Inflammatory and growth mediators in growing preterm infants

Glucose-regulatory hormones and growth in very preterm infants fed fortified human milk

BACKGROUND

Bovine colostrum (BC) contains a range of milk bioactive components, and it is unknown how human milk fortification with BC affects glucose-regulatory hormones in very preterm infants (VPIs). This study aimed to investigate the associations between hormone concentrations and fortification type, birth weight (appropriate/small for gestational age, AGA/SGA), milk intake, postnatal age, and body growth.

METHODS

225 VPIs were randomized to fortification with BC or conventional fortifier (CF). Plasma hormones were measured before, one and two weeks after start of fortification. ΔZ-scores from birth to 35 weeks postmenstrual age were calculated.

RESULTS

Compared with CF, infants fortified with BC had higher plasma GLP-1, GIP, glucagon, and leptin concentrations after start of fortification. Prior to fortification, leptin concentrations were negatively associated with growth, while IGF-1 concentrations associated positively with growth during fortification. In AGA infants, hormone concentrations generally increased after one week of fortification. Relative to AGA infants, SGA infants showed reduced IGF-1 and leptin concentrations.

CONCLUSION

Fortification with BC increased the plasma concentrations of several glucose-regulatory hormones. Concentrations of IGF-1 were positively, and leptin negatively, associated with growth. Glucose-regulatory hormone levels were affected by birth weight, milk intake and postnatal age, but not closely associated with growth in VPIs.

IMPACT

Little is known about the variation in glucose-regulatory hormones in the early life of very preterm infants (VPIs). This study shows that the levels of glucose-regulatory hormones in plasma of VPIs are highly variable and modified by birth weight (appropriate or small for gestational age, AGA or SGA), the type of fortifier, enteral nutritional intake, and advancing postnatal age. The results confirm that IGF-1 levels are positively associated with early postnatal growth in VPIs, yet the levels of both IGF-1 and other glucose-regulatory hormones appeared to explain only a small part of the overall variation in growth rates.

Postnatal Cytokine Trajectories in Very Preterm Infants

Inflammation often accompanies preterm birth and contributes to poor neurodevelopment in preterm infants. The purpose of this study was to describe postnatal cytokine trajectories among non-infected very preterm infants during the first weeks of life. Blood samples for cytokine analysis were collected weekly from infants born between 28 and 31 weeks post-menstrual age. We used linear mixed models to calculate slopes for each cytokine and allowed the slopes to differ by infant biological sex and post-menstrual age at birth. Levels of interleukin-6, interleukin-8, and interleukin-1 receptor antagonist decreased, on average, during the neonatal period. Monocyte chemoattractant protein-1 levels increased over time, and tumor necrosis factor-alpha levels were stable. Interleukin-6 and interleukin-8 slopes differed by post-menstrual age at birth but were unaffected by infant sex. Knowledge of average cytokine trajectories may be useful in identifying infants with unresolving inflammation that increases their risk for poor neurodevelopment.

IL-6 Predicts Poor Early Post-Natal Growth in Very Low-Birth-Weight Infants in a Low-Middle Income Setting

BACKGROUND

Extra-uterine growth restriction (EUGR) is common in preterms and may be associated with elevated pro-inflammatory cytokines.

OBJECTIVE

Describe postnatal growth in a cohort of very low-birth-weight (VLBW) infants and determine the association of interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α) in umbilical cord blood with growth at 40 weeks and 12 months postmenstrual age (PMA).

METHODS

Single-centre, prospective cohort study conducted from 1 June 2017 to 31 January 2019 with follow-up to 31 March 2020. Infants <1500 g at birth were enrolled, cord blood collected for IL-6 and TNF-α assays and postnatal care, including anthropometry, provided to 12 months PMA. Informed consent and ethics approval were obtained.

RESULTS

In total, 279 patients were enrolled; 84 (30.1%) died before 12 months and 91 (32.6%) lost to follow-up. Anthropometry was available for 151 infants at 40 weeks and 105 at 12 months. Z-Scores at 40 weeks for males and females combined were -2.5, -2.1 and -1.2 for weight, length and head circumference. EUGR occurred in 103/113 (91.2%), 98/107 (91.6%) and 70/109 (64.2%) participants for weight, length and head circumference. Elevated IL-6 was associated with restricted weight (56.0 vs. 14.5 pg/ml, p = 0.02) and length (60.4 vs. 7.3 pg/ml, p = 0.01) at 40 weeks. There was no difference in IL-6 at 12 months and no difference in TNF-α at 40 weeks or 12 months.

CONCLUSION

The study reports significant EUGR. Elevated IL-6 was associated with growth restriction at 40 weeks but not 12 months PMA.

Body composition and neuromotor development in the year after NICU discharge in premature infants

BACKGROUND

Hypothesis: neuromotor development correlates to body composition over the first year of life in prematurely born infants and can be influenced by enhancing motor activity.

METHODS

Forty-six female and 53 male infants [27 ± 1.8 (sd) weeks] randomized to comparison or exercise group (caregiver provided 15-20 min daily of developmentally appropriate motor activities) completed the year-long study. Body composition [lean body and fat mass (LBM, FM)], growth/inflammation predictive biomarkers, and Alberta Infant Motor Scale (AIMS) were assessed.

RESULTS

AIMS at 1 year correlated with LBM (r = 0.32, p < 0.001) in the whole cohort. However, there was no effect of the intervention. LBM increased by ~3685 g (p < 0.001)); insulin-like growth factor-1 (IGF-1) was correlated with LBM (r = 0.36, p = 0.002). IL-1RA (an inflammatory biomarker) decreased (-75%, p < 0.0125). LBM and bone mineral density were significantly lower and IGF-1 higher in the females at 1 year.

CONCLUSIONS

We found an association between neuromotor development and LBM suggesting that motor activity may influence LBM. Our particular intervention was ineffective. Whether activities provided largely by caregivers to enhance motor activity in prematurely born infants can affect the interrelated (1) balance of growth and inflammation mediators, (2) neuromotor development, (3) sexual dimorphism, and/or (4) body composition early in life remains unknown.

Modifications of Own Mothers' Milk Fortification Protocol Affect Early Plasma IGF-I and Ghrelin Levels in Preterm Infants. A Randomized Clinical Trial

The aim was to investigate the effect of two own mother’s milk (OMM) fortification protocols on (a) IGF-I and ghrelin plasma levels at 35 post-conceptional weeks (PCW, T2) and whether this effect is maintained after elimination of the differences in OMM fortification, and (b) growth until 12 months corrected age. Forty-eight OMM-fed preterm infants (GA 24–32 weeks) were randomly allocated to the fixed-fortification (FF) group (n = 23) and the protein-targeting fortification (PTF) group (n = 25) targeting the recommended daily protein intake (PI). Plasma IGF-I and ghrelin were assessed at 35 (T2) and 40 (T3) PCW while growth was longitudinally assessed until 12 months corrected age. PTF group had lower IGF-I and higher ghrelin than FF group at T2, while receiving lower daily protein and energy amounts. PI correlated positively to T2-IGF-I and inversely to T3-ghrelin while energy intake (EI) correlated inversely to T2- and T3-ghrelin. Group and PI were independent predictors of adjusted T2-IGF-I, while group and EI were predictors of adjusted and T2-ghrelin. Growth parameter z-scores were comparable between groups up to 12 months corrected age. Modifications of OMM fortification have a transient effect on early plasma IGF-I and ghrelin levels in preterm infants in a way consistent with the previously recognized protein-energy/endocrine balance, indicating a potential programming effect.

Postnatal weight gain and retinopathy of prematurity

Infants meeting retinopathy of prematurity (ROP) screening guidelines based on birth weight and gestational age undergo serial examinations by ophthalmologists for detection and treatment. However, less than 10% require treatment, and less than half develop ROP. Slow postnatal weight gain is highly predictive of ROP, and investigators have incorporated weight gain measures to develop more specific criteria for ROP screening. Such clinical prediction model use involves a large development study, validation studies specific to the target populations, and ongoing impact surveillance, with adjustment as necessary. Of the many weight gain inclusive prediction models intended to improve the precision of ROP screening, the Postnatal Growth and ROP (G-ROP) modified screening criteria were developed using the largest dataset and may provide the most robust model for clinical use. A recently completed G-ROP validation study will evaluate the generalizability of these modified criteria prior to clinical use.

How are maternal dietary patterns and maternal/fetal cytokines associated with birth weight? A path analysis

The aim of the study was to investigate how maternal dietary patterns and maternal/fetal cytokines are associated with birth weight and whether cytokines mediate the association. A total of 469 pregnant women and their children were recruited for this prospective study. Dietary patterns in pregnancy were identified using factor analysis of data from three consecutive 24 h dietary recalls. Maternal and umbilical blood serum cytokines (adiponectin (APN), IL-6 and interferon-γ) were measured via ELISA. Path analysis was used to explore the relationships between maternal diet, cytokines and birth weight. Four dietary patterns were identified: a mainly fruit, dairy products and poultry diet (FDP); a mainly vegetables, beans and pork diet (VBP); a mainly fish, shrimp and soup diet (FS) and a mainly tuber and egg diet (TE). Path analysis showed the order of effects of dietary patterns on birth weight was FS>FDP>TE>VBP (β=0·130, 0·109, –0·094 and 0·046, respectively). Only the TE pattern’s effect was negative. Maternal and fetal APN were positively associated with birth weight (β=0·045 and 0·226, respectively), and they mediated the association between the TE pattern and birth weight (indirect effect was 5·3 %). Maternal IL-6 was negatively associated with birth weight (β=–0·067) and mediated the association between maternal FDP and VBP patterns and birth weight (indirect effects were 10·1 and 100·0 %, respectively). All variables in the path explained 33·6 % of variation. These results suggested that maternal dietary patterns in pregnancy are associated with birth weight and mediated directly and indirectly through some maternal/fetal serum cytokines.

Children's Hospital of Philadelphia Score to predict severe retinopathy in Indian preterm infants

BACKGROUND

Retinopathy of Prematurity (ROP) screenings are expensive and entail heavy workload. Predictive models using postnatal weight gain reduces the number of ophthalmological examinations. The objective was to validate Children's Hospital of Philadelphia (CHOP) score to predict severe ROP in resource limited settings.

METHODS

Prior to ophthalmic examination, the CHOP score was calculated to predict severe ROP (point estimate = 0.014) in 191 preterm infants. Cut-off point estimate, most suitable in resource limited settings was assessed.

RESULTS

CHOP Score cutoff point (0.014) showed 67% sensitivity, 75% specificity. With CHOP score cut-off point (0.010), the corresponding values were 100% sensitivity, 51% specificity, PPV 12% and NPV 100%.

CONCLUSION

CHOP Score (0.014) is a poor tool to predict the onset of severe ROP. However, CHOP Score (0.010) is a promising tool to predict the onset of severe ROP and reduces the need for ophthalmological examinations by 50% in resource limited settings.

Neurodevelopmental outcomes among extremely premature infants with linear growth restriction

OBJECTIVE

To compare neurodevelopmental outcomes in linear growth-restricted (LGR) infants born <29 weeks with and without weight gain out of proportion to linear growth.

STUDY DESIGN

We compared 2-year neurodevelopmental outcomes between infants with and without LGR and between LGR infants with and without weight gain out of proportion to linear growth. The outcomes were Bayley-III cognitive, motor, and language scores, cerebral palsy, Gross Motor Function Classification System (GMFCS) level ≥ 2, and neurodevelopmental impairment.

RESULT

In total, 1227 infants were analyzed. LGR infants were smaller and less mature at birth, had higher BMI, and had lower Bayley-III language scores (82.3 vs. 85.0, p < 0.05). Among infants with LGR, infants with high BMI had lower language scores compared with those with low-to-normal BMI (80.8 vs. 83.3, p < 0.05), and were more likely to have GMFCS level ≥2 and neurodevelopmental impairment.

CONCLUSION

Among infants with LGR, weight gain out of proportion to linear growth was associated with poorer neurodevelopmental outcomes.

Early Elevation in Interleukin-6 is Associated with Reduced Growth in Extremely Low Birth Weight Infants

Objective To determine whether reduced growth velocity (GV) in extremely low birth weight infants is preceded by elevated inflammatory cytokines. Study Design GV was determined at 36 weeks' postmenstrual age (PMA) in 768 infants 401 to 1,000 g birth weight (BW). Association between blood cytokines measured through day of life 21 and GV was explored using linear regression models that adjusted for late-onset sepsis (LOS), BW, small for gestational age (SGA), gender, race, energy intake, and center. Results Serum interleukin-6 (IL-6) was increased at days 14 and 21 in LOS infants. LOS was associated with reduced energy intake and GV for weight (weight-GV) at 36 weeks' PMA. Linear regression analysis controlling for LOS and energy intake showed significant relationships between increased IL-6 at days 14 and 21 with reduced weight-GV at 36 weeks' PMA (p < 0.0001). The relationship between day 21 IL-6 and weight-GV was not associated with LOS (p = 0.12) when controlling for BW and energy intake. Both BW (p = 0.02) and energy intake (p = 0.003) influenced the relationship between day 14 IL-6 and weight-GV. Conclusion IL-6 elevation during the first month of life is associated with lower weight-GV at 36 weeks' PMA and may have a direct effect upon energy balance and postnatal growth.

Neurodevelopmental outcomes in postnatal growth-restricted preterm infants with postnatal head-sparing

OBJECTIVE

To compare neurodevelopmental outcomes in postnatal growth-restricted infants born <29 weeks with and without postnatal head-sparing (PHS).

STUDY DESIGN

We analyzed developmental outcomes at 2 years of age among postnatally growth-restricted infants with and without head-sparing. The primary outcome was Bayley III cognitive composite score; secondary outcomes included Bayley III motor composite score, moderate/severe cerebral palsy, gross motor functional classification scale level⩾2, and presence or absence of neurodevelopmental impairment (NDI).

RESULTS

Of 1098 infants evaluated at 18 to 22 months, 658 were postnatally growth restricted, of whom 301 had head-sparing. In the multivariate model including independent risk factors for poor growth and poor developmental outcome, infants with head-sparing had higher adjusted motor composite scores (mean difference 4.65, P<0.01), but no differences in other neurodevelopmental outcomes.

CONCLUSION

PHS is associated with improved neurodevelopmental outcome in extremely preterm infants, specifically Bayley III motor scores, but whether beneficial effects of PHS persist later in life is unknown.

Bridging the Gaps: the Promise of Omics Studies in Pediatric Exercise Research

In this review, we highlight promising new discoveries that may generate useful and clinically relevant insights into the mechanisms that link exercise with growth during critical periods of development. Growth in childhood and adolescence is unique among mammals and is a dynamic process regulated by an evolution of hormonal and inflammatory mediators, age-dependent progression of gene expression, and environmentally modulated epigenetic mechanisms. Many of these same processes likely affect molecular transducers of physical activity. How the molecular signaling associated with growth is synchronized with signaling associated with exercise is poorly understood. Recent advances in "omics"-namely genomics and epigenetics, metabolomics, and proteomics-now provide exciting approaches and tools that can be used for the first time to address this gap. A biologic definition of "healthy" exercise that links the metabolic transducers of physical activity with parallel processes that regulate growth will transform health policy and guidelines that promote optimal use of physical activity.

Exercise and type 1 diabetes (T1DM)

Physical exercise is firmly incorporated in the management of type 1 diabetes (T1DM), due to multiple recognized beneficial health effects (cardiovascular disease prevention being preeminent). When glycemic values are not excessively low or high at the time of exercise, few absolute contraindications exist; practical guidelines regarding amount, type, and duration of age-appropriate exercise are regularly updated by entities such as the American Diabetes Association and the International Society for Pediatric and Adolescent Diabetes. Practical implementation of exercise regimens, however, may at times be problematic. In the poorly controlled patient, specific structural changes may occur within skeletal muscle fiber, which is considered by some to be a disease-specific myopathy. Further, even in well-controlled patients, several homeostatic mechanisms regulating carbohydrate metabolism often become impaired, causing hypo- or hyperglycemia during and/or after exercise. Some altered responses may be related to inappropriate exogenous insulin administration, but are often also partly caused by the "metabolic memory" of prior glycemic events. In this context, prior hyperglycemia correlates with increased inflammatory and oxidative stress responses, possibly modulating key exercise-associated cardio-protective pathways. Similarly, prior hypoglycemia correlates with impaired glucose counterregulation, resulting in greater likelihood of further hypoglycemia to develop. Additional exercise responses that may be altered in T1DM include growth factor release, which may be especially important in children and adolescents. These multiple alterations in the exercise response should not discourage physical activity in patients with T1DM, but rather should stimulate the quest for the identification of the exercise formats that maximize beneficial health effects.

Algorithms for the prediction of retinopathy of prematurity based on postnatal weight gain

Current ROP screening guidelines represent a simple risk model with two dichotomized factors, birth weight and gestational age at birth. Pioneering work has shown that tracking postnatal weight gain, a surrogate for low insulin-like growth factor 1, may capture the influence of many other ROP risk factors and improve risk prediction. Models including weight gain, such as WINROP, ROPScore, and CHOP ROP, have demonstrated accurate ROP risk assessment and a potentially large reduction in ROP examinations, compared to current guidelines. However, there is a need for larger studies, and generalizability is limited in countries with developing neonatal care systems.

Insulin-like growth factor I: could it be a marker of prematurity in the foal?

Insulin-like growth factor (IGF)-I represents one of the most important growth regulators, playing a central role in fetal and neonatal growth. Plasma IGF-I levels increase rapidly after birth, and they are influenced by numerous factors, including sex, age, nutritional state, and premature birth. The aims of this study were: (1) to evaluate the IGF-I plasma profile in healthy newborn foals during the first 2 weeks of life; (2) to assess the possible influence of sex and birth weight on this hormone; (3) to analyze the percentage increment of IGF-I values in healthy foals; (4) to evaluate the influence of prematurity on IGF-I profile; (5) to verify the role of IGF-I as a diagnostic marker of prematurity; and (6) to analyze the percentage increment of IGF-I in premature foals. Thirty-four healthy term foals were enrolled as the control group and from each foal plasma was collected within 6 hours from birth, at 12 hours, daily from Day 1 to Day 7, and at Days 10 and 14 after birth. Eleven foals aged younger than 1 week and diagnosed as premature and hospitalized at a Equine Perinatology Unit were also enrolled; from each foal plasma was collected daily from the day of admission to discharge or death. Insulin-like growth factor I was analyzed by RIA. In the control group, an increasing trend of IGF-I concentrations was found, with higher values from Day 4 to 10 compared with data obtained at less than 6 hours of life, and from Day 5 to 10 compared with 12 and 24 hours and 3 days. No differences were found in healthy foals analyzed in relation to birth weight and sex. In premature foals an increasing trend was observed but no statistical differences were found among sampling times, and no differences were found between healthy and premature foals. The IGF value in premature foals at admission was always higher compared with the lowest recorded level in healthy age-matched foals, thus this parameter does not seem to have a diagnostic role for prematurity in foals. Finally, the evaluation of the percentage increment of IGF-I concentrations showed a significant increase in full-term foals on Day 5, 6, 7, and 10 compared with 12 and 24 hours, and no differences were observed in premature foals. In conclusion, prematurity in newborn foals seems to affect only partially IGF-I plasma concentrations and it does not seem to be a reliable marker for this pathological condition.

Pneumococcal carriage at age 2 months is associated with growth deficits at age 6 months among infants in South India

Nasopharyngeal colonization is the first step in the pathway to Streptococcus pneumoniae (Spn) infection, a leading cause of childhood morbidity and mortality. We investigated the effect of Spn colonization at ages 2 and 4 mo on growth at age 6 mo among 389 infants living in rural South India by using data from an Spn carriage study nested within a randomized, double-blind, placebo-controlled community trial designed to evaluate the impact of newborn vitamin A supplementation on Spn carriage in the first 6 mo of life. Primary outcomes were weight, length, and anthropometric indices of nutritional status. Growth data at age 6 mo were available for 84% (389 of 464) of infants in the Spn carriage study. Carriage at age 2 mo was associated with increased odds of stunting [OR: 3.07 (95% CI: 1.29, 7.36) P = 0.012] and lower weight [β: -266 g (95% CI: -527, -5) P = 0.045], length [β: -1.31 cm (95% CI: -2.32, -0.31) P = 0.010], and length-for-age Z scores [β: -0.59; (95% CI: -1.05, -0.13) P = 0.012] at age 6 mo. Spn carriage at age 4 mo did not affect growth. Carriage of invasive serotypes at age 2 mo was associated with decreases in mean weight [β: -289 g; (95% CI: -491, -106) P = 0.002] and length [β:-0.38 cm (95% CI: -1.49, -0.01) P = 0.047] at age 6 mo. Newborn vitamin A supplementation did not modify the association between Spn carriage and growth. Results suggest that pneumococcal carriage at age 2 mo is an independent risk factor for poor growth in young infants. Future studies need to clarify the role of Spn carriage on growth retardation in low-income countries.

How type of parturition and health status influence hormonal and metabolic profiles in newborn foals

Thyroid hormones, insulin growth factor I (IGF-I) and non-esterified fatty acids (NEFA) represent important hormonal and metabolic factors associated with perinatal growth and maturation. Their action could be influenced by the type of parturition and the health status of the foal and therefore the aim of this work is to evaluate their plasma concentrations in newborn foals during the first 2 wks of life. Three groups of subjects were enrolled: 15 healthy foals born by spontaneous parturition, 24 healthy foals born by induced parturition and 26 pathologic foals. From each of the healthy foals, blood was collected at 10, 20 and 30 minutes, 3 and 12 hours from birth, daily from Day 1 to Day 7, and at Day 10 and 14 of life. In pathologic foals samples were collected twice a day from the day of admission at the hospital until the day of discharge or death. Thyroid hormones (T3 and T4) and IGF-I were analyzed by radioimmunoassay and NEFA by enzymatic-colorimetric methods. In all the three groups a declining trend of T3 and T4 plasma concentrations was detectable, with lower levels in the pathologic group compared to healthy foals. Spontaneous foals showed higher levels of T3 at 7 d compared to induced foals, while T4 levels were higher in spontaneous vs. induced foals before 6 h of life, at three and seven days. IGF-I showed increasing plasma concentrations in all three considered groups. No differences were found between healthy and pathologic foals. NEFA in spontaneous and induced healthy foals showed a declining trend with higher levels during the first hours of life. Pathologic foals presented higher levels compared to spontaneous foals only at 24 h and 10 d. These data suggest that the type of foaling could influence the reference ranges for thyroid hormones. Moreover, pathologic foals showed some hormonal and metabolic differences related to their health status. Above all changes of thyroid hormones levels, early in postnatal life, could be a cause, and not only a consequence, of the diseased condition of these foals.

Potential underlying mechanisms for greater weight gain in massaged preterm infants

In this paper, potential underlying mechanisms for massage therapy effects on preterm infant weight gain are reviewed. Path analyses are presented suggesting that: (1) increased vagal activity was associated with (2) increased gastric motility, which, in turn, was related to (3) greater weight gain; and (4) increased IGF-1 was related to greater weight gain. The change in vagal activity during the massage explained 49% of the variance in the change in gastric activity. And, the change in vagal activity during the massage explained 62% of the variance in the change in insulin. That the change in gastric activity was not related to the change in insulin suggests two parallel pathways via which massage therapy leads to increased weight gain: (1) insulin release via the celiac branch of the vagus; and (2) increased gastric activity via the gastric branch of the vagus.

A clinical prediction model to stratify retinopathy of prematurity risk using postnatal weight gain

OBJECTIVE

To develop an efficient clinical prediction model that includes postnatal weight gain to identify infants at risk of developing severe retinopathy of prematurity (ROP). Under current birth weight (BW) and gestational age (GA) screening criteria, <5% of infants examined in countries with advanced neonatal care require treatment.

PATIENTS AND METHODS

This study was a secondary analysis of prospective data from the Premature Infants in Need of Transfusion Study, which enrolled 451 infants with a BW < 1000 g at 10 centers. There were 367 infants who remained after excluding deaths (82) and missing weights (2). Multivariate logistic regression was used to predict severe ROP (stage 3 or treatment).

RESULTS

Median BW was 800 g (445-995). There were 67 (18.3%) infants who had severe ROP. The model included GA, BW, and daily weight gain rate. Run weekly, an alarm that indicated need for eye examinations occurred when the predicted probability of severe ROP was >0.085. This identified 66 of 67 severe ROP infants (sensitivity of 99% [95% confidence interval: 94%-100%]), and all 33 infants requiring treatment. Median alarm-to-outcome time was 10.8 weeks (range: 1.9-17.6). There were 110 (30%) infants who had no alarm. Nomograms were developed to determine risk of severe ROP by BW, GA, and postnatal weight gain.

CONCLUSION

In a high-risk cohort, a BW-GA-weight-gain model could have reduced the need for examinations by 30%, while still identifying all infants requiring laser surgery. Additional studies are required to determine whether including larger-BW, lower-risk infants would reduce examinations further and to validate the prediction model and nomograms before clinical use.

Insulin-like growth factor-1 (IGF-1) serum concentration among 7-year-old extremely low birth weight children--an indicator of growth problems

BACKGROUND

The study aim was to compare somatic development, body composition, insulin growth factor-1 (IGF-1) serum concentration and serum lipid profile between small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) 7-year-old extremely low birth weight (ELBW) children and full-term (FT) controls.

MATERIALS AND METHODS

Fifty-seven AGA ELBW children [mean birth weight (BW) 850 g and mean gestational age (GA) 26.4 weeks] and 24 SGA ELBW children (mean BW 833 g, mean GA 29.5 weeks) were evaluated. The control group included 37 age- and sex-matched FT children from one outpatient center.

RESULTS

Nine AGA and four SGA were found to have short stature defined as height < 3rd percentile for chronological age (p = 0.9). In the AGA cohort, the results of weight, head circumference, triceps skin fold and body mass index (BMI) measurements were significantly reduced in the short-stature subgroup. IGF-1 serum concentrations differed significantly between short-stature and normal-stature subgroups (121 vs. 193 ng/mL; p = 0.02). In the SGA cohort, weight and serum concentrations of total cholesterol (5.03 vs. 4.26 mmol/L; p = 0.04), LDL cholesterol (3.24 vs. 2.38 mmol/L; p = 0.01) and IGF-1 (113 vs. 211 ng/mL; p = 0.01) differed significantly between the short-stature and normal-stature subgroups.

CONCLUSIONS

Short stature at the age of 7 years was diagnosed in a similar percentage of AGA and SGA former ELBW infants. In both cohorts short-stature children have significantly lower weight and serum IGF-1 levels. IGF-1 seems to be involved in prolonged growth restriction among ELBW infants, regardless of whether they were AGA or SGA.

Increased rat neonatal activity influences adult cytokine levels and relative muscle mass

Little is known about the effect of physical activity in early life on subsequent growth and regulation of inflammation. We previously reported that exposure of muscles in growing rats to IL-6 results in decreased muscle growth apparently because of a state of resistance to growth factors such IGF-I and that running exercise could ameliorate this growth defect. Herein, we hypothesized that increased activity, for a brief period during neonatal life, would pattern the adult rat toward a less inflammatory phenotype. Neonatal rats were induced to move about their cage for brief periods from d 5 to d 15 postpartum. Additional groups were undisturbed controls (CONs) and handled (HAND). Subgroups of rats were sampled at the age of 30 and 65 d. Relative to CON and HAND groups, the neonatal exercise (EX) group demonstrated a decrease in circulating levels of TNFα, IL-6, and IL-1β in adulthood, primarily in male rats. In addition, adult male EX rats had lower body mass and increased skeletal muscle mass suggesting a leaner phenotype. The results of this study suggest that moderate increases in activity early in life can influence the adult toward a more healthy phenotype with regard to inflammatory mediators and relative muscle mass.

Systemic immune responses in pregnancy and periodontitis: relationship to pregnancy outcomes in the Obstetrics and Periodontal Therapy (OPT) study

BACKGROUND

Our previous studies reported on the obstetric, periodontal, and microbiologic outcomes of women participating in the Obstetrics and Periodontal Therapy (OPT) Study. This article describes the systemic antibody responses to selected periodontal bacteria in the same patients.

METHODS

Serum samples, obtained from pregnant women at baseline (13 to 16 weeks; 6 days of gestation) and 29 to 32 weeks, were analyzed by enzyme-linked immunosorbent assay for serum immunoglobulin G (IgG) antibody to Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia (previously T. forsythensis), and Treponema denticola.

RESULTS

At baseline, women who delivered live preterm infants had significantly lower total serum levels of IgG antibody to the panel of periodontal pathogens (P = 0.0018), to P. gingivalis (P = 0.0013), and to F. nucleatum (P = 0.0200) than women who delivered at term. These differences were not significant at 29 to 32 weeks. Changes in IgG levels between baseline and 29 to 32 weeks were not associated with preterm birth when adjusted for treatment group, clinical center, race, or age. In addition, delivery of low birth weight infants was not associated with levels of antibody at baseline or with antibody changes during pregnancy.

CONCLUSIONS

Live preterm birth is associated with decreased levels of IgG antibody to periodontal pathogens in women with periodontitis when assessed during the second trimester. Changes in IgG antibody during pregnancy are not associated with birth outcomes.

Growth factors, inflammatory cytokines and postnatal bone strength in preterm infants

AIM

To assess the relationships between growth factors, inflammatory cytokines and postnatal bone development in preterm infants.

METHODS

Fifty premature infants (24-32 weeks gestational age, mean birth weight: 1,024 +/- 50 g) participated in the study. Bone strength was determined weekly by quantitative ultrasound measurements of bone speed of sound (SOS). Blood serum measurements of growth factors included circulating IGF-I and GH binding protein. Measurements of circulating cytokines included the pro-inflammatory mediator interleukin (IL)-6, and the anti-inflammatory mediator IL-1 receptor antagonist. Samples were collected when the preterm infants were stabilized and prior to discharge.

RESULTS

Despite a significant increase in body weight (from 1,024 +/- 50 to 2,420 +/- 59 g, p < 0.001) and body length (from 35.4 +/- 0.6 to 44.6 +/- 0.4 cm, p < 0.001) there was a significant decrease in bone SOS during the follow-up period. There was a significant increase in growth factors and a decrease in inflammatory cytokines during the follow-up. Participants were divided into preterm infants who increased bone SOS (bone gainers, n = 16, from 2,867 +/- 38 to 2,910 +/- 41 m/sec), or decreased bone SOS (bone losers, n = 34, from 2,967 +/- 33 to 2,818 +/- 28 m/sec) during follow-up. Baseline bone SOS was significantly lower in the bone gainers. Baseline circulating growth factors were higher and inflammatory cytokines lower in the bone gainers; however, only the difference in IL-6 reached statistical significance (6.4 +/- 1.6 versus 10.5 +/- 1.2 pg/ml, in bone gainers and losers, respectively; p < 0.05).

CONCLUSIONS

Preterm infants with lower bone SOS at birth tend to 'catch-up' during early postnatal weeks. Increases in bone strength in preterm infants were associated with reduced inflammatory state as suggested by lower levels of circulating IL-6.

Insulin and insulin-like growth factor-1 increased in preterm neonates following massage therapy

OBJECTIVE

To determine if massage therapy increased serum insulin and insulin-like growth factor-1 (IGF-1) in preterm neonates.

STUDY DESIGN

Forty-two preterm neonates who averaged 34.6 weeks (M = 29.5 wk gestational age; M birth weight = 1237 g) and were in the "grower" (step-down) nursery were randomly assigned to a massage therapy group (body stroking and passive limb movements for three, 15-minute periods per day for 5 days) or a control group that received the standard nursery care without massage therapy. On Days 1 and 5, the serum collected by clinical heelsticks was also assayed for insulin and IGF-1, and weight gain and kilocalories consumed were recorded daily.

RESULTS

Despite similar formula intake, the massaged preterm neonates showed greater increases during the 5-day period in (1) weight gain; (2) serum levels of insulin; and (3) IGF-1. Increased weight gain was significantly correlated with insulin and IGF-1.

DISCUSSION

Previous data suggested that preterm infant weight gain following massage therapy related to increased vagal activity, which suggests decreased stress and gastric motility, which may contribute to more efficient food absorption. The data from this study suggest for the first time that weight gain was also related to increased serum insulin and IGF-1 levels following massage therapy.

CONCLUSION

Preterm infants who received massage therapy not only showed greater weight gain but also a greater increase in serum insulin and IGF-1 levels, suggesting that massage therapy might be prescribed for all growing neonates.