Hormonal profile among children with short stature

Linear growth occurs in 3 phases. During fetal and early infant life, growth is largely regulated by nutrition, during childhood by growth hormone [GH] and during puberty by GH and sex steroids. Short stature may be the normal expression of genetic potential, in which case the growth rate is normal at least at the 25[th] percentile, or it may be the result of a condition causing growth failure with a growth rate below the appropriate growth velocity for age. Short stature has been shown to have far reaching effects on psychological well being including poor academic achievement, behavioral problems, morbidity related to the underlying cause and increased risk for reduced bone mass. One hundred fifty-nine patients divided into 4 groups were studied. Group 1 [Pituitary dwarf] consisted of 26 patients [16 males and 10 females] aged 4-12 years. Group II [Congenital hypothyroidism] included 23 patients [14 males and 9 females] aged 2-12 years. Group III [Down's syndrome] consisted of 10 patients [5 males and 5 females] aged 3-12 years. A hundred apparently healthy children [50 males and 50 females] aged 2.5-12 years were considered as [Control group] group IV. All children were examined thoroughly, anthropometric measurements [14 items] were evaluated according to percentiles and Z-score diagrams. Bone age was determined by plain X-ray left wrist. Hormonal study was done including T[3], T[4], TSH, overnight urinary growth hormone [GH] and creatinine. Serum growth hormone [insulin-induced hypoglycemia test] and insulin like growth factor-1 [IGF-1] were measured for the pituitary dwarf group. The height, sitting height and arm span measurements showed a marked decrease below normal mean Z-scor e [more than -2SD] in the three studied groups of patients. Hormonal profile: There was a significant decrease in serum levels of both T[3] and T[4] in congenital hypothyroidism and insignificant change in the other two groups. 3 patients from Down's syndrome group reached a hypothyroidal level of T[3], T[4], and TSH. Generally urinary growth hormone showed a significant decrease in the three studied groups of patients. Pituitary dwarf group showed a significant decrease in both serum and urinary growth hormones and also serum IGF-1 with a positive correlation between serum growth hormone and both urinary growth hormone and serum IGF-1. Height, sitting height and arm span are simple and accurate measurements for early detection and follow up of the short child. Assessment of the thyroid hormonal profile is essential as early as possible in all children with short stature with and without clinical stigmata of hypothyroidism. Determination of urinary growth hormone is as accurate as serum GH, moreover it is easier. Measurement of serum IGF-1 is an important era in diagnosis of short stature

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. However, the day-to-day variability and wide normal range limit its usefulness in mild forms of hGH insufficiency