Nocturnal urinary growth hormone excretion as a criterion for growth hormone deficiency.
Nocturnal urinary growth hormone (U-hGH) levels measured by a sensitive immunoenzymometric assay were compared with hGH levels in serum before and after a clonidine test in healthy children and in children with short stature to determine whether U-hGH measurement is useful for the screening of hGH deficiency. The study was carried out on 19 healthy children (10 prepubertal and 9 pubertal subjects) and on 20 children with short stature, 10 with growth hormone deficiency (hGHD) and 10 with constitutional growth retardation. The diagnosis of hGHD was based on a blunted response to two provocative hGH tests in the appropriate clinical setting. Overnight urinary hGH secretion (mean of 3 collections) was measured by an immunoenzymometric assay. The best discrimination was obtained when the results were expressed as ng/h. Only one individual in the prepubertal group (U-hGH, 0.05 ng/h) and one patient in the growth retardation group (U-hGH, 0.08 ng/h) had a urinary hGH value below the highest value (0.17 ng/h) observed in the growth hormone deficiency group. The coefficient of correlation between urinary hGH in ng/h and post-clonidine peak was 0.50 (P = 0.0015), between urinary hGH in ng/l and post-clonidine peak was 0.48 (P = 0.0025), between urinary hGH in ng/l per hour and post-clonidine peak was 0.47 (P = 0.0027). The highest specificity (0.93), sensitivity (0.90), false negative rate (0.96) and false positive rate (0.82) were obtained when U-hGH was expressed as ng/h per night. Measurement of urinary nocturnal hGH excretion is a useful, simple, noninvasive method for the diagnosis of hGH deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)
Disciplina de Endocrinologia, Escola Paulista de Medicina, São Paulo, SP, Brasil.
E S
ES
Fortes
A R
AR
Chacra
H S
HS
Kunii
J G
JG
Vieira
E M
EM
Russo
D000293:Adolescent; D000365:Age Determination by Skeleton; D002648:Child; D002940:Circadian Rhythm; D003000:Clonidine; D005260:Female; D006130:Growth Disorders; D013006:Growth Hormone / Q000097:blood / Q000172:deficiency* / Q000652:urine*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011627:Puberty
D013006:Growth Hormone; D003000:Clonidine