of adult GH‐deficient patients receiving GH replacement. Patients were entered and data provided by interested physicians.

Age at Growth Hormone Therapy Start and First-Year Responsiveness to Growth Hormone Are Major Determinants of Height Outcome in Idiopathic Short Stature

Aim: To develop methods to identify factors associated with a favorable outcome in GH-treated children with idiopathic short stature (ISS). Methods: From 4,685 children listed as having ISS within KIGS (Pfizer International Growth Database), we studied (a) the prediction model group (n = 657) to develop the first-year prediction model, and (b) the near adult height group (NAH; n = 256) which received GH for >4 years to develop descriptive models for adult height and overall height gain. Results: NAH group at GH start: age was 10.0 years, height –2.5 SD score (SDS), weight –2.3 SDS, height minus mid-parental height (MPH) –1.5 SDS; GH dose 0.19 mg/kg/week. Height gain was 1.1 SDS at a median age of 17.2 years. Growth response correlated positively with GH dose and weight at the start of GH treatment, and negatively with age and height SDS minus MPH SDS. The model explains 39% (error SD 1.2 cm) of the variability. Adult height correlated (R2 = 0.64) positively with height at GH start, MPH and the first-year responsiveness to GH, and negatively with age. Conclusions: Prepubertal children with ISS who show an appropriate first-year response to GH are likely to benefit from long-term treatment, even on low GH dosages.

Short stature in Noonan syndrome: response to growth hormone therapy

BACKGROUND Growth hormone (GH) has been used to promote growth in both the short and long term in a number of dysmorphic syndromes, including Turner syndrome. As this condition shares many clinical features with Noonan syndrome, it would seem logical to treat the latter group with GH. AIMS To assess the short and long term response to GH therapy in patients with Noonan syndrome. METHODS Analysis of patients with Noonan syndrome in the Pharmacia & Upjohn International Growth Study (this post-marketing database contains data on the majority of patients currently treated with GH in the UK). A questionnaire was also sent to participating clinicians. RESULTS Data on 66 patients (54 males) were available for study. At the start of GH therapy children were short, compared with both normal and Noonan children. During the first year of GH therapy height velocity increased from a mean of 4.9 to 7.2 cm per year. For patients treated long term with GH, mean height SDS increased from −2.9 pretreatment to −2.6 after one year and −2.3 after five years. Of the 10 patients at near final height, only one had a height above the 3rd centile for normal adults and above the mean for untreated Noonan patients. The mean increment in final height was 3.1 cm (range −1.1 to 6.5 cm). CONCLUSIONS GH therapy in patients with Noonan syndrome will improve height velocity in the short term. Longer-term therapy results in a waning of effect; initial indications are that final height is not improved substantially in most patients.

Headache, Idiopathic Intracranial Hypertension and Slipped Capital Femoral Epiphysis during Growth Hormone Treatment: A Safety Update from the KIGS Database

Background: Several uncommon adverse effects may be related to growth hormone (GH) treatment. Three potential side effects, headache, idiopathic intracranial hypertension (IIH) and slipped capital femoral epiphysis (SCFE), will be discussed. Data from 57,968 children in the KIGS (Pfizer International Growth Study database) were analyzed to determine the effects of recombinant human GH (Genotropin®) on these side effects. The diagnostic groups were idiopathic GH deficiency (IGHD) (n = 27,690), congenital GHD (CGHD) (n = 2,547), craniopharyngioma (n = 1,155), cranial tumours (n = 2,203), Turner syndrome (TS) (n = 6,092), idiopathic short stature (ISS) (n = 5,286), small for gestational age (SGA) (n = 2,973), chronic renal insufficiency (CRI) (n = 1,753) and Prader-Willi syndrome (PWS) (n = 1,368). Results: Total incidence (per 100,000 treatment years) of headache was 793.5 (n = 569). The incidence was significantly higher in the groups of patients with craniopharyngiomas, CGHD and cranial tumours than in the other diagnostic groups (p < 0.05 for all). IIH occurred in 41 children resulting in a total incidence (per 100,000 treatment years) of 27.7. The incidence (per 100,000 treatment years) was significantly lower in patients with IGHD (12.2) than in those with TS (56.4) (p = 0.0004), CGHD (54.5) (p = 0.0064), PWS (68.3) (p = 0.0263) and CRI (147.8) (p < 0.001). No cases of IIH were reported in the ISS group of patients. The median duration from onset of GH therapy to IIH ranged from 0.01 to 1.3 years in various diagnostic groups. SCFE was observed in a total of 52 children resulting in a total incidence (per 100,000 treatment years) of 73.4. The incidence (per 100,000 treatment years) was significantly lower in patients with IGHD (18.3) and in those children with ISS (14.5) than in the TS (84.5), cranial tumours (86.1) and craniopharyngioma groups (120.5) (p < 0.05 for all). No cases of SCFE were reported in the SGA and PWS groups. The median duration from onset of GH therapy to SCFE ranged from 0.4 to 2.5 years. Conclusions: The incidences of IIH and SCFE in this analysis are lower than the values reported in previous KIGS analyses and comparable to other databases. Patients with TS, organic GHD, PWS and CRI seem to be more prone to these side effects.