Reduced growth hormone secretion in Turner syndrome: is body weight a key factor?
The age-related decline in spontaneous growth hormone (GH) secretion has been suggested to cause growth failure in girls with Turner syndrome (TS). We studied 23 girls (mean age +/- SD: 11.1 +/- 2.7 years) diagnosed to have TS by karyotype analysis. The control group consisted of 18 prepubertal age-matched subjects (10.7 +/- 2.5 years) with growth retardation due to familial short stature and/or constitutional growth delay. In addition, 18 children (10.9 +/- 3.3 years) diagnosed to have GH deficiency by two different provocative tests were chosen as a further comparison group. Spontaneous 12-hour nocturnal GH secretion was assessed by RIA at 30-min intervals. Plasma insulin-like growth factor 1 (IGF-1) levels were determined by RIA after acid-ethanol extraction. Girls with TS had a percentage of ideal body weight significantly higher than controls (p < 0.0001) and showed spontaneous GH secretion significantly lower than controls (mean +/- SD: 3.2 +/- 1.6 in TS vs. 5.5 +/- 1.3 microgram/l in controls; p < 0.0001) but higher than GH-deficient patients (1.3 +/- 0.8 microgram/l; p < 0.0001). No significant difference was found in IGF-1 levels between TS patients and controls, whereas GH-deficient children showed IGF-1 levels significantly lower than those of TS patients (p < 0.0005). As expected, GH concentrations correlated with bone age in controls (r = 0.51, p < 0.05), whereas no relationship was seen in TS. interestingly, in TS, GH levels were negatively related to the percentage of ideal body weight (r = -0.43, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Cianfarani
S
S
Department of Paediatrics, Tor Vergata University, Rome, Italy.
Vaccaro
F
F
Pasquino
A M
AM
Marchione
S A
SA
Passeri
F
F
Spadoni
G L
GL
Bernardini
S
S
Spagnoli
A
A
Boscherini
B
B
D000293:Adolescent; D000365:Age Determination by Skeleton; D000375:Aging; D001835:Body Weight; D002648:Child; D005260:Female; D006130:Growth Disorders / Q000503:physiopathology; D013006:Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D011627:Puberty / Q000502:physiology; D014424:Turner Syndrome / Q000150:complications / Q000503:physiopathology*
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone