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Dive into the research topics where Elbrich P. C. Siemensma is active.

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Featured researches published by Elbrich P. C. Siemensma.


The Journal of Clinical Endocrinology and Metabolism | 2012

Beneficial Effects of Growth Hormone Treatment on Cognition in Children with Prader-Willi Syndrome: A Randomized Controlled Trial and Longitudinal Study

Elbrich P. C. Siemensma; Roderick F. A. Tummers-de Lind van Wijngaarden; Dederieke A. M. Festen; Zyrhea C. E. Troeman; A. A. E. M. (Janielle) van Alfen-van der Velden; Barto J. Otten; Joost Rotteveel; Roelof J. Odink; G. C. B. Bindels-de Heus; Mariette van Leeuwen; Danny A. J. P. Haring; W. Oostdijk; Gianni Bocca; E. C. A. Mieke Houdijk; A. S. Paul van Trotsenburg; J. J. Gera Hoorweg-Nijman; Hester van Wieringen; René C. F. M. Vreuls; Petr Jira; Eelco J. Schroor; Evelyn van Pinxteren-Nagler; Jan Willem Pilon; L. Lunshof; Anita Hokken-Koelega

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.


The Journal of Clinical Endocrinology and Metabolism | 2009

Efficacy and Safety of Long-Term Continuous Growth Hormone Treatment in Children with Prader-Willi Syndrome

Roderick F. A. de Lind van Wijngaarden; Elbrich P. C. Siemensma; Dederieke A. M. Festen; Barto J. Otten; Edgar van Mil; Joost Rotteveel; Roelof J. Odink; G. C. B. Bindels-de Heus; Mariettee van Leeuwen; Danny A. J. P. Haring; Gianni Bocca; E. C. A. Mieke Houdijk; J. J. Gera Hoorweg-Nijman; René C. F. M. Vreuls; Petr Jira; A. S. Paul van Trotsenburg; Boudewijn Bakker; Eelco J. Schroor; Jan Willem Pilon; Jan M. Wit; Stenvert L. S. Drop; Anita Hokken-Koelega

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.


The Journal of Clinical Endocrinology and Metabolism | 2013

Eight Years of Growth Hormone Treatment in Children With Prader-Willi Syndrome : Maintaining the Positive Effects

N. E. Bakker; R. J. Kuppens; Elbrich P. C. Siemensma; R. F. A. Tummers-de Lind van Wijngaarden; Dederieke A. M. Festen; G. C. B. Bindels-de Heus; Gianni Bocca; Danny A. J. P. Haring; J. J. G. Hoorweg-Nijman; Euphemia C. A. M. Houdijk; Petr Jira; L. Lunshof; Roelof J. Odink; W. Oostdijk; Joost Rotteveel; Eelco J. Schroor; A. A. E. M. Van Alfen; van Maria Leeuwen; E. Van Pinxteren-Nagler; H. Van Wieringen; René C. F. M. Vreuls; Nitash Zwaveling-Soonawala; M. A. J. de Ridder; Anita Hokken-Koelega

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.


The Journal of Clinical Endocrinology and Metabolism | 2012

Testicular failure in boys with Prader-Willi syndrome: Longitudinal studies of reproductive hormones

Elbrich P. C. Siemensma; Roderick F. A. de Lind van Wijngaarden; Barto J. Otten; Frank H. de Jong; Anita Hokken-Koelega

CONTEXT The pathophysiology of hypogonadism in boys with Prader-Willi Syndrome (PWS) remains uncertain. Several reports described hypogonadotropic hypogonadism, some reported primary gonadal failure, and others a combination of both. OBJECTIVES The aim of the study was to evaluate gonadal function over time in boys with PWS and the effect of GH treatment. MEASUREMENTS We made a longitudinal assessment of inhibin B, FSH, testosterone, and LH levels in prepubertal boys and male adolescents with PWS. PATIENTS AND METHODS We studied 68 boys participating in the Dutch PWS Cohort study. Serum inhibin B, FSH, LH, and testosterone levels were compared with reference values. RESULTS Boys with PWS had normal inhibin B levels between 6 months and 10 yr of age, but after onset of puberty, inhibin B levels declined to less than the 5th percentile, and FSH levels increased to more than the 95th percentile. Two years after the onset of puberty and in young adults, inhibin B levels were significantly lower (P=0.008 and P<0.0001), and FSH levels were significantly higher (P=0.034 and P<0.0001) than at onset of puberty. Testosterone levels increased but remained below the 5th percentile, and LH levels increased but not above the 95th percentile. Age showed a significant correlation with inhibin B levels (r=-0.31; P=0.001) after 9 yr of age. GH treatment had no significant effect on inhibin B levels. CONCLUSION Our study indicates that the majority of male patients with PWS have primary testicular failure, which becomes apparent after onset of puberty. Hypogonadotropic hypogonadism did not appear to be the main reason of hypogonadism in most boys.


Research in Developmental Disabilities | 2013

Impaired theory of mind and symptoms of Autism Spectrum Disorder in children with Prader–Willi syndrome

Sin Ting Lo; Elbrich P. C. Siemensma; Philippe Collin; Anita Hokken-Koelega

In order to evaluate the social cognitive functioning in children with Prader-Willi syndrome (PWS), Theory of Mind (ToM) and symptoms of Autism Spectrum Disorder were evaluated. Sixty-six children with PWS aged 7-17 years were tested using the Theory of Mind test-R and the Diagnostic Interview for Social Communication disorders. We tested the correlation between Total ToM Standard Deviation Score (Total ToM SDS) and genetic subtype of paternal deletion or maternal uniparental disomy, and total IQ, verbal IQ and performal IQ. Prevalence and symptoms of Autism Spectrum Disorder were assessed. Median (interquartile range) of total ToM SDS of those aged 7-17 years was -3.84 (-5.73, -1.57). Their Total ToM SDS correlated with total IQ (β=0.662, p<0.001, adj.R(2)=0.407), in particular with verbal IQ (β=0.502, p=0.001, adj.R(2)=0.409), but not with performal IQ (β=0.241, p>0.05, adj.R(2)=0.259). No difference in Total ToM SDS was found between children with deletion and maternal uniparental disomy (β=-0.143, p>0.05, adj.R(2)=-0.016). Compared to the reference group of healthy children aged 7-12 years, children with PWS in the same age group had a median ToM developmental delay of 4 (3-5) years. One third of children with PWS scored positive for Autism Spectrum Disorder. Most prominent aberrations in Autism Spectrum Disorder were focused on maladaptive behavior. Our findings demonstrate a markedly reduced level of social cognitive functioning, which has consequences for the approach of children with PWS, i.e. adjustment to the childs level of social cognitive functioning.


The Journal of Clinical Endocrinology and Metabolism | 2012

Ovarian function and reproductive hormone levels in girls with Prader-Willi syndrome: a longitudinal study.

Elbrich P. C. Siemensma; A. A. E. M. (Janielle) van Alfen-van der Velden; Barto J. Otten; Joop S.E. Laven; Anita Hokken-Koelega

CONTEXT The etiology of hypogonadism in girls with Prader-Willi syndrome (PWS) remains uncertain. OBJECTIVES The aim of the study was to evaluate gonadal function longitudinally in girls and female adolescents with PWS. MEASUREMENTS We performed a longitudinal assessment of anti-müllerian hormone (AMH), gonadotropins, estradiol (E(2)), inhibin B and A, and pubertal development in girls and female adolescents with PWS. PATIENTS AND METHODS Sixty-one girls participating in the Dutch PWS Cohort study participated in the study. Serum AMH, gonadotropins, E(2), and inhibin B and A levels were compared with reference values. RESULTS AMH levels in girls and female adolescents with PWS were comparable to reference levels between 6 months and 22 yr of age. From 10 yr of age, FSH and LH levels increased to above the 5th percentile compared to reference levels. E(2) and inhibin B levels were in the low normal range in the majority, and inhibin A levels were low but detectable in almost half the female adolescents with PWS. The median age at puberty onset was comparable, but the median ages at attaining Tanner M3 (P = 0.05) and M4 (P < 0.0001) were significantly higher in girls with PWS than in healthy references. CONCLUSION Our study shows that the primordial follicle pool and number of small antral follicles are conserved in girls and female adolescents with PWS. We found no classical hypogonadotropic hypogonadism. However, maturation of follicles and progression of pubertal development are impaired, which might be due to dysregulation of LH secretion. Because these impairments are not absolute, ovulation and thus conception cannot be ruled out in individual female adolescents with PWS.


Clinical Endocrinology | 2011

Pubarche and serum dehydroepiandrosterone sulphate levels in children with Prader–Willi syndrome

Elbrich P. C. Siemensma; Roderick F. A. de Lind van Wijngaarden; Barto J. Otten; Frank H. de Jong; Anita Hokken-Koelega

Context  Premature pubarche (PP) is reported in children with Prader–Willi Syndrome (PWS). Pubarche is preceded by adrenarche – an increase in serum levels of adrenal androgens, most specifically dehydroepiandrosterone sulphate (DHEAS).


Research in Developmental Disabilities | 2013

Growth hormone combined with child-specific motor training improves motor development in infants with Prader-Willi syndrome: a randomized controlled trial.

L. Reus; Ben Pelzer; Barto J. Otten; Elbrich P. C. Siemensma; Janiëlle van Alfen-van der Velden; Dederieke A. M. Festen; Anita Hokken-Koelega; Maria W.G. Nijhuis-van der Sanden

Although severe motor problems in infants with Prader-Willi syndrome (PWS) are striking, motor development has never been studied longitudinally and the results of growth hormone (GH) treatment on motor development are contradictory. The authors studied whether GH treatment can enhance the effect of physical training on motor development in infants with PWS. Twenty-two infants were followed for two years during a randomized controlled trial. The treatment and control groups began GH after baseline or following a control period, respectively. Both groups followed a child-specific physical training program. Motor performance was measured every three months. Multi-level regression analysis revealed that motor development differed significantly between infants (p<.001), and this could be partially explained by baseline motor developmental level (p<.01). GH treatment enhanced the effects of child-specific physical training on both motor developmental rate and motor developmental potential. Moreover, this effect was more pronounced when GH treatment was initiated at a younger age.


Clinical Endocrinology | 2017

Metabolic health profile in young adults with Prader–Willi syndrome: results of a 2-year randomized, placebo-controlled, crossover GH trial

Renske Kuppens; N.E. Bakker; Elbrich P. C. Siemensma; Stephany H. Donze; Theo Stijnen; Anita Hokken-Koelega

Patients with Prader–Willi syndrome (PWS) have an increased fat mass and decreased lean body mass. GH‐treated young adults with PWS who have attained adult height benefit from continuation of growth hormone (GH) treatment, as GH maintained their improved body composition, whereas fat mass increased during the placebo period. Adults with PWS are predisposed to T2DM and cardiovascular disease. Whether GH affects metabolic health profile of this patient group is unknown.


Hormone Research in Paediatrics | 2015

Dietary Energy Intake, Body Composition and Resting Energy Expenditure in Prepubertal Children with Prader-Willi Syndrome before and during Growth Hormone Treatment: A Randomized Controlled Trial

Nienke Bakker; Elbrich P. C. Siemensma; C. Koopman; Anita Hokken-Koelega

Background/Aims: Dietary management is a difficult but key aspect of care in children with Prader-Willi syndrome (PWS). We therefore investigated the effect of growth hormone (GH) treatment on reported energy intake in children with PWS, in relation with body composition, resting energy expenditure (REE) and hormone levels. Methods: In a randomized controlled GH trial including 47 children with PWS, we assessed 5-day dietary records and dual-energy X-ray absorptiometry for body composition. REE was calculated by Müllers equation, based on fat mass, fat free mass and gender. Results: Baseline energy intake of children with PWS was lower than normal daily energy requirements (p < 0.001), and decreased with age to 50% in prepubertal children. Energy intake in infants [m/f: 11/8; median (interquartile range [IQR]) age 2.7 years (1.5-3.2)] increased after 1 year of GH treatment (p = 0.008); this tended to be higher in the GH group than in the untreated group (p = 0.07). In prepubertal children [m/f: 14/14; median (IQR) age 6.8 years (5.1-8.1)], the increase in energy intake was higher in the GH group, but this was not different compared to the untreated group. REE was not different between the GH group and the untreated group. Increase in energy intake during 2 years of GH treatment was correlated with lower fat percentage standard deviation scores (p = 0.037) and higher adiponectin levels (p = 0.007). Conclusion: Our study demonstrates that parents of children with PWS are very well capable of restricting energy intake up to 50% compared to daily energy requirements for age- and sex-matched healthy children. GH treatment was associated with a slight increase in energy intake, but also improved body composition and adiponectin levels, which suggests a protective effect of GH treatment.

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Anita Hokken-Koelega

Erasmus University Medical Center

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Barto J. Otten

Radboud University Nijmegen Medical Centre

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Nienke Bakker

Boston Children's Hospital

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Eelco J. Schroor

VU University Medical Center

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Gianni Bocca

University Medical Center Groningen

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Joost Rotteveel

VU University Medical Center

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Renske Kuppens

Erasmus University Medical Center

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