Growth hormone for short stature not due to classic growth hormone deficiency

Evaluation of catch-up growth from orthodontic treatment and supplemental growth hormone therapy by using Z-scores

Pituitary dwarfism causes short stature due to partial or complete inhibition of growth hormone (GH) secretion. Supplemental therapy with human GH (rhGH) accelerates the statural growth of patients, but there is limited information about its effects on craniofacial growth. This study describes the orthodontic treatment of 2 patients (a boy and a girl) diagnosed with pituitary dwarfism and treated with rhGH therapy. Growing children have different growth velocities depending on age and sex, and this complicates the assessment of treatment effects; therefore, we used the Z-score to evaluate changes in stature and craniofacial components. Growth in craniofacial structures and stature were both enhanced by rhGH therapy during orthodontic treatment.

Comparison of final heights of growth hormone-treated vs. untreated children with idiopathic growth failure

We measured adult heights (Ht) of 94 healthy GH-sufficient children (peak GH > 10 ng/mL, polyclonal RIA) whose Ht at presentation were more than 2 SD below the mean for chronological age, with normal weight-to-Ht ratios, normal body proportions, and pathologic growth velocity for chronological age. Group 1 (n 36, 6 females) received standardized doses (0.3 mg/kg x week) of GH (mean duration = 41 months), while group 2 (n = 58, 17 females) received no treatment. Our conclusion was that the mean final Ht SD score in the GH-treated group (-1.5) was significantly greater than in the untreated group (-2.1); P < .001. Genetic predisposition to short stature was evident in both groups: the midparental Ht SD score was -1.1 in the treated and -1.0 in the untreated group. Midparental Ht was met or exceeded by 42% of the GH-treated group but only 15% of the untreated group. Final Ht was not significantly different from predicted Ht, except from GH-treated girls, who exceeded their predicted Ht. Although the mean Ht gains (6.8 cm in girls and 3 cm in boys) were modest and variable, GH treatment provided significantly better Ht outcomes for the majority of children with idiopathic growth failure.

Effect of clonidine on the height of a child with glycogen storage disease type VI: a 13 year follow-up study

A 9-month-old male was found to have hepatomegaly when he was treated by his doctor for bronchitis. At the age of 2 years and 3 months, glycogen storage disease (GSD) of type VI (GSD VI) was diagnosed in this patient. Despite the recommended diet therapy, his growth was not good, changing under or along the line of -2.0 SD. At the age of 6 years, oral clonidine therapy (0.15 mg/day, 0.2 mg/m2 body surface per day) was started. Six to 10 months after the initiation of clonidine therapy, his height began to increase more than the values for -2.0 SD and once reached the value for -1.0 SD at the age of 10 years. His growth rate and bone age increased. Clonidine therapy was continued regularly for 7 years until the age of 13 years, 11 months. At that time his development was normal and his height reached 150.8 cm (-1.34 SD). However, cessation of the treatment at the patient's free will resulted in a reduction of the growth rate at age 15 years 6 months. These observations suggest the effect of clonidine therapy on height. Side effects were not noted during the clonidine therapy. Other clinical and laboratory findings of GSD VI also completely improved during treatment. In conclusion, administration of clonidine could be another treatment modality in children with GSD, not only of type VI but also I and III.

Prediction of the outcome of growth hormone therapy in children with idiopathic short stature. A multivariate discriminant analysis

OBJECTIVE

To identify, with the use of pretreatment clinical data, the children with idiopathic short stature responsive to treatment with growth hormone (GH).

DESIGN

Open, prospective study in a university hospital.

SUBJECTS

Patients admitted to the study met the following criteria: birth weight at least 2.5 kg, no sign of dysmorphic disease, stature less than the 3rd percentile for chronologic age (CA), linear growth velocity (GV) less than the 25th percentile for bone age (BA), no sign of puberty, maximal GH response to pharmacologic stimulation greater than 10 micrograms/L, no evidence of organic disease, treatment with daily subcutaneous administration of GH at a dose of 12 to 16 IU/m2 per week.

MAIN OUTCOME MEASURES

Eight pretreatment growth variables and the increase of GV after 6 months of therapy were measured. Children with a change in GV that was greater than 2.5 cm/yr after 6 months of GH therapy were considered responders to GH.

RESULTS

We studied 67 patients (44 boys). Forty patients (60%) were responders. With univariate analysis the variables found to have predictive value were GV (z score for gender and CA), bone age (z score for gender and CA), and percentage of ideal body weight. These variables were employed in a multivariate discriminant analysis. Growth velocity and BA showed the best independent discriminant analysis. Growth velocity and BA showed the best independent discriminant significance in predicting responsiveness to the initial 6 months of GH therapy. The obtained equation was as follows: Score = -0.40 + 0.92X1 - 0.87X2, where X1 is the GV z value for CA and X2 is the BA z value for CA). Using this scoring system, we obtained a specificity of 96.3% and a sensitivity of 92.5% in predicting responsiveness to GH (chi-square with Yates correction, 48.2; p < 0.001).

CONCLUSIONS

Discriminant analysis may permit the pretreatment prediction of responsiveness to the initial 6 months of GH therapy in short children without GH deficiency.

Effect of combined treatment with gonadotropin releasing hormone analogue and growth hormone in patients with central precocious puberty who had subnormal growth velocity and impaired height prognosis

Growth hormone-insulin-like growth factor-I status and response to growth hormone therapy (0.6 IU/kg/week sc, six times a week for 12 months) were evaluated in 12 girls (chronological age 9.4 +/- 1.6 years) suffering from central precocious puberty with growth velocity less than 4 cm/year and no substantial increase or decrease in predicted adult height during gonadotropin releasing hormone Bn-RH) analogue treatment (D-Trp6-LH-RH, 60 micrograms/kg im/28 days). At baseline, large variations were observed in nocturnal growth hormone (GH) means (pathological values stimulated levodopa GH peaks (pathological values (< 10.0 micrograms/l) 28.6%) and serum insulin-like growth factor-I (IGF-I) levels. Neither GH-nor IGF-I levels were correlated with growth velocity. During recombinant GH therapy, growth velocity increased significantly (baseline 3.0 +/- 0.9 cm/year; 6 months 6.4 +/- 1.9 cm/year, p < 0.001 versus baseline; 12 months 6.0 +/- 1.3 cm/year, p < 0.0001 versus baseline). There was a significant increase in height SDS for bone age (baseline -1.6 +/- 0.5 SDS; 12 months -1.04 +/- 0.6 SDS; p < 0.002) and in predicted adult height (baseline 152.0 +/- 3.6 cm; 12 months 155.9 +/- 3.4 cm; p < 0.002). Our results suggest that combined therapy with Gn-RH analogues and recombinant GH can improve growth velocity and predicted adult height in girls with central precocious puberty and impaired height prognosis during Gn-RH analogue treatment.

Screening test for growth hormone deficiency: usefulness of L-dopa-propranolol provocative test

This is a retrospective review of 185 short children who were tested for growth hormone (GH) secretion using the L-dopa-propranolol provocative test. One hundred and thirty-three children were deemed to have passed the screening test when a GH concentration of greater than 15 miu/L was elicited after stimulation. Fifty-two failed the screening test, of which 33 were diagnosed as having growth hormone deficiency (GHD) when they had inadequate growth hormone response to insulin-induced hypoglycaemia. The other 19 were low-responders since they showed adequate GH response to insulin tolerance test (ITT). The low-responder rate to L-dopa-propranolol provocative test among short children who are not GH deficient was 12.5%. The low cost of L-dopa and propranolol, the simplicity and safety of the test, and the acceptable rate of low-responders make the test an effective screening test for GHD.

Clinical diagnoses of children with extremely short stature and their response to growth hormone

This study was undertaken to determine the prevalence of clinical diagnoses in a group of children with extremely short stature (standard deviation score for height, < -2.5) and to determine whether the classification might help in predicting response to human growth hormone (hGH) treatment. We classified 49 children referred consecutively to our outpatient clinic for evaluation of short stature with heights < -2.5 standard deviation score and bone ages < 9 years for girls or < 10 years for boys (to avoid an effect of puberty on the response to hGH). The diagnostic categories were growth hormone (GH) deficiency, constitutional delay, familial short stature, and primordial short stature. After referral, Turner syndrome was diagnosed in two children. The remaining 47 children were classified according to primary criteria, considered essential for the diagnosis, and secondary criteria, considered necessary but of lesser importance. There were five children, four children, no children, and one child classified, respectively, with GH deficiency, constitutional delay, familial short stature, and primordial short stature by using the most rigorous definitions of the diagnoses. There was significant overlap in the diagnoses other than GH deficiency. Growth hormone deficiency defined by the primary criterion of peak stimulated GH values < 5 micrograms/L was the most definitive. Of the 47 children, 7 were classified as GH deficient by this criterion and 5 were classified as GH deficient by the primary and secondary criteria. The mean pretreatment growth rate (3.1 +/- 1.9 cm/yr) of the group with stimulated GH values < 5 micrograms/L was significantly less than that in the other groups (4.2 +/- 1.5 cm/yr). The mean growth rate of the children with GH deficiency during treatment with hGH was greater than that in the other groups and was 3.4 times greater than the pretreatment growth rate. The mean growth rate of children in the other groups during hGH treatment was twofold greater than the pretreatment growth rate. We conclude that except for GH deficiency, children with an extreme degree of short stature are not easily classified by standard diagnostic criteria, and that most short children have a positive response to hGH therapy regardless of the diagnosis; therefore a specific clinical diagnosis should not be used to exclude children from hGH therapy.

Conventional and nonconventional uses of growth hormone

Although GH has been available as a therapeutic agent for the GH-deficient child for more than 30 years, the conditions of its use have yet to be optimized. The availability of biosynthetic material has provided researchers with the opportunity to develop the protocols necessary to begin to finally answer the most fundamental questions pertaining to dose, frequency, and duration of treatment. It has also permitted the initiation of prospective trials in a large number of conditions that result in childhood short stature, with the expectation that some or many of them will be treated effectively and safely. Finally, it has opened the door to an entire spectrum of potentially new uses of GH and other growth factors for so-called nonconventional indications. That these have implications that range from the short-term rapid healing of a burn graft site, to the more efficient induction of ovulation, to the long-term preservation of lean body mass has excited the interest of investigators in many fields of medicine and physiology. Thus, the recent progress reported in this paper is really the beginning of the new research that will take place with GH and growth factors.

Long-term treatment with growth hormone of children with short stature and normal growth hormone secretion

Children with short stature but normal growth rate and/or normal growth hormone response to sleep and secretagogues were treated with recombinant methionyl human growth hormone, 0.3 mg/kg per week. In each year of treatment, about 80% of the subjects maintained an increase in growth rate greater than the defined limit (greater than 1 cm/yr above pretreatment growth rate) for continuation of human growth hormone treatment. Comparison of the group that continued to respond to human growth hormone with the group that did not maintain an accelerated growth rate did not reveal differences in bone age delay, sleep or secretagogue-stimulated human growth hormone secretion, degree of short stature either absolute or relative to target height, and somatomedin C concentration before or after initiation of therapy. The group that failed to respond to the human growth hormone treatment in the first year of treatment was younger and had a higher pretreatment growth rate. Review of the longitudinal growth curves revealed five patterns of response to human growth hormone treatment: (1) failure to increase growth rate in two subjects with height SD scores within 1 SD of target height, (2) failure to increase growth rate in five subjects with height SD scores greater than 1 SD less than the target height, (3) acceleration in growth rate in three subjects that was not maintained until achievement of a height within 1 SD of the target height, (4) acceleration of growth rate in five subjects that was maintained until achievement of a height within 1 SD of the target height, and (5) acceleration in growth rate that was maintained during the 3 years of treatment in 15 subjects who had not attained a height within 1 SD of the target height. We conclude that human growth hormone treatment of some but not all short children with "normal" growth hormone secretion will result in sustained acceleration of growth rate and attainment of prepubertal heights that are closer to but do not exceed their genetic height potential. A clinical trial of human growth hormone may be necessary to determine which subjects will benefit from the treatment.

Profile of growth hormone deficiency in Bombay

Of the 430 children referred for the evaluation of short stature 100 (23%) were confirmed to have growth hormone deficiency. The male to female ratio was 1.94:1. Less than 10% belonged to the lower socio-economic group. Most of the cases (73%) presented between the ages of 6-15 years though growth failure was usually recognised earlier. Minimum of two stimulation tests were performed in each case. Seventy five GH deficient children had idiopathic GHD (IGHD) and 31% of these were familial. Fourteen had organic causes and 11 had GH resistance. Of 75 with IGHD, 18 had abnormal deliveries, breech or birth asphyxia. Multitropic pituitary hormone deficiency (MPHD) was found in 9/75 cases of idiopathic GHD and in three of the organic group. The height age was much more retarded than chronologic age in the GH resistant group (p less than 0.05) and the HA/BA ratio was also lowest in this group (p less than 0.001). Growth velocity was less than 4 cm/year in all the GHD children but was lowest in those with MPHD. The interesting feature of this study is the marked predominance of the familial cases 31% and a high incidence of growth hormone resistant cases (11%).