Comparison of physical activity and body composition in a cohort of children born extremely preterm or with extremely low birth weight to matched term-born controls: a follow-up study

Mineral supplementation for very preterm infants fed fortified human milk

OBJECTIVES

The safety and feasibility of human milk fortification with bovine colostrum (BC) were investigated in very preterm infants (FortiColos trial, NCT03537365). The BC product contained lower calcium, phosphate, and iron levels compared to the conventional fortifier (CF). We tested whether fortification with BC plus extra phosphate was sufficient to support the infants' mineral status assessed by blood biochemistry.

METHODS

In a randomised controlled trial (FortiColos, NCT03537365), mineral status was compared after fortification with BC versus CF. Blood calcium, phosphate, and haemoglobin were determined before and up to 3 weeks after the start of fortification (at the mean age of 8-9 days). The maximum supplemental doses of calcium, phosphate, and iron given were retrieved from patient medical records. Results were adjusted for gestational age, birth weight, and enteral nutrition with the mother's own milk and/or donor human milk.

RESULTS

Blood values of calcium, phosphate, and haemoglobin were similar between groups. Infants in both groups required supplementation with calcium and phosphate, but infants fed BC required higher maximum doses of phosphate and calcium (p < 0.05) to maintain acceptable blood values. Regardless of fortification groups, the most immature (<29 weeks of gestation) and small for gestational age infants showed a higher risk for requiring additional phosphate (odds ratio [OR]: 3.9, p < 0.001; OR: 2.14, p = 0.07, respectively).

CONCLUSIONS

The use of BC as a fortifier for human milk requires additional phosphate and calcium relative to a CF. Regardless of the fortification product, the most immature and small infants require additional mineral supplementation.

Impact of preterm birth on muscle mass and function: a systematic review and meta-analysis

Individuals born preterm present lower exercise capacity. Along with the cardiopulmonary responses and activity level, muscle strength is a key determinant of exercise capacity. This systematic review aimed to summarize the current knowledge on the impact of preterm birth on skeletal muscle mass and function across the lifespan. The databases PubMed, MEDLINE, EBM, Embase, CINAHL Plus, Global Index Medicus, and Google Scholar were searched using keywords and MeSH terms related to skeletal muscle, preterm birth, and low birth weight. Two independent reviewers undertook study selection, data extraction, and quality appraisal using Covidence review management. Data were pooled to estimate the prematurity effect on muscle mass and function using the R software. From 4378 studies retrieved, 132 were full-text reviewed and 25 met the inclusion/exclusion criteria. Five studies presented a low risk of bias, and 5 had a higher risk of bias due to a lack of adjustment for confounding factors and presenting incomplete outcomes. Meta-analyses of pooled data from homogenous studies indicated a significant reduction in muscle thickness and jump test (muscle power) in individuals born preterm versus full-term with standardized mean difference and confidence interval of - 0.58 (0.27, 0.89) and - 0.45 (0.21, 0.69), respectively.    Conclusion: Overall, this systematic review summarizing the existing literature on the impact of preterm birth on skeletal muscle indicates emerging evidence that individuals born preterm, display alteration in the development of their skeletal muscle mass and function. This work also highlights a clear knowledge gap in understanding the effect of preterm birth on skeletal muscle development. What is Known: • Preterm birth, which occurs at a critical time of skeletal muscle development and maturation, impairs the development of different organs and tissues leading to a higher risk of comorbidities such as cardiovascular diseases. • Preterm birth is associated with reduced exercise capacity. What is New: • Individuals born preterm display alterations in muscle mass and function compared to individuals born at term from infancy to adulthood. • There is a need to develop preventive or curative interventions to improve skeletal muscle health in preterm-born individuals.

Small for gestational age preterm infants and later adiposity and height: A systematic review and meta-analysis

BACKGROUND

Overweight and obesity and their consequent morbidities are important worldwide health problems. Some research suggests excess adiposity origins may begin in fetal life, but unknown is whether this applies to infants born preterm.

OBJECTIVE

The objective of the study was to assess the association between small for gestational age (SGA) birth and later adiposity and height among those born preterm.

DATA SOURCES

MEDLINE, EMBASE and CINAHL until October 2022.

STUDY SELECTION AND DATA EXTRACTION

Studies were included if they reported anthropometric (adiposity measures and height) outcomes for participants born preterm with SGA versus non-SGA. Screening, data extraction and risks of bias assessments were conducted in duplicate by two reviewers.

SYNTHESIS

We meta-analysed across studies using random-effects models and explored potential heterogeneity sources.

RESULTS

Thirty-nine studies met the inclusion criteria. In later life, preterm SGA infants had a lower body mass index (-0.66 kg/m2 , 95% CI -0.79, -0.53; 32 studies, I2  = 16.7, n = 30,346), waist circumference (-1.20 cm, 95% CI -2.17, -0.23; 13 studies, I2  = 19.4, n = 2061), lean mass (-2.62 kg, 95% CI -3.45, 1.80; 7 studies, I2  = 0, n = 205) and height (-3.85 cm, 95% CI -4.73, -2.96; 26 studies, I2  = 52.6, n = 4174) compared with those preterm infants born non-SGA. There were no differences between preterm SGA and preterm non-SGA groups in waist/hip ratio, body fat, body fat per cent, truncal fat per cent, fat mass index or lean mass index, although power was limited for some analyses. Studies were rated at high risk of bias due to potential residual confounding and low risk of bias in other domains.

CONCLUSIONS

Compared to their preterm non-SGA peers, preterm infants born SGA have lower BMI, waist circumference, lean body mass and height in later life. No differences in adiposity were observed between SGA preterm infants and non-SGA preterm infants.

Exercise Capacity in Very Low Birth Weight Adults: A Systematic Review and Meta-Analysis

There is an association between very low birth weight (VLBW) and cardiovascular morbidity and mortality in adulthood. Aerobic fitness, measured as the maximal oxygen consumption (VO2 max), is a good indicator of cardiopulmonary health and predictor of cardiovascular mortality. Our aim was to determine the effect of birth weight on aerobic exercise capacity and physical activity. We systematically identified studies reporting exercise capacity (VO2 max and VO2 peak) and physical activity levels in participants born at VLBW aged eighteen years or older compared to term-born controls from six databases (MEDLINE, OVID, EMBASE, CI NAHL, CENTRAL, and Google Scholar). Meta-analysis of eligible studies was conducted using a random effect model. We screened 6202 articles and identified 15 relevant studies, 10 of which were eligible for meta-analysis. VLBW participants had a lower VO2 max compared to their term counterparts (-3.35, 95% CI: -5.23 to -1.47, p = 0.0005), as did VLBW adults who had developed bronchopulmonary dysplasia (-6.08, 95% CI -11.26 to -0.90, p = 0.02). Five of nine studies reported significantly reduced self-reported physical activity levels. Our systematic review and meta-analysis demonstrated reduced maximal aerobic exercise capacity in adults born at VLBW compared to term-born controls.

Association of Preterm Birth and Low Birthweight with Bone Fractures during Childhood

Preterm birth and low birthweight have been associated with increased fracture risk in children. Our aim was to analyze bone fractures during childhood in preterm, and low-birthweight newborns compared to full-term and normal-birthweight newborns. We conducted a nationwide register-based cohort study in Finland from 1998 to 2017 and utilized the Medical Birth Register and Care Register for Health Care. All newborns alive 28 days after birth were included, and data on all fracture visits in specialized healthcare units were gathered. Incidences per 100,000 person-years with 95% confidence intervals (CI) were calculated, and comparisons were made by incidence rate ratios (IRRs). Kaplan-Meier analysis was used to analyze the timing of fractures during childhood (0-20 years). We included a total of 997,468 newborns and 95,869 fractures; the mean follow-up was 10.0 years, and the overall incidence of fractures was 963 per 100,000 person-years. Very preterm (<32 gestational weeks) newborns had 23% lower fracture incidence than term newborns (IRR 0.77; CI: 0.70-0.85). Preterm newborns (32 to 36 gestational weeks) had a fracture rate (IRR 0.98; CI: 0.95-1.01) similar to that of term newborns. Birthweight showed a linear increase in the fracture rates as newborns with birthweight less than 1000 g had the lowest fracture incidence of 773 per 100,000 person-years and the highest incidence (966 per 100,000 person-years) was among newborns with birthweight 2500 g or more. Children born very preterm or with extremely low birthweight have in general a lower fracture incidence during childhood compared to children born full term and with normal birthweight. These findings possibly reflect, in addition to improvements of neonatal intensive care and early nutrition, the fact that childhood fracture incidences are more dependent on issues other than early life events. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Sleep, 24-hour activity rhythms, and cardiometabolic risk factors in school-age children

STUDY OBJECTIVES

Disturbed sleep and 24-hour activity rhythms are linked to adverse cardiometabolic profiles in adults and adolescents, and these associations may originate in early life. We aimed to study associations of sleep and 24-hour rhythms with cardiometabolic risk factors in school-age children.

METHODS

This cross-sectional population-based study comprised 894 children aged 8-11 years from the Generation R Study. Sleep (duration, efficiency, number of awakenings, and time awake after sleep onset) and 24-hour activity rhythms (social jet lag, interdaily stability, and intradaily variability) were assessed using triaxial wrist actigraphy for 9 consecutive nights. Cardiometabolic risk factors included adiposity (body mass index Z-score, fat mass index using dual-energy X-ray absorptiometry, and visceral fat mass and liver fat fraction using magnetic resonance imaging), blood pressure, and blood markers (glucose, insulin, and lipids). We adjusted for season, age, sociodemographics, and lifestyle factors.

RESULTS

Each increase in interquartile range of nightly awakenings (2 times) was associated with -0.12 standard deviation (95% confidence interval: -0.21, -0.04) lower body mass index and 0.15 mmol/L (0.10, 0.21) higher glucose. Among boys, an increase in interquartile range of intradaily variability (0.12) was associated with higher fat mass index (+0.07 kg/m2; 95% confidence interval: 0.03, 0.11) and visceral FM (+0.08 g; 95% confidence interval: 0.02, 0.15). We observed no associations with blood pressure or clustering of cardiometabolic risk factors.

CONCLUSIONS

Already at school age, greater fragmentation of the 24-hour activity rhythm is associated with general and organ adiposity. In contrast, more nightly awakenings were associated with lower body mass index. Future research should bring clarity to these disparate observations in order to create potential targets for obesity prevention programs.

CITATION

Beunders VAA, Koopman-Verhoeff ME, Vermeulen MJ, et al. Sleep, 24-hour activity rhythms, and cardiometabolic risk factors in school-age children. J Clin Sleep Med. 2023;19(7):1219-1229.

Gestational age, intrauterine growth and body composition at 11 years of age

OBJETIVE

To assess the association of gestational age (GA) and intrauterine growth with body composition at 11 years of age.

METHOD

Analysis of data from the 2004 Pelotas birth cohort, whose outcomes were fat mass (FM, kg), fat mass index (FMI, kg/m2), fat-free mass (FFM, kg), fat-free mass index (FFMI, kg/m2) - measured by air displacement plethysmography - and body mass index for age (BMI/age, Z-score). The exposures of interest were the gestational index (GA) of infants born at less than 33 weeks, from 34 to 36 and from 37 to 41, and intrauterine growth categorized as small (SGA), adequate (AGA) and large (LGA) for gestational age. Analysis of variance was used to compare means and linear regression was used to assess the strength of association. The analyses were adjusted according to variables collected at birth, such as monthly family income, maternal characteristics - education, age, pre-gestational body mass index (BMI), weight gain during pregnancy, smoking during pregnancy, type of delivery, and parity - and adolescent characteristics - skin color and birth weight. For analysis, FM and FMI underwent logarithmic transformation due to data asymmetry.

RESULTS

A total of 3,401 adolescents were analyzed, including boys and girls born at less than 33 weeks, with lower FM and FFM means than those born at term. However, in the adjusted analyses, there was no association between GA and any of the outcomes in either sex. LGA boys had a 10.5% higher FMI (p = 0.026) and +0.3 BMI/age Z-score (p = 0.019) as compared to AGA boys, and LGA girls had +0.3 kg/m 2 of FFMI (p = 0.039) than AGA girls.

CONCLUSION

GA was not associated with body composition at 11 years of age. However, LGA boys had higher BMI and BMI/age Z-score, and LGA girls had higher FFMI than AGA girls.

The impact of an early intervention home-based program on body composition in preterm-born preschoolers with very low birth weight

Background and aims

Early child interventions focused on the family prevented neurodevelopmental and behavioral delays and can provide more knowledge regarding responsive feeding, thus creating learning opportunities to promote better quality nutrition and preventing failure to thrive. The aim is to verify the impact of a continuous program of early home-based intervention on the body composition of preschool infants who were born preterm with very low birth weight (VLBW).

Methods

This is a longitudinal analysis from a randomized controlled trial, including VLBW preterm children, born in a tertiary hospital in Southern Brazil and followed up at the high-risk institutional ambulatory clinic. Participants were divided into the intervention group (IG): skin-to-skin care with the mother (kangaroo care), breastfeeding policy, and tactile-kinesthetic stimulation by mothers until hospital discharge. Subsequently, they received a program of early intervention with orientation and a total of 10 home visits, independently from the standard evaluation and care that was performed following the 18 months after birth; conventional group (CG): standard care according to the routine of the newborn intensive care unit (NICU), which includes kangaroo care, and attending to their needs in the follow-up program. Body composition estimation was performed using bioelectrical impedance analyses (BIA), and physical activity and feeding practices questionnaires were evaluated at preschool age, as well as anthropometric measurements and biochemical analysis.

Results

Data of 41 children at 4.6 ± 0.5 years old were evaluated (CG n = 21 and IG n = 20). Body weight, height, body mass index, waist and arm circumferences, and triceps and subscapular skinfold did not differ between groups. The IG presented higher segmented fat-free mass (FFM) when compared to the CG (right arm FFM: 0.74 vs. 0.65 kg, p = 0.040; trunk FFM: 6.86 vs. 6.09 kg, p = 0.04; right leg FFM: 1.91 vs. 1.73 kg, p = 0.063). Interaction analyses showed that segmented FFM and FFM Index were associated with higher iron content in the IG. In the CG, interaction analyses showed that increased visceral fat area was associated with higher insulin resistance index.

Conclusion

An early intervention protocol from NICU to a home-based program performed by the mothers of VLBW preterm children of low-income families presents a small effect on FFM.

Effect of physical therapy on bone remodelling in preterm infants: a multicenter randomized controlled clinical trial

Background

Preterm infants have a low level of bone mineralization compared to those born at term, since 80% of calcium incorporation occurs at the end of pregnancy. The purpose of the present study was to investigate the effect of reflex locomotion therapy on bone modeling and growth in preterm infants and to compare its effect with those of other Physiotherapy modalities.

Methods

A multicentre randomized controlled clinical trial was conducted (02/2016 – 07/2020). 106 preterm infants born at the Virgen de la Arrixaca University Clinical Hospital, the General University Hospital of Elche and the Torrecárdenas University Hospital of Almería, between 26 and 34 weeks with hemodynamic stability, complete enteral nutrition and without any metabolic, congenital, genetic, neurological or respiratory disorders were evaluated for inclusion. Infants were randomly assigned to three groups: one group received reflex locomotion therapy (EGrlt); another group received passive mobilizations with gentle joint compression (EGpmc); and the control group received massage (CG). All treatments were carried out in the neonatal units lasting one month. The main outcome measure was bone formation and resorption measured with bone biomarkers. A mixed ANOVA was used to compare the results of bone biomarkers, and anthropometric measurements.

Results

Infants were randomized to EGrlt (n = 38), EGpmc (n = 32), and CG (n = 36). All groups were similar in terms of gender (p = 0.891 female 47.2%), gestational age (M = 30.753, SD = 1.878, p = 0.39) and birth weight (M = 1413.45, SD = 347.36, p = 0.157). At the end of the study, significant differences were found between the groups in their interaction in bone formation, measured with osteocalcin [F (2,35) = 4.92, p = 0.013, η_p² = 0.043], in benefit of the EGrlt.

Conclusions

Reflex locomotion therapy has been effective in improving bone formation, more so than other Physiotherapy modalities. Therefore, reflex locomotion therapy could be considered one of the most effective physiotherapeutic modalities for the prevention and treatment of osteopenia of prematurity.

Trial registrstion

Trial retrospectively registered at ClinicalTrials.gov. First posted on 22/04/2020. Registration number: NCT04356807.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03402-2.

Body Composition Assessment by Air-Displacement Plethysmography Compared to Dual-Energy X-ray Absorptiometry in Full-Term and Preterm Aged Three to Five Years

It is important to monitor body composition longitudinally, especially in children with atypical body composition trajectories. Dual-energy X-ray absorptiometry (DXA) can be used and reference values are available. Air-displacement plethysmography (ADP) is a relatively new technique, but reference values are lacking. In addition, estimates of fat-free mass density (Dffm), needed in ADP calculations, are based on children aged >8 years and may not be valid for younger children. We, therefore, aimed to investigate whether DXA and ADP results were comparable in young children aged 3−5 years, either born full-term or preterm, and if Dffm estimates in the ADP algorithm could be improved. In 154 healthy children born full-term and 67 born < 30 weeks of the inverse pressure-volume gestation, aged 3−5 years, body composition was measured using ADP (BODPOD, with default Lohman Dffm estimates) and DXA (Lunar Prodigy). We compared fat mass (FM), fat mass percentage (FM%) and fat-free mass (FFM), between ADP and DXA using Bland−Altman analyses, in both groups. Using a 3-compartment model as reference method, we revised the Dffm estimates for ADP. In full-term-born children, Bland−Altman analyses showed considerable fixed and proportional bias for FM, FM%, and FFM. After revising the Dffm estimates, agreement between ADP and DXA improved, with mean differences (LoA) for FM, FM%, and FFM of −0.67 kg (−2.38; 1.04), −3.54% (−13.44; 6.36), and 0.5 kg (−1.30; 2.30), respectively, but a small fixed and proportional bias remained. The differences between ADP and DXA were larger in preterm-born children, even after revising Dffm estimates. So, despite revised and improved sex and age-specific Dffm estimates, results of ADP and DXA remained not comparable and should not be used interchangeably in the longitudinal assessment of body composition in children aged 3−5 years, and especially not in very preterm-born children of that age.

Motor outcomes of children born extremely preterm; from early childhood to adolescence

Children and adolescents born extremely preterm (EP; <28 weeks' gestation) are at greater risk of motor impairment, including cerebral palsy and developmental coordination disorder, than their term born peers. Importantly, motor impairment has implications beyond performing motor skills; it negatively affects outcomes as diverse as school success, emotional wellbeing, physical health, and physical activity (PA) participation. This review will outline what is known about PA participation across childhood and adolescence for children born EP and term, recognising that PA may improve physical, social, and mental health outcomes. Critically, PA participation occurs in the context of children's and adolescents' daily lives, and is influenced by the family, social and physical environment, as well as by the child's personal factors, such as motor impairment. Further research is needed to better understand PA participation levels and correlates for children and adolescents born preterm, to better inform effective and sustainable interventions.

Update on Calcium and Phosphorus Requirements of Preterm Infants and Recommendations for Enteral Mineral Intake

Background: With current Ca and P recommendations for enteral nutrition, preterm infants, especially VLBW, fail to achieve a bone mineral content (BMC) equivalent to term infants. During the first 3 years, most notably in light at term equivalent age (<−2 Z score) VLBW infants’ BMC does not catch up. In adults born preterm with VLBW or SGA, lower adult bone mass, lower peak bone mass, and higher frequency of osteopenia/osteoporosis have been found, implying an increased risk for future bone fractures. The aim of the present narrative review was to provide recommendation for enteral mineral intake for improving bone mineral accretion. Methods: Current preterm infant mineral recommendations together with fetal and preterm infant physiology of mineral accretion were reviewed to provide recommendations for improving bone mineral accretion. Results: Current Ca and P recommendations systematically underestimate the needs, especially for Ca. Conclusion: Higher enteral fortifier/formula mineral content or individual supplementation is required. Higher general mineral intake (especially Ca) will most likely improve bone mineralization in preterm infants and possibly the long-term bone health. However, the nephrocalcinosis risk may increase in infants with high Ca absorption. Therefore, individual additional enteral Ca and/or P supplementations are recommended to improve current fortifier/formula mineral intake.

Low birth weight and its relation to physical fitness parameters in children: Its negative effect on muscle strength and cardiorespiratory endurance

BACKGROUND

There is increasing evidence that low birth weight has a negative effect on physical fitness, muscle strength, and cardiorespiratory endurance, although the findings are inconsistent.

OBJECTIVES

This study aimed to evaluate whether birth weight acts as a prenatal determinant of physical fitness parameters and to determine the role of environmental or biological variables on this effect.

METHODS

One hundred and sixty-seven children aged 6-14 years were included in this study. The anthropometric data, physical activity index, standing long jump, flexibility, handgrip strength, and cardiorespiratory fitness were evaluated.

RESULTS

A positive correlation was found between birth weight and cardiorespiratory fitness (r = .349; p < .001), right handgrip strength (r = .337; p < .001), and left handgrip strength (r = .320; p < .001), suggesting that children with low birth weight had the worst performance in both cardiorespiratory endurance and grip strength tests. These findings remained significant after adjustment for prematurity, sex, age, physical activity index, and body mass index (BMI). Stepwise multiple regression analyses revealed a significant interaction of high birth weight, older age, and low BMI in predicting better cardiorespiratory endurance (R² = .308). When handgrip strength was tested as the dependent variable, we found that high birth weight, male sex, and older age emerged as important determinants for both sides.

CONCLUSION

Children aged 6-14 years born with a birth weight < 2.5 kg have low handgrip strength and cardiorespiratory fitness, which seems to be mediated partially by influences of both prenatal environment (e.g., birth weight) and biological variables (e.g., age, sex, BMI).

Fat Distribution among Children Born Extremely Low Birth Weight and Very Low Birth Weight: A Cohort Study

Background: Fat distribution is associated with chronic diseases and birth weight may influence fat distribution throughout life. Our aim was to compare fat distribution in children born extremely low birth weight (ELBW) and very low birth weight (VLBW). Methods: This retrospective cohort study evaluated children born ELBW and VLBW around the 7th year of life. Fat distribution was assessed by ultrasonography measurements of abdominal subcutaneous and visceral fat thickness. Multiple linear regression analysis was performed. Results: We studied 63 children. Visceral fat thickness but not subcutaneous fat thickness was significantly increased in children born ELBW compared with children born VLBW, respectively, 3.13 (±1.08) versus 1.86 (±0.76) mm. This result remained after adjustment for age, gender, and BMI; adjusted coefficient 0.118, 95% confidence interval 0.009-0.227, p = 0.034. Conclusion: Children born ELBW seem to have increased visceral fat thickness compared with children born VLBW.