Second-tier Testing for 21-Hydroxylase Deficiency in the Netherlands: A Newborn Screening Pilot Study

CONTEXT

Newborn screening (NBS) for classic congenital adrenal hyperplasia (CAH) consists of 17-hydroxyprogesterone (17-OHP) measurement with gestational age-adjusted cutoffs. A second heel puncture (HP) is performed in newborns with inconclusive results to reduce false positives.

OBJECTIVE

We assessed the accuracy and turnaround time of the current CAH NBS algorithm in comparison with alternative algorithms by performing a second-tier 21-deoxycortisol (21-DF) pilot study.

METHODS

Dried blood spots (DBS) of newborns with inconclusive and positive 17-OHP (immunoassay) first HP results were sent from regional NBS laboratories to the Amsterdam UMC Endocrine Laboratory. In 2017-2019, 21-DF concentrations were analyzed by LC-MS/MS in parallel with routine NBS. Diagnoses were confirmed by mutation analysis.

RESULTS

A total of 328 DBS were analyzed; 37 newborns had confirmed classic CAH, 33 were false-positive and 258 were categorized as negative in the second HP following the current algorithm. With second-tier testing, all 37 confirmed CAH had elevated 21-DF, while all 33 false positives and 253/258 second-HP negatives had undetectable 21-DF. The elevated 21-DF of the other 5 newborns may be NBS false negatives or second-tier false positives. Adding the second-tier results to inconclusive first HPs reduced the number of false positives to 11 and prevented all 286 second HPs. Adding the second tier to both positive and inconclusive first HPs eliminated all false positives but delayed referral for 31 CAH patients (1-4 days).

CONCLUSION

Application of the second-tier 21-DF measurement to inconclusive first HPs improved our CAH NBS by reducing false positives, abolishing the second HP, and thereby shortening referral time.

Iron status and its association with HbA1c levels in Dutch children with diabetes mellitus type 1

Children with diabetes mellitus (DM) type 1 may be at risk for iron deficiency (ID) although this has been little studied. ID is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. Unfortunately, absolute ID is often not distinguished from functional ID. Furthermore, iron-deficient anemia may influence hemoglobin A1c (HbA1c) levels. We aimed to determine the prevalence and type of ID and investigate its association with HbA1c levels in pediatric DM type 1 patients. We performed a two-center prospective observational study in which the iron status of Dutch children with DM type 1 was determined during a regular check-up. Absolute ID and functional ID were found in 13/227 (5.7%) and 100/214 (47%) patients, respectively, while only 15/113 (13%) patients also had anemia. HbA1c levels in patients with and without a deprived iron status (absolute or functional) were not significantly different (65 ± 17 vs. 65 ± 16 mmol/mol, p = 0.815).

CONCLUSION

Functional, but not absolute, ID was common in Dutch pediatric DM type 1 patients. HbA1c levels were not associated with ID, which can be explained by the relatively mild deprived iron status in our patients.

TRIAL REGISTRATION

NTR4642 What is Known: • Iron deficiency is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. • Children with diabetes mellitus type 1 may be at risk for both types of iron deficiency and this can influence their hemoglobin A1c levels although this has been little studied. What is New: • In Dutch children with diabetes mellitus type 1, functional, but not absolute iron deficiency, is common and should not be treated with iron replacement therapy. • Hemoglobin A1c levels were not associated with iron deficiency, probably due to the relatively mild deprived iron status in our patients.

New insights into factors influencing adult height in short SGA children: Results of a large multicentre growth hormone trial

BACKGROUND

Growth hormone (GH) treatment is effective in improving adult height (AH) in short children born SGA. However, there is a wide variation in height gain, even after adjustment for predictive variables. It is therefore important to investigate new factors which can influence the response to GH.

OBJECTIVE

To investigate the efficacy of GH treatment (1 mg/m(2/) day) in short SGA children on AH. To assess the relation between spontaneous catch-up growth after birth and growth during puberty on the total height gain SDS to AH.

PATIENTS

Longitudinal GH trial in 170 children.

RESULTS

Median age at start of GH was 7·1 years and height -3·0 SDS. AH was -1·8 SDS (TH-corrected AH -1·1 SDS) in boys and -1·9 SDS (TH-corrected AH -1·3 SDS) in girls. Spontaneous catch-up growth after birth was ≥0·5 SDS in 42% of children. In contrast to expectation, spontaneous catch-up growth was negatively correlated with total height gain SDS during GH (P = 0·009). During puberty, height SDS declined (-0·4 SDS in boys and -0·5 SDS in girls) resulting in a lower total height gain SDS than expected. Pubertal height gain was 25·5 cm in boys and 15·3 cm in girls, significantly lower compared to AGA children (P < 0·001). At onset of puberty, BA for boys and girls was moderately advanced (P = 0·02 and P < 0·001, respectively). Growth velocity was comparable to AGA children during the first two years of puberty, but thereafter significantly lower until reaching AH (P < 0·001).

CONCLUSION

In contrast to our hypothesis, children with greater spontaneous catch-up growth after birth show a lower total height gain SDS during GH. Height SDS declines from mid-puberty, due to a marked early deceleration of growth velocity.

Bone mineral density in children and adolescents with Prader-Willi syndrome: a longitudinal study during puberty and 9 years of growth hormone treatment

CONTEXT

Longitudinal data on bone mineral density (BMD) in children and adolescents with Prader-Willi Syndrome (PWS) during long-term GH treatment are not available.

OBJECTIVE

This study aimed to determine effects of long-term GH treatment and puberty on BMD of total body (BMDTB), lumbar spine (BMDLS), and bone mineral apparent density of the lumbar spine (BMADLS) in children with PWS.

DESIGN AND SETTING

This was a prospective longitudinal study of a Dutch PWS cohort.

PARTICIPANTS

Seventy-seven children with PWS who remained prepubertal during GH treatment for 4 years and 64 children with PWS who received GH treatment for 9 years participated in the study.

INTERVENTION

The children received GH treatment, 1 mg/m(2)/day (≅ 0.035 mg/kg/d).

MAIN OUTCOME MEASURES

BMDTB, BMDLS, and BMADLS was measured by using the same dual-energy x-ray absorptiometry machine for all annual measurements.

RESULTS

In the prepubertal group, BMDTB standard deviation score (SDS) and BMDLSSDS significantly increased during 4 years of GH treatment whereas BMADLSSDS remained stable. During adolescence, BMDTBSDS and BMADLSSDS decreased significantly, in girls from the age of 11 years and in boys from the ages of 14 and 16 years, respectively, but all BMD parameters remained within the normal range. Higher Tanner stages tended to be associated with lower BMDTBSDS (P = .083) and a significantly lower BMADLSSDS (P = .016). After 9 years of GH treatment, lean body mass SDS was the most powerful predictor of BMDTBSDS and BMDLSSDS in adolescents with PWS.

CONCLUSIONS

This long-term GH study demonstrates that BMDTB, BMDLS, and BMADLS remain stable in prepubertal children with PWS but decreases during adolescence, parallel to incomplete pubertal development. Based on our findings, clinicians should start sex hormone therapy from the age of 11 years in girls and 14 years in boys unless there is a normal progression of puberty.

Eight years of growth hormone treatment in children with Prader-Willi syndrome: maintaining the positive effects

BACKGROUND

The most important reason for treating children with Prader-Willi syndrome (PWS) with GH is to optimize their body composition.

OBJECTIVES

The aim of this ongoing study was to determine whether long-term GH treatment can counteract the clinical course of increasing obesity in PWS by maintaining the improved body composition brought during early treatment.

SETTING

This was a multicenter prospective cohort study.

METHODS

We have been following 60 prepubertal children for 8 years of continuous GH treatment (1 mg/m(2)/d ≈ 0.035 mg/kg/d) and used the same dual-energy x-ray absorptiometry machine for annual measurements of lean body mass and percent fat.

RESULTS

After a significant increase during the first year of GH treatment (P < .0001), lean body mass remained stable for 7 years at a level above baseline (P < .0001). After a significant decrease in the first year, percent fat SD score (SDS) and body mass index SDS remained stable at a level not significantly higher than at baseline (P = .06, P = .14, resp.). However, body mass index SDSPWS was significantly lower after 8 years of GH treatment than at baseline (P < .0001). After 8 years of treatment, height SDS and head circumference SDS had completely normalized. IGF-1 SDS increased to +2.36 SDS during the first year of treatment (P < .0001) and remained stable since then. GH treatment did not adversely affect glucose homeostasis, serum lipids, blood pressure, and bone maturation.

CONCLUSION

This 8-year study demonstrates that GH treatment is a potent force for counteracting the clinical course of obesity in children with PWS.

Beneficial effects of growth hormone treatment on cognition in children with Prader-Willi syndrome: a randomized controlled trial and longitudinal study

BACKGROUND

Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited.

METHODS

Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores.

RESULTS

During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores.

CONCLUSIONS

Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.

Long-term effect of lifestyle intervention on adiposity, metabolic parameters, inflammation and physical fitness in obese children: a randomized controlled trial

Background:

Behavioral lifestyle intervention, combined with parental involvement, is preferred over standard care or self-help in childhood obesity. The short-term results of such interventions are promising, but long-term follow-up results are equivocal.

Objective:

The objective of the present study was the short (3 months) and long-term (1 and 2 years follow-up) effect evaluation of a family-based multidisciplinary cognitive behavioral lifestyle intervention on markers of adiposity, metabolism, inflammation and physical fitness compared with standard care in children with obesity. Also the association between these outcome variables was determined.

Methods:

In this prospective longitudinal clinical trial, obese children were randomly assigned to a 3-month family-based cognitive behavioral multidisciplinary lifestyle treatment (n=40; body mass index-standard deviation score (BMI-SDS) 4.2±0.7; age; 13.3±2.0 years) or to a control group receiving an initial advice on physical activity and nutrition (n=39; BMI-SDS 4.3±0.6; age 13.1±1.9 years). Anthropometric data, physical fitness, metabolic parameters and inflammatory state were evaluated at baseline, after intervention (at 3 months) and at 1-year follow-up. At 2-year follow-up, anthropometric data and physical fitness were measured in the intervention group.

Results:

An intervention effect after 1 year was found for adiposity (P=0.02 for BMI-SDS, P=0.03 for waist circumference (WC)-SDS), physical fitness (absolute measured peak value of oxygen uptake (ml min⁻¹), standardized for age and gender (VO_2peak-SDS), P<0.01) and insulin resistance (HOMA-SDS, P=0.04). No significant intervention effect was found for serum lipid profile, high-sensitive C-reactive protein or for adiponectin. At 2-year follow-up, BMI-SDS in the intervention group (n=31) was 3.8±1.2 SDS, significantly less than at baseline (P=0.02).

Conclusion:

A positive 1-year follow-up treatment effect was found for adiposity, physical fitness and glucose homeostasis, but not for inflammatory markers. There was a significant long-term treatment effect on adiposity, although almost all children remained obese.

Efficacy and safety of long-term continuous growth hormone treatment in children with Prader-Willi syndrome

BACKGROUND

Children with Prader-Willi syndrome (PWS) have abnormal body composition and impaired growth. Short-term GH treatment has beneficial effects.

OBJECTIVES

The aim of the study was to investigate effects of long-term continuous GH treatment on body composition, growth, bone maturation, and safety parameters.

SETTING

We conducted a multicenter prospective trial.

DESIGN

Fifty-five children with a mean +/- sd age of 5.9 +/- 3.2 yr were followed during 4 yr of continuous GH treatment (1 mg/m(2) . d). Data were annually obtained in one center: fat percentage (fat%) and lean body mass (LBM) by dual-energy x-ray absorptiometry, height, weight, head circumference, bone age, blood pressure, and fasting IGF-I, IGF binding protein-3, glucose, insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, and low-density lipoprotein. sd scores (SDS) were calculated according to Dutch and PWS reference values (SDS and SDS(PWS)).

RESULTS

Fat%SDS was significantly lower after 4 yr of GH treatment (P < 0.0001). LBMSDS significantly increased during the first year (P = 0.02) but returned to baseline values the second year and remained unchanged thereafter. Mean +/- sd height normalized from -2.27 +/- 1.2 SDS to -0.24 +/- 1.2 SDS (P < 0.0001). Head circumference SDS increased from -0.79 +/- 1.0 at start to 0.07 +/- 1.1 SDS after 4 yr. BMISDS(PWS) significantly decreased. Mean +/- sd IGF-I and the IGF-I/IGF binding protein-3 ratio significantly increased to 2.08 +/- 1.1 and 2.32 +/- 0.9 SDS, respectively. GH treatment had no adverse effects on bone maturation, blood pressure, glucose homeostasis, and serum lipids.

CONCLUSIONS

Our study in children with PWS shows that 4 yr of continuous GH treatment (1 mg/m(2) . d) improves body composition by decreasing fat%SDS and stabilizing LBMSDS and head circumference SDS and normalizes heightSDS without adverse effects. Thus, long-term continuous GH treatment is an effective and safe therapy for children with PWS.

Bone mineral density and effects of growth hormone treatment in prepubertal children with Prader-Willi syndrome: a randomized controlled trial

BACKGROUND

Bone mineral density (BMD) is unknown in children with Prader-Willi syndrome (PWS), but is decreased in adults with PWS. In patients with GH deficiency, BMD increases during GH treatment.

OBJECTIVES

The aim of the study was to evaluate BMD in children with PWS and to study the effects of GH treatment.

DESIGN

We conducted a randomized controlled GH trial. Forty-six prepubertal children were randomized into either a GH-treated group (1.0 mg/m(2) . d) or a control group for 2 yr. At start, 6, 12, and 24 months of study, total body and lumbar spine BMD were measured by dual-energy x-ray absorptiometry, and lumbar spine bone mineral apparent density (BMAD) was calculated.

RESULTS

Baseline total body and lumbar spine BMD sd score (SDS) were normal [mean (sd), -0.2 SDS (1.1) and -0.4 SDS (1.2), respectively]. BMADSDS, which corrects for short stature, was also normal [mean (sd), 0.40 SDS (1.1)]. Total body BMDSDS decreased during the first 6 months of GH (P < 0.0001), but increased during the second year of treatment. After 24 months of study, total body and lumbar spine BMDSDS, and the BMADSDS did not significantly differ between GH-treated children and randomized controls (P = 0.30, P = 0.44, and P = 0.47, respectively). Results were similar when corrected for body mass index SDS. Repeated measurements analysis showed a significant positive association between IGF-I SDS and total body and lumbar spine BMDSDS, but not with BMADSDS.

CONCLUSIONS

Our results show that prepubertal children with PWS have a normal BMD. GH treatment had no effect on BMD, except for a temporary decrease of total body BMDSDS in the first 6 months.