Growth parameters and endocrine function in relation to echocardiographic parameters in children with ventricular septal defect without heart failure.

To determine the effect of ventricular function, size of ventricular septal defect (VSD), and endocrine function on linear growth in children with VSD, we studied 88 children with VSD over a period of 1 year. Growth was assessed by determining the height standard deviation scores (HtSDS) and growth velocity (GV) every 4 months. Two hundred age-matched normal children served as controls for the growth data. Endocrine evaluation was performed in 30 randomly selected children with VSD, and 20 age-matched children with constitutional delay of growth (CSS). Growth hormone (GH) response to clonidine provocation was evaluated and circulating free thyroxine (FT4) and insulin-like growth factor-I (IGF-I) concentrations measured. Echocardiographic evaluation of the different cardiac parameters including shunt size and shunt fraction (Qp/Qs) was performed using a colour-coded echodoppler. The HtSDS, body mass index (BMI), and mid-arm circumference (MAC) of children with VSD were significantly decreased compared to those for the normal control group. The dietary intake evaluated by the recall method, appeared to be adequate in the majority of these children (83/88). IGF-I concentrations were reduced in children with VSD (87.5 +/- 29 ng/ml) versus normal age-matched children (169 +/- 42 ng/ml). Basal and clonidine-stimulated GH concentrations were significantly higher in children with VSD (4.6 +/- 2.1 microg/l and 28.8 +/- 7.9 microg/l respectively) versus controls (17.8 +/- 4.2 microg/l). In these patients (n = 88) the HtSDS was correlated negatively with the size of the shunt (r = -0.793, p < 0.001), shunt fraction (Qp/Qs) (r = -0.76, p < 0.001), pulmonary mean gradient (r = -0.4, p = 0.006), and pulmonary maximum velocity (r = -0.32, p = 0.02). Growth velocity (GV) was correlated negatively with pulmonary maximum gradient (r = -0.3, p = 0.02), pulmonary maximum velocity (r = -0.37, p = 0.007), and pulmonary stroke volume (Qp) (r = -0.345, p = 0.01). The BMI and IGF-I concentrations were correlated significantly with the size of the shunt (r = -0.453, p < 0.01), Qp/Qs (r = -0.432, p < 0.01), HtSDS (r = 0.565, p < 0.01), and BMI (r = 0.435, p < 0.01). It appears that in patients with VSD, the size of the left-to-right shunt and the abnormal hemodynamics in the pulmonary circulation are important factors in the etiology of impaired growth. It is suggested that the hypermetabolic status of these patients compromise nutrition and this decreases IGF-I synthesis with subsequent slowing of linear growth and weight gain.

Defective growth hormone (GH) secretion and short-term treatment in Noonan syndrome.

Auxological and endocrine data from 12 prepubertal children (3 males, 9 females) with Noonan syndrome (NS) were compared with those of 15 children with constitutional short stature (CSS), 20 children with partial GH deficiency (GHD), and 6 children with Turner syndrome (TS). Four children with NS were treated with human growth hormone (hGH) (n = 4) (25 units/m2 week, divided on daily s.c. doses). In children with NS, the peak serum GH response to clonidine (5.4 +/- 2.7 ug/L) and glucagon (7.4 +/- 3.4 ug/L) were significantly lower than those for children with CSS (14.8 +/- 3.4 and 12.8 +/- 2.8 ug/L respectively). Nine out of the 12 (75%) children with NS did not mount normal GH peak (10 ug/L or more) after provocation. The 12-h integrated GH secretion in the 3 children with NS who had normal GH response to provocation (2.7 +/- 0.7 ug/L) was markedly lower compared to that for children with CSS (6.7 +/- 1.2 ug/L). The serum insulin-like growth factor-1 (IGF-I) concentrations were lower in children with NS (67 +/- 32 ng/ml) vs CSS (165 +/- 35 ng/ml), but not different from those for GHD children (59 +/- 33 ng/ml). In 4 children with NS, hGH therapy for a year increased height growth velocity from 4.1 +/- 0.3 cm/yr to 7.4 +/- 0.6 cm/yr and height standard deviation score (Ht SDS) from -2.2 +/- 0.6 to -1.45 +/- 0.3. This growth acceleration was accompanied by an increase in IGF-I concentration (from 52 +/- 21 ng/ml to 89 +/- 25 ng/ml). In summary, these results prove a defect of the GH secretion in children with NS and suggest that GH therapy has an important role in the management of their short stature.

Nocturnal growth hormone (GH) secretion and GH response to clonidine provocation in children before and after long-term prednisone therapy.

Glucocorticoids reduce growth hormone (GH) response to the majority of exogenously administered stimuli and can variably inhibit growth in man and animals. Recently, however, glucocorticoids have been shown to have varying effects on GH secretion depending on the time of administration and, furthermore, to be potent secretagogues. We evaluated growth parameters, GH response to high-dose clonidine and integrated (12-h) nocturnal and mean (12-h) nocturnal GH secretion in 10 prepubertal children before and after long-term alternate-day prednisone therapy (LTPT). Height standard deviation scores (HtSDS) and growth velocity standard deviation scores (GVSDS) decreased significantly after LTPT. GH response to clonidine as well as integrated and mean nocturnal GH secretion were significantly after LTPT. GH response to clonidine as well as integrated and mean nocturnal GH secretion were significantly depressed after LTPT v. before treatment. We compared growth parameters and GH data of two groups of children before and after LTPT. Group 1 had low GH peak response to clonidine after LTPT, and group 2 had normal GH response to clonidine. Group 1 children had significantly more impairment of their statural growth and nocturnal GH secretion. Growth parameters (HtSDS and GVSDS) during LTPT correlated significantly with the peak GH response to clonidine (r=0.69 and 0.78, respectively) as well as to the growth parameters before therapy (r > 0.9). It appears that LTPT impairs both physiologic and pharmacologically provoked GH secretion and consequently retards growth in children. However, this effect is variable and is affected by the attained statural growth before therapy.