Evaluation of 24-hour growth hormone spontaneous secretion: comparison with a nocturnal and diurnal 12-hour study.
Spontaneous growth hormone (GH) secretion in 116 short children was studied by sampling blood for GH measurement every 20 min over 24 h. We calculated 24-h mean GH concentration (MGHC), diurnal 12-h MGHC (dMGHC) and nocturnal 12-h MGHC (nMGHC). The children were subdivided into four groups: prepubertal children with 'classical' GH deficiency (group 1, n = 12, low responses to two provocative stimuli tests and MGHC less than 3 ng/ml), prepubertal children with 'nonclassical' GH deficiency (group 2, n = 36, normal GH responses to two provocative tests and MGHC less than 3 ng/ml), short normal children (normal GH responses to two provocative tests and MGHC greater than 3 ng/ml) at stage P1 of puberty (group 3, n = 41) and at stage P2 of puberty (group 4, n = 27). The values of MGHC, dMGHC and nMGHC were significantly higher in groups 3 and 4 than in groups 1 and 2, and in group 4 than in group 3. The values of MGHC and nMGHC were significantly higher in group 2 than in group 1. MGHC correlated highly with nMGHC and dMGHC (r = 0.97 and 0.94, respectively; p less than 0.001). On the basis of regression equations between MGHC and nMGHC or dMGHC, the study of the diagnostic accuracy showed values higher for nMGHC than for dMGHC: 94.1 vs. 89.6% for sensitivity, and 93.7 vs. 89.7% for specificity, respectively.
Department of Pediatrics, University of Pisa, Italy.
G
G
Saggese
G
G
Cesaretti
L
L
Cinquanta
N
N
Giannessi
C
C
Bracaloni
G
G
Di Spigno
C
C
Cioni
D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D005260:Female; D006130:Growth Disorders / Q000503:physiopathology*; D013006:Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000503:physiopathology; D007328:Insulin; D007980:Levodopa; D008297:Male; D011627:Puberty
D007328:Insulin; D007980:Levodopa; D013006:Growth Hormone