Increased adiposity in adults born preterm and their children

Body composition in adults born preterm with very low birth weight

BACKGROUND

Studies on body composition in preterm very low birth weight (VLBW < 1500 g) survivors are inconsistent and trajectories later in life unknown. We assessed body composition and its change from young to mid-adulthood in VLBW adults.

METHODS

We studied 137 VLBW adults and 158 term-born controls from two birth cohorts in Finland and Norway at mean age 36 years. Body composition was assessed by 8-polar bioelectrical impedance. We compared results with dual-energy x-ray absorptiometry measurements at 24 years.

RESULTS

In mid-adulthood, VLBW women and men were shorter than controls. Fat percentage (mean difference in women 1.1%; 95% CI, -1.5% to 3.5%, men 0.8%; -2.0% to 3.6%) and BMI were similar. VLBW women had 2.9 (0.9 to 4.8) kg and VLBW men 5.3 (2.7 to 8.1) kg lower lean body mass than controls, mostly attributable to shorter height. Between young and mid-adulthood, both groups gained fat and lean body mass (p for interaction VLBW x age>0.3).

CONCLUSION

Compared with term-born controls, VLBW adults had similar body fat percentage but lower lean body mass, largely explained by their shorter height. This could contribute to lower insulin sensitivity and muscular fitness previously found in VLBW survivors and predispose to functional limitations with increasing age.

IMPACT

In mid-adulthood, individuals born preterm with very low birth weight had similar body fat percentage but lower lean body mass than those born at term. This was largely explained by their shorter height. First study to report longitudinal assessments of body size and composition from young to mid-adulthood in very low birth weight adults. Lower lean body mass in very low birth weight adults could contribute to lower insulin sensitivity and muscular fitness and lead to earlier functional limitations with increasing age.

Cardiometabolic sex differences in adults born small for gestational age

Aim

This study aimed to assess the cardiometabolic sex similarities and differences in adults born small for gestational age.

Methods

This study was an ambispective cohort study from a birth registry in Barcelona, Spain, including 523 adult participants (20-40 years-old) subdivided as born small for gestational age (SGA, if birth weight <10th centile) or adequate fetal growth for gestational age (AGA). Cardiometabolic health was assessed by echocardiography, electrocardiogram, blood pressure measurement, vascular ultrasound, anthropometric measurements, and serum glycemia and lipid profile. Stratified analyses by sex were performed by estimation of adjusted absolute difference (AAD) using inverse probability weighting.

Results

Compared with AGA, the stratified analyses by sex showed a more pronounced reduction in ejection fraction [AAD: female -1.73 (95% CI -3.2 to -0.28) vs. male -1.33 (-3.19 to 0.52)] and increment in heart rate [female 3.04 (0.29-5.8) vs. male 2.25 (-0.82 to 5.31)] in SGA females compared with SGA males. In contrast, a more pronounced reduction in PR interval [female -1.36 (-6.15 to 3.42) vs. male -6.61 (-11.67 to -1.54)] and an increase in systolic blood pressure [female 0.06 (-2.7 to 2.81) vs. male 2.71 (-0.48 to 5.9)] and central-to-peripheral fat ratio [female 0.05 (-0.03 to 0.12) vs. male 0.40 (0.17-0.62)] were mainly observed in SGA male compared with SGA female.

Conclusions

Sex differences were observed in the effect of SGA on cardiometabolic endpoints with female being more prone to cardiac dysfunction and male to electrocardiographic, vascular, and metabolic changes. Future research including sex-stratification data is warranted.

Association of antenatal corticosteroids with kidney function in adolescents born preterm with very low birth weight

OBJECTIVE

Investigate if antenatal corticosteroids (ANCS) are associated with worse kidney function in adolescence and if greater adiposity magnifies this association.

STUDY DESIGN

Prospective cohort of 162 14-year-olds born preterm with very low birth weight (<1500 g). Outcomes were estimated glomerular filtration rate (eGFR) and first-morning urine albumin-to-creatinine ratio (UACR). We used adjusted generalized linear models, stratified by waist-to-height ratio (WHR) ≥ 0.5.

RESULTS

Fifty-five percent had ANCS exposure and 31.3% had WHR ≥ 0.5. In adjusted analyses of the entire cohort, ANCS was not significantly associated with eGFR or UACR. However, the ANCS-eGFR association was greater in those with WHR ≥ 0.5 (β -16.8 ml/min/1.73 m2, 95% CL -31.5 to -2.1) vs. WHR < 0.5: (β 13.9 ml/min/1.73 m2, 95% CL -0.4 to 28.1), interaction term p = 0.02.

CONCLUSION

ANCS exposure was not associated with worse kidney function in adolescence, though ANCS may be associated with lower eGFR if children develop obesity by adolescence.

Gestational age and trajectories of body mass index and height from birth through adolescence in the Danish National Birth Cohort

Preterm birth is associated with smaller body dimensions at birth. The impact on body size in later life, measured by body mass index (BMI) and height, remains unclear. A prospective register-based cohort study with 62,625 singletons from the Danish National Birth Cohort born 1996-2003 for whom information on gestational age (GA) at birth, length or weight at birth, and at least two growth measurements scheduled at the ages of 5 and 12 months, and 7, 11 and 18 years were available. Linear mixed effects with splines, stratified by sex, and adjusted for confounders were used to estimate standardised BMI and height. GA was positively associated with BMI in infancy, but differences between preterm and term children declined with age. By age 7, preterm children had slightly lower BMI than term children, whereas no difference was observed by adolescence (mean difference in BMI z-score - 0.28 to 0.15). GA was strongly associated with height in infancy, but mean differences between individuals born preterm and term declined during childhood. By adolescence, the most preterm individuals remained shorter than their term peers (mean difference in height z-score from - 1.00 to - 0.28). The lower BMI in preterm infants relative to term infants equalizes during childhood, such that by adolescence there is no clear difference. Height is strongly positively associated with GA in early childhood, whilst by end of adolescence individuals born preterm remain slightly shorter than term peers.

A. Sørensen T, Elhakeem A, Santos AC, Pinot de Moira A, Heude B, Iñiguez C, Pizzi C, Simons E, Voerman E, Corpeleijn E, Zariouh F, Santorelli G, Inskip HM, Barros H, Carson J, Harris JR, Nader JL, Ronkainen J, Strandberg-Larsen K, Santa-Marina L, Calas L, Cederkvist L, Popovic M, Charles MA, Welten M, Vrijheid M, Azad M, Subbarao P, Burton P, Mandhane PJ, Huang RC, Wilson RC, Haakma S, Fernández-Barrés S, Turvey S, Santos S, Tough SC, Sebert S, Moraes TJ, Salika T, Jaddoe VWV, Lawlor DA, Nybo Andersen AM. Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

BACKGROUND

Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence.

METHODS AND FINDINGS

We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries.

CONCLUSIONS

This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

The impact of neonatal parameters and parental factors on body fat level in early childhood

Parental and pregnancy characteristics can affect proportions and tissue composition of the child's bodyand thereforecan influence their present and future health, as well as overall wellbeing. The aim of this study was to examine the differences between selected parental and birth-related parameters among preschool (3-7 years of age) children of varying adiposity status (n=541 girls and n=571 boys).The research was carried out in 20 randomly selected kindergartens in Krakow (Poland). Thickness of 6 skinfolds (biceps, triceps, subscapular, suprailiac, abdominal and calf) was measured. Sum of skinfolds was calculated and participants were divided into low, normal or high body fat groups. Birth-related characteristics were obtained using a questionnaire filled out by the children's parents. Children of mothers who gained the most gestational weight were characterised by high adiposity. Preschoolers with the highest birth weight, body length and head circumference had the greatest adiposity. Children of relatively younger mothers had higher body fat, in comparison to the rest of the study group. Parents of preschoolers in the high adiposity category were characterised by a greater body mass, compared to the parents of children in other body fat groups and that boys with the highest adiposity relatively more often had a close relative with obesity. Children in varying adiposity categories differed in terms of some birth-related factors. Particular attention should be paid to familial and parental characteristics, because they may influence the child's predisposition to excess adiposity deposition later in life.

Body composition of children with different gestation time

OBJECTIVES

To examine the differences in body composition between prepubescent children, depending on the time of gestation.

METHODS

The study was conducted among children aged 3-10 years. The thickness of 5 (triceps, subscapular, suprailiac, abdominal, calf) skinfolds, mid-upper arm circumference, body height, weight and femur breadth was measured. Sum of 3 skinfolds, Body Mass Index (BMI) and muscle mass were calculated. Gestation time was obtained using a questionnaire.

RESULTS

Children in the short gestation time category were generally characterized by the greatest values of the analyzed characteristics, particularly above the ages of 6-8 years. Femur breadth and muscle mass were similar up to the mentioned age in all of the gestation time categories. BMI and all of the adiposity characteristics, below the age of 6 years, were the greatest in the long gestation time category.

CONCLUSIONS

Results of the present study are important, as excess body mass and adiposity are associated with increased risk of cardiovascular and metabolic abnormalities later in life. Special emphasis should be placed on the prevention of overweight and obesity among premature babies and the education of their parents.

Impact of very preterm birth and post-discharge growth on cardiometabolic outcomes at school age: a retrospective cohort study

Background

Adverse metabolic outcomes later in life have been reported among children or young adults who were born as preterm infants. This study was conducted to examine the impact of very preterm/very low birth weight (VP/VLBW) birth and subsequent growth after hospital discharge on cardiometabolic outcomes such as insulin resistance, fasting glucose, and systolic and diastolic blood pressure (BP) among children at 6–8 years of age.

Methods

This retrospective cohort study included children aged 6–8 years and compared those who were born at < 32 weeks of gestation or weighing < 1,500 g at birth (n = 60) with those born at term (n = 110). Body size, fat mass, BP, glucose, insulin, leptin, adiponectin, and lipid profiles were measured. Weight-for-age z-score changes between discharge and early school-age period were also calculated, and factors associated with BP, fasting glucose, and insulin resistance were analyzed.

Results

Children who were born VP/VLBW had significantly lower fat masses, higher systolic BP and diastolic BP, and significantly higher values of fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR), compared to children born at term. VP/VLBW was correlated with HOMA-IR and BPs after adjusting for various factors, including fat mass index and weight-for-age z-score changes. Weight-for-age z-score changes were associated with HOMA-IR, but not with BPs.

Conclusions

Although children aged 6–8 years who were born VP/VLBW showed significantly lower weight and fat mass, they had significantly higher BPs, fasting glucose, HOMA-IR, and leptin levels. The associations of VP/VLBW with cardiometabolic factors were independent of fat mass and weight gain velocity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02851-5.

Adults Born Preterm: Long-Term Health Risks of Former Very Low Birth Weight Infants

BACKGROUND

Advances in neonatology now enable increasing numbers of very low birth weight neonates (<1500 g) to survive into early adulthood and beyond. What are the implications for their long-term care?

METHODS

Selective literature search on the outcome of very low birth weight neonates in adulthood ("adults born preterm").

RESULTS

Robust data are available on the pulmonary, metabolic, cardiovascular, renal, neurocognitive, sensory-visual, social-emotional, mental, reproductive, and musculoskeletal long-term risks. On the somatic level, elevated rates have been documented for asthma (odds Ratio [OR] 2.37), diabetes mellitus (OR 1.54), and chronic renal disease (hazard ratio [HR] 3.01), along with the cardiovascular and cerebrovascular sequelae of a tendency toward arterial hypertension. On the psychosocial level, the main findings are deficits in romantic partnerships (OR 0.72) and a lower reproduction rate (relative risk [RR] male/female 0.24/0.33). The affected women also have an elevated risk of preterm delivery.

CONCLUSION

A risk profile with both somatic and psychosocial aspects can be discerned for adults who were born prematurely, even if some of these risks are present in low absolute numbers. As the ability to compensate for latent deficits declines with age, such adults may suffer from "premature aging as the late price of premature birth." A holistic approach to care with personalized prevention strategies-which for most of them was discontinued at discharge from pediatric follow-up-therefore seems appropriate in adulthood as well.

Expression of specific signaling components related to muscle protein turnover and of branched-chain amino acid catabolic enzymes in muscle and adipose tissue of preterm and term calves

Postnatal metabolism depends on maturation of key metabolic pathways around birth. In this regard, endogenous glucose production is impaired in calves born preterm. Concerning protein metabolism, the rates of protein turnover are greater during the neonatal period than at any other period of postnatal life. The mammalian target of rapamycin (mTOR) and the ubiquitin-proteasome system (UPS) are considered as the major regulators of cellular protein turnover. The objectives of this study were to investigate (1) the changes in plasma AA profiles, (2) the mRNA abundance of mTOR signaling and UPS-related genes in skeletal muscle, and (3) the mRNA abundance of branched-chain AA (BCAA) catabolic enzymes in skeletal muscle and adipose tissue in neonatal calves with different degree of maturation during the transition to extrauterine life. Calves (n = 7/treatment) were born either preterm (PT; delivered by cesarean section 9 d before term) or at term (T; spontaneous vaginal delivery) and were left unfed for 1 d. Calves in treatment TC were also spontaneously born but were fed colostrum and transition milk for 4 d. Blood samples were collected from all calves at birth and at 24 h of life. Additional blood samples were taken 2 h after feeding (26 h of life) for PT and T calves, and on d 4 of life for TC, to determine plasma glucose, urea, and AA. Tissue samples from 3 muscles [M. longissimus dorsi (MLD), M. semitendinosus (MST), and M. masseter (MM)], and kidney fat were collected following euthanasia at 26 h after birth (PT, T) or on d 4 of life (TC) at 2 h after feeding. The concentrations of the majority of plasma AA (Ala, Gln, Asn, Cit, Lys, Orn, Thr, and Tyr), nonessential AA, and total AA were greater during the first 24 h and also before and 2 h after feeding in PT than in T. The ratio of plasma BCAA to the aromatic AA (Tyr and Phe) was greatest in TC, followed by T, and least in PT. The mRNA abundance of mTOR and ribosomal protein S6 kinase 1 (S6K1) in MLD and MM was greater in PT and T than in TC. The mRNA abundance of muscle-specific ligases FBXO32 (F-box only protein 32) in the 3 different skeletal muscles and TRIM63 (tripartite motif containing 63) in MLD was greater in PT and T than in TC; in MM, TRIM63 mRNA was greatest in PT. The mRNA for BCKDHA and BCKDHB (the α and β polypeptide of branched-chain α-keto acid dehydrogenase) in kidney fat was elevated in PT and T compared with TC, suggesting a possible enhancement of BCAA oxidation as energy source to cover the energetic and nutritional postnatal demands in PT and T in a starved state. The increased abundances of mTOR-associated signaling factors and muscle-specific ligase mRNA indicate a greater rate of protein turnover in muscles of PT and T in a starved state. Elevated plasma concentrations of several AA may result from enhanced muscle proteolysis and impaired conversion to glucose in the liver of PT calves.

Improving long-term health outcomes of preterm infants: how to implement the findings of nutritional intervention studies into daily clinical practice

Preterm-born children are at risk for later neurodevelopmental problems and cardiometabolic diseases; early-life growth restriction and suboptimal neonatal nutrition have been recognized as risk factors. Prevention of these long-term sequelae has been the focus of intervention studies. High supplies of protein and energy during the first weeks of life (i.e., energy > 100 kcal kg-1 day-1 and a protein-to-energy ratio > 3 g/100 kcal) were found to improve both early growth and later neurodevelopmental outcome. Discontinuation of this high-energy diet is advised beyond 32-34 weeks postconceptional age to prevent excess fat mass and possible later cardiometabolic diseases. After discharge, nutrition with a higher protein-to-energy ratio (i.e., > 2.5-3.0 g/100 kcal) may improve growth and body composition in the short term.Conclusion: Preterm infants in their first weeks of life require a high-protein high-energy diet, starting shortly after birth. Subsequent adjustments in nutritional composition, aimed at achieving optimal body composition and minimizing the long-term cardiometabolic risks without jeopardizing the developing brain, should be guided by the growth pattern. The long-term impact of this strategy needs to be studied. What is Known: • Preterm infants are at risk for nutritional deficiencies and extrauterine growth restriction. • Extrauterine growth restriction and suboptimal nutrition are risk factors for neurodevelopmental problems and cardiometabolic disease in later life. What is New: • Postnatally, a shorter duration of high-energy nutrition may prevent excess fat mass accretion and its associated cardiometabolic risks and an early switch to a protein-enriched diet should be considered from 32-34 weeks postconceptional age. • In case of formula feeding, re-evaluate the need for the continuation of a protein-enriched diet, based on the infant's growth pattern.

Lower insulin sensitivity remains a feature of children born very preterm

BACKGROUND

The first report of children born very preterm (<32 weeks of gestation) having insulin resistance was made 16 years ago. However, neonatal care has improved since. Thus, we aimed to assess whether children born very preterm still have lower insulin sensitivity than term controls.

METHODS

Participants were prepubertal children aged 5 to 11 years born very preterm (<32 weeks of gestation; n = 51; 61% boys) or at term (37-41 weeks; n = 50; 62% boys). Frequently sampled intravenous glucose tolerance tests were performed, and insulin sensitivity was calculated using Bergman's minimal model. Additional clinical assessments included anthropometry, body composition using whole-body dual-energy X-ray absorptiometry scans, clinic blood pressure, and 24-hour ambulatory blood pressure monitoring.

RESULTS

Children born very preterm were 0.69 standard deviation score (SDS) lighter (P < .001), 0.53 SDS shorter (P = .003), and had body mass index 0.57 SDS lower (P = .003) than children born at term. Notably, children born very preterm had insulin sensitivity that was 25% lower than term controls (9.4 vs 12.6 × 10^-4 minutes^-1 ·[mU/L]; P = .001). Other parameters of glucose metabolism, including fasting insulin levels, were similar in the two groups. The awake systolic blood pressure (from 24-hour monitoring) tended to be 3.1 mm Hg higher on average in children born very preterm (P = .054), while the clinic systolic blood pressure was 5.4 mm Hg higher (P = .002).

CONCLUSIONS

Lower insulin sensitivity remains a feature of children born very preterm, despite improvements in neonatal intensive care. As reported in our original study, our findings suggest the defect in insulin action in prepubertal children born very pretermis primarily peripheral and not hepatic.

Prematurity and body composition at 6, 18, and 30 years of age: Pelotas (Brazil) 2004, 1993, and 1982 birth cohorts

Background

We aimed to investigate the association between preterm birth and body composition at 6, 18, and 30 years of age using data from three population-based birth cohort studies.

Methods

Gestational age (GA), defined by the date of the last menstrual period (categorized in ≤33, 34–36, and ≥ 37 weeks), was gathered in the first 24-h after delivery for all live births occurring in the city of Pelotas, Brazil, in 2004, 1993 and 1982. Body composition was assessed by air-displacement plethysmography. Outcomes included fat mass (FM, kg), percent FM (%FM), FM index (FMI, kg/m²), fat-free mass (FFM, kg); percent FFM (%FFM), FFM index (FFMI, kg/m²), body mass index (BMI, kg/m² at 18 years in the 1993 cohort and 30 years in the 1982 cohort), and BMI Z-score (at 6 years in the 2004 cohort). We further explored the association of birth weight for GA with body composition indicators and BMI. Crude and adjusted linear regressions provided beta coefficients with 95% confidence intervals (95%CI).

Results

A total of 3036, 3027, and 3369 participants, respectively, from the 2004, 1993, and 1982 cohorts were analyzed. At 6 years, preterm boys (born at 34–36 weeks) presented lower adjusted mean of FM (β = − 0.80 kg, − 1.45;-0.16, p = 0.046), %FM (β = − 2.39%, − 3.90;-0.88, p = 0.008), FMI (β = − 0.70 kg/m², − 1.13;-0.27, p = 0.004) as well as lower FFM (β = − 0.4 kg, − 0.77; − 0.12, p = 0.010) and FFMI (β = − 0.3 kg/m², − 0.46;-0.10, p < 0.001), and BMI Z-score (β = − 0.69,; − 0.99;-0.40, p < 0.001); but higher %FFM (β = 2.4%, 0.87;-3.90, p = 0.008), when compared to boys born at term (≥37). At 30 years, FM (15.7 kg, 0.25;31.1, p = 0.102) was higher among males born at ≤33 weeks. No association was observed for females from the three cohorts and for 18-year-old males. The association of birth weight for GA with body composition and BMI was not significant in any cohort. At 6 years, SGA boys had lower FFMI than boys AGA.

Conclusions

Our results suggest that preterm birth is associated with decreased body fat and fat-free mass in childhood but higher fat mass in adulthood. Nevertheless, results were only significant for males. SGA boys also showed lower FFMI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10368-w.

Perinatal determinants of growth trajectories in children born preterm

BACKGROUND

A growing amount of evidence indicates in utero and early life growth has profound, long-term consequences for an individual's health throughout the life course; however, there is limited data in preterm infants, a vulnerable population at risk for growth abnormalities.

OBJECTIVE

To address the gap in knowledge concerning early growth and its determinants in preterm infants.

METHODS

A retrospective cohort study was performed using a population of preterm (< 37 weeks gestation) infants obtained from an electronic medical record database. Weight z-scores were acquired from discharge until roughly two years corrected age. Linear mixed effects modeling, with random slopes and intercepts, was employed to estimate growth trajectories.

RESULTS

Thirteen variables, including maternal race, hypertension during pregnancy, preeclampsia, first trimester body mass index, multiple status, gestational age, birth weight, birth length, head circumference, year of birth, length of birth hospitalization stay, total parenteral nutrition, and dextrose treatment, were significantly associated with growth rates of preterm infants in univariate analyses. A small percentage (1.32% - 2.07%) of the variation in the growth of preterm infants can be explained in a joint model of these perinatal factors. In extremely preterm infants, additional variation in growth trajectories can be explained by conditions whose risk differs by degree of prematurity. Specifically, infants with periventricular leukomalacia or retinopathy of prematurity experienced decelerated rates of growth compared to infants without such conditions.

CONCLUSIONS

Factors found to influence growth over time in children born at term also affect growth of preterm infants. The strength of association and the magnitude of the effect varied by gestational age, revealing that significant heterogeneity in growth and its determinants exists within the preterm population.

Neonatal intensive care unit (NICU) exposures exert a sustained influence on the progression of gut microbiota and metabolome in the first year of life

Emerging evidence has shown a link between the perturbations and development of the gut microbiota in infants with their immediate and long-term health. To better understand the assembly of the gut microbiota in preterm infants, faecal samples were longitudinally collected from the preterm (n = 19) and term (n = 20) infants from birth until month 12. 16S rRNA gene sequencing (n = 141) and metabolomics profiling (n = 141) using nuclear magnetic resonance spectroscopy identified significant differences between groups in various time points. A panel of amino acid metabolites and central metabolism intermediates significantly correlated with the relative abundances of 8 species of bacteria were identified in the preterm group. In contrast, faecal metabolites of term infants had significantly higher levels of metabolites which are commonly found in milk such as fucose and β-hydroxybutyrate. We demonstrated that the early-life factors such as gestational age, birth weight and NICU exposures, exerted a sustained effect to the dynamics of gut microbial composition and metabolism of the neonates up to one year of age. Thus, our findings suggest that intervention at this early time could provide ‘metabolic rescue’ to preterm infants from aberrant initial gut microbial colonisation and succession.

Neonatal intensive care unit (NICU) exposures exert a sustained influence on the progression of gut microbiota and metabolome in the first year of life

Emerging evidence has shown a link between the perturbations and development of the gut microbiota in infants with their immediate and long-term health. To better understand the assembly of the gut microbiota in preterm infants, faecal samples were longitudinally collected from the preterm (n = 19) and term (n = 20) infants from birth until month 12. 16S rRNA gene sequencing (n = 141) and metabolomics profiling (n = 141) using nuclear magnetic resonance spectroscopy identified significant differences between groups in various time points. A panel of amino acid metabolites and central metabolism intermediates significantly correlated with the relative abundances of 8 species of bacteria were identified in the preterm group. In contrast, faecal metabolites of term infants had significantly higher levels of metabolites which are commonly found in milk such as fucose and β-hydroxybutyrate. We demonstrated that the early-life factors such as gestational age, birth weight and NICU exposures, exerted a sustained effect to the dynamics of gut microbial composition and metabolism of the neonates up to one year of age. Thus, our findings suggest that intervention at this early time could provide 'metabolic rescue' to preterm infants from aberrant initial gut microbial colonisation and succession.

Cardiovascular risk factors in those born preterm - systematic review and meta-analysis

Emerging evidence demonstrates a link between preterm birth (PTB) and later life cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to compare conventional CVD risk factors between those born preterm and at term. PubMed, CINAHL, SCOPUS, and EMBASE databases were searched. The review protocol is registered in PROSPERO (CRD42018095005). CVD risk factors including systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index, lipid profile, blood glucose, and fasting insulin among those born preterm (<37 weeks' gestation) were compared with those born at term (≥37 weeks' gestation). Subgroup analyses based on gender, age, gestational at birth (<32 weeks' gestation and <28 weeks' gestation), and PTB associated with small for gestational age or average for gestational age were also performed. Fifty-six studies provided data on 308,987 individuals. Being born preterm was associated with 3.26 mmHg (95% confidence interval [CI] 2.08 to 4.44) higher mean SBP and 1.32 mmHg (95% CI: 0.61 to 2.04) higher mean DBP compared to being born at term. Subgroup analyses demonstrated that SBP was higher among (a) preterm compared to term groups from early adolescence until adulthood; (b) females born preterm but not among males born preterm compared to term controls; and (c) those born at <32 weeks or <28 weeks compared to term. Our meta-analyses demonstrate higher SBP and DBP among those born preterm compared to term. The difference in SBP is evident from early adolescence until adulthood.

A Behavioral Epigenetics Model to Predict Oral Feeding Skills in Preterm Infants

BACKGROUND

Preterm infants experience a multitude of prenatal and postnatal stressors, resulting in cumulative stress exposure, which may jeopardize the timely attainment of developmental milestones, such as achieving oral feeding. Up to 70% of preterm infants admitted to the neonatal intensive care unit experience challenges while initiating oral feeding. Oral feeding skills require intact neurobehavioral development. Evolving evidence demonstrates that cumulative stress exposure results in epigenetic modification of glucocorticoid-related genes. Epigenetics is a field of study that focuses on phenotypic changes that do not involve alterations in the DNA sequence. Epigenetic modification of glucocorticoid-related genes alters cortisol reactivity to environmental stimuli, which may influence neurobehavioral development, and is the essence of the evolving field of Preterm Behavioral Epigenetics. It is plausible that early-life cumulative stress exposure and the ensuing epigenetic modification of glucocorticoid-related genes impair neurobehavioral development required for achievement of oral feeding skills in preterm infants.

PURPOSE

The purpose of this article is to build upon the evolving science of Preterm Behavioral Epigenetics and present a conceptual model that explicates how cumulative stress exposure affects neurobehavioral development and achievement of oral feeding skills through epigenetic modification of glucocorticoid-related genes.

METHODS/RESULTS

Using the Preterm Behavioral Epigenetics framework and supporting literature, we present a conceptual model in which early-life cumulative stress exposure, reflected by DNA methylation of glucocorticoid-related genes and altered cortisol reactivity, disrupts neurobehavioral development critical for achievement of oral feeding skills.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Future investigations guided by the proposed conceptual model will benefit preterm infant outcomes by introducing epigenetic-based approaches to assess and monitor preterm infant oral feeding skills. Furthermore, the proposed model can guide future investigations that develop and test epigenetic protective interventions to improve clinical outcomes, representing an innovation in neonatal care.

Premature birth, low birth weight, small for gestational age and chronic non-communicable diseases in adult life: A systematic review with meta-analysis

BACKGROUND

Individuals who were born prematurely (PT), with low birth weight (LBW), or small for gestational age (SGA) appear to present a set of permanent changes that make them more susceptible to develop chronic non-communicable diseases (CNCD) in adult life.

AIM

Investigating the association between PT birth, LBW or SGA at birth and CNCD incidence in adult life.

METHODS

Systematic review with meta-analysis of studies available in three databases - two of them are official (PubMed and Web of Science) and one is gray literature (OpenGrey) - based on pre-established search and eligibility criteria.

RESULTS

Sixty-four studies were included in the review, 93.7% of them only investigated one of the exposure variables (46.7% LBW, 35.0% PT and 18.3% SGA at birth), whereas 6.3% investigated more than one exposure variable (50.0% LBW and PT; 50.0% SGA and PT). There was association among all exposure variables in the following outcomes: cardiometabolic (CMD) and glycidic metabolism (GMD) disorders, changes in body composition and risk of developing metabolic syndrome (MS). Female sex was identified as risk factor in the exposure-outcome association. Eighteen (18) articles were included in the meta-analysis. There was positive association between LBW and incidence of CMD (OR: 1.25 [95%CI: 1.11; 1.41]; 07 studies), GMD (OR: 1.70 [95%CI: 1.25; 2.30]; 03 studies) and MS (OR: 1.75 [95%CI: 1.27; 2.40]; 02 studies) in adult life. PT was positively associated with CMD (OR: 1.38 [95%CI: 1.27; 1.51]; 05 studies).

CONCLUSIONS

LBW and PT are associated with CMD and GMD development, as well as with the risk of developing MS in adult life.

Adult outcomes after preterm birth

Extremely preterm birth reflects global disruption of the third trimester environment. Young adults born preterm have an adverse cardiovascular and metabolic health profile, together with molecular evidence of accelerated ageing and a reduced life expectancy. The underlying mechanism for these observations is unknown. This review summarises recent evidence of the lifetime effects of preterm birth and highlights the risks survivors face.

Accelerated weight gain, prematurity, and the risk of childhood obesity: A meta-analysis and systematic review

The purpose of this systematic review and meta-analysis of the literature was to analyze and evaluate the impact of prematurity and accelerated weight gain on the risk of childhood and adolescent obesity. CINAHL, Embase, PubMed, and Web of Science databases were searched until December 2019 which yielded 19 studies with a total of 169,439 children enrolled were systematically reviewed. The results revealed that preterm infants had a greater likelihood of childhood obesity (defined as BMI ≥95th percentile for age-sex), than term infants (OR = 1.19, 95% CI [1.13, 1.26]). However, no difference of childhood obesity was found between "small for gestational age"(SGA) and "appropriate for gestational age"(AGA) among preterms. Accelerated weight gain (defined as weight gain velocity during first two years after birth) significantly increased the likelihood of subsequent childhood obesity among preterms (aOR = 1.87, 95% CI [1.57, 2.231]). In conclusion, accelerated weight gain at infancy among preterm children may be a critical contributor to obesity in later life. Establishing optimal growth trajectories and timely referral to health care providers may be of clinical importance.

Lower insulin sensitivity in young adults born preterm in Thailand

BACKGROUND

Previous studies reported impaired glucose homeostasis among preterm survivors, but consisted almost exclusively of Caucasians. It is unknown whether Asians born preterm display similar impairments.

AIM

To assess glucose homeostasis and other cardiometabolic outcomes among young adults born preterm in Thailand.

METHODS

Participants were 575 young adult offspring of mothers from the Chiang Mai Low Birth Weight Study, born in 1989 to 1990 and followed up in 2010: 54.1% females, median age 20.6 years, including 33 individuals (5.7%) born preterm. After an overnight fast, participants underwent clinical assessments, including blood sampling (glucose, insulin, and lipid profile). Insulin sensitivity was assessed using HOMA-IR and insulin secretion estimated using HOMA-β.

RESULTS

In unadjusted analyses, young Thai adults born preterm were 3.2 cm shorter (P = .037), 6 kg lighter (P = .016), and had HOMA-β 34% higher (P = .026) than those born at term. Adjusted analyses accounting for important confounders showed marked impairments in glucose homeostasis among preterm survivors: fasting insulin levels were 32% greater (P = .011), with HOMA-IR and HOMA-β that were 31% (P = .020) and 43% higher (P = .005), respectively, compared to peers born at term. There were no other contrasting observations between groups, with anthropometric differences disappearing after adjustment for confounders.

DISCUSSION

Young adults in Thailand born preterm were more insulin resistant than peers born at term. The observed impairments in glucose metabolism among young Thai adults born preterm corroborate findings reported mostly on Caucasians. The challenge for general practitioners and public health professionals is to encourage those born preterm to make healthier lifestyle choices early on.

Large-for-gestational-age phenotypes and obesity risk in adulthood: a study of 195,936 women

While there is evidence that being born large-for-gestational-age (LGA) is associated with an increased risk of obesity later in life, the data are conflicting. Thus, we aimed to examine the associations between proportionality at birth and later obesity risk in adulthood. This was a retrospective study using data recorded in the Swedish Birth Register. Anthropometry in adulthood was assessed in 195,936 pregnant women at 10-12 weeks of gestation. All women were born at term (37-41 weeks of gestation). LGA was defined as birth weight and/or length ≥2.0 SDS. Women were separated into four groups: appropriate-for-gestational-age according to both weight and length (AGA - reference group; n = 183,662), LGA by weight only (n = 4,026), LGA by length only (n = 5,465), and LGA by both weight and length (n = 2,783). Women born LGA based on length, weight, or both had BMI 0.12, 1.16, and 1.08 kg/m² greater than women born AGA, respectively. The adjusted relative risk (aRR) of obesity was 1.50 times higher for those born LGA by weight and 1.51 times for LGA by both weight and height. Length at birth was not associated with obesity risk. Similarly, women born LGA by ponderal index had BMI 1.0 kg/m² greater and an aRR of obesity 1.39 times higher than those born AGA. Swedish women born LGA by weight or ponderal index had an increased risk of obesity in adulthood, irrespective of their birth length. Thus, increased risk of adult obesity seems to be identifiable from birth weight and ignoring proportionality.

Feeding the Late and Moderately Preterm Infant: A Position Paper of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition

Nutritional guidelines and requirements for late or moderately preterm (LMPT) infants are notably absent, although they represent the largest population of preterm infants. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition (CoN) performed a review of the literature with the aim to provide guidance on how to feed infants born LMPT, and identify gaps in the literature and research priorities.Only limited data from controlled trials are available. Late preterm infants have unique, often unrecognized, vulnerabilities that predispose them to high rates of nutritionally related morbidity and hospital readmissions. They frequently have feeding difficulties that delay hospital discharge, and poorer rates of breastfeeding initiation and duration compared with term infants. This review also identified that moderately preterm infants frequently exhibit postnatal growth restriction.The ESPGHAN CoN strongly endorses breast milk as the preferred method of feeding LMPT infants and also emphasizes that mothers of LMPT infants should receive qualified, extended lactation support, and frequent follow-up. Individualized feeding plans should be promoted. Hospital discharge should be delayed until LMPT infants have a safe discharge plan that takes into account local situation and resources.In the LMPT population, the need for active nutritional support increases with lower gestational ages. There may be a role for enhanced nutritional support including the use of human milk fortifier, enriched formula, parenteral nutrition, and/or additional supplements, depending on factors, such as gestational age, birth weight, and significant comorbidities. Further research is needed to assess the benefits (improved nutrient intakes) versus risks (interruption of breast-feeding) of providing nutrient-enrichment to the LMPT infant.

Preterm Birth as a Risk Factor for Metabolic Syndrome and Cardiovascular Disease in Adult Life: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine if preterm birth is associated with components of the metabolic syndrome in adult life.

STUDY DESIGN

A structured literature search was performed using PubMed. All comparative studies reported metabolic and cardiovascular outcomes in adults (≥18 years of age) born preterm (<37 weeks of gestation) compared with adults born at term (37-42 weeks of gestation) and published through March 2018 were included. The major outcomes assessed were body mass index, waist circumference, waist-to-hip ratio, fat mass, systolic blood pressure (SBP), diastolic blood pressure (DBP), 24-hour SBP, 24-hour DBP, endothelium-dependent brachial artery flow-mediated dilation, carotid intima-media thickness, pulse wave velocity, fasting glucose and insulin, Homeostasis Model Assessment-Estimated Insulin Resistance Index, and lipid profiles. Quality appraisal was performed using a modified version of the Newcastle-Ottawa scale. A meta-analysis was performed for comparable studies which reported sufficient data.

RESULTS

Forty-three studies were included, including a combined total of 18 295 preterm and 294 063 term-born adults. Prematurity was associated with significantly higher fat mass (P = .03), SBP (P < .0001), DBP (P < .0001), 24-hour SBP (P < .001), and 24-hour DBP (P < .001). Furthermore, preterm-born adults presented higher values of fasting glucose (P = .01), insulin (P = .002), Homeostasis Model Assessment-Estimated Insulin Resistance Index (P = .05), and total cholesterol levels (P = .05) in comparison with adults born at term, in random effect models. No statistically significant difference was found between preterm and term-born adults for the other outcomes studied.

CONCLUSIONS

Preterm birth is strongly associated with a number of components of the metabolic syndrome and cardiovascular disease in adult life.

Preterm Birth is Associated With Increased Blood Pressure in Young Adult Women

Background While there is some evidence of elevated blood pressure later in life in preterm survivors, data on adult women are still lacking. Thus, we assessed the associations between preterm birth and blood pressure in young adult women. Methods and Results We studied 5232 young adult women who volunteered for military service in Sweden between 1990 and 2007. Anthropometric and clinic blood pressure data were collected during the medical examination at the time of conscription. There was a progressive decline in systolic and diastolic blood pressures, as well as in mean arterial pressure, with increasing gestational age. Women born preterm had an adjusted increase in systolic blood pressure of 3.8 mm Hg (95% CI , 2.5-5.1; P<0.0001) and mean arterial pressure of 1.9 mm Hg (95% CI , 0.9-2.8; P=0.0001) compared with young women born at term. Rates of systolic hypertension were also considerably higher in young women born preterm (14.0% versus 8.1%, P<0.0001), as were rates of isolated systolic hypertension. The adjusted relative risk of systolic hypertension in women born preterm was 1.72 (95% CI , 1.26-2.34; P<0.001) that of women born at term or post-term, but there was no significant difference in the risk of diastolic hypertension (adjusted relative risk, 1.60; 95% CI , 0.49-5.20). Conclusions Young adult women born preterm display elevated systolic blood pressure and an increased risk of hypertension compared with peers born at term or post-term.

Cardiometabolic risk in obese children

Obesity in childhood remains a significant and prevalent public health concern. Excess adiposity in youth is a marker of increased cardiometabolic risk (CMR) in adolescents and adults. Several longitudinal studies confirm the strong association of pediatric obesity with the persistence of adult obesity and the future development of cardiovascular disease, diabetes, and increased risk of death. The economic and social impact of childhood obesity is further exacerbated by the early onset of the chronic disease burden in young adults during their peak productivity years. Furthermore, rising prevalence rates of severe obesity in youth from disadvantaged and/or minority backgrounds have prompted the creation of additional classification schemes for severe obesity to improve CMR stratification. Current guidelines focus on primary obesity prevention efforts, as well as screening for clustering of multiple CMR factors to target interventions. This review summarizes the scope of the pediatric obesity epidemic, the new severe obesity classification scheme, and examines the association of excess adiposity with cardiovascular and metabolic risk. We will also discuss potential questions for future investigation.

Assessment of body adiposity preterm children at the beginning of school age

In Poland, like in other developed countries, 6.3% of babies are born prematurely. Preterm babies suffer from numerous health issues. The aim of the study was to assess body adiposity in preterm children at the beginning of school age. The study population consisted of 61 children aged 5 to 8 years who had been born preterm. We performed standard anthropometric measurements according to internationally recognized methodology. The following parameters were used: Body Weight (BW), Body Heigh (BH), Waist Circumference (WC), Body Mass Index (BMI), Waist to Height Ratio (WtHR), Triceps Skinfold Thickness (TST), Subscapular Skinfold Thickness (SST), Umbilical Skinfold Thickness (UST), as well as total sum of the above parameters, or the Global Adiposity (GA). The anthropometric measurements were taken according to international anthropometric methodology. All anthropometric parameters for body adiposity were significantly lower in the study population than in the reference system. We found a statistically significant relationship between: the number of fetuses and: UST (p = 0.007) and z-score UST (p = 0.030); combined number of unfavorable perinatal events: and UST (p = 0.013) and z-score UST (p = 0.007), GA (p = 0.038) and z-score GA (p = 0.040). Preterm children who are about to start school have significantly lower values of anthropometric features that characterize their body adiposity. In preterm children at early school age number of fetuses diversifies UST; and combined number of unfavorable perinatal events diversifies UST and GA. It is recommended that more studies are conducted on positively oriented modification of body adiposity in these children, as well as its long term monitoring.

Birth Intervals and Health in Adulthood: A Comparison of Siblings Using Swedish Register Data

A growing body of research has examined whether birth intervals influence perinatal outcomes and child health as well as long-term educational and socioeconomic outcomes. To date, however, very little research has examined whether birth spacing influences long-term health. We use contemporary Swedish population register data to examine the relationship between birth-to-birth intervals and a variety of health outcomes in adulthood: for men, height, physical fitness, and the probability of falling into different body mass index categories; and for men and women, mortality. In models that do not adjust carefully for family background, we find that short and long birth intervals are clearly associated with height, physical fitness, being overweight or obese, and mortality. However, after carefully adjusting for family background using a within-family sibling comparison design, we find that birth spacing is generally not associated with long-term health, although we find that men born after very long birth intervals have a higher probability of being overweight or obese in early adulthood. Overall, we conclude that birth intervals have little independent effect on long-term health outcomes.

Effect of foetal and infant growth and body composition on respiratory outcomes in preterm-born children

Body composition and growth outcomes of preterm-born subjects have been studied by many researchers. In general, preterm-born children have lower height and weight especially in infancy. Despite showing potential for catch-up growth, they continue to lag behind their term counterparts in adolescence and adulthood. The various methods of studying body composition and the differing gestations and ages at which it is assessed may go some way to explaining the inconsistent results observed in different studies. In addition, there is a paucity of data on the effects of foetal and infant growth and of body composition on later respiratory outcomes. In largely term-born subjects, foetal growth and growth trajectories appear to have differential effects on later respiratory outcomes. Early weight gain in infancy appears to be associated with increased respiratory symptoms in childhood but catch-up growth in infancy appears to be associated with possible improved lung function status.

Exercise capacity and cardiac function in adolescents born post-term

There is some evidence that children born post-term (≥42 weeks of gestation) have metabolic abnormalities that may be associated with an increased risk of adverse health outcomes in adulthood. However, there are no data as to whether adolescents born post-term display alterations in aerobic capacity or cardiovascular function. We studied 48 adolescents (56% males) in Auckland (New Zealand) with a mean age of 14.3 years (SD = 1.7): 25 born post-term and 23 born at term (37-41 weeks of gestation). Assessments included metabolic markers in blood, whole body DXA scans, 24-hour ambulatory blood pressure monitoring, maximal exercise capacity, as well as cardiac MRI scan at rest and during submaximal exercise. Exercise capacity was lower in the post-term than in control participants (44.5 vs 47.8 ml/kgffm/min; p = 0.04). There were no differences in left ventricular volumes at rest and during exercise between groups. The 24-hour ambulatory blood pressure monitoring also showed no differences between the two groups. Being born post-term was associated with reduced exercise capacity, but with no observed differences in central cardiac function. We speculate that the reduction in exercise capacity may be due to changes in the peripheral vascular system.

Influence of maternal adiposity, preterm birth and birth weight centiles on early childhood obesity in an Indigenous Australian pregnancy-through-to-early-childhood cohort study

Childhood obesity rates are higher among Indigenous compared with non-Indigenous Australian children. It has been hypothesized that early-life influences beginning with the intrauterine environment predict the development of obesity in the offspring. The aim of this paper was to assess, in 227 mother-child dyads from the Gomeroi gaaynggal cohort, associations between prematurity, Gestation Related-Optimal Weight (GROW) centiles, maternal adiposity (percentage body fat, visceral fat area), maternal non-fasting plasma glucose levels (measured at mean gestational age of 23.1 weeks) and offspring BMI and adiposity (abdominal circumference, subscapular skinfold thickness) in early childhood (mean age 23.4 months). Maternal non-fasting plasma glucose concentrations were positively associated with infant birth weight (P=0.005) and GROW customized birth weight centiles (P=0.008). There was a significant association between maternal percentage body fat (P=0.02) and visceral fat area (P=0.00) with infant body weight in early childhood. Body mass index (BMI) in early childhood was significantly higher in offspring born preterm compared with those born at term (P=0.03). GROW customized birth weight centiles was significantly associated with body weight (P=0.01), BMI (P=0.007) and abdominal circumference (P=0.039) at early childhood. Our findings suggest that being born preterm, large for gestational age or exposed to an obesogenic intrauterine environment and higher maternal non-fasting plasma glucose concentrations are associated with increased obesity risk in early childhood. Future strategies should aim to reduce the prevalence of overweight/obesity in women of child-bearing age and emphasize the importance of optimal glycemia during pregnancy, particularly in Indigenous women.

Deltoid muscle morphometry as an index of impaired skeletal muscularity in neonatal intensive care

We hypothesised that extremely premature infants would have decreased muscle mass at term-corrected age compared to term-born infants and that the degree of reduced muscle mass acquisition would correlate with the duration of invasive mechanical ventilation. The MRI brain scans of infants admitted in the neonatal unit at King's College Hospital between 1 January 2010 and 1 June 2016 were retrospectively reviewed. The coronal cross-sectional area of the left deltoid muscle (DCSA) was measured in 17 infants born < 28 weeks of gestation and in 20 infants born at term. The prematurely born infants had a median (IQR) gestation age of 25 weeks (24-27) and the term infants 40 weeks (38-41). The duration of invasive mechanical ventilation for the prematurely born infants was 39 days (14-62) and that for the term infants 4 days (2-5), p < 0.001. DCSA was smaller in prematurely born infants (median 189, IQR 176-223 mm²) compared to term-born infants (median 302, IQR 236-389 mm²), p < 0.001. DCSA was related to gestation age (r = 0.545, p = 0.001), weight z-score at MRI (r = 0.658, p < 0.001) and days of invasive mechanical ventilation (r = - 0.583, p < 0.001). In conclusion, extremely premature infants studied at term had a lower muscle mass compared to term-born infants.

CONCLUSION

Our results suggest that prolonged mechanical ventilation in infants admitted in neonatal intensive care is associated with reduced skeletal muscle mass acquisition. What is Known: • Prolonged mechanical ventilation in adult intensive care patients has been associated with skeletal muscle dysfunction and atrophy. • The cross-sectional area of the deltoid muscle has been used to evaluate muscle atrophy in infants with a previous branchial plexus birth injury. What is New: • Premature infants studied at term exhibit lower cross-sectional area of the deltoid muscle than their term counterparts. • Prolonged mechanical ventilation could be associated with skeletal muscle impairment.

Pulmonary sequelae and functional limitations in children and adults with bronchopulmonary dysplasia

Preterm infants with bronchopulmonary dysplasia (BPD) often suffer from life-long pulmonary impairments in pulmonary physical function. This review summarizes our current understanding of the chronic pulmonary impairments and physical functional limitations associated with BPD from preterm birth to adulthood. It also identifies opportunities for intervention in children and adults living with chronic lung disease (CLD) after preterm birth.

Antenatal corticosteroids and cardiometabolic outcomes in adolescents born with very low birth weight

BackgroundExposure to antenatal corticosteroids (ANCS) is associated with adverse cardiometabolic outcomes in animal models; however, long-term outcomes in clinical studies are not well characterized. We hypothesized that exposure to ANCS would be associated with markers of increased cardiometabolic risk in adolescents born with very low birth weight (VLBW).MethodsIn an observational cohort of 186 14-year-old adolescents born with VLBW, we measured resting blood pressure (BP), BP response to cold, ambulatory BP, and anthropometrics; performed dual-energy X-ray absorptiometry; and analyzed blood samples for uric acid, cholesterol, glycated hemoglobin, and high-sensitivity C-reactive protein. Multivariate analyses were used to evaluate associations with ANCS, adjusting for race, sex, and maternal hypertensive pregnancy.ResultsThere were no ANCS group differences in BP measures or blood biomarkers. Compared with adolescents unexposed to ANCS, those exposed to ANCS were taller (exposed-unexposed mean difference 3.1 cm (95% confidence interval (CI) 0.7, 5.5)) and had decreased waist-to-height ratio (exposed-unexposed mean difference -0.03 (95% CI -0.058, -0.002)). Males exposed to ANCS had lower total cholesterol (exposed-unexposed mean difference -0.54 mmol/l (95%CI -0.83, -0.06)).ConclusionAmong adolescents born with VLBW, ANCS exposure was not associated with markers of increased cardiometabolic risk.

Adults born preterm: a review of general health and system-specific outcomes

In this review of 126 publications, we report that an overwhelming majority of adults born at preterm gestations remain healthy and well. However, a small, but a significant fraction of them remain at higher risk for neurological, personality and behavioural abnormalities, cardio-pulmonary functional limitations, systemic hypertension and metabolic syndrome compared to their term-born counterparts. The magnitude of increased risk differed across organ systems and varied across reports. The risks were proportional to the degree of prematurity at birth and seemed to occur more frequently among preterm infants born in the final two decades of the 20th century and later. These findings have considerable public health and clinical practice relevance.

CONCLUSION

Preterm birth needs to be considered a chronic condition, with a slight increase in the risk for long-term morbidities among adults born preterm. Therefore, obtaining a history of gestational age and weight at birth should be a routine part of care for patients of all age groups.

Long-term effects of premature birth on somatic development in women through adolescence and adulthood

Objectives

To evaluate the long-term consequences of preterm birth on anthropometric parameters in women in adolescence and into adulthood.

Methods

Seventy girls born preterm (age 12.22 ± 1.52 years) and 48 born at term participated in the first stage. Eighteen years later, 13 of the same women participated in a follow-up and were compared with a control group of 27 women. We compared anthropometric results across the two examinations, and in the second stage, also assessed body composition using bioelectrical impedance analysis.

Results

No significant differences were found in anthropometric parameters or the content of individual components of the body between the preterm-born and control groups. However, the preterm-born group showed a tendency for higher average fat mass and lower fat-free and soft lean mass compared with the control group, and had a significantly higher mean waist–hip ratio.

Conclusions

Preterm birth does not adversely affect somatic development in girls during adolescence, but shows a correlation with an elevated waist–hip ratio in adulthood.

Early life characteristics, social mobility during childhood and risk of stroke in later life: findings from a Swedish cohort

Aims: To investigate if early life characteristics and social mobility during childhood are associated with incident thrombotic stroke (TS), haemorrhagic stroke (HS) and other stroke (OS). Methods: Our study population consists of all live births at Uppsala University Hospital in 1915–1929 (Uppsala Birth Cohort; n = 14,192), of whom 5532 males and 5061 females were singleton births and lived in Sweden in 1964. We followed them from 1 January 1964 until first diagnosis of stroke (in the National Patient Register or Causes of Death Register), emigration, death, or until 31 December 2008. Data were analysed using Cox regression, stratifying by gender. Results: Gestational age was negatively associated with TS and OS in women only. Women had increased risk of TS if they were born early preterm (<35 weeks) (HR 1.54 (95% CI 1.02–2.31)) or preterm (35–36 weeks) (HR 1.37 (95% CI 1.03–1.83)) compared to women born at term. By contrast, only women who were early preterm (HR 1.98 (95% CI 1.27–3.10) had an increased risk of OS. Men who were born post-term (⩾42 weeks) had increased risk of HS (HR 1.45 (95% CI 1.04–2.01)) compared with men born at term, with no association for women. TS was associated with social mobility during childhood in women: women whose families were upwardly or downwardly mobile had increased risk of TS compared to women who were always advantaged during childhood. Conclusions: Gestational age and social mobility during childhood were associated with increased risk of stroke later in life, particularly among women, but there was some heterogeneity between stroke subtypes.

Association Between Preterm Birth and Lower Adult Height in Women

We examined whether being born preterm was associated with changes in adult anthropometry in women. We assessed data on 201,382 women (born in 1973-1988) from the Swedish Birth Register. The mean age was 26.0 years. Of the women in our cohort, 663 were born very preterm (<32 weeks of gestation), 8,247 were born moderately preterm (at least 32 weeks but <37 weeks), and 192,472 were born at term (37-41 weeks). Subgroup analyses were carried out among siblings and also after adjustment for maternal anthropometric data. Statistical tests were 2-sided. Decreasing gestational age was associated with lower height (-1.1 mm per week of gestation; P < 0.0001), so that women who were born very preterm were on average 12 mm shorter than women who were born moderately preterm (P < 0.0001) and 17 mm shorter than women born at term (P < 0.0001). Compared with women who were born at term, those who were born very preterm had 2.9 times higher odds of short stature (<155.4 cm), and those born moderately preterm had 1.43 times higher odds. Subgroup analyses showed no differences between women born moderately preterm and those born at term but accentuated differences from women born very preterm. Among siblings (n = 2,388), very preterm women were 23 mm shorter than those born at term (P = 0.003), with a 20-mm difference observed in subgroup analyses (n = 27,395) that were adjusted for maternal stature (P < 0.001). A shorter final height was associated with decreasing gestational age, and this association was particularly marked in women born very preterm.

Former Very Preterm Infants Show an Unfavorable Cardiovascular Risk Profile at a Preschool Age

Cardiovascular disease is the leading cause of death worldwide. Evidence points towards an unfavorable cardiovascular risk profile of former preterm infants in adolescence and adulthood. The aim of this study was to determine whether cardiovascular risk predictors are detectable in former very preterm infants at a preschool age. Five- to seven-year-old children born at <32 weeks’ gestational age were included in the study. Same-aged children born at term served as controls. Basic data of study participants were collected by means of follow-up databases and standardized questionnaires. At study visit, anthropometric data, blood pressure readings and aortic intima-media thickness were assessed. Blood samples were obtained after an overnight fast. In comparison to children born at term, former preterm infants had higher systolic and diastolic blood pressure readings (odds ratio [95% confidence interval] per 1-SD higher blood pressure level 3.2 [2.0–5.0], p<0.001 and 1.6 [1.1–1.2], p = 0.008), fasting glucose levels (OR [95% CI] 5.2 [2.7–10.1], p<0.001), homeostasis model assessment index (OR [95% CI] 1.6 [1.0–2.6], p = 0.036), and cholesterol levels (OR [95% CI] 2.1 [1.3–3.4], p = 0.002). Systolic prehypertension (23.7% vs. 2.2%; OR [95% CI] 13.8 [3.1–60.9], p = 0.001), elevated glucose levels (28.6% vs. 5.9%; OR [95% CI] 6.4 [1.4–28.8], p = 0.016), and hypercholesterolemia (77.4% vs. 52.9%; OR [95% CI] 3.0 [1.3–7.1], p = 0.010) were significantly more prevalent in the preterm group. As former very preterm infants display an unfavorable cardiovascular risk profile already at a preschool age, implementation of routine cardiovascular follow-up programs might be warranted.

Exploring the contribution of maternal antibiotics and breastfeeding to development of the infant microbiome and pediatric obesity

Pediatric obesity, a significant public health concern, has been associated with adult premature mortality and the development of type 2 diabetes and cardiovascular disease. Evidence has suggested that the gut microbiota is associated with pediatric obesity. Establishment of the infant gut microbiome is dependent on a dynamic maternal-infant microbiota exchange during early life. The objective of this review is to describe maternal factors such as feeding practices and antibiotic use that may influence the infant gut microbiome and risk for obesity. The complex components in human milk have many nutritional benefits to the infant; however, the microbiome in human milk may be an important factor to help regulate the infant's weight. We discuss maternal antibiotics and the effects on breast milk as critical exposures that alter the infant's gut microbiome and influence the risk of pediatric obesity.

Response to IGF-1 Generation Test in Short Prepubertal Children Born Very Preterm or at Term

AIMS

To investigate whether short children born very preterm (<32 weeks of gestation) exhibit features of growth hormone (GH) resistance compared to term peers.

METHODS

We studied 26 prepubertal children (aged 7.0 ± 2.0 years) with short stature (height adjusted for parents' heights <10th percentile), who were born appropriate for gestational age and either very preterm (n = 11) or at term (n = 15). Children underwent insulin-like growth factor-1 (IGF-1) generation test via a daily recombinant human GH (rhGH) dose (0.05 mg/kg/day) over 4 consecutive days. Hormone and binding proteins were measured at baseline and day 5.

RESULTS

At baseline, preterm children had lower IGF-binding protein 1 (IGFBP-1; -22%; p = 0.049) and IGFBP-3 (-24%; p = 0.013) concentrations than term children. Preterm children also had insulin concentrations that tended to be 39% higher (p = 0.059) than term peers. After stimulation, IGF-1 and IGFBP-3 concentrations increased similarly in term and preterm groups, while GH-binding protein (GHBP) concentrations decreased in both groups. Preterm children had higher GHBP (+50%; p = 0.049), insulin (+86%; p = 0.005), and leptin (+107%; p = 0.020) but lower IGFBP-1 (-47%; p = 0.006) concentrations than term children following rhGH stimulation.

CONCLUSIONS

Preterm children who are short for genetic height potential show no evidence of GH resistance that would explain their short stature. However, there was indirect evidence of insulin resistance in the preterm children, as previously described in this group.

Body Mass Index, Overweight, and Obesity in Swedish Women Born Post-term

BACKGROUND

There is increasing evidence that post-term birth (≥42 weeks of gestation) is associated with adverse long-term outcomes. We assessed whether women born post-term displayed increased risk of overweight and obesity in adulthood.

METHODS

Data were collected at first antenatal visit (~10-12 weeks of gestation) on singleton Swedish women aged ≥18 years in 1991-2009 (mean age 26.1 years), who were born post-term (n = 27 153) or at term (37-41 weeks of gestation; n = 184 245). Study outcomes were evaluated for continuous associations with gestational age. Stratified analyses were carried out comparing women born post-term or at term. Analyses were also run with a 2-week buffer between groups to account for possible errors in gestational age estimation, comparing women born very post-term (≥43 weeks of gestation; n = 5761) to those born within a narrower term window (38-40 weeks of gestation; n = 130 110).

RESULTS

Increasing gestational age was associated with greater adult weight and body mass index (BMI). Stratified analyses showed that women born post-term were 0.5 kg heavier and had BMI 0.2 kg/m(2) greater than those born at term. Differences were more marked between women born very post-term (≥43 weeks) vs. a narrower term group (38-40 weeks): 1.0 kg and 0.3 kg/m(2) . The adjusted relative risks of overweight/obesity and obesity in women born very post-term were 1.13 and 1.12 times higher, respectively, than in those born at term.

CONCLUSIONS

Post-term birth is associated with greater BMI and increased risk of overweight and obesity in adulthood, particularly among women born ≥43 weeks of gestation.

Dietary behaviors of adults born prematurely may explain future risk for cardiovascular disease

Being born prematurely associates with greater cardiovascular disease (CVD) risk in adulthood. Less understood are the unique and joint associations of dietary patterns and behaviors to this elevated risk among adults who are born prematurely. We aimed to model the associations between term status, dietary and lifestyle behaviors with CVD risk factors while accounting for the longitudinal effects of family protection, and medical or environmental risks. In wave-VIII of a longitudinal study, 23-year olds born prematurely (PT-adults, n = 129) and full term (FT-adults, n = 38) survey-reported liking for foods/beverages and activities, constructed into indexes of dietary quality and sensation-seeking, dietary restraint and physical activity. Measured CVD risk factors included fasting serum lipids and glucose, blood pressure and adiposity. In bivariate relationships, PT-adults reported lower dietary quality (including less affinity for protein-rich foods and higher affinity for sweets), less liking for sensation-seeking foods/activities, and less restrained eating than did FT-adults. In comparison to nationally-representative values and the FT-adults, PT-adults showed greater level of CVD risk factors for blood pressure and serum lipids. In structural equation modeling, dietary quality completely mediated the association between term status and HDL-cholesterol (higher quality, lower HDL-cholesterol) yet joined term status to explain variability in systolic blood pressure (PT-adults with lowest dietary quality had highest blood pressures). Through lower dietary quality, being born prematurely was indirectly linked to higher cholesterol/HDL, higher LDL/HDL and elevated waist/hip ratios. The relationship between dietary quality and CVD risk was strongest for PT-adults who had developed greater cumulative medical risk. Protective environments failed to attenuate relationships between dietary quality and elevated CVD risk among PT-adults. In summary, less healthy dietary behaviors contribute to elevated CVD risk among young adults who are born prematurely.

Delayed growth, motor function and learning in preterm pigs during early postnatal life

Preterm birth interrupts normal fetal growth with consequences for postnatal growth and organ development. In preterm infants, many physiological deficits adapt and disappear with advancing postnatal age, but some may persist into childhood. We hypothesized that preterm birth would induce impaired organ growth and function during the first postnatal week in pigs, while motor abilities and behavioral characteristics would show more persistent developmental delay. Cesarean-delivered preterm ( n = 112, 90% gestation) or term ( n = 56, 100% gestation) piglets were reared under identical conditions and euthanized for blood and organ collection on postnatal days 0, 5, or 26. Body weight gain remained lower in preterm vs. term pigs up to day 26 (25.5 ± 1.5 vs. 31.0 ± 0.5 g·kg−1·day−1, P < 0.01) when relative weights were higher for brain and kidneys and reduced for liver and spleen. Neonatal preterm pigs had reduced values for blood pH, Po2, glucose, lactate, hematocrit, and cortisol, but at day 26, most values were normalized, although plasma serotonin and IGF 1 levels remained reduced. Preterm pigs showed delayed neonatal arousal and impaired physical activity, coordination, exploration, and learning, relative to term pigs (all P < 0.05). Supplementation of parenteral nutrition during the first 5 days with an enteral milk diet did not affect later outcomes. In preterm pigs, many physiological characteristics of immaturity disappeared by 4 wk, while some neurodevelopmental deficits remained. The preterm pig is a relevant animal model to study early dietary and pharmacological interventions that support postnatal maturation and neurodevelopment in preterm infants.

Identification of Eight Different Isoforms of the Glucocorticoid Receptor in Guinea Pig Placenta: Relationship to Preterm Delivery, Sex and Betamethasone Exposure

The placental glucocorticoid receptor (GR) is central to glucocorticoid signalling and for mediating steroid effects on pathways associated with fetal growth and lung maturation but the GR has not been examined in the guinea pig placenta even though this animal is regularly used as a model of preterm birth and excess glucocorticoid exposure. Guinea pig dams received subcutaneous injections of either vehicle or betamethasone at 24 and 12 hours prior to preterm or term caesarean-section delivery. At delivery pup and organ weights were recorded. Placentae were dissected, weighed and analysed using Western blot to examine GR isoform expression in nuclear and cytoplasmic extracts. A comparative examination of the guinea pig GR gene identified it is capable of producing seven of the eight translational GR isoforms which include GRα-A, C1, C2, C3, D1, D2, and D3. GRα-B is not produced in the Guinea Pig. Total GR antibody identified 10 specific bands from term (n = 29) and preterm pregnancies (n = 27). Known isoforms included GRγ, GRα A, GRβ, GRP, GRA and GRα D1-3. There were sex and gestational age differences in placental GR isoform expression. Placental GRα A was detected in the cytoplasm of all groups but was significantly increased in the cytoplasm and nucleus of preterm males and females exposed to betamethasone and untreated term males (KW-ANOVA, P = 0.0001, P = 0.001). Cytoplasmic expression of GRβ was increased in female preterm placentae and preterm and term male placentae exposed to betamethasone (P = 0.01). Nuclear expression of GRβ was increased in all placentae exposed to betamethasone (P = 0.0001). GRα D2 and GRα D3 were increased in male preterm placentae when exposed to betamethasone (P = 0.01, P = 0.02). The current data suggests the sex-specific placental response to maternal betamethasone may be dependent on the expression of a combination of GR isoforms.