A. Hellström - Academia.edu (original) (raw)

Papers by A. Hellström

Research paper thumbnail of Longitudinal infusion of a complex of insulin-like growth factor-I and IGF-binding protein-3 in five preterm infants: pharmacokinetics and short-term safety

Pediatric Research, 2013

Background: In preterm infants, low levels of insulin-like growth factor-I (IGF-I) and IGF bindin... more Background: In preterm infants, low levels of insulin-like growth factor-I (IGF-I) and IGF binding protein 3 (IGFBP-3) are associated with impaired brain growth and retinopathy of prematurity (ROP). Treatment with IGF-I/IGFBP-3 may be beneficial for brain development and may decrease the prevalence of ROP. Methods: In a phase II pharmacokinetics and safety study, five infants (three girls) with a median (range) gestational age (Ga) of 26 wk + 6 d (26 wk + 0 d to 27 wk + 2 d) and birth weight of 990 (900-1,212) g received continuous intravenous infusion of recombinant human (rh)IGF-I/rhIGFBP-3. Treatment was initiated during the first postnatal day and continued for a median (range) duration of 168 (47-168) h in dosages between 21 and 111 µg/kg/24 h. results: Treatment with rhIGF-I/rhIGFBP-3 was associated with higher serum IGF-I and IGFBP-3 concentrations (P < 0.001) than model-predicted endogenous levels. Of 74 IGF-I samples measured during study drug infusion, 37 (50%) were within the target range, 4 (5%) were above, and 33 (45%) were below. The predicted dose of rhIGF-I/rhIGFBP-3 required to establish circulating levels of IGF-I within the intrauterine range in a 1,000 g infant was 75-100 µg/kg/24 h. No hypoglycemia or other adverse effects were recorded. conclusion: In this study, continuous intravenous infusion of rhIGF-I/rhIGFBP-3 was effective in increasing serum concentrations of IGF-I and IGFBP-3, and was found to be safe.

Research paper thumbnail of Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants

Archives of disease in childhood. Fetal and neonatal edition, Jan 12, 2015

Poor weight gain during the first weeks of life in preterm infants is closely associated with the... more Poor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be an important contributing factor. This study aimed to evaluate the effect of energy and macronutrient intakes during the first 4 weeks of life on the risk for severe ROP (stages 3-5). A population-based study including all Swedish extremely preterm infants born before 27 gestational weeks during a 3-year period. Each infant was classified according to the maximum stage of ROP in either eye as assessed prospectively until full retinal vascularisation. The detailed daily data of actual intakes of enteral and parenteral nutrition and growth data were obtained from hospital records. Of the included 498 infants, 172 (34.5%) had severe ROP and 96 (19.3%) were treated. Energy and macronutrient intakes were less than recommended and the infants showed severe postnatal growth failure. Higher intakes of en...

Research paper thumbnail of The Specificity of the WINROP Algorithm Can Be Significantly Increased by Reassessment of the WINROP Alarm

Neonatology, 2015

Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infan... more Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infants. The introduction of new ROP screening surveillance systems, with higher sensitivity and specificity than established ROP screening guidelines, has the potential to reduce the number of stressful eye examinations in these infants. To improve the specificity of the WINROP (Weight, Insulin-like growth factor-I, Neonatal, ROP) surveillance system, identifying extremely preterm infants requiring treatment for ROP. Two cohorts that had previously been subjected to WINROP analyses were included and reevaluated in this study. The weight at WINROP alarm for extremely preterm infants, born at gestational age &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;27 weeks, was reevaluated and by establishing &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;safe&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; WINROP alarm weight limits, an intersample reassessment of WINROP alarm was performed. The two cohorts were as follows: (1) the Extremely Preterm Infants in Sweden Study (EXPRESS) cohort, infants born in Sweden during 2004-2007 (n = 407), and (2) extremely preterm infants in a North American cohort, born during 2006-2009 (n = 566). In the EXPRESS cohort, 12.5% (40/319) of the infants who previously received a WINROP alarm were now reassessed as having no alarm; the specificity of WINROP in EXPRESS increased from 23.9% (86/360) to 35.0% (126/360). In the North American cohort, 15.4% (81/526) were reassessed as having no alarm; the specificity increased from 8.5% (38/447) to 26.6% (119/447). The sensitivity persisted as 97.5% in EXPRESS (45/47) and 98.3% (117/119) in the North American cohort. The specificity of the WINROP surveillance system for extremely preterm infants can be significantly improved by reassessment using the weight at WINROP alarm. © 2015 S. Karger AG, Basel.

Research paper thumbnail of 122 Postnatal Energy and Protein Deficits are Associated with Poor Neonatal Growth: Preliminary Results From a Swedish Population-Based Study

Research paper thumbnail of Reduced retinal vascularization in children with growth hormone insufficiency

Growth Hormone & IGF Research, 1998

The neovascularization in diabetic retinopathy is believed to involve locally produced angiogenic... more The neovascularization in diabetic retinopathy is believed to involve locally produced angiogenic factors. In addition, there are indications that GH may influence retinal vascularization. To investigate the role of GH in retinal vascularization, we examined the retinal vascular pattern in children with congenital GH deficiency. Retinal vessel morphology was evaluated by digital image analysis of ocular fundus photographs in 39 children (5 girls and 34 boys, aged 3.6 -18.7 yr) with congenital GH deficiency, and it was compared to that of 100 healthy controls. Twenty children had received GH treatment (0.1 IU/kg daily). All children were born at term, and none of the children had any clinical signs of ocular disease or reduced vision. Children with GH insufficiencies, regardless of whether they were treated with GH, had a significantly lower number of vascular branching points than the reference group (P Ͻ 0.0001). Thirty-three percent of the GH-insufficient individuals had a number of vascular branching points less than or equal to the fifth percentile of the reference group. The reduced retinal vascularization observed in children with congenital GH deficiency suggests that GH may be of importance for angiogenesis. (J Clin Endocrinol Metab 84: [795][796][797][798] 1999)

Research paper thumbnail of Longitudinal Postnatal Weight Measurements for the Prediction of Retinopathy of Prematurity

Archives of Ophthalmology, 2010

Research paper thumbnail of Importance of Early Postnatal Weight Gain for Normal Retinal Angiogenesis in Very Preterm Infants

Archives of Ophthalmology, 2012

Objective: To assess WINROP (https://winrop.com), an algorithm using postnatal weight measurement... more Objective: To assess WINROP (https://winrop.com), an algorithm using postnatal weight measurements, as a tool for the prediction of retinopathy of prematurity (ROP) in a large geographically and racially diverse study population.

Research paper thumbnail of Association between urinary tract infection, renal damage and birth size

Acta Paediatrica, 2007

The aim of this study was to investigate whether birth size is associated with permanent renal da... more The aim of this study was to investigate whether birth size is associated with permanent renal damage in children with urinary tract infection (UTI). A cohort of 1221 children under 16 y of age was diagnosed with their first symptomatic UTI between 1970 and 1979. Of these, 74 had urographic renal scarring in childhood and 57 were re-examined as adults. The birth files of 48 of these patients (35F, 13M) were available, and birthweight and birthlength in relation to gestational age were analysed and compared with a Swedish reference population. Children who had renal damage without vesicoureteric reflux were significantly smaller at birth (median weight, -0.76 SDS) compared with both children who had renal damage and reflux (median weight, -0.01 SDS) and the reference population. The demonstration of low birthweight among children with UTI and renal damage but no reflux suggests that low birthweight may be a risk factor for the development of renal damage.

Research paper thumbnail of Knee-heel length measurements in preterm infants: evaluation of a simple electronically equipped instrument

Acta Paediatrica, 2007

To compare and evaluate a mini-knemometer with a simple and inexpensive electronic caliper with r... more To compare and evaluate a mini-knemometer with a simple and inexpensive electronic caliper with regard to precision, handling error (technical error) and estimation of growth velocity. Thirty-five prematurely born infants, with a median gestational age of 29 (range 24-33) wk and a median birthweight of 960 (range 480-2,480) g, were measured on 409 different occasions with both instruments. On each occasion, five independent readings were made. There was no significant difference in precision between the two instruments, when measuring growth velocity over a 4 wk period (median 0.41, range 0.10-0.59 mm d(-1)). The handling error in this study, calculated as the mean standard deviation, was 0.36 (SD 0.18, coefficient of variation 0.38%) mm for the simple electronic caliper and 0.59 mm for the mini-knemometer. Short-term growth was detectable within 2 d when growth velocity was normal. Longitudinal measurement of lower leg length is a gentle and useful complementary method for assessing growth in preterm infants. An inexpensive electronic caliper is well suited for routine use in clinical practice, with measurements taken once or twice a week.

Research paper thumbnail of Neonatal IGF-1/IGFBP-1 axis and retinopathy of prematurity are associated with increased blood pressure in preterm children

Acta Paediatrica, 2014

Aim: Preterm children are at risk of developing increased blood pressure (BP). We evaluated possi... more Aim: Preterm children are at risk of developing increased blood pressure (BP). We evaluated possible associations between BP, early insulin-like growth factor-1 (IGF-1) and IGF-binding protein-1 (IGFBP-1) levels and retinopathy of prematurity (ROP) in preterm children.

Research paper thumbnail of WINROP Identifies Severe Retinopathy of Prematurity at an Early Stage in a Nation-Based Cohort of Extremely Preterm Infants

PLoS ONE, 2013

Objective: To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sigh... more Objective: To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sight-threatening retinopathy of prematurity (ROP type 1) in a nation-based extremely preterm infant cohort.

Research paper thumbnail of Longitudinal infusion of a complex of insulin-like growth factor-I and IGF-binding protein-3 in five preterm infants: pharmacokinetics and short-term safety

Pediatric Research, 2013

Background: In preterm infants, low levels of insulin-like growth factor-I (IGF-I) and IGF bindin... more Background: In preterm infants, low levels of insulin-like growth factor-I (IGF-I) and IGF binding protein 3 (IGFBP-3) are associated with impaired brain growth and retinopathy of prematurity (ROP). Treatment with IGF-I/IGFBP-3 may be beneficial for brain development and may decrease the prevalence of ROP. Methods: In a phase II pharmacokinetics and safety study, five infants (three girls) with a median (range) gestational age (Ga) of 26 wk + 6 d (26 wk + 0 d to 27 wk + 2 d) and birth weight of 990 (900-1,212) g received continuous intravenous infusion of recombinant human (rh)IGF-I/rhIGFBP-3. Treatment was initiated during the first postnatal day and continued for a median (range) duration of 168 (47-168) h in dosages between 21 and 111 µg/kg/24 h. results: Treatment with rhIGF-I/rhIGFBP-3 was associated with higher serum IGF-I and IGFBP-3 concentrations (P < 0.001) than model-predicted endogenous levels. Of 74 IGF-I samples measured during study drug infusion, 37 (50%) were within the target range, 4 (5%) were above, and 33 (45%) were below. The predicted dose of rhIGF-I/rhIGFBP-3 required to establish circulating levels of IGF-I within the intrauterine range in a 1,000 g infant was 75-100 µg/kg/24 h. No hypoglycemia or other adverse effects were recorded. conclusion: In this study, continuous intravenous infusion of rhIGF-I/rhIGFBP-3 was effective in increasing serum concentrations of IGF-I and IGFBP-3, and was found to be safe.

Research paper thumbnail of Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants

Archives of disease in childhood. Fetal and neonatal edition, Jan 12, 2015

Poor weight gain during the first weeks of life in preterm infants is closely associated with the... more Poor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be an important contributing factor. This study aimed to evaluate the effect of energy and macronutrient intakes during the first 4 weeks of life on the risk for severe ROP (stages 3-5). A population-based study including all Swedish extremely preterm infants born before 27 gestational weeks during a 3-year period. Each infant was classified according to the maximum stage of ROP in either eye as assessed prospectively until full retinal vascularisation. The detailed daily data of actual intakes of enteral and parenteral nutrition and growth data were obtained from hospital records. Of the included 498 infants, 172 (34.5%) had severe ROP and 96 (19.3%) were treated. Energy and macronutrient intakes were less than recommended and the infants showed severe postnatal growth failure. Higher intakes of en...

Research paper thumbnail of The Specificity of the WINROP Algorithm Can Be Significantly Increased by Reassessment of the WINROP Alarm

Neonatology, 2015

Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infan... more Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infants. The introduction of new ROP screening surveillance systems, with higher sensitivity and specificity than established ROP screening guidelines, has the potential to reduce the number of stressful eye examinations in these infants. To improve the specificity of the WINROP (Weight, Insulin-like growth factor-I, Neonatal, ROP) surveillance system, identifying extremely preterm infants requiring treatment for ROP. Two cohorts that had previously been subjected to WINROP analyses were included and reevaluated in this study. The weight at WINROP alarm for extremely preterm infants, born at gestational age &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;27 weeks, was reevaluated and by establishing &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;safe&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; WINROP alarm weight limits, an intersample reassessment of WINROP alarm was performed. The two cohorts were as follows: (1) the Extremely Preterm Infants in Sweden Study (EXPRESS) cohort, infants born in Sweden during 2004-2007 (n = 407), and (2) extremely preterm infants in a North American cohort, born during 2006-2009 (n = 566). In the EXPRESS cohort, 12.5% (40/319) of the infants who previously received a WINROP alarm were now reassessed as having no alarm; the specificity of WINROP in EXPRESS increased from 23.9% (86/360) to 35.0% (126/360). In the North American cohort, 15.4% (81/526) were reassessed as having no alarm; the specificity increased from 8.5% (38/447) to 26.6% (119/447). The sensitivity persisted as 97.5% in EXPRESS (45/47) and 98.3% (117/119) in the North American cohort. The specificity of the WINROP surveillance system for extremely preterm infants can be significantly improved by reassessment using the weight at WINROP alarm. © 2015 S. Karger AG, Basel.

Research paper thumbnail of 122 Postnatal Energy and Protein Deficits are Associated with Poor Neonatal Growth: Preliminary Results From a Swedish Population-Based Study

Research paper thumbnail of Reduced retinal vascularization in children with growth hormone insufficiency

Growth Hormone & IGF Research, 1998

The neovascularization in diabetic retinopathy is believed to involve locally produced angiogenic... more The neovascularization in diabetic retinopathy is believed to involve locally produced angiogenic factors. In addition, there are indications that GH may influence retinal vascularization. To investigate the role of GH in retinal vascularization, we examined the retinal vascular pattern in children with congenital GH deficiency. Retinal vessel morphology was evaluated by digital image analysis of ocular fundus photographs in 39 children (5 girls and 34 boys, aged 3.6 -18.7 yr) with congenital GH deficiency, and it was compared to that of 100 healthy controls. Twenty children had received GH treatment (0.1 IU/kg daily). All children were born at term, and none of the children had any clinical signs of ocular disease or reduced vision. Children with GH insufficiencies, regardless of whether they were treated with GH, had a significantly lower number of vascular branching points than the reference group (P Ͻ 0.0001). Thirty-three percent of the GH-insufficient individuals had a number of vascular branching points less than or equal to the fifth percentile of the reference group. The reduced retinal vascularization observed in children with congenital GH deficiency suggests that GH may be of importance for angiogenesis. (J Clin Endocrinol Metab 84: [795][796][797][798] 1999)

Research paper thumbnail of Longitudinal Postnatal Weight Measurements for the Prediction of Retinopathy of Prematurity

Archives of Ophthalmology, 2010

Research paper thumbnail of Importance of Early Postnatal Weight Gain for Normal Retinal Angiogenesis in Very Preterm Infants

Archives of Ophthalmology, 2012

Objective: To assess WINROP (https://winrop.com), an algorithm using postnatal weight measurement... more Objective: To assess WINROP (https://winrop.com), an algorithm using postnatal weight measurements, as a tool for the prediction of retinopathy of prematurity (ROP) in a large geographically and racially diverse study population.

Research paper thumbnail of Association between urinary tract infection, renal damage and birth size

Acta Paediatrica, 2007

The aim of this study was to investigate whether birth size is associated with permanent renal da... more The aim of this study was to investigate whether birth size is associated with permanent renal damage in children with urinary tract infection (UTI). A cohort of 1221 children under 16 y of age was diagnosed with their first symptomatic UTI between 1970 and 1979. Of these, 74 had urographic renal scarring in childhood and 57 were re-examined as adults. The birth files of 48 of these patients (35F, 13M) were available, and birthweight and birthlength in relation to gestational age were analysed and compared with a Swedish reference population. Children who had renal damage without vesicoureteric reflux were significantly smaller at birth (median weight, -0.76 SDS) compared with both children who had renal damage and reflux (median weight, -0.01 SDS) and the reference population. The demonstration of low birthweight among children with UTI and renal damage but no reflux suggests that low birthweight may be a risk factor for the development of renal damage.

Research paper thumbnail of Knee-heel length measurements in preterm infants: evaluation of a simple electronically equipped instrument

Acta Paediatrica, 2007

To compare and evaluate a mini-knemometer with a simple and inexpensive electronic caliper with r... more To compare and evaluate a mini-knemometer with a simple and inexpensive electronic caliper with regard to precision, handling error (technical error) and estimation of growth velocity. Thirty-five prematurely born infants, with a median gestational age of 29 (range 24-33) wk and a median birthweight of 960 (range 480-2,480) g, were measured on 409 different occasions with both instruments. On each occasion, five independent readings were made. There was no significant difference in precision between the two instruments, when measuring growth velocity over a 4 wk period (median 0.41, range 0.10-0.59 mm d(-1)). The handling error in this study, calculated as the mean standard deviation, was 0.36 (SD 0.18, coefficient of variation 0.38%) mm for the simple electronic caliper and 0.59 mm for the mini-knemometer. Short-term growth was detectable within 2 d when growth velocity was normal. Longitudinal measurement of lower leg length is a gentle and useful complementary method for assessing growth in preterm infants. An inexpensive electronic caliper is well suited for routine use in clinical practice, with measurements taken once or twice a week.

Research paper thumbnail of Neonatal IGF-1/IGFBP-1 axis and retinopathy of prematurity are associated with increased blood pressure in preterm children

Acta Paediatrica, 2014

Aim: Preterm children are at risk of developing increased blood pressure (BP). We evaluated possi... more Aim: Preterm children are at risk of developing increased blood pressure (BP). We evaluated possible associations between BP, early insulin-like growth factor-1 (IGF-1) and IGF-binding protein-1 (IGFBP-1) levels and retinopathy of prematurity (ROP) in preterm children.

Research paper thumbnail of WINROP Identifies Severe Retinopathy of Prematurity at an Early Stage in a Nation-Based Cohort of Extremely Preterm Infants

PLoS ONE, 2013

Objective: To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sigh... more Objective: To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sight-threatening retinopathy of prematurity (ROP type 1) in a nation-based extremely preterm infant cohort.