Sex Hormones, Gonad Size, and Metabolic Profile in Adolescent Girls Born Small for Gestational Age with Catch-up Growth.

STUDY OBJECTIVE: To characterize and compare sex hormone concentrations, and uterine and ovarian volumes in adolescent girls born small for gestational age (SGA) who had experienced catch-up growth and girls born at a size appropriate for gestational age (AGA), and to investigate the association between these parameters and glucose metabolism, perinatal factors, and early growth. DESIGN: A prospective, longitudinal, observational study from birth until adolescence. SETTING: Mean age at final assessment was 12.7 ± 0.1 years. PARTICIPANTS: We followed 55 girls (20 SGA, 35 AGA). INTERVENTIONS AND MAIN OUTCOME MEASURES: Sex hormone concentrations (gonadotropins, estradiol, testosterone, and sex hormone binding globulin) were analyzed, and the oral glucose tolerance test conducted. Uterine and ovarian sizes were assessed using pelvic ultrasound. RESULTS: Uterine and ovarian volumes were smaller in SGA-born compared with AGA-born girls (P = .013 and P = .039, respectively). SGA girls had lower sex hormone binding globulin levels (P = .039) and higher testosterone levels (P = .003), free androgen index (P < .001), and glycemia 2 hours post glucose load (P = .005) compared with AGA-born girls. Birth weight and early infancy height velocity explained 37.4% of variation in ovarian volume (P = .004), and body mass index at birth, increase in peripheral skinfold thickness during second year of life, and early childhood height velocity explained 43.2% of variation in testosterone levels in adolescence (P = .006). CONCLUSION: SGA-born girls who experienced catch-up growth remain at risk of biochemical hyperandrogenism in adolescence, and have reduced uterine and ovarian volumes, which might influence future reproductive function. Ovarian size and androgen levels in adolescence might be influenced by early growth and subcutaneous fat deposition.

Adrenal Function in Adolescence is Related to Intrauterine and Postnatal Growth.

Background and objectives: Intrauterine growth restriction is thought to be implicated in long-term programming of hypothalamic-pituitary-adrenal axis activity. We investigated adrenal function in adolescents born small for gestational age (SGA) in relation to their postnatal growth and cardiovascular parameters. Materials and Methods: Anthropometric parameters, blood pressure, heart rate, dehydroepiandrosterone sulfate (DHEAS), and cortisol levels were assessed in 102 adolescents aged 11-14 years followed from birth (47 SGA and 55 born appropriate for gestational age (AGA)). Results: Mean DHEAS levels were higher in SGA adolescents with catch-up growth (SGACU+), compared with AGA. Second-year height velocity and body mass index (BMI) gain during preschool years were positively related to DHEAS levels. Morning cortisol levels and systolic and diastolic blood pressure were higher in SGA adolescents without catch-up growth (SGACU-) compared with AGA. Second-year BMI gain was inversely, and 2-12 years increase in subscapular skinfold thickness was directly associated with cortisol levels. Size at birth and postnatal growth explained 47.8% and 38.2% of variation in DHEAS and cortisol levels, respectively. Conclusion: Adrenal function in adolescence is affected by prenatal and postnatal growth: small size at birth with postnatal catch-up growth is related to higher DHEAS secretion, whereas increased cortisol levels and blood pressure are higher in short SGA adolescents.

[Postnatal growth in children born small and appropriate for gestational age during the first years of life]. / Ponatalinis mazu ir atitinkanciu gestacijos amziu vaiku augimas per pirmuosius seserius gyvenimo metus.

UNLABELLED: The aim of the study was to evaluate growth pattern of small- and appropriate-for-gestational-age children and to identify prenatal and postnatal risk factors for short stature and development of components of metabolic syndrome. A total of 109 small- and 239 appropriate-for-gestational-age infants were enrolled in the study. Within 24 hours after birth and at 2, 5, 9, 12, 18, 24 months, and 6 years of age, anthropometric data were recorded for study children. Cord blood samples from study infants were collected, and insulin-like growth factor-1 (IGF), IGF-binding protein-3, and leptin levels were measured. Birth weight and height (P<0.001) and insulin-like growth factor-1, IGF-binding protein-3, and leptin levels (P<0.05) were lower in children born small for gestational age vs. children born appropriate for gestational age. At 2, 5, 12, 18, and 24 months and 6 years of age, children born small for gestational age remained shorter and weighed less (P<0.001). Waist-to-hip ratio, heart rate at 6 years of age and gain in body mass index from birth up to 6 years of age was higher in children born small for gestational age. Height gain during the first year of life was mainly influenced by birth length and target height. Maternal weight before pregnancy and cord leptin levels were the most significant factors influencing postnatal weight gain during the first years of life. CONCLUSIONS: During the first 6 years of life, children born small for gestational age remained shorter and lighter. A greater catch-up in body mass index and tendency towards central pattern of fat distribution during the first years of life might be predisposing factors for the development of long-term metabolic complications in these individuals.

Leptin levels at birth and in early postnatal life in small- and appropriate-for-gestational-age infants.

UNLABELLED: The aim of this study was to evaluate leptin concentration at birth and in early postnatal life in small- and appropriate-for-gestational-age infants and to assess its relationship with infants' anthropometry at birth and some characteristics of maternal pregnancy. MATERIALS AND METHODS: A total of 367 infants born after 32-42 weeks of gestation were enrolled in the study. Umbilical cord blood samples were collected from 80 small- and 287 appropriate-for-gestational-age newborns. Altogether, 166 venous blood samples were taken from these neonates on days 2-6 of life. RESULTS: Cord leptin levels were significantly lower in small- compared to appropriate-for-gestational-age infants. We observed a positive correlation between cord leptin and birth weight, all neonatal anthropometric parameters, placental weight, and some maternal nutritional factors. In multivariate analysis, cord leptin concentration explained up to 15% of the variation in sum of newborn's skinfold thickness but only 5% of the variation in birth weight. Postnatally, leptin concentration decreased markedly to the similar low levels in both infant groups and remained so during the first postnatal week. CONCLUSIONS: Significantly lower cord leptin concentration in small-for-gestational-age neonates reflects a lower fat mass content compared to appropriate-for-gestational-age infants. However, an abrupt decrease in leptin levels shortly after birth in both groups suggests that placenta could be an important source of leptin in fetal circulation. The impact of low leptin levels at birth in small-for-gestational-age infants on their postnatal appetite and weight gain remains to be elucidated in future studies.