J. Endocrinol. Invest. 13; 475-480,1990
GHRH-test in short children with "non classic" GH deficiency. A comparison with "classic" GH deficiency and short normal statu re. G. Saggese, G. Cesaretti, N. Giannessi, L. Cinquanta, C. Bracaloni, C. Cioni, G. Di Spigno, and R. Di Porto Clinica Pediatrica, Universita di Pisa, Pisa, Italy ABSTRACT. In this study GHRH-test has been performed (2 Ilg/Kg of an iv bolus of GHRH 1-44) sampling for GH measurement every 15 min over 2 hours in three groups of short children. Group 1 consisted of 10 subjects with classic GH deficiency (CGHD): GH response< 10 ng/ml to two conventional tests and 24-h mean GH concentration (MGHC) < 3 ng/ml; group 2 consisted of 16 subjects with non-classic GH deficiency (NCGHD): response > 10 ng/ml to at least one conventional test and MGHC < 3 ng/ml; group 3 consisted of 18 subjects with short normal stature: GH response> 10 ng/ml to at least one conventional test and MGHC > 3 ng/ml. GH peak and area under the curve (AUC) values were significantly lower in group 1 than groups
2 and 3 and in group 2 than group 3. GH peak and AUC values statistically correlated with height, height velocity, bone age/chronological age ratio and MGHC. Six children in group 1, 14 children in group 2 and all 18 children in group 3 showed after GHRH a GH peak> 10 ng/ml and were considered as 'responders'. Considering only the responders, GH peak and AUC values were significantly lower in group 1 than groups 2 and 3 and in group 2 than group 3. In conclusion, our data have shown that 87% of children with NCGHD responded to a single bolus of GHRH with an increase in GH levels> 10 ng/ml and that their responses were intermediate compared to those of CGHD and short normal subjects.
INTRODUCTION The availability of GHRH for diagnostic purpose has allowed to obtain some important data on the nature of the GH deficiency in short children leading to a better distinction between hypothalamic and pituitary disorders. Previous studies have shown that in subjects with 'classic' GH deficiency (CGHD), diagnosed on the basis of conventional stimuli, the response to GHRH administration is frequently normal suggesting a defect at a suprapituitary level (1-5). A few years ago, firstly Spiliotis et al. (6) described a eondition of short stature, named 'GH neuroseeretory dysfunetion' and eharaehterized by a poor height veloeity (HV) and an impaired spontaneous GH seeretion in spite of normal responses to eonventional pravoeative stimuli. GH response to GHRH in this subset of short stature, that mayaiso
be eonsidered as "non-elassie" GH deficieney (NCGHD) (7), has been investigated only in few oeeasions: Chalew et al. (8) deseribed in 15 ehildren a large variability of responses overlapping those of subjects with normal stature; Shulman et Bereu (9) found values intermediate between the contra I and classie GH defieient groups, whereas Pienkowski et al. (10) did not show any signifieant differences between 25 subjects with low GH spontaneous seeretion and 39 subjeets with normal seeretion; finally Butenandt (11) demonstrated anormal G H response in 8 ehildren with neuroseeretory dysfunction. In this study we have performed GHRH test in a group of short ehildren eomparing the results obtained in NCGHD with those of CGHD and of 'short normal' stature in order to investigate the physiopathologieal basis of GH defieieney. PATIENTS AND METHODS We studied 44 prepubertal short children (26 boys, 18 girls) with a ehronological age (CA) of 8.72 ± 1.64 yr (m ± SO). Auxologieal examination included: height (mean of
Key-words. GHRH-test, classic and non-classic GH deficiency, short normal stature Correspondence: Prof. Giuseppe Saggese, Clinica Pediatrica. Universita di Pisa, Via Roma, 35 - 56100 Pisa. Italy. Received November 27,1989; accepted February 12,1990.
475
G. Saggese, G. Cesaretti, N. Giannessi, et al.
Table 1 - Auxological features and hormonal data of the examined subjects Group
Subjects n
CA yr
Height SO Scores
Height velocity SO Scores
BA yr
BNCA ratio
L-Oopa GH (ng/ml)
ITT MGHC GH (ng/ml) GH (ng/ml)
10
m±SO range
7.76±1.49 5.61/967
-3.22±0.28 -264/-355
-3.26±0.45 -3.90/-2.82
5.00±0.9 3.50/601
0.64±0.05 056/071
3.0±1.9 0.7/6.5
3.3±1.4 0.5/5.7
1.6±0.6 0.6/2.5
2
16
m±SO range
9.04±1.66 5.83/11.83
-2.31±0.25 -2.78/-1.87
-2.82±0.64 -411/-196
6.29±1.32 3.67/8.40
0.69±0.07 054/079
13.3±7.7 2.9/35.0
14.1±7.0 23/271
2.3±0.5 11/29
3
18
m±SO range
8.98±158 5.83/10.67
-2.19±0.18 -2.48/-1.95
-1.89±0.57 -3.08/-081
6.95±1.40 4.11/9.23
0.77±0.05 070/092
135± 7.4 23/25.9
15.1±8.2 26/271
4.9± 1.7 3.2/96
Group 1. "classic" GH deficiency Group 2. "non - classic" GH deficiency Group 3. "short normal" stature CA chronological age; BA bone age; ITT. insulin tolerance test; MGHe. 24 - h mean GH concentration.
three measurements using a wall-mounted stadiometer), weight and HV. Bone age (BA) was determined according to TW2 method (12). Height and HV have been expressed as SO scores (SOS) for CA or BA, respectively, using the standards of Tanner et al. (13). Also height age (HA) was evaluated according to Tanner et al. (13). All subjects showed astature< -1.8 SOS and a body weight within 1 SOS for HA. All children had been tested for GH by two pharmacological stimuli tests: insulin-induced hypoglycemia (0.1 U/Kg i.v. of regular insulin) and L-Oopa administration (500 mg/1.73 sq.m. of body surface, oraily). Blood sampling has been performed for GH measurement every 20 min for 2 h during both the tests. Twenty-four h spontaneous GH evaluation consisted of sampling 1 ml of blood every 20 min over 24 h through anindwelling iv catheter (placed in a forearm vein one h before the start of the study). The 24-h mean GH concentration (MGHC), as arithmetic mean of all obtained 73 values, has been calculated. On the basis of auxologic features and hormonal data the patients have been subdivided into three groups (Table 1): group 1 (n = 10) with CGHO: abnormal response (GH peak< 10 ng/ml) to both conventional tests, low HV and delayed BA; MGHC resulted < 3 ng/ml; group 2 (n = 16) with NCGHO: normal response to at least one conventional test and MGHC < 3 ng/ml; group 3 (n = 18) short normal children: normal response to at least one conventional test and MGHC > 3 ng/ml. Systemic or chromosomal diseases were excluded from this study. No patient had received previously GH therapy. Following an overnight fast, GHRH test was per-
formed administering an iv bolus of GHRH 1-44 (Groliberin, Kabivitrum AB, Stockholm) (2 Ilg/Kg) and sampling blood for GH measurement at the following times: -15, 0, 15,30,45, 60, 90, and 120 min. The mean basal value (MBV; mean of values at times -15 min and 0 min), the peak (the highest value) and the area under the curve (AUC) were calculated. Informed consent was obtained from the children's parents. GH was evaluated in duplicate by a two-site immunoradiometric assay using two different antibodies in excess (Pharmacia Oiagnostics, AB, Uppsala, Sweden) in the same assay. The intra- and inter-assay coefficients of variation ranged from 2.55.1 % and from 3.5-5.6%, respectively. Crossreactivity was< 1% for human chorionic somatomammotropin and prolactin. Sampies measuring below the
Table 2 - GH va lues after GHRH administration in the examined
subjects. Group
MBV ng/ml
Peak ng/ml
AUe ng/ml x min
m±SD range
0.55±0.21 0.3/09
10.93±4.93 49/160
794.8±399.5 327/1191
2
m±SD range
1.48±0.62 06/2.5
22.58±7.02 4.2/28.1
1525.2±5186 307/1774
3
m±SD range
2.07±0.87 06/3.7
34.00±1.94 29.9/37.4
2369.2±144.6 2018/2603
Statistical analysis. MBV vs. peak. p
GHRH-test in short children with "non classic" GH deficiency. A comparison with "classic" GH deficiency and short normal statu re. G. Saggese, G. Cesaretti, N. Giannessi, L. Cinquanta, C. Bracaloni, C. Cioni, G. Di Spigno, and R. Di Porto Clinica Pediatrica, Universita di Pisa, Pisa, Italy ABSTRACT. In this study GHRH-test has been performed (2 Ilg/Kg of an iv bolus of GHRH 1-44) sampling for GH measurement every 15 min over 2 hours in three groups of short children. Group 1 consisted of 10 subjects with classic GH deficiency (CGHD): GH response< 10 ng/ml to two conventional tests and 24-h mean GH concentration (MGHC) < 3 ng/ml; group 2 consisted of 16 subjects with non-classic GH deficiency (NCGHD): response > 10 ng/ml to at least one conventional test and MGHC < 3 ng/ml; group 3 consisted of 18 subjects with short normal stature: GH response> 10 ng/ml to at least one conventional test and MGHC > 3 ng/ml. GH peak and area under the curve (AUC) values were significantly lower in group 1 than groups
2 and 3 and in group 2 than group 3. GH peak and AUC values statistically correlated with height, height velocity, bone age/chronological age ratio and MGHC. Six children in group 1, 14 children in group 2 and all 18 children in group 3 showed after GHRH a GH peak> 10 ng/ml and were considered as 'responders'. Considering only the responders, GH peak and AUC values were significantly lower in group 1 than groups 2 and 3 and in group 2 than group 3. In conclusion, our data have shown that 87% of children with NCGHD responded to a single bolus of GHRH with an increase in GH levels> 10 ng/ml and that their responses were intermediate compared to those of CGHD and short normal subjects.
INTRODUCTION The availability of GHRH for diagnostic purpose has allowed to obtain some important data on the nature of the GH deficiency in short children leading to a better distinction between hypothalamic and pituitary disorders. Previous studies have shown that in subjects with 'classic' GH deficiency (CGHD), diagnosed on the basis of conventional stimuli, the response to GHRH administration is frequently normal suggesting a defect at a suprapituitary level (1-5). A few years ago, firstly Spiliotis et al. (6) described a eondition of short stature, named 'GH neuroseeretory dysfunetion' and eharaehterized by a poor height veloeity (HV) and an impaired spontaneous GH seeretion in spite of normal responses to eonventional pravoeative stimuli. GH response to GHRH in this subset of short stature, that mayaiso
be eonsidered as "non-elassie" GH deficieney (NCGHD) (7), has been investigated only in few oeeasions: Chalew et al. (8) deseribed in 15 ehildren a large variability of responses overlapping those of subjects with normal stature; Shulman et Bereu (9) found values intermediate between the contra I and classie GH defieient groups, whereas Pienkowski et al. (10) did not show any signifieant differences between 25 subjects with low GH spontaneous seeretion and 39 subjeets with normal seeretion; finally Butenandt (11) demonstrated anormal G H response in 8 ehildren with neuroseeretory dysfunction. In this study we have performed GHRH test in a group of short ehildren eomparing the results obtained in NCGHD with those of CGHD and of 'short normal' stature in order to investigate the physiopathologieal basis of GH defieieney. PATIENTS AND METHODS We studied 44 prepubertal short children (26 boys, 18 girls) with a ehronological age (CA) of 8.72 ± 1.64 yr (m ± SO). Auxologieal examination included: height (mean of
Key-words. GHRH-test, classic and non-classic GH deficiency, short normal stature Correspondence: Prof. Giuseppe Saggese, Clinica Pediatrica. Universita di Pisa, Via Roma, 35 - 56100 Pisa. Italy. Received November 27,1989; accepted February 12,1990.
475
G. Saggese, G. Cesaretti, N. Giannessi, et al.
Table 1 - Auxological features and hormonal data of the examined subjects Group
Subjects n
CA yr
Height SO Scores
Height velocity SO Scores
BA yr
BNCA ratio
L-Oopa GH (ng/ml)
ITT MGHC GH (ng/ml) GH (ng/ml)
10
m±SO range
7.76±1.49 5.61/967
-3.22±0.28 -264/-355
-3.26±0.45 -3.90/-2.82
5.00±0.9 3.50/601
0.64±0.05 056/071
3.0±1.9 0.7/6.5
3.3±1.4 0.5/5.7
1.6±0.6 0.6/2.5
2
16
m±SO range
9.04±1.66 5.83/11.83
-2.31±0.25 -2.78/-1.87
-2.82±0.64 -411/-196
6.29±1.32 3.67/8.40
0.69±0.07 054/079
13.3±7.7 2.9/35.0
14.1±7.0 23/271
2.3±0.5 11/29
3
18
m±SO range
8.98±158 5.83/10.67
-2.19±0.18 -2.48/-1.95
-1.89±0.57 -3.08/-081
6.95±1.40 4.11/9.23
0.77±0.05 070/092
135± 7.4 23/25.9
15.1±8.2 26/271
4.9± 1.7 3.2/96
Group 1. "classic" GH deficiency Group 2. "non - classic" GH deficiency Group 3. "short normal" stature CA chronological age; BA bone age; ITT. insulin tolerance test; MGHe. 24 - h mean GH concentration.
three measurements using a wall-mounted stadiometer), weight and HV. Bone age (BA) was determined according to TW2 method (12). Height and HV have been expressed as SO scores (SOS) for CA or BA, respectively, using the standards of Tanner et al. (13). Also height age (HA) was evaluated according to Tanner et al. (13). All subjects showed astature< -1.8 SOS and a body weight within 1 SOS for HA. All children had been tested for GH by two pharmacological stimuli tests: insulin-induced hypoglycemia (0.1 U/Kg i.v. of regular insulin) and L-Oopa administration (500 mg/1.73 sq.m. of body surface, oraily). Blood sampling has been performed for GH measurement every 20 min for 2 h during both the tests. Twenty-four h spontaneous GH evaluation consisted of sampling 1 ml of blood every 20 min over 24 h through anindwelling iv catheter (placed in a forearm vein one h before the start of the study). The 24-h mean GH concentration (MGHC), as arithmetic mean of all obtained 73 values, has been calculated. On the basis of auxologic features and hormonal data the patients have been subdivided into three groups (Table 1): group 1 (n = 10) with CGHO: abnormal response (GH peak< 10 ng/ml) to both conventional tests, low HV and delayed BA; MGHC resulted < 3 ng/ml; group 2 (n = 16) with NCGHO: normal response to at least one conventional test and MGHC < 3 ng/ml; group 3 (n = 18) short normal children: normal response to at least one conventional test and MGHC > 3 ng/ml. Systemic or chromosomal diseases were excluded from this study. No patient had received previously GH therapy. Following an overnight fast, GHRH test was per-
formed administering an iv bolus of GHRH 1-44 (Groliberin, Kabivitrum AB, Stockholm) (2 Ilg/Kg) and sampling blood for GH measurement at the following times: -15, 0, 15,30,45, 60, 90, and 120 min. The mean basal value (MBV; mean of values at times -15 min and 0 min), the peak (the highest value) and the area under the curve (AUC) were calculated. Informed consent was obtained from the children's parents. GH was evaluated in duplicate by a two-site immunoradiometric assay using two different antibodies in excess (Pharmacia Oiagnostics, AB, Uppsala, Sweden) in the same assay. The intra- and inter-assay coefficients of variation ranged from 2.55.1 % and from 3.5-5.6%, respectively. Crossreactivity was< 1% for human chorionic somatomammotropin and prolactin. Sampies measuring below the
Table 2 - GH va lues after GHRH administration in the examined
subjects. Group
MBV ng/ml
Peak ng/ml
AUe ng/ml x min
m±SD range
0.55±0.21 0.3/09
10.93±4.93 49/160
794.8±399.5 327/1191
2
m±SD range
1.48±0.62 06/2.5
22.58±7.02 4.2/28.1
1525.2±5186 307/1774
3
m±SD range
2.07±0.87 06/3.7
34.00±1.94 29.9/37.4
2369.2±144.6 2018/2603
Statistical analysis. MBV vs. peak. p
