Late effects of early growth hormone treatment in Down syndrome.

OBJECTIVE: Down syndrome (DS) is associated with short stature and psychomotor delay. We have previously shown that growth hormone (GH) treatment during infancy and childhood normalizes growth velocity and improves fine motor skill performance in DS. The aim of this study was to investigate late effects of early GH treatment on growth and psychomotor development in the DS subjects from the previous trial. DESIGN: Twelve of 15 adolescents with DS (3 F) from the GH group and 10 of 15 controls (5 F) participated in this follow-up study. Fifteen other subjects with DS (6 F) were included as controls in anthropometric analyses. Cognitive function was assessed with the Leiter International Performance Scale-Revised (Leiter-R) and selected subtests of the Wechsler Intelligence Scale for Children, Third edition (WISC-III). The Bruininks-Oseretsky Test of Motor Proficiency, Second edition (BOT-2), was used to assess general motor ability. RESULTS: Although early GH treatment had no effect on final height, the treated subjects had a greater head circumference standard deviation score (SDS) than the controls (-1.6 SDS vs. -2.2 SDS). The adolescents previously treated with GH had scores above those of the controls in all subtests of Leiter-R and WISC-III, but no difference in Brief IQ-score was seen between the groups. The age-adjusted motor performance of all subjects was below -2 SD, but the GH-treated subjects performed better than the controls in all but one subtest. CONCLUSION: The combined finding of a greater head circumference SDS and better psychomotor performance indicates that DS subjects may benefit from early GH treatment.

Normal growth hormone secretion in overweight young adults with Down syndrome.

Down syndrome (DS) is associated with short stature and obesity. Adults with DS have several features in common with growth hormone (GH) deficient adult subjects. The aim of this study was to investigate GH secretion in young adults with DS and its relation to body composition as well as glucose and lipid metabolism. Ten young adults with DS (aged 24-32 years; 5 F) and ten controls matched for age and sex were examined regarding spontaneous nocturnal GH secretion and body composition. Stable isotope tracers were used to study glucose and lipid metabolism in the DS subjects. There was no difference in secretion of GH between the DS subjects and controls. The DS subjects had a higher BMI, fat mass proportion and HOMA (homeostasis model assessment) index compared with the controls. The rates of production of glucose and glycerol (reflecting lipolysis) in the DS subjects were increased (15.5+/-5.07 and 3.5+/-1.68 micromol/kg/min, respectively). The DS subjects showed normal GH secretion despite increased BMI and fat mass. The increased HOMA index and high rate of glucose production indicate peripheral and hepatic insulin resistance in adult DS subjects.

Increased neonatal thyrotropin in Down syndrome.

AIM: Down syndrome (DS) is frequently associated with thyroid dysfunction. The aim of this study was to investigate the blood concentration of thyrotropin (TSH) observed at neonatal screening of infants with DS and its possible association with development of hypothyroidism during childhood. METHODS: TSH levels from neonatal screening of 73 children (34 F) with DS born in 1986-1996 were studied retrospectively and compared with those of controls. The DS children were followed up regarding thyroid function to the age of 10 years in this descriptive study. RESULTS: The DS infants had a higher mean TSH level and a higher TSH standard deviation score (SDS) than controls (7.0 +/- 7.45 mU/L vs. 3.9 +/- 2.43 mU/L and 1.1 +/- 2.67 vs. 0, respectively). The differences were mainly attributable to higher values in the male DS children. The TSH level at screening did not predict thyroid dysfunction during childhood. CONCLUSION: Infants with DS, especially boys, showed elevated levels of TSH at neonatal screening, indicating the occurrence of mild hypothyroidism already in early life. The TSH levels could not predict development of manifest thyroid disease later in childhood.

Growth charts for Down's syndrome from birth to 18 years of age.

BACKGROUND: Growth in children with Down's syndrome (DS) differs markedly from that of normal children. The use of DS specific growth charts is important for diagnosis of associated diseases, such as coeliac disease and hypothyroidism, which may further impair growth. AIMS: To present Swedish DS specific growth charts. METHODS: The growth charts are based on a combination of longitudinal and cross sectional data from 4832 examinations of 354 individuals with DS (203 males, 151 females), born in 1970-97. RESULTS: Mean birth length was 48 cm in both sexes. Final height, 161.5 cm for males and 147.5 cm for females, was reached at relatively young ages, 16 and 15 years, respectively. Mean birth weight was 3.0 kg for boys and 2.9 kg for girls. A body mass index (BMI) >25 kg/m(2) at 18 years of age was observed in 31% of the males and 36% of the females. Head growth was impaired, resulting in a SDS for head circumference of -0.5 (Swedish standard) at birth decreasing to -2.0 at 4 years of age. CONCLUSION: Despite growth retardation the difference in height between the sexes is the same as that found in healthy individuals. Even though puberty appears somewhat early, the charts show that DS individuals have a decreased pubertal growth rate. Our growth charts show that European boys with DS are taller than corresponding American boys, whereas European girls with DS, although being lighter, have similar height to corresponding American girls.