Pre- and peripubertal sex steroids are inversely associated with birth weight in preterm boys.

OBJECTIVE: The relationship between sex hormone concentrations during childhood and birth weight (BW) is poorly understood. We aimed to investigate this relationship and the associations with anthropometric data at 5, 6, 7, 8, and 10 years of age in preterm boys. DESIGN: A prospective longitudinal single-centre study, including 58 boys with a BW of 1325-3320 g and gestational age (GA) of 32 + 2 to 36 + 6 weeks. PATIENTS AND MEASUREMENTS: Data on GA, BW and anthropometric data between 5 and 10 years of age were recorded. Testicular development was assessed at 8 and 10 years of age. Serum concentrations of sex steroids were analysed with gas chromatography-tandem mass spectrometry at 5-10 years and luteinizing hormone (LH) and follicle-stimulating hormone (FSH) with immunoassays at 10 years of age. RESULTS: At 8 years of age, testosterone and estrone correlated negatively with BW, (ρ = -0.35, p = .021) and (ρ = -0.34, p = .024), respectively. At 10 years of age, testosterone, dihydrotestosterone, estrone and estradiol correlated negatively with BW (ρ = -0.39, p = .010), (ρ = -0.38, p = .013), (ρ = -0.44, p = .003) and (ρ = -0.36, p = .019), respectively. Weight gain from birth correlated with testosterone at 5 years (ρ = 0.40, p = .002), 7 years (ρ = 0.30, p = .040), 8 years (ρ = 0.44, p = .003) and 10 years (ρ = 0.40, p = .008) of age. At 10 years of age, testosterone correlated with LH (ρ = 0.42, p = .006) and FSH (ρ = 0.33, p = .033) but not with testicular volume. CONCLUSIONS: Lower BW was associated with increased sex steroid concentrations from 8 years of age, independently of clinical signs of puberty.

Adrenal androgen trajectories are established during childhood in preterm boys.

AIM: We investigated longitudinal adrenal androgen concentrations and any relationship between gestational age, birth size, anthropometric parameters and adrenal androgen concentrations during childhood in boys born moderate to late preterm. METHODS: This longitudinal, prospective study included 58 boys born at 32+0 to 36+6 weeks of gestation. Dehydroepiandrosterone sulphate and androstenedione were analysed by liquid chromatography-tandem mass spectrometry, and anthropometric data were recorded from 5 to 10 years of age. RESULTS: Dehydroepiandrosterone sulphate concentrations correlated with weight standard deviations scores (SDS) from 7 to 10 years of age and waist-to-height ratios at seven and 10 years of age. Androstenedione correlated with weight SDS from 7 to 10 years of age and waist-to-height ratios at 10 years of age. Longitudinal analysis showed a relationship between weight SDS and waist-to-height SDS and dehydroepiandrosterone sulphate (p < 0.001 and p < 0.001, respectively) and androstenedione (p = 0.002 and p = 0.003, respectively), independently of age. CONCLUSION: The trajectories of anthropometric parameters and adrenal androgen secretion were consistent from 5 to 10 years of age in this cohort. The body composition reflected by current weight and the waist-to-height ratio, rather than gestational age and birth size, was associated with adrenal androgen secretion.

Metabolic Risk Factors Associated with Visceral and Subcutaneous Adipose Tissue in a Sex-Specific Manner in Seven-Year-Olds.

OBJECTIVE: This study aimed to investigate how visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volumes were associated with metabolic risk factors in 7-year-old children. METHODS: A total of 81 children (52% girls) from a Swedish birth cohort were studied. At 6 years of age, anthropometric data, fasting insulin, glucose, cholesterol, and blood pressure were collected on 53 children with normal weight and 28 children with overweight or obesity, and insulin resistance was estimated. At 7 years of age, magnetic resonance imaging quantified VAT and SAT. Sex and regression analyses were conducted. RESULTS: SAT was more strongly associated with metabolic risk factors than VAT. The associations between VAT and metabolic risk factors were stronger in girls (P < 0.05). When VAT was adjusted for birth weight and maternal BMI and education, it accounted for 51% of insulin variance (ß = 11.72; P = 0.001) but only in girls. The key finding of this study was that adjusted SAT accounted for 63% of the fasting insulin variance in girls (ß = 2.76; P < 0.001). Waist circumference was the best anthropometric marker for insulin resistance. CONCLUSIONS: Insulin resistance was associated with abdominal adipose tissue and its associated metabolic risk factors in children as young as 7 years old.

Ophthalmological findings in relation to auxological data in moderate-to-late preterm preschool children.

PURPOSE: To evaluate ophthalmological findings in preschool children born moderate-to- late preterm (MLP) and relate the findings to auxological data at birth and at 5.5 years of age. METHODS: Seventy-eight MLP children [gestational age (GA) 32-36 weeks; 34 girls; mean age 5.7 years] were investigated. Gestational age, weight, length and head circumference at birth and at the time of assessment were registered. Visual acuity (VA), refraction, orthoptic evaluation, slit-lamp examination and ophthalmoscopy were conducted, and a history of visuoperceptual problems was recorded. The data were compared with age- and sex-matched controls born full term (n = 35). RESULTS: Ophthalmological abnormalities were noted in 82% of MLP children and 47% of controls (p = 0.0004). There was a significant difference with regard to impaired motility (p = 0.03), heterophoria at distance (p = 0.006) and refraction expressed as spherical equivalent dioptre (p = 0.01). Amongst auxological data at birth, birthweight (BW) was the strongest predictor to ophthalmological abnormalities (p = 0.0003). In a stepwise logistic regression, GA was the strongest predictor of VA outcome at time of assessment (p = 0.0036). Moderate-to-late preterm birth showed a 2.4-fold increased risk of refractive errors compared with full-term children (RR 2.39: 95% CI 1.10-5.20; p = 0.02). CONCLUSION: Based on our findings, MLP birth may be associated with increased ocular morbidity compared with their full-term counterparts. Auxological data at birth, especially BW, seems to be an important factor when conducting an ophthalmological diagnosis in preschool MLP children, and an increased VA was correlated to a higher GA.

Measurements of total and regional body composition in preschool children: A comparison of MRI, DXA, and anthropometric data.

OBJECTIVE: There are clear sex differences in the distribution of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in adults, with males having more VAT and less SAT than females. This study assessed whether these differences between the sexes were already present in preschool children. It also evaluated which measures of body composition were most appropriate for assessing abdominal obesity in this age group. DESIGN AND METHODS: One-hundred and five children (57 boys and 48 girls) participated in the study. Body composition was measured using dual-energy X-ray absorptiometry (DXA). Weight, height, and waist circumference (WC) were also recorded. Magnetic resonance imaging (MRI) of the entire abdomen using sixteen 10-mm-thick T1 -weighted slices was performed in a subgroup of 48 children (30 boys and 18 girls); SAT and VAT volumes were measured using semiautomated segmentation. RESULTS: Boys had significantly more VAT than girls (0.17 versus 0.10 l, P < 0.001). Results showed that VAT correlated significantly with all measurements of anthropometry (P < 0.01) after adjusting for SAT and for total fat mass measured with DXA. The mean limits of agreement between DXA and MRI regarding truncal FM were calculated to be -11.4 (range -17.8 to -3.6), using a Bland-Altman plot. CONCLUSION: Sex differences in adipose tissue distribution are apparent at an early age. MRI is the best method with which to study abdominal fat distribution in young children.

Normal visual evoked potentials in preschool children born small for gestational age.

AIM: Previous studies have shown visual evoked potential (VEP) abnormalities in infants and animals born small for gestational age (SGA) compared with controls. The current exploratory study aims to investigate whether VEP abnormalities persist in older ages. METHODS: Pattern VEP latencies were obtained in 21 children (11 girls, 10 boys), born SGA and moderately preterm, at an average age of 5 years and 8 months. Fifty-one children (24 girls, 27 boys, mean age of 5 years and 7 months), also born moderately preterm but with normal height and weight at birth, served as controls RESULTS: Visual evoked potential results showed no significant differences in latency between children born SGA and controls born appropriate for gestational age (AGA) for either binocular stimulation, right eye or left eye stimulation. CONCLUSIONS: Our findings do not indicate any differences in VEP latency at preschool age for children born SGA compared with children born AGA. The results may support previous studies, suggesting that children born SGA show accelerated neurophysiologic maturation during their first year of life and that previously delayed VEP latencies after catch-up stay unchanged compared with controls.

Adipose tissue distribution in children: automated quantification using water and fat MRI.

PURPOSE: To develop and validate a method for rapid acquisition and automated processing of magnetic resonance (MR) images for analysis of abdominal adipose tissue distribution in children. MATERIALS AND METHODS: The study included 21 (10 girls, 11 boys) healthy 5-year-old children. Rapid water and fat MR imaging (6 sec) was performed using a 2-point-Dixon technique on a 1.5T MR scanner using an 8-channel cardiac coil. An automated image processing algorithm was developed for automated segmentation of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), respectively. The results from the fully automated analysis were compared to those from a semiautomated analysis, performed by three operators, from the same images. RESULTS: The automated analysis was seen to give results with strong correlation to the reference measurements (r >or= 0.997); however, the SAT volume was underestimated by 9.4 +/- 3.8%. The accuracy of the automated segmentation of VAT and SAT (TP: true positive, FP: false positive, mean +/- SD, %) was TP: 83.6 +/- 8.5, FP: 12.7 +/- 6.8; and TP: 89.9 +/- 3.6, FP: 0.7 +/- 0.3, respectively. CONCLUSION: A method for rapid imaging and fully automated postprocessing of abdominal adipose tissue distribution is presented. The method allows robust and time-efficient measurement of adipose tissue distribution in young children.