The diagnostic value of integrated growth hormone secretion studies shorter than 24 hours in normal- and short-growing children.
Spontaneous growth hormone (GH) secretion is evaluated by measurement of the 24-hour integrated concentration of GH (24-hour IC-GH), a major diagnostic procedure, or by shorter protocols such as monitoring 6 h during sleep. We have evaluated several possibilities for shortening the procedure by comparing the results of an abbreviated procedure to the 24-hour IC-GH studies. The study population consisted of 50 children with classic GH deficiency (group GHD), determined by provocative testing, and 45 children who had a subnormal secretion of GH (group N), determined by low 24-hour IC-GH but normal GH provocative tests. Twenty-two children of normal height and stature served as a control group. All the children were prepubertal, while there was no overlap between the lower 5th percentile of the 24-hour IC-GH of the control subjects (3.3 micrograms/l) and the upper 97th percentile of the 24-hour IC-GHs of the N and GHD groups (2.9 and 2.7 micrograms/l, respectively), there was a considerable overlap between the IC-GH of control subjects and that of the GHD and N groups measured in all the abbreviated blood withdrawal protocols, except for the 10-hour daytime and the 12-hour nighttime protocols of the GHD patients. It should be noted that there was only a small overlap between the control and the GHD groups during the 12-hour daytime protocol. We have found that the longer the blood collection period the greater the sensitivity and the specificity. We conclude that the 24-hour IC-GH test is the best diagnostic tool for identifying children with subnormal GH secretion.
Zadik
Z
Z
Pediatric Endocrine Unit, Kaplan Hospital, Rehovot, Israel.
Chalew
S A
SA
Kowarski
A
A
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis* / Q000503:physiopathology; D013006:Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D008297:Male; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors
D013006:Growth Hormone