Gender does not influence prepubertal growth velocity during standard growth hormone therapy--analysis of United States KIGS data

The metabolic outcomes of growth hormone treatment in children are gender specific

OBJECTIVE

To evaluate the impact of gender on the clinical and metabolic parameters in prepubertal growth hormone deficiency (GHD) children at diagnosis and during GH treatment (GHT).

DESIGN

The data of 105 prepubertal children (61 males, 44 females, mean age 6.8 ± 0.7 years) affected by idiopathic GHD were retrospectively evaluated.

METHODS

Body height, BMI, waist circumference (WC), IGF-I, HbA1c, lipid profile, fasting and after-OGTT glucose and insulin levels, insulin sensitivity and secretion indices were evaluated at baseline and after 24 months of GHT.

RESULTS

At baseline, no significant difference was found in all clinical, hormonal and metabolic parameters between males and females. After 24 months of GHT, both males and females showed a significant increase in height (both P < 0.001), BMI (both P < 0.001), WC (P < 0.001 and P = 0.004, respectively), IGF-I (both P < 0.001), fasting glucose (P < 0.001 and P = 0.001, respectively), fasting insulin (both P < 0.001) and Homa-IR (both P < 0.001), with a concomitant significant decrease in insulin sensitivity index (ISI) (both P < 0.001) and oral disposition index (DIo) (P = 0.001 and P < 0.001, respectively). At 24 months of GHT, females showed significantly higher BMI (P = 0.027), lower ISI (P < 0.001) and DIo (P < 0.001), in concomitance with a significant greater change from baseline to 24 months of BMI (P = 0.013), WC (P < 0.001), ISI (P = 0.002) and DIo (P = 0.072), although the latter does not reach statistical significance.

CONCLUSIONS

Twenty-four months of GHT in prepubertal children leads to different metabolic outcomes according to gender, with a greater reduction in insulin sensitivity in females, regardless of auxological and hormonal parameters. Therefore, prepubertal GHD females should probably need a more proper monitoring in clinical practice.

Recombinant growth hormone therapy in children with short stature in Kuwait: a cross-sectional study of use and treatment outcomes

BACKGROUND

Recombinant Growth hormone (rGH) therapy is approved in many countries for treatment of short stature in a number of childhood diagnoses. Despite the increasing body of international literature on rGH use, there is paucity of data on rGH use in Kuwait and the broader Middle-East which share unique ethnic and socio-cultural backgrounds. This study aimed to describe the pattern of use and treatment outcomes of rGH therapy in Kuwait.

METHODS

This is a cross-sectional retrospective review of children treated with rGH in the Department of Pediatrics, in a major hospital in Kuwait between December 2013 and December 2014. Data were extracted using standard data extraction form and the response to rGH therapy was defined as a gain of ≥ 0.3 standard deviation score (SDS) of height per year.

RESULTS

A total of 60 children were treated with rGH in the center. Their Median (Interquartile) age at rGH initiation was 9.0 (6.2, 10.7) years. The most common indications for rGH therapy were Growth Hormone Deficiency (GHD) 23 (38.3 %), Idiopathic Short Stature (ISS) 12 (20.0 %) and Small for Gestational Age (SGA) 9 (15.0 %). After excluding patients with TS, no significant differences were found in gender of those who received rGH therapy in all indications combined or in each group (p ≥ 0.40). At 1-year follow-up, children in all groups had median height SDS change of ≥ 0.3 SDS except for children with ISS. Age at rGH initiation was negatively associated with 1-year treatment response, Adjusted odds ratio (AOR) 0.56 (95 % CI: 0.04-1.49); p = 0.011).

CONCLUSIONS

GHD is the most common indication of rGH therapy. All indications except for ISS showed significant 1-year treatment response to therapy. Treatment outcomes in patients with ISS should be further investigated in Kuwait. Younger age at initiation of rGH therapy was independently associated with significant response to therapy suggesting the importance of identifying children with short stature and prompt initiation of rGH therapy.

Growth hormone regimens in Australia: analysis of the first 3 years of treatment for idiopathic growth hormone deficiency and idiopathic short stature

OBJECTIVE

To investigate response to growth hormone (GH) in the first, second and third years of treatment for all idiopathic GH-deficient (GHD) and idiopathic short stature (ISS) patients in Australia.

CONTEXT

Eligibility for subsidized GH treatment in Australia is determined on auxological criteria for the indication of Short Stature and Slow Growth (SSSG), which includes ISS (SSSG-ISS). The biochemical GHD (BGHD, peak GH < 10 mU/l) and SSSG indications are treated similarly: starting dose of 4·5 mg/m(2)/week with provision for incremental dosing. Some ISS patients were specifically diagnosed with familial short stature (SSSG-FSS).

DESIGN

Responses for each year of treatment for BGHD, SSSG-ISS and SSSG-FSS cohorts were compared in relation to influencing variables and with international benchmarks. The effect of incremental dosing was assessed.

PATIENTS

Australian BGHD, SSSG-ISS and SSSG-FSS patients who had completed 1, 2, or 3 years of treatment and were currently receiving GH.

MEASUREMENTS

Growth hormone dose, change in height-standard deviation score (ΔSDS) and growth velocity (GV).

RESULTS

First-year response was 2-3 times greater than that in subsequent years: ΔSDS(1st year) = 0·92, 0·50 and 0·46 for BGHD, SSSG-ISS and SSSG-FSS, respectively. Responses were similar to international reports and inversely related to age at commencement of GH. First-year GV-for-age for BGHD patients was similar to international standards for idiopathic GHD. However, girls had an inferior response to boys when treatment commenced at <6 years of age. First-year GV-for-age for SSSG-ISS/FSS patients was less than ISS standards. Dose increments attenuated the first- to second-year decline in response to BGHD but marginally improved the responses for SSSG-ISS/FSS.

CONCLUSIONS

The Australian auxology-based GH programme produces comparable responses to international programmes. A lower starting dose is offset by the initiation of treatment at younger ages. Incremental dosing does not appear optimal. A first-year dose of 6·4-6·9 mg/m(2)/week for GHD and 8·9 mg/m(2)/week for ISS with early commencement of GH treatment may be most efficacious.

Identification of factors associated with good response to growth hormone therapy in children with short stature: results from the ANSWER Program®

OBJECTIVE

To identify factors associated with growth in children on growth hormone (GH) therapy using data from the American Norditropin Studies: Web-enabled Research (ANSWER) Program® registry.

METHODS

GH-naïve children with GH deficiency, multiple pituitary hormone deficiency, idiopathic short stature, Turner syndrome, or a history of small for gestational age were eligible (N = 1,002). Using a longitudinal statistical approach, predictive factors were identified in patients with GHD for change from baseline in height standard deviation score (ΔHSDS) following 2 years of treatment.

RESULTS

Gradual increases in ΔHSDS over time were observed for all diagnostic categories. Significant predictive factors of ΔHSDS, ranked by significance were: height velocity (HV) at 4 months > baseline age > baseline HSDS > baseline body mass index (BMI) SDS > baseline insulin-like growth factor I (IGF-I) SDS; gender was not significant. HV at 4 months and baseline BMI SDS were positively correlated, whereas baseline age, HSDS, and IGF-I SDS were negatively correlated with ΔHSDS.

CONCLUSIONS

These results may help guide GH therapy based on pretreatment characteristics and early growth response.

Factors influencing the one- and two-year growth response in children treated with growth hormone: analysis from an observational study

To assess gender-, pubertal-, age-related differences in change from baseline height standard deviation score (ΔHSDS), data from 5,797 growth hormone (GH) naïve pediatric patients (<18 years) with growth hormone deficiency (GHD), multiple pituitary hormone deficiency (MPHD), Turner syndrome (TS), small for gestational age (SGA), Noonan syndrome (NS), and idiopathic short stature (ISS) were obtained from the ANSWER (American Norditropin Studies: Web-enabled Research) Program registry. For patients with SGA, ΔHSDS at year 1 was significantly greater for males versus females (P = .016), but no other gender differences were observed. For patients with GHD, ΔHSDS was greater in prepubertal than in pubertal patients. Younger patients for both genders (<11 years for boys; <10 years for girls) showed a greater ΔHSDS (P < .05 for GHD, MPHD, and ISS). Overall, positive ΔHSDSs were observed in all patients, with greater growth responses in younger prepubertal children, emphasizing the importance of starting GH treatment early.

Growth hormone action in puberty: effects by gender

OBJECTIVE

Adult females receiving GH may be less sensitive to the metabolic effects of GH than males, however these differences are less well studied in adolescence. We aimed to investigate if metabolic effects of GH vary by gender during puberty.

DESIGN

Sixteen adolescents (8 M/8 F, mean age (SE): 13.1+/-0.2 yr) with significant short stature due to either GH insufficiency or idiopathic short stature were studied before and after 8 w of daily GH therapy. Differences in rates of protein and glycerol turnover ((13)C leucine and d5-glycerol infusions), substrate oxidation rates (indirect calorimetry), hormones, growth factors, lipid concentrations, body composition (DEXA) and 1 yr growth velocity were measured.

RESULTS

Protein synthesis rates per kg FFM were similar in boys and girls before and after GH and increased similarly on treatment in both genders. Rates of whole body lipolysis were similar at baseline and increased after GH in both genders comparably. Plasma lipids were similar between boys and girls before and after GH, and triglycerides increased post-GH in both. Insulin increased after GH comparably in both genders, yet no significant difference in glucose or adiponectin concentrations during treatment or between genders was observed. IGF-I concentrations were similar between boys and girls at baseline, but with a more robust increase in males after 8 w of GH (boys: +629+/-65 ng/ml, girls: +331+/-67, p=0.007). Body composition changes and bone mineral density were similar between genders after GH. HT SDS increased comparably after 1 yr (boys -2.2+/-0.09 to -1.77+/-0.11, p=0.0002; girls -2.49+/-0.24 to -2.02+/-0.25, p=0.04). There were no gender differences on the linear growth responses after 12 mo.

CONCLUSIONS

As compared to girls, boys had: (1) similar sensitivity to GH for protein synthesis, lipolysis, lipid concentrations and body composition changes as well as comparable glucose and adiponectin concentrations; (2) higher IGF-I responses to 8 w of GH. Differences in IGF-I during GH treatment may account in part for the gender differences in physique and strength that develop during human puberty; however, using conventional doses of GH, these differences do not translate into differences in linear growth after 12 mo. Contrary to adults, these data do not support the need for different GH dosing depending on gender during puberty.