Lipid profile and carotid intima-media thickness in a prospective cohort of very preterm subjects at age 19 years: effects of early growth and current body composition

Beyond survival: the lasting effects of premature birth

Preterm birth, defined as birth before 37 weeks of gestation, is a major public health concern. It affects about 10% of all newborns globally and is the main cause of infant death and morbidity. Prematurity increases the likelihood of respiratory distress syndrome, cerebral palsy, and developmental abnormalities. Furthermore, premature newborns are at risk of acquiring chronic noncommunicable diseases later in life due to interference with organ system development during the in-utero and perinatal period. Because of the greater risk of long-term repercussions, preterm birth should be considered a chronic disorder, and gestational age and other birth histories should be included in all medical records for patients of all ages, especially when assessing the risk of multiple chronic diseases. Conventional methods for assessing preterm infant development, as well as reliable and precise growth monitoring, can lead to the early detection of growth decline and the adjustment of feeding regimens as needed. Because of its unique composition and useful components, human milk is a powerful tool for mitigating the negative outcomes associated with prematurity. It contains a variety of growth factors that promote the development of organs and systems, counteracting the negative effects of the abrupt interruption of intrauterine development and promoting better outcomes in all altered functions. Despite its multiple benefits, human milk cannot totally restore the lasting damage caused by premature birth. Premature infants cannot be completely overcome by nutrition alone, and yet adequate nutritional intake and human milk feeding are critical to their health and development.

Associations of Fetal and Infant Growth Patterns With Early Markers of Arterial Health in School-Aged Children

IMPORTANCE

Fetal life and infancy might be critical periods for predisposing individuals to develop cardiovascular disease in adulthood.

OBJECTIVE

To examine the associations of fetal and infant weight growth patterns with early markers of arterial health.

DESIGN, SETTING, AND PARTICIPANTS

This population-based prospective cohort study was conducted from early fetal life onward among 4484 offspring of women in Rotterdam, the Netherlands, delivering between April 1, 2002, and January 31, 2006. Statistical analysis was performed between January 1 and August 31, 2021.

EXPOSURES

Estimated fetal weight was measured in the second and third trimester. Data on weight and gestational age at birth were collected from midwives. Infant weight was measured at 6, 12, and 24 months.

MAIN OUTCOMES AND MEASURES

The common carotid intima-media thickness (cIMT) and carotid distensibility were measured as early markers of arterial health.

RESULTS

Follow-up measurements were available for 4484 children (2260 girls [50.4%]; median age, 9.7 years [95% range, 9.3-10.5 years]; and 2578 [57.5%] of Dutch ethnicity). Gestational age at birth was not associated with markers of arterial health. A 500-g-higher birth weight was associated with increased cIMT (standard deviation score [SDS], 0.08 mm [95% CI, 0.05-0.10 mm]) and a lower carotid distensibility (SDS, -0.05 × 10-3 kPa-1; [95% CI, -0.08 to -0.03 × 10-3 kPa-1]). Compared with children with a birth weight of 2500 to 4500 g, those weighing more than 4500 g had the lowest carotid distensibility (difference in SDS, -0.22 × 10-3 kPa-1 [95% CI, -0.42 to -0.02 × 10-3 kPa-1]). Conditional regression analyses showed that higher third-trimester fetal weight and birth weight were associated with increased cIMT (difference in SDS: third-trimester fetal weight, 0.08 mm [95% CI, 0.04-0.12 mm]; birth weight, 0.05 mm [95% CI, 0.01-0.09 mm]) and that higher weight at 6, 12, and 24 months was associated with increased cIMT (difference in SDS: 6 months, 0.05 mm [95% CI, 0.01-0.10 mm]; 12 months, 0.06 mm [95% CI, 0.02-0.10 mm]; and 24 months, 0.07 mm [95% CI, 0.03-0.11 mm]) and lower carotid distensibility (difference in SDS: 6 months, -0.04 × 10-3 kPa-1 [95% CI, -0.09 to -0.001 × 10-3 kPa-1]; 12 months, -0.05 × 10-3 kPa-1 [95% CI, -0.09 to -0.01 × 10-3 kPa-1]; and 24 months, -0.10 × 10-3 kPa-1 [95% CI, -0.15 to -0.06 × 10-3 kPa-1]). Compared with children with normal fetal and infant growth, children with normal fetal growth that was followed by accelerated infant growth had the highest cIMT (SDS, 0.19 mm [95% CI, 0.07-0.31 mm]) and lowest carotid distensibility (SDS, -0.16 × 10-3 kPa-1 [95% CI, -0.28 to -0.03 × 10-3 kPa-1]). The observed associations were largely explained by childhood body mass index.

CONCLUSIONS AND RELEVANCE

In this cohort study of 4484 children aged approximately 10 years, higher fetal and infant weight growth patterns were associated with early markers of impaired arterial health. Childhood body mass index seemed to be involved in the underlying pathways of the observed associations.

Early Contributors to Healthy Arterial Aging Versus Premature Atherosclerosis in Young Adults: The Bogalusa Heart Study

Background

Early identification of healthy arterial aging versus premature atherosclerosis is important for optimal atherosclerotic cardiovascular disease risk stratification and prevention. We sought to identify predictors for the long‐term absence of carotid plaque among young adults.

Methods and Results

We included 508 participants from the Bogalusa Heart Study without clinical atherosclerotic cardiovascular disease who were free of carotid plaque at baseline (2001–2002) and underwent ultrasound imaging at follow‐up (2013–2016). Modified Poisson regression estimated the persistent absence of plaque over 12.8 years. Participants were on average age 36.2 years at baseline, 64% were women, and 29% were Black. Although nearly all participants (97%) had a 10‐year atherosclerotic cardiovascular disease risk <7.5%, there were 162 people (32%) who developed premature atherosclerosis. Aside from younger age (risk ratio [RR], 1.21; 95% CI, 1.07–1.36, per 10 years) and a total cholesterol/high‐density lipoprotein cholesterol ratio <3.5 (RR, 1.15; 95% CI, 1.01–1.30), normal values of traditional risk factors did not predict long‐term absence of plaque. Independent from traditional markers including glomerular filtration rate, serum calcium‐phosphate product (RR, 1.07; 95% CI, 1.01–1.14, per 1‐SD lower), phosphate (RR, 1.15; 95% CI, 1.03–1.29, per 1 mg/dL lower), and dietary sodium <2300 mg/day (RR, 1.20; 95% CI, 1.02–1.41) were significantly associated with the non‐development of plaque.

Conclusions

Nearly one third of young adults with a low burden of traditional risk factors developed premature atherosclerosis. Beyond younger age and an ideal lipoprotein profile, lower calcium‐phosphate homeostasis and low sodium intake were associated with long‐term absence of carotid plaque. These results suggest that dietary and intrinsic minerals are early contributors to the development of arterial aging phenotypes.

Adulthood blood levels of hsa-miR-29b-3p associate with preterm birth and adult metabolic and cognitive health

Preterm birth (PTB) is associated with increased risk of type 2 diabetes and neurocognitive impairment later in life. We analyzed for the first time the associations of PTB with blood miRNA levels in adulthood. We also investigated the relationship of PTB associated miRNAs and adulthood phenotypes previously linked with premature birth. Blood MicroRNA profiling, genome-wide gene expression analysis, computer-based cognitive testing battery (CANTAB) and serum NMR metabolomics were performed for Young Finns Study subjects (aged 34-49 years, full-term n = 682, preterm n = 84). Preterm birth (vs. full-term) was associated with adulthood levels of hsa-miR-29b-3p in a fully adjusted regression model (p = 1.90 × 10^-4, FDR = 0.046). The levels of hsa-miR-29b-3p were down-regulated in subjects with PTB with appropriate birthweight for gestational age (p = 0.002, fold change [FC] = - 1.20) and specifically in PTB subjects with small birthweight for gestational age (p = 0.095, FC = - 1.39) in comparison to individuals born full term. Hsa-miR-29b-3p levels correlated with the expressions of its target-mRNAs BCL11A and CS and the gene set analysis results indicated a target-mRNA driven association between hsa-miR-29b-3p levels and Alzheimer's disease, Parkinson's disease, Insulin signaling and Regulation of Actin Cytoskeleton pathway expression. The level of hsa-miR-29b-3p was directly associated with visual processing and sustained attention in CANTAB test and inversely associated with serum levels of VLDL subclass component and triglyceride levels. In conlcusion, adult blood levels of hsa-miR-29b-3p were lower in subjects born preterm. Hsa-miR-29b-3p associated with cognitive function and may be linked with adulthood morbidities in subjects born preterm, possibly through regulation of gene sets related to neurodegenerative diseases and insulin signaling as well as VLDL and triglyceride metabolism.

Carotid Intima-Media Thickness but Not Carotid Artery Plaque in Healthy Individuals Is Linked to Lean Body Mass

Background Lean body mass has been identified as a key determinant of left ventricular mass and wall thickness. However, the importance of lean body mass or other body-size measures as normative determinants of carotid intima-media thickness (cIMT), a widely used early indicator of atherosclerosis, has not been well established. Methods and Results Carotid artery ultrasound measurements of cIMT and carotid artery plaque burden (derived from plaque number and maximum size) and measurements of body size, including height, body mass index, weight, body fat proportion, and lean body mass ([1-body fat proportion]×weight), were recorded in 25 020 participants from 10 regions of China. Analyses were restricted to a healthy younger subset (n=6617) defined as never or long-term ex-regular smokers aged <60 years (mean age, 50) without previous ischemic heart disease, stroke, diabetes mellitus, or hypertension and with plasma non-high-density lipoprotein cholesterol <4 mmol/L. Among these 6617 participants, 86% were women (because most men smoked) and 9% had carotid artery plaque. In both women and men separately, lean body mass was strongly positively associated with cIMT, but was not associated with plaque burden: overall, each 10 kg higher lean body mass was associated with a 0.03 (95% CI, 0.03-0.04) mm higher cIMT (P=5×10-33). Fat mass, height, and other body-size measures were more weakly associated with cIMT. Conclusions The strong association of lean body mass with cIMT, but not with plaque burden, in healthy adults suggests a normative relationship rather than reflecting atherosclerotic pathology. Common mechanisms may underlie the associations of lean body mass with cIMT and with nonatherosclerotic vascular traits.

Mechanisms linking preterm birth to onset of cardiovascular disease later in adulthood

Cardiovascular disease (CVD) rates in adulthood are high in premature infants; unfortunately, the underlying mechanisms are not well defined. In this review, we discuss potential pathways that could lead to CVD in premature babies. Studies show intense oxidant stress and inflammation at tissue levels in these neonates. Alterations in lipid profile, foetal epigenomics, and gut microbiota in these infants may also underlie the development of CVD. Recently, probiotic bacteria, such as the mucin-degrading bacterium Akkermansia muciniphila have been shown to reduce inflammation and prevent heart disease in animal models. All this information might enable scientists and clinicians to target pathways to act early to curtail the adverse effects of prematurity on the cardiovascular system. This could lead to primary and secondary prevention of CVD and improve survival among preterm neonates later in adult life.

The Impact of Being Born Preterm or Small for Gestational Age on Early Vascular Aging in Adolescents

OBJECTIVE

To assess the impact of being born preterm or small for gestational age (SGA) on early vascular aging (EVA) in a cohort of healthy Tyrolean adolescents.

STUDY DESIGN

This study is part of an ongoing clinical trial, EVA Tyrol, a regional cohort study being conducted in western Austria. EVA was assessed in adolescents (mean age, 16 years) by means of carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (cIMT), and blood pressure measurements. Adolescents were grouped as either term or preterm. Subsequently, being born SGA was taken into consideration in subgroup analysis. Complete data on gestational age and birth weight were available for 930 adolescents.

RESULTS

Systolic blood pressure and diastolic blood pressure were significantly higher in the preterm (mean gestational age, 34.8 ± 2.3 weeks) and appropriate for gestational age (AGA) group than in the term and AGA group (P < .05). This finding remained significant in linear regression analysis after adjustment for covariables in all models. PWV was significantly higher in the term-SGA group than in the term-AGA group (6.67 ± 1.73 m/s vs 6.07 ± 1.09 m/s; P < .05). In the linear regression analysis, this finding remained significant in all models. There were no differences in cIMT between study groups.

CONCLUSION

Being born preterm or SGA might render persons susceptible to EVA. Long-term follow-up of preterm and SGA individuals is warranted to confirm these results.

Developmental origins of health and disease: current knowledge and potential mechanisms

Epidemiologic and clinical research has provided a large body of evidence supporting the developmental origins of health and disease (DOHaD), but there has been a relative dearth of mechanistic studies in humans due to the complexity of working with large, longitudinal cohorts. Nonetheless, animal models of undernutrition have provided substantial evidence for the potential epigenetic, metabolic, and endocrine mechanisms behind DOHaD. Furthermore, recent research has explored the interaction between the environment and the gastrointestinal system by investigating how the gut microbial ecology may impact the capacity for nutrient processing and absorption in a manner that may limit growth. This review presents a summary of current research that supports the concept of DOHaD, as well as potential mechanisms and interactions that explain how nutrition in utero and during early childhood influences lifelong health.

Preterm arteries in childhood: dimensions, intima-media thickness, and elasticity of the aorta, coronaries, and carotids in 6-y-old children born extremely preterm

BACKGROUND

Preterm birth increases risk for adult cardiovascular disease. We hypothesized that arteries in 6-y-old children born preterm are narrower, with thicker intima-media and stiffer than in peers born at term.

METHODS

Children born extremely preterm (EXP, n = 176, birthweights: 348-1,161 g) and at term (CTRL, n = 174, birthweights: 2,430-4,315 g) were included. Using ultrasonography, we determined diameters of the coronaries (CA), common carotid arteries (CCA) and aorta, the carotid intima media thickness (cIMT), and the stiffness index of the CCA and aorta.

RESULTS

Arteries were 5-10% narrower in EXP than in CTRL (P < 0.005) but after adjustment for body surface area, diameter differences diminished or disappeared. EXP-children born small for gestational age exhibited similar arterial dimensions as those born appropriate for date. The cIMT was 0.38 (SD = 0.04) mm and did not differ between groups. Carotid but not aortic stiffness was lower in EXP than in CTRL.

CONCLUSION

In 6-y-old children born extremely preterm, conduit arteries are of similar or smaller size than in controls born at term, and they have no signs of accelerated intima media thickening or arterial stiffening. While these findings are reassuring for these children and their families, the causal pathways from preterm birth to adult cardiovascular disease remain unknown.

Risk for Nonalcoholic Fatty Liver Disease in Young Adults Born Preterm

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. Accelerated catch-up in weight during infancy in subjects born at full term has been associated with increased risk for NAFLD in adulthood, but this association has not been studied in subjects born preterm.

METHODS

In 162 young adults born at a gestational age <36 weeks, we assessed the associations between fatty liver index (FLI, 0-100) and birth weight standard deviation score and first-year weight gain. We performed comparisons between subjects with and without accelerated catch-up in weight in the first year after term age. An FLI score was assigned to each participant to determine the clinical relevance, and regression analyses were performed.

RESULTS

Accelerated weight gain in the first 3 months after term age was associated with FLI as a continuous variable, whereas gestational age and low birth weight were not. Of the subjects with accelerated catch-up in weight-for-length after term age, 7.3% had a high FLI at the age of 21 years, whereas none of the subjects without accelerated catch-up in weight had a high FLI.

CONCLUSION

Our study shows that accelerated weight gain after term age is associated with an increased risk of developing NAFLD in young adults born preterm.

Preterm at birth is not associated with greater cardiovascular risk in adolescence

OBJECTIVE

To determine the effects of preterm birth and gender on subsequent cardiovascular risk factors among urban adolescents in a capital in the Brazilian northeast and to compare them with a group of adolescents term at birth.

METHODS

In a retrospective double cohort, data of birth weight were extracted from hospital registers of children born in a same day of birth, between 1992 and 2002. We classified the preterm as a unique group born before 37 weeks of gestation. A total of 134 adolescents, aged 10-20 years were found and investigated. We measured anthropometric and clinical data, blood lipid profile and glucose after overnight fasting.

RESULTS

Preterm subjects had less years of scholar education, especially between females (p = 0.01). Preterm females also had lower height (p = 0.00) and waist-hip circumference ratio (p = 0.01). Preterm males had lower cesarean delivery (p = 0.05) and greater family history of cardiovascular disease (p = 0.05). Although the differences on clinical or laboratorial measurements were small and non-significant for cardiovascular risk factors, systolic blood pressure (SBP) and diastolic blood pressure (DBP) tended to be higher in preterm groups, especially for females (SBP = 4.1 mmHg and DBP = 1.6 mmHg, p = 0.12 and p = 0.38, respectively).

CONCLUSION

Premature did not increase cardiovascular risk adolescents in this sample. The lower association between premature and poor health outcomes among adolescents in a low average socioeconomic status population from a capital in the Brazilian northeast corroborates previous findings in other countries.

Postnatal growth in preterm infants and later health outcomes: a systematic review

In preterm infants, poor postnatal growth is associated with adverse neurocognitive outcomes; conversely, rapid postnatal growth is supposedly harmful for future development of metabolic diseases.

CONCLUSION

In this systematic review, observational studies reported consistent positive associations between postnatal weight or head growth and neurocognitive outcomes; however, there was limited evidence from the few intervention studies. Evidence linking postnatal weight gain to later adiposity and other cardiovascular disease risk factors in preterm infants was also limited.

Prematurity and programming of cardiovascular disease risk: a future challenge for public health?

There is substantial epidemiological evidence linking low birth weight with adult cardiometabolic disease risk factors. This has led to the concept of 'early life programming' or the 'developmental origins of disease' which proposes that exposure to adverse conditions during critical stages of early development results in compensatory mechanisms predicted to aid survival. There is growing evidence that preterm infants, many of whom are of low birth weight, are also at increased risk of adult cardiometabolic disease. In this article, we provide a broad overview of the evidence linking preterm birth and cardiovascular disease risk and discuss potential consequences for public health.

In adolescence, extreme prematurity is associated with significant changes in the microvasculature, elevated blood pressure and increased carotid intima-media thickness

OBJECTIVES

Increased carotid intima-media thickness (cIMT) and loss of capillary density are antecedents of cardiovascular disease in adults. Former preterm infants are at risk for metabolic precursors of vascular disease, but vascular changes have not yet been studied in this population.

PATIENTS AND METHODS

In 54 former preterm (birth weigh (BW) 753±152 g) and 12 term children (BW 3395±558 g), functional vessel density (FVD) on the forearm and cIMT were obtained at a mean (±SD) age of 11.8±1.5 years. FVD was measured using sidestream dark field imaging before, during and after arterial occlusion, and cIMT using high resolution B-mode ultrasonography. Statistical comparisons were made using the t test, Mann-Whitney U test and the sign test for symmetry, with a two-sided p value as appropriate.

RESULTS

The systolic blood pressure of the former preterm children was significantly increased compared to reference values (females 119±8, z score 1.23; males 118±11, z score 1.14 mm Hg), as were the cIMT values (0.45±0.03 mm vs 0.38±0.04 mm; p<0.001). FVD was significantly higher in former preterm children compared to controls at baseline (mean±SD 33.6±14.5 cm/cm(2) vs 23.0±7.1 cm/cm(2); p=0.002) with decreased reactivity during arterial occlusion (χ(2) 7.14, p=0.008).

CONCLUSIONS

Preterm birth is associated with significant permanent alteration in the microcirculation and increased cIMT and systolic blood pressure. It is unknown whether these changes are due to preterm birth and rapid maturation of the skin or to nutritional factors, as previously thought. This is an important area of future research.

Cardiovascular risk factors in adolescents born preterm

BACKGROUND

Adolescents and adults born as small preterm infants show more pronounced risk factors of cardiovascular disease. Whether similar risks apply across all degrees of preterm birth is poorly known.

METHODS

We studied the association between preterm birth and cardiovascular risk factors in 6642 16-year-old adolescents of the population-based Northern Finland Birth Cohort 1986. Of these, 79 (1.2%) were born at <34 gestational weeks (early preterm), 238 (3.6%) at 34 to 36 weeks (late preterm), and 6325 at term (controls).

RESULTS

Girls born early preterm had 6.7 mm Hg (95% confidence interval: 3.1-10.2) higher systolic blood pressure (BP) and 3.5 mm Hg (1.1-5.8) higher diastolic BP, but no difference in serum lipid levels compared with control girls. Boys showed no differences in BP, but boys born early preterm had 6.7% (0.2%-13.7%) higher total cholesterol, 11.7% (2.1%-22.3%) higher low-density lipoprotein cholesterol, and 12.3% (3.1%-22.4%) higher apolipoprotein B concentrations. The differences were similar (BP) or stronger (lipids) when adjusted for maternal smoking, birth weight SD score, parental education, pubertal stage, BMI, and lifestyle. There were similar associations with length of gestation as a continuous variable. Accordingly, mean differences between late preterm and controls were in the same direction but weaker, although most were not statistically significant.

CONCLUSIONS

Preterm birth was associated with elevated BP in adolescent girls and an atherogenic lipid profile in boys. Because these associations were strongest among those born early preterm, our findings are consistent with a dose-response relationship between shorter length of gestation and cardiovascular risk factors.

Aortic intima-media thickness measured by trans-abdominal ultrasound as an early life marker of subclinical atherosclerosis

Atherosclerosis is a chronic inflammatory process that begins in early life. Improved identification of markers of early atherosclerosis via neonatal aortic intima-media thickness (aIMT) measurement may allow the development of interventions to prevent or reduce later cardiovascular disease.

CONCLUSION

Using aIMT, studies have shown that antenatal factors such as intra-uterine growth retardation, prematurity, maternal factors and inflammation are associated with early cardiovascular changes.

Birth weight and longitudinal growth in infants born below 32 weeks' gestation: a UK population study

OBJECTIVE

To describe birth weight and postnatal weight gain in a contemporaneous population of babies born <32 weeks' gestation, using routinely captured electronic clinical data.

DESIGN

Anonymised longitudinal weight data from 2006 to 2011.

SETTING

National Health Service neonatal units in England.

METHODS

Birth weight centiles were constructed using the LMS method, and longitudinal weight gain was summarised as mean growth curves for each week of gestation until discharge, using SITAR (Superimposition by Translation and Rotation) growth curve analysis.

RESULTS

Data on 103 194 weights of 5009 babies born from 22-31 weeks' gestation were received from 40 neonatal units. At birth, girls weighed 6.6% (SE 0.4%) less than boys (p<0.0001). For babies born at 31 weeks' gestation, weight fell after birth by an average of 258 g, with the nadir on the 8th postnatal day. The rate of weight gain then increased to a maximum of 28.4 g/d or 16.0 g/kg/d after 3 weeks. Conversely for babies of 22 to 28 weeks' gestation, there was on average no weight loss after birth. At all gestations, babies tended to cross weight centiles downwards for at least 2 weeks.

CONCLUSIONS

In very preterm infants, mean weight crosses centiles downwards by at least two centile channel widths. Postnatal weight loss is generally absent in those born before 29 weeks, but marked in those born later. Assigning an infant's target centile at birth is potentially harmful as it requires rapid weight gain and should only be done once weight gain has stabilised. The use of electronic data reflects contemporary medical management.

Adult lipids associated with early life growth in traditional Melanesian societies undergoing rapid modernization: a longitudinal study of the mid-20th century

Both poor fetal development and accelerated post-natal growth have been linked to adult dyslipidemias in many studies conducted in developed societies. It is not known, however, whether these relationships only characterize populations with typical Western diets or if they also may develop in groups at the early stages of a dietary transition. Our longitudinal study of traditional rural populations in the Southwest Pacific during a period of extremely rapid modernization in diet and life-styles shows a nascent association between child growth retardation, subsequent growth acceleration, and adult lipid values in spite of a continuing prevalence of very low lipid levels. However, our results do not entirely conform to results from populations with "modern" diets. Outcome (i.e., young adult) cholesterol and triglyceride levels are more consistently related to initial measures of body fat and growth in body fat measures than with stature, while outcome apo A-1 is more consistently related to initial stature or stature growth than to measures of body fat. We suggest this may reflect a pattern characteristic of the initial stages of "modernization" associated with dietary change, with stronger and more pervasive relationships emerging only later as populations complete the dietary transition.

Relative intima-media thickening after preterm birth

AIM

Preterm infants are at increased risk of early arterial growth arrest and cardiovascular mortality. We assessed intima-media thickness (IMT) - an early marker of accelerated vascular ageing - in very preterm infants.

METHODS

Longitudinal cohort study of 21 very preterm and 29 term infants, all with appropriate birthweights. Intima-media thickness was assessed by M-Mode ultrasound of the aorta and carotid arteries at three occasions during a 6-month period corresponding to the third trimester of pregnancy and ending 3 months after term equivalent age.

RESULTS

No differences in absolute aortic or carotid IMT were found. However, in relation to vessel lumen diameter, the IMT switched from being narrower in preterm infants, compared with foetuses at 28 weeks of gestation, to being significantly thicker in both the aorta and carotid artery in older infants born preterm, compared with term controls of equivalent postmenstrual age. Although the aortic and carotid artery diameters increased significantly with postnatal age, IMT did not.

CONCLUSION

In relation to vessel diameter, subjects born preterm show thicker intima-media in the great arteries than infants born at term. It remains to be established whether this relative intima-media thickening persists and may be a risk marker for future cardiovascular disease.

Lipoprotein subclass profiles in young adults born preterm at very low birth weight

BACKGROUND

Adults born preterm at very low birth weight (VLBW ≤ 1500g) have increased risk factors for cardiovascular diseases including high blood pressure and impaired glucose regulation. Non-optimal lipoprotein profile is generally also likely to affect the increased cardiovascular risk, but lipoprotein subclass level data on adults born at VLBW are sparse.

SUBJECTS AND METHODS

We studied 162 subjects born at VLBW and 169 term-born controls, aged 19 to 27 years. Total lipid, triglyceride and cholesterol concentrations of 14 lipoprotein subclasses were determined by proton nuclear magnetic resonance spectroscopy in the fasting state and in 2-hour serum samples from an oral glucose tolerance test.

FINDINGS

In comparison to controls, VLBW subjects had significantly higher fasting concentration of triglycerides in chylomicrons and largest very-low-density lipoprotein particles [XXL-VLDL-TG, difference 0.026 (95% CI: 0.004 to 0.049), P=0.024], and of triglycerides in small high-density lipoprotein particles [S-HDL-TG, 0.026 (95% CI: 0.002 to 0.051), P=0.037]. The seemingly important role of triglycerides was further supported by principal component analysis in which the first component was characterized by multiple lipoprotein triglyceride measures.

CONCLUSIONS

Young adults born at VLBW and their peers born at term had triglyceride-related differences in both VLDL and HDL subclasses. These differences suggest that the increased risk factors for cardiovascular diseases among the VLBW individuals in adulthood may partly relate to impaired triglyceride metabolism.

Feeding preterm infants today for later metabolic and cardiovascular outcomes

Preterm birth continues to contribute disproportionately to neonatal morbidity and subsequent physical and neurodevelopmental disabilities. Epidemiologic studies have described additional long-term health consequences of preterm birth such as an increased risk of hypertension and insulin resistance in adult life. It is not known whether the influence of infant and childhood growth rates and early nutrition on long-term outcomes is the same or different among preterm infants and neonates with intrauterine growth restriction. Our goal is to review the effects of fetal growth, postnatal growth, and early nutrition on long-term cardiovascular and metabolic outcomes in preterm infants. Present evidence suggests that even brief periods of relative undernutrition during a sensitive period of development have significant adverse effects on later development. Our review suggests that growth between birth and expected term and 12-18 months post-term has no significant effect on later blood pressure and metabolic syndrome, whereas reduced growth during hospitalization significantly impacts later neurodevelopment. In contrast, growth during late infancy and childhood appears to be a major determinant of later metabolic and cardiovascular well being, which suggests that nutritional interventions during this period are worthy of more study. Our review also highlights the paucity of well-designed, controlled studies in preterm infants of the effects of nutrition during hospitalization and after discharge on development, the risk of developing hypertension, or insulin resistance.

Does preterm birth influence cardiovascular risk in early adulthood?

OBJECTIVE

To investigate the effect of preterm birth on risk factors for cardiovascular disease (CVD), independent of birth size.

STUDY DESIGN

Observational study using data of 406 healthy participants aged 18-24 years, from the PROgramming factors for Growth And Metabolism and Prematurity and Small for Gestational Age studies. Associations between gestational age (GA), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), blood pressure variability, heart rate (HR), pulse wave velocity, and carotid intima media thickness (cIMT) were studied. To study the differential effects of preterm birth and small birth size for gestational age, these parameters were also analyzed in subgroups born either preterm or term: young adults born small for gestational age with short or normal adult stature, and young adults born appropriate for gestational age with normal adult stature.

RESULTS

Subjects born preterm (GA <36 weeks) had higher unadjusted SBP, PP, SBP and DBP variability, and HR, but a lower DBP than subjects born term. GA was inversely associated with SBP, PP, blood pressure variability, and HR, and positively associated with DBP, also after adjustment for confounders. There was no effect of GA on pulse wave velocity and cIMT, a marker of atherosclerosis. Of all the CVD risk factors measured, higher PP affected cIMT the most.

CONCLUSIONS

Young adults born preterm might have a higher risk for CVD than those born term.

Bone maturation in extremely low birth weight infants in relation to birth weight and endocrine parameters

Modern intensive care techniques have led to higher survival rates of extremely low birth weight infants (ELBW, birth weight <1,000 g). Previous studies have suggested a link between abnormal birth parameters and subsequent endocrine disturbances, but a possible impact on bone maturation during childhood has not been studied. ELBW children were studied (mean chronological age (CA), 6.01 years; range, 4.5-8.2). Skeletal maturation was assessed according to Greulich and Pyle (8). Bone age (BA) was defined as retarded when DeltaBA-CA was < -1 SD and accelerated when DeltaBA-CA was >+1 SD. BA was either retarded or accelerated in 15 patients (24.6%). Twenty-one of 61 radiograms (34.4%) showed a discordant BA with a marked gender difference (14/24 boys; 7/37 girls). DeltaBA-CA correlated significantly with BMI (r = 0.36; p = 0.005) and height SDS (r = 0.35; p = 0.006). We found significant correlations between BA and androgens. Insulin-like growth factor binding protein-1 (IGFBP-1), which decreases in insulin-resistant individuals, correlated negatively with BA. In conclusion, bone maturation in ELBW children is correlative with height and weight. It is modulated by a variety of metabolic factors, including IGFBP-1 and androgens. Bone age, together with height and weight catch-up, can thus possibly serve as early indicators of insulin resistance later in life.

Does gender-specific BMI development modulate insulin sensitivity in extremely low birth weight infants?

BACKGROUND

Increasing numbers of extremely low birth weight infants (ELBW, birth weight < 1,000 g) survive. We studied the impact of birth weight, gender, and catch-up growth on metabolic parameters in ELBW infants.

CHILDREN

Sixty-three ELBW children were investigated at a mean age of 5.8 years. Forty-eight showed catch-up growth.

RESULTS

ELBW children who were small for gestational age were significantly shorter than those whose size was appropriate for their gestational age (height SDS: -1.1 [SD 0.8] vs -0.4 [0.9]; p < 0.001). This corresponded with significantly lower standard deviation scores for IGF-I (-1.1 [1.3] vs 0.1 [0.8]; p < 0.05) and IGFBP-3 (-0.7 [1.7] vs 0.4 [1.1]; p < 0.05). No differences were found regarding fasting insulin, glucose, HOMA and IGFBP-1. The catch-up group showed lower IGFBP-1 concentrations than the non-catch-up group. IGFBP-1 decreased in individuals who became more insulin resistant. No differences were found regarding mean IGF-1 and IGFBP-3 SDS. A gender-related pattern was found for weight development: girls demonstrated a normalization of BMI from the age of 2 years whereas boys remained at a mean BMI of -1.96 SDS. Corresponding to this, girls showed lower IGFBP-1 levels than boys.

CONCLUSION

Metabolic parameters in ELBW children are modulated by subsequent catch-up growth and sex-dependent weight development, resulting in measurable differences even in early childhood.

Low birth weight and the developing vascular tree: a systematic review

Low birth weight (LBW) is a risk factor for hypertension, stroke and coronary heart disease in adults. Mechanisms underlying cardiovascular disease may therefore be initiated in early life. Studies to investigate the initiating events and emergence of vascular risk markers in infancy and childhood have been an area of particular interest in recent years. The aim of this review is to focus on the early development of the human vascular tree in relation to LBW. Specific characteristics, including endothelial function, intima-media thickness, microvascular density, arterial dimensions and elasticity, will be discussed. LBW due to different causes--poor foetal growth or preterm birth--results in different patterns of altered development of the vascular system, which can already be seen in infancy. Follow-up studies in children and young adults indicate that vascular compromise in many ways persists in those born either small for gestational age or prematurely.

CONCLUSION

LBW is associated with structural and functional changes in the vascular tree, which have implications for cardiovascular health in adult life.

Gestational age and risk factors for cardiovascular disease: evidence from the 1958 British birth cohort followed to mid-life

BACKGROUND

Increases in pre-term births and improved survival rates have led to interest in the association between gestational age and health in adulthood. Associations between gestational age and risk factors for cardiovascular disease have not been fully investigated.

METHODS

Using data from the 1958 British birth cohort (7847 singletons), the associations between gestational age and blood pressure, glycosylated haemoglobin (HbA1c), lipid levels and body mass index (BMI) at age 44-45 years were examined.

RESULTS

After adjustment for sex, birthweight standardized for gestational age and sex and current BMI there was a reduction in systolic blood pressure of 0.53 mmHg (95% CI: 0.32, 0.75) for every 1 week increase in gestational age. There was a non-linear association between gestational age and diastolic blood pressure, with those cohort members born at earlier gestational ages found to have higher diastolic blood pressure than those born at term. These associations remained after adjustments. A 'U'-shaped association was found between gestational age and BMI among women (P = 0.02 for sex x gestational age interaction) which attenuated after adjustment. There was also a weak inverse association between gestational age and total cholesterol specific to women (P = 0.01 for sex x gestational age interaction). No clear associations were found between gestational age and BMI or total cholesterol in men, or between gestational age and HbA1c or other lipid levels in either sex.

CONCLUSIONS

In the 1958 British birth cohort duration of gestation was associated with blood pressure in mid-life. Understanding this association is necessary to inform policy and preventative interventions.

An overview of mortality and sequelae of preterm birth from infancy to adulthood

Survival rates have greatly improved in recent years for infants of borderline viability; however, these infants remain at risk of developing a wide array of complications, not only in the neonatal unit, but also in the long term. Morbidity is inversely related to gestational age; however, there is no gestational age, including term, that is wholly exempt. Neurodevelopmental disabilities and recurrent health problems take a toll in early childhood. Subsequently hidden disabilities such as school difficulties and behavioural problems become apparent and persist into adolescence. Reassuringly, however, most children born very preterm adjust remarkably well during their transition into adulthood. Because mortality rates have fallen, the focus for perinatal interventions is to develop strategies to reduce long-term morbidity, especially the prevention of brain injury and abnormal brain development. In addition, follow-up to middle age and beyond is warranted to identify the risks, especially for cardiovascular and metabolic disorders that are likely to be experienced by preterm survivors.

Intima-media thickness of the abdominal aorta of neonate with different gestational ages

PURPOSE

To determine aortic intima-media thickness (aIMT) values in newborns with different gestational ages and to asses the effect of antenatal steroids on aIMT.

METHODS

Two hundred forty newborns from healthy mothers had their distal abdominal aIMT measured during abdominal sonographic examination. The neonates were divided into 4 groups (60 in each group) according to gestational age: group I (25-28 weeks), group II (29-32 weeks), group III (33-37 weeks), and group IV (38-42 weeks).

RESULTS

The interobserver and intersubject intraclass correlation coefficient was 0.93 and 0.94, respectively. Mean aIMT was 0.316 mm, 0.335 mm, 0.348 mm, and 0.385 mm, respectively, in group I, II, III, and IV, increasing significantly with gestational age at birth (p < 0.0001). There was no apparent effect of antenatal steroid use on aIMT. Multivariate regression models for mean aIMT demonstrated a significant association with aortic lumen diameter (p < 0.0001).

CONCLUSION

Abdominal aIMT can be reproducibly measured in neonates and may be a useful tool for epidemiologic studies.

Functional outcomes and participation in young adulthood for very preterm and very low birth weight infants: the Dutch Project on Preterm and Small for Gestational Age Infants at 19 years of age

OBJECTIVE

Young adults who were born very preterm or with a very low birth weight remain at risk for physical and neurodevelopmental problems and lower academic achievement scores. Data, however, are scarce, hospital based, mostly done in small populations, and need additional confirmation.

METHODS

Infants who were born at < 32 weeks of gestation and/or with a birth weight of < 1500 g in The Netherlands in 1983 (Project on Preterm and Small for Gestational Age Infants) were reexamined at age 19. Outcomes were adjusted for nonrespondents using multiple imputation and categorized into none, mild, moderate, or severe problems.

RESULTS

Of 959 surviving young adults, 74% were assessed and/or completed the questionnaires. Moderate or severe problems were present in 4.3% for cognition, 1.8% for hearing, 1.9% for vision, and 8.1% for neuromotor functioning. Using the Health Utility Index and the London Handicap Scale, we found 2.0% and 4.5%, respectively, of the young adults to have > or = 3 affected areas in activities and participation. Special education or lesser level was completed by 24%, and 7.6% neither had a paid job nor followed any education. Overall, 31.7% had > or = 1 moderate or severe problems in the assessed areas.

CONCLUSIONS

A total of 12.6% of young adults who were born very preterm and/or with a very low birth weight had moderate or severe problems in cognitive or neurosensory functioning. Compared with the general Dutch population, twice as many young adults who were born very preterm and/or with a very low birth weight were poorly educated, and 3 times as many were neither employed nor in school at age 19.

Comparison of current health, functional limitations, and health care use of young adults who were born with extremely low birth weight and normal birth weight

OBJECTIVE

The objective of this study was to compare the current health status, physical ability, functional limitations, and health care use of extremely low birth weight and normal birth weight young adults.

METHODS

A longitudinal study was conducted of a population-based cohort of 166 extremely low birth weight survivors (501-1000 g birth weight; 1977-1982 births) and a group of 145 sociodemographically comparable normal birth weight individuals. Current health status, history of illnesses, hospitalizations, use of health resources, and physical self-efficacy were assessed through questionnaires that were administered to the young adults by masked interviewers.

RESULTS

Individuals completed the assessments at a mean age of 23 years. Neurosensory impairments were identified in 27% of extremely low birth weight and 2% of normal birth weight individuals. No differences were reported in the current health status for physical or mental summary scores. Extremely low birth weight young adults reported a higher prevalence of chronic health conditions in the past 6 months. A significantly higher proportion of extremely low birth weight individuals had functional limitations in seeing, hearing, and dexterity and experienced clumsiness and learning difficulties. Except for prescription glasses, medications for depression, and home-care services for extremely low birth weight individuals, there were no significant differences between groups in use of health care resources. Extremely low birth weight individuals had significantly weaker hand grip strength and lower scores for physical self-efficacy, perceived physical ability, and physical self-confidence.

CONCLUSIONS

Extremely low birth weight young adults seem to enjoy similar current health status to their normal birth weight peers. However, they continue to have significantly poorer physical abilities and a higher prevalence of chronic health conditions and functional limitations. Contrary to expectations, they do not pose a significant burden to the health care system at young adulthood.

Growth trajectories of extremely low birth weight infants from birth to young adulthood: a longitudinal, population-based study

We compared sex-specific growth attainment of a population-based cohort of 147/166 (89%) extremely low birthweight (ELBW < 1000 g) and 131/145 (90%) sociodemographically comparable normal birthweight (NBW) cohort at young adulthood, and examined the pattern of growth trajectories and correlates of growth at ages 1, 2, 3, and 8 y, and teen and young adulthood (mean age, 23.3 versus 23.6 y). The proportion considered small for gestational age was ELBW 25% versus NBW 3%; and 26% versus 2% had neurosensory impairments. Weight for age z-scores for ELBW showed substantial decline to age 3 y, with subsequent significant catch-up to adolescence and smaller gains to adulthood. Height for age z-scores showed both sexes of ELBW were disadvantaged at every age compared with NBW and their expected mid-parental height. The BMI z-scores for ELBW showed a sustained incline from age 3 to adulthood, where both sexes normalized to above zero, and were comparable to their peers. ELBW children showed growth failure during infancy, followed by accelerated weight gain and crossing of BMI percentiles at adolescence, a pattern that may increase the risk of insulin resistance and coronary heart disease. However, normalization of BMI for both sexes at adulthood suggests that final growth was proportionate.