Evidence of Arteriolar Narrowing in Low-Birth-Weight Children

Reconsidering the developmental origins of adult disease paradigm: The 'metabolic coordination of childbirth' hypothesis

In uncomplicated pregnancies, birthweight is inversely associated with adult non-communicable disease (NCD) risk. One proposed mechanism is maternal malnutrition during pregnancy. Another explanation is that shared genes link birthweight with NCDs. Both hypotheses are supported, but evolutionary perspectives address only the environmental pathway. We propose that genetic and environmental associations of birthweight with NCD risk reflect coordinated regulatory systems between mother and foetus, that evolved to reduce risks of obstructed labour. First, the foetus must tailor its growth to maternal metabolic signals, as it cannot predict the size of the birth canal from its own genome. Second, we predict that maternal alleles that promote placental nutrient supply have been selected to constrain foetal growth and gestation length when fetally expressed. Conversely, maternal alleles that increase birth canal size have been selected to promote foetal growth and gestation when fetally expressed. Evidence supports these hypotheses. These regulatory mechanisms may have undergone powerful selection as hominin neonates evolved larger size and encephalisation, since every mother is at risk of gestating a baby excessively for her pelvis. Our perspective can explain the inverse association of birthweight with NCD risk across most of the birthweight range: any constraint of birthweight, through plastic or genetic mechanisms, may reduce the capacity for homeostasis and increase NCD susceptibility. However, maternal obesity and diabetes can overwhelm this coordination system, challenging vaginal delivery while increasing offspring NCD risk. We argue that selection on viable vaginal delivery played an over-arching role in shaping the association of birthweight with NCD risk.

Computer-assisted evaluation of retinal vessel tortuosity in moderate-to-late preterm children

PURPOSE

Since very preterm children often have increased retinal tortuosity that may indicate decisive architectural changes in the systemic microvascular network, we used a new semi-automatic software to measure retinal vessel tortuosity on fundus digital images of moderate-to-late preterm (MLP) children.

METHODS

In this observational case-control study, the global and local tortuosity parameters of retinal vessels were evaluated on fundus photographs of 36 MLP children and 36 age- and sex-matched controls. The associations between birth parameters and parameters reflecting retinal vessel tortuosity were evaluated using correlation analysis.

RESULTS

Even after incorporation of anatomical factors, the global and local tortuosity parameters were not significantly different between groups. The MLP group showed a smaller arteriolar caliber (0.53  ±  0.2) than the controls (0.56  ±  0.2; p  =  0.013). Other local tortuosity parameters, such as vessel length, distance to fovea, and distance to optic disc, were not significantly different between arteries and veins. Tortuosity in both groups was higher among vessels closer to the fovea (r  =  -0.077, p < 0.001) and the optic disc (r  =  -0.0544, p  =  0.009). Global tortuosity showed a weakly positive correlation with gestational age and a weakly negative correlation with birth weight in both groups.

CONCLUSION

MLP patients did not display increased vessel tortuosity in comparison with the controls; however, the arteriolar caliber in the MLP group was smaller than that in children born full-term. Larger studies should confirm this finding and explore associations between cardiovascular and metabolic status and retinal vessel geometry in MLP children.

Association of maternal birth weight and maternal preterm birth with subsequent risk for adverse reproductive outcomes: The Women's Health Initiative

BACKGROUND

Advancements in medical technology and pharmacologic interventions have drastically improved survival of infants born preterm and low birth weight, but knowledge regarding the long-term health impacts of these individuals is limited and inconsistent.

AIM

To investigate whether an individual's birthweight or history of being born preterm increases the risk of an adverse reproductive outcome.

STUDY DESIGN

Nested case-control study within the Women's Health Initiative.

SUBJECTS

79,934 individuals who self-reported their personal birthweight category and/or preterm birth status.

OUTCOMES MEASURES

Self-reported pregnancy outcomes: subfertility, miscarriage, stillbirth, preeclampsia, gestational diabetes, gestational hypertension, preterm birth, low birthweight infant, high birthweight infant. Logistic regression models were used to estimate unadjusted and adjusted odds ratios (OR).

RESULTS

After adjustments, individuals reporting their birthweight <6lbs. were 20 % more likely to have a stillbirth or 70 % more likely to have a low birthweight infant and were less likely to have a full-term birth or high birthweight infant during their pregnancy. Individuals reporting a birthweight ≥10 lbs. were more likely to have a high birthweight infant (OR 3.49, 95 % CI 2.73-4.39) and less likely to have a low birthweight infant (OR 0.64, 95 % CI 0.47-0.82). Individuals born preterm were at increased risk for infertility, miscarriage, preeclampsia, gestational diabetes, and delivering a preterm or low birthweight infant.

CONCLUSIONS

As more individuals born preterm and/or low birthweight survive to adulthood, the incidence and prevalence of poor reproductive outcomes may increase. Women born at extremes of birthweight and prematurity may need to be monitored more closely during their own pregnancies.

RATE OF AND TIME TO COMPLETE RETINAL VASCULARIZATION IN PREMATURE INFANTS AND ASSOCIATED FACTORS

PURPOSE

To evaluate the rate of and time to complete vascularization in premature infants and to explore associated factors.

METHODS

A monocentric, retrospective cohort study including 541 premature infants who underwent screening for retinopathy of prematurity (ROP) between July 2016 and June 2019. Patients underwent regular dilated fundus examinations with indirect ophthalmoscopy until complete vascularization. The worse eye of each patient was included for analyses. The proportion of infants with complete retinal vascularization at the last visit and the time to full vascularization was analyzed.

RESULTS

Among all infants (average gestational age 31.29 ± 3.12 weeks), 490 (90.57%) had complete records of retinal vascularization outcomes, of whom 439 (89.59%) achieved complete vascularization. The average postmenstrual age for complete vascularization was 45.39 ± 11.04 weeks, and 95.22% achieved completion before 64 weeks of postmenstrual age. Retinopathy of prematurity developed in 118 (22.56%) infants; 33 (6.10%) received antivascular endothelial growth factor treatment. For all infants screened for ROP, lower birth weight, presence of ROP, and antivascular endothelial growth factor therapy predicted delayed complete vascularization; for infants diagnosed with ROP, only lower birth weight predicted delayed complete vascularization. Subgroup analysis showed significant differences between patients without ROP, with untreated ROP, and with treated ROP in time to complete vascularization and its rate (99.7%, 66.2%, and 16.7%, respectively).

CONCLUSION

Lower birth weight predicted delayed complete vascularization. Antivascular endothelial growth factor therapy and the presence of ROP, including ROP severity, may also affect time to complete vascularization. These findings should help improve the understanding and management of persistent avascular retina in preterm infants.

Retinal vessel diameters and function in cardiovascular risk and disease

In the last two decades evidence has gradually accumulated suggesting that the eye may be a unique window for cardiovascular risk stratification based on the assessment of subclinical damage of retinal microvascular structure and function. This can be facilitated by non-invasive analysis of static retinal vessel diameters and dynamic recording of flicker light-induced and endothelial function-related dilation of both retinal arterioles and venules. Recent new findings have made retinal microvascular biomarkers strong candidates for clinical implementation as reliable risk predictors. Beyond a review of the current evidence and state of research, the article aims to discuss the methodological benefits and pitfalls and to identify research gaps and future directions. Above all, the potential use for screening and treatment monitoring of cardiovascular disease risk are highlighted. The article provides fundamental comprehension of retinal vessel imaging by explaining anatomical and physiological essentials of the retinal microcirculation leading to a detailed description of the methodological approach. This allows for better understanding of the underlying retinal microvascular pathology associated with the prevalence and development of cardiovascular disease. A body of new evidence is presented on the clinical validity and predictive value of retinal vessel diameters and function for incidence cardiovascular disease and outcome. Findings in children indicate the potential for utility in childhood cardiovascular disease prevention, and the efficacy of exercise interventions highlight the treatment sensitivity of retinal microvascular biomarkers. Finally, coming from the availability of normative data, solutions for diagnostic challenges are discussed and conceptual steps towards clinical implementation are put into perspective.

Neuronal Dysfunction Is Linked to the Famine-Associated Risk of Proliferative Retinopathy in Patients With Type 2 Diabetes

Persons with type 2 diabetes born in the regions of famine exposures have disproportionally elevated risk of vision-threatening proliferative diabetic retinopathy (PDR) in adulthood. However, the underlying mechanisms are not known. In the present study, we aimed to investigate the plausible molecular factors underlying progression to PDR. To study the association of genetic variants with PDR under the intrauterine famine exposure, we analyzed single nucleotide polymorphisms (SNPs) that were previously reported to be associated with type 2 diabetes, glucose, and pharmacogenetics. Analyses were performed in the population from northern Ukraine with a history of exposure to the Great Ukrainian Holodomor famine [the Diagnostic Optimization and Treatment of Diabetes and its Complications in the Chernihiv Region (DOLCE study), n = 3,583]. A validation of the top genetic findings was performed in the Hong Kong diabetes registry (HKDR, n = 730) with a history of famine as a consequence of the Japanese invasion during WWII. In DOLCE, the genetic risk for PDR was elevated for the variants in ADRA2A, PCSK9, and CYP2C19*2 loci, but reduced at PROX1 locus. The association of ADRA2A loci with the risk of advanced diabetic retinopathy in famine-exposed group was further replicated in HKDR. The exposure of embryonic retinal cells to starvation for glucose, mimicking the perinatal exposure to famine, resulted in sustained increased expression of Adra2a and Pcsk9, but decreased Prox1. The exposure to starvation exhibited a lasting inhibitory effects on neurite outgrowth, as determined by neurite length. In conclusion, a consistent genetic findings on the famine-linked risk of ADRA2A with PDR indicate that the nerves may likely to be responsible for communicating the effects of perinatal exposure to famine on the elevated risk of advanced stages of diabetic retinopathy in adults. These results suggest the possibility of utilizing neuroprotective drugs for the prevention and treatment of PDR.

Perinatal famine is associated with excess risk of proliferative retinopathy in patients with type 2 diabetes

PURPOSE

Intrauterine undernutrition is associated with increased risk of type 2 diabetes. Children born premature or small for gestational age were reported to have abnormal retinal vascularization. However, whether intrauterine famine act as a trigger for diabetes complications, including retinopathy, is unknown. The aim of the current study was to evaluate long-term effects of perinatal famine on the risk of proliferative diabetic retinopathy (PDR).

METHODS

We studied the risk for PDR among type 2 diabetes patients exposed to perinatal famine in two independent cohorts: the Ukrainian National Diabetes Registry (UNDR) and the Hong Kong Diabetes Registry (HKDR). We analysed individuals born during the Great Famine (the Holodomor, 1932-1933) and the WWII (1941-1945) famine in 101 095 (3601 had PDR) UNDR participants. Among 3021 (251 had PDR) HKDR participants, we studied type 2 diabetes patients exposed to perinatal famine during the WWII Japanese invasion in 1942-1945.

RESULTS

During the Holodomor and WWII, perinatal famine was associated with a 1.76-fold (p = 0.019) and 3.02-fold (p = 0.001) increased risk of severe PDR in the UNDR. The risk for PDR was 1.66-fold elevated among individuals born in 1942 in the HKDR (p < 0.05). The associations between perinatal famine and PDR remained statistically significant after corrections for HbA1c in available 18 507 UNDR (p_{additive interaction}  < 0.001) and in 3021 HKDR type 2 diabetes patients (p < 0.05).

CONCLUSION

In conclusion, type 2 diabetes patients, exposed to perinatal famine, have increased risk of PDR compared to those without perinatal famine exposure. Further studies are needed to understand the underlying mechanisms and to extend this finding to other diabetes complications.

A Deep Learning Architecture for Vascular Area Measurement in Fundus Images

Purpose

To develop a novel evaluation system for retinal vessel alterations caused by hypertension using a deep learning algorithm.

Design

Retrospective study.

Participants

Fundus photographs (n = 10 571) of health-check participants (n = 5598).

Methods

The participants were analyzed using a fully automatic architecture assisted by a deep learning system, and the total area of retinal arterioles and venules was assessed separately. The retinal vessels were extracted automatically from each photograph and categorized as arterioles or venules. Subsequently, the total arteriolar area (AA) and total venular area (VA) were measured. The correlations among AA, VA, age, systolic blood pressure (SBP), and diastolic blood pressure were analyzed. Six ophthalmologists manually evaluated the arteriovenous ratio (AVR) in fundus images (n = 102), and the correlation between the SBP and AVR was evaluated manually.

Main Outcome Measures

Total arteriolar area and VA.

Results

The deep learning algorithm demonstrated favorable properties of vessel segmentation and arteriovenous classification, comparable with pre-existing techniques. Using the algorithm, a significant positive correlation was found between AA and VA. Both AA and VA demonstrated negative correlations with age and blood pressure. Furthermore, the SBP showed a higher negative correlation with AA measured by the algorithm than with AVR.

Conclusions

The current data demonstrated that the retinal vascular area measured with the deep learning system could be a novel index of hypertension-related vascular changes.

Denser Retinal Microvascular Network Is Inversely Associated With Behavioral Outcomes and Sustained Attention in Children

Changes in geometry of the retinal microvascular network, including vessel width, vessel density, and tortuosity, have been associated with neurological disorders in adults. We investigated metrics of the retinal microvasculature in association with behavior and cognition in 8- to 12-year-old children. Digital fundus images of 190 children (48.2% girls, mean age 9.9 years) were used to calculate retinal vessel diameters, fractal dimension, lacunarity, and tortuosity. Parents filled out a Strengths and Difficulties Questionnaire (SDQ) for behavioral screening. Cognitive performance testing included a computerized version of the Stroop test (selective attention), the Continuous Performance (sustained attention), the Digit-Symbol (visual scanning and information-processing speed) and the Pattern Comparison (visuospatial analytic ability) tests from the Neurobehavioral Evaluation System (NES3) battery. Retinal vessel geometry was significantly associated with the SDQ problem score, which increased with 1.1 points (95% CI: 0.3 to 1.9 points) per interquartile (IQR) increment in retinal fractal dimension, and decreased 1.4 points (95% CI: −2.4 to −0.4 points) or decreased 1.0 points (95% CI: −2.1 to 0.1 points) per IQR increment in retinal vascular lacunarity or tortuosity, respectively. Sensitivity analyses showed that results were driven by the hyperactivity/inattention and conduct problem scales of the SDQ. Correspondingly, mean reaction time on the Continuous Performance test increased by 11 ms (95% CI: 4.4 to 17.6 ms) with an IQR increase in fractal dimension. The results indicate that a denser retinal microvascular network, exemplified by a higher fractal dimension and lower lacunarity, are inversely associated with behavioral outcomes and sustained attention in children.

The impact of maternal asthma during pregnancy on offspring retinal microvascular structure and its relationship to placental growth factor production in utero

Asthma is a common chronic disease in pregnancy that affects placental function and fetal growth and associated with cardio-metabolic disorders in the offspring but the mechanisms are unknown. This study explored whether maternal asthma in pregnancy is associated with the development of offspring microvascular structure and whether it was related to biomarkers of angiogenesis in utero. Children aged 4 to 6 years, born to either asthmatic mothers (n = 38) or healthy controls (n = 25), had their retinal microvascular structure examined. Maternal plasma PlGF concentrations at 18 and 36 weeks' gestation were measured. There was a significant global difference in all retinal microvascular measures between children of asthmatic mothers relative to controls and increased retinal venular tortuosity in children born to asthmatic mothers (7.1 (95% CI 0.7-13.5); P = .031). A rise in plasma PlGF from 18 to 36 weeks' gestation was observed in the control population which was significantly lower in the asthma group by 190.9 pg/mL. PlGF concentrations were correlated with microvascular structure including arteriolar branching and venular tortuosity. These exploratory findings indicate that exposure to maternal asthma during pregnancy is associated with persistent changes in microvascular structure in childhood that may be driven by alterations to angiogenic mechanisms in utero.

Low birth weight trends: possible impacts on the prevalences of hypertension and chronic kidney disease

Worldwide, hypertension and chronic kidney disease (CKD) are highly prevalent disorders and are strong risk factors for cardiovascular disease and end-stage renal disease (ESRD). The developmental origins of health and disease (DOHAD) concept suggests that undesirable perinatal environmental conditions, such as malnutrition, contribute to disease development in adults. Among the known hypertension and CKD risk factors, DOHAD plays a potential role in determining susceptibility to the onset of these diseases in later adulthood. Since low birth weight (LBW) is a surrogate marker for adverse fetal environmental conditions, the high incidence of LBW in developing countries and its increasing incidence in most developed countries (attributed to multiple pregnancies and prepregnancy maternal factors, such as undernutrition, advanced maternal age, and smoking) is concerning. Thus, LBW is an important public health problem not only because of the associated infant mortality and morbidity but also because it is a risk factor for adult-onset hypertension/CKD. During their reproductive years, pregnant women who were born with LBWs have an increased risk of hypertensive disorders of pregnancy, which contribute to the risk of developing cardiovascular disease and ESRD. The offspring of LBW females are also likely to be LBW, which suggests that susceptibility to hypertension/CKD may reflect transgenerational inheritance. Therefore, there is global concern about the increasing prevalence of LBW-related diseases. This review summarizes the relevance of hypertension and CKD in conjunction with DOHAD and discusses recent studies that have examined the impact of the upward LBW trend on renal function and blood pressure.

Response Gene to Complement 32 Maintains Blood Pressure Homeostasis by Regulating α-Adrenergic Receptor Expression

RATIONALE

Hypertension prevalence is much higher among children and adolescents with low birth weight and greater postnatal weight gain than in individuals with normal birth weight. However, the cause and molecular mechanisms underlying this complication remain largely unknown. Our previous studies have shown that RGC-32 (response gene to complement 32)-deficient (RGC-32^-/-) mice are born significantly smaller but grow faster than their WT (wild type) controls, which allows adult RGC-32^-/- mice to attain body weights similar to those of control mice.

OBJECTIVE

The objective of this study is to determine whether RGC-32^-/- mice develop hypertension, and if so, to elucidate the underlying mechanisms.

METHODS AND RESULTS

By using a radiotelemetry system, we found that RGC-32^-/- mice exhibit higher mean arterial pressure than WT mice (101±4 versus 119±5 mm Hg), which enabled us to use RGC-32^-/- mice to study the mechanisms underlying low birth weight-related hypertension. The increased blood pressure in RGC-32^-/- mice was associated with increased vascular tone and decreased distensibility of small resistance arteries. The increased vascular tone was because of an increase in the relative contribution of sympathetic versus parasympathetic activity and was linked to increased expression of AT1R (angiotensin II type I receptor) and α1-AdR (α1-adrenergic receptor) in arterial smooth muscles. Mechanistically, RGC-32 regulated AT1R gene transcription by interacting with Sp1 (specificity protein 1) transcription factor and further blocking its binding to the AT1R promoter, leading to suppression of AT1R expression. The attenuation of AT1R leads to reduction in α1-AdR expression, which was critical for the balance of sympathetic versus parasympathetic control of vascular tone. Of importance, downregulation of RGC-32 in arterial smooth muscles was also associated with low birth weight and hypertension in humans.

CONCLUSIONS

Our results indicate that RGC-32 is a novel protein factor vital for maintaining blood pressure homeostasis, especially in individuals with low birth weight.

Hemoglobin A1c and retinal arteriolar narrowing in children with type 1 diabetes: the diagnostics of early atherosclerosis risk in kids study

BACKGROUND/OBJECTIVE

Microvascular alterations play a key role in the development of diabetes complications. Retinal vessel analysis is a unique method to examine microvascular changes in brain-derived vessels.

METHODS

Sixty-seven pediatric and adolescent type 1 diabetes patients and 58 healthy control persons (mean age 12.4 ± 2.9 years) underwent non-mydriatic retinal photography of both eyes. Central retinal arteriolar and central retinal venular (CRVE) diameter equivalents as well as the arteriolar-to-venular ratio were calculated using a semiautomated software. All anthropometric and laboratory parameters were measured according to standardized procedures for children.

RESULTS

Retinal vessel diameter did not differ between type 1 diabetic children and healthy controls. However, there was an independent association of higher hemoglobin A1c (HbA1c) levels with arteriolar narrowing. Arteriolar narrowing of 5.4 μm was observed with each percent increase in HbA1c. Longer duration of diabetes was associated with wider retinal arterioles. CRVE was not associated with diabetes duration or HbA1c.

CONCLUSIONS

Microvascular arteriolar alterations are already present in childhood and may indicate subclinical atherosclerosis and increased risk of diabetes complications later in life. Future research will have to investigate the potential use of retinal vessel diameters for treatment monitoring and guidance of therapy in children.

Retinal microvasculature: population epidemiology and concordance in Australian children aged 11-12 years and their parents

OBJECTIVES

To describe distributions and concordance of retinal microvasculature measurements in a population-based sample of Australian parent-child dyads at child age 11-12 years.

DESIGN

Cross-sectional Child Health CheckPoint study, between waves 6 and 7 of the national population-based Longitudinal Study of Australian Children (LSAC).

SETTING

Assessment centres in seven Australian cities, February 2015-March 2016.

PARTICIPANTS

Of the 1874 participating families, 1288 children (51% girls) and 1264 parents (87% mothers, mean age 43.7) were analysed. Diabetic participants and non-biological pairs were excluded from concordance analyses.

OUTCOME MEASURES

Retinal photographs were taken by non-mydriatic fundus camera. Trained graders scored vascular calibre using semi-automated software, yielding estimates of central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) and arteriolar-venular ratio (AVR). Pearson's correlation coefficients and multivariable linear regression models assessed parent-child concordance. Survey weights and methods accounted for LSAC's complex sampling, stratification and clustering within postcodes.

RESULTS

Mean (SD) of CRAE and CRVE were larger in children (159.5 (11.8) and 231.1 (16.5) μm, respectively) than parents (151.5 (14.0) and 220.6 (19.0) μm), yielding similar AVR (children 0.69 (0.05), parents 0.69 (0.06)). Correlation coefficients for parent-child pairs were 0.22 (95% CI 0.16 to 0.27) for CRAE, 0.23 (95% CI 0.17 to 0.28) for CRVE and 0.18 (95% CI 0.13 to 0.24) for AVR. Mother-child and father-child values were similar (0.20 and 0.32 for CRAE, 0.22 and 0.29 for CRVE, respectively). Relationships attenuated slightly on adjustment for age, sex, blood pressure, diabetes and body mass index. Percentiles and concordance are presented for the whole sample and by sex.

CONCLUSIONS

Arteriolar and venular calibre were similar to previously documented measures in midlife adult and late childhood populations. Population parent-child concordance values align with moderate polygenic heritability reported in smaller studies.

Detection of FZD4, LRP5 and TSPAN12 Genes Variants in Malay Premature Babies with Retinopathy of Prematurity

Purpose:

To determine the mutational analyses of familial exudative vitreoretinopathy (FEVR)-causing genes in Malay patients with retinopathy of prematurity (ROP) to obtain preliminary data for gene alterations in the Malay community.

Methods:

A comparative cross-sectional study involving 86 Malay premature babies (ROP = 41 and non-ROP = 45) was performed from September 2012 to December 2014. Mutation analyses in (FEVR)-causing genes (NDP, FZD4, LRP5, and TSPAN12) were performed using DNA from premature babies using polymerase chain reaction (PCR) and direct sequencing. Sequencing results were confirmed with PCR-Restriction Fragment Length Polymorphism (RFLP).

Results:

We found variants of FZD4, LRP5, and TSPAN12 in this study. One patient from each group showed a non-synonymous alteration in FZD4, c.502C>T (p.P168S). A synonymous variant of LRP5 [c.3357G>A (p.V1119V)] was found in 30 ROP and 28 non-ROP patients. Two variants of TSPAN12, c.765G>T (p.P255P) and c.*39C>T (3′UTR), were also recorded (29 and 21 in ROP, 33 and 26 in non-ROP, respectively). Gestational age and birth weight were found to be significantly associated with ROP (P value < 0.001 and 0.001, respectively).

Conclusion:

Analysis of data obtained from the ROP Malay population will enhance our understanding of these FEVR-causing gene variants. The c.3357G>A (p.V1119V) variant of LRP5, and c.765G>T (p.P255P) and c.*39C>T variants of TSPAN12 could be common polymorphisms in the Malay ethnic group; however, this requires further elucidation. Future studies using larger groups and higher numbers of advanced cases are necessary to evaluate the relationship between FEVR-causing gene variants and the risk of ROP susceptibility in Malaysian infants.

Early Life Microcirculatory Plasticity and Blood Pressure Changes in Low Birth Weight Infants Born to Normotensive Mothers: A Cohort Study

BACKGROUND

Capillary rarefaction (CR) is an established hallmark of essential hypertension (EH). The aim of this study was to examine early changes in capillary density (CD) and blood pressure (BP) in low birth weight (LBW) infants who are at risk of developing EH in later life.

METHODS

We studied 77 LBW infants and 284 normal birth weight (NBW) infants, all born to mothers with normotension, in a longitudinal multicenter study. Intravital capillaroscopy was used to measure functional basal capillary density (BCD) and maximal capillary density (MCD) at birth, 3, 6, and 12 months.

RESULTS

We found that LBW infants, born preterm and at term, had a significantly higher CD at birth, then underwent significant CR in the 1st 3 months culminating in a CD similar to that seen in NBW infants. NBW infants showed a gradual reduction in CD between birth and 12 months. Non-Caucasian ethnicity and preterm birth were significant predictors of a higher CD at birth. Systolic BP in NBW infants increased significantly from birth to 3 months, and we identified a significant negative correlation between systolic BP and MCD.

CONCLUSIONS

This study has identified a process of early “accelerated capillary remodeling” in LBW infants, which corrects their higher CD at birth. This remodeling is unlikely to explain the CR seen in adult individuals with, or at risk of developing EH. Further follow-up studies are required to determine the timing and mechanisms involved in CR, which is likely to occur after the 1st year of life but before early adulthood.

Visual Function and Fundus Morphology in Relation to Growth and Cardiovascular Status in 10-Year-Old Moderate-to-Late Preterm Children

PURPOSE

To study visual function and ocular fundus morphology in relation to growth, metabolic status, and blood pressure in moderate-to-late preterm (MLP) children at 10 years of age.

DESIGN

Prospective cohort study.

METHODS

In this population-based observational study, nonsyndromic MLP children born in Gothenburg, Sweden, were examined neonatally in the years 2002-2003 concerning length, weight, head circumference, and insulin-like growth factor I (IGF-I). At 10 years of age, 33 children (10 girls) were examined regarding previously mentioned variables, and regarding visual acuity, refraction, fundus morphology, IGF binding protein 3, leptin, adiponectin, and blood pressure. An age- and sex-matched control group consisted of 28 children (9 girls).

RESULTS

Myopia was more commonly found in MLP children than in controls (P = .004, 95% CI 1.8 to 49.8). The MLP group had smaller optic disc area (P = .01, 95% CI -0.5 to -0.1), smaller rim area (P = .001, 95% CI -0.5 to -0.2), fewer branching points (P = .0001, 95% CI -5.7 to -2.1), and higher index of tortuosity of arteries (P = .03, 95% CI 0.002 to 0.03) and veins (P = .02, 95% CI 0.003 to 0.02). Refraction correlated with IGF-I (P = .0005, r_s = 0.60 in right eye, and P = .002, r_s = 0.55 in left eye) at 10 years of age. Tortuosity of arteries at assessment correlated with neonatal IGF-I levels (P = .03, r_s = -0.39). Tortuosity of veins correlated with a leptin/adiponectin ratio at assessment (P = .04, r_s = 0.37).

CONCLUSION

The findings suggest that being born MLP is associated with myopia, smaller optic disc and rim areas, and abnormal retinal vascularization. Furthermore, metabolic status and growth factors seem to have an impact on ocular development.

Update on retinal vascular caliber

Retinal vessels are the only blood vessels that can be viewed directly, in vivo, repetitively and non-invasively. Retinal vessel caliber is influenced by physiological (age, sex, race, blood pressure, blood glucose, body mass index) and pathological (atherosclerosis, dyslipidemia, smoking) determinants. There are studies on large population groups that demonstrate the associations between retinal vasculature and subclinical or clinical changes in systemic diseases (hypertension, diabetes, stroke, renal or cardiac diseases). The assessment of retinal vessels can provide information about the pathophysiology of many diseases, but it also has a direct applicability in clinic, being used as a screening method that predicts the risk of their occurrence.

Retinal vascular caliber associated with cardiac and renal target organ damage in never-treated hypertensive patients

OBJECTIVE

The aim of this study was to assess the relationship between retinal vascular caliber and target organ damage in HT patients.

METHODS

Data were collected on cardiac, renal, vascular, and retinal variables in 88 consecutive never-treated HT subjects. Retinal vascular calibers were measured from fundus photographs by using a semi-automated computer-assisted program and summarized as CRAE and CRVE.

RESULTS

Mean CRAE and CRVE were significantly lower in patients with left ventricular hypertrophy (left ventricular mass ≥110 g/m² for women, 125 g/m² for men) than in those with normal left ventricular (CRAE: 129.4±3.7 vs 138.2±2.3 μm; P=.04; CRVE: 195.6±4.4 vs 209.8±2.7 μm; P=.008). CRAE and CRVE were negatively correlated with urinary albumin excretion (β±SE=-15.4±3.2, P<.0001 and β±SE=-11.9±4.4, P=.001, respectively) but were not correlated with estimated glomerular filtration rate (P=.21 and P=.75, respectively), carotid-to-femoral pulse wave velocity (P=.24 and P=.14), or carotid augmentation index (P=.43 and P=.16).

CONCLUSION

In never-treated HT patients, reduced CRAE and CRVE were associated with cardiac and renal preclinical damage, ie, left ventricular hypertrophy and albuminuria, but not estimated glomerular filtration rate or vascular stiffness.

Recent versus chronic fine particulate air pollution exposure as determinant of the retinal microvasculature in school children

BACKGROUND

Microvascular changes may represent an underlying mechanism through which exposure to fine particulate matter with a diameter ≤ 2.5µm (PM_2.5) contributes to age-related disease development. We investigated the effect of recent and chronic exposure to PM_2.5 on the microcirculation, exemplified by retinal vessel diameters, using repeated measurements in 8- to 12-year-old children.

METHODS

221 children (49.1% girls; mean age 9.9 years) were examined repeatedly (25 one, 124 two, and 72 three times) adding up to 489 retinal vessel examinations. Same-day exposure to PM_2.5 was measured at school. In addition, recent (same and previous day) and chronic (yearly mean) exposure was modelled at the child's residence using a high-resolution interpolation model. Residential proximity to major roads was also assessed. Changes in retinal vessel diameters associated with recent and chronic exposures were estimated using mixed models, while adjusting for other known covariates such as sex, age, BMI, blood pressure and birth weight.

RESULTS

Each 10µg/m³ increment in same-day exposure to PM_2.5 measured at school was associated with 0.35µm (95% CI: 0.09-0.61µm) narrower retinal arterioles and 0.35µm (-0.03 to 0.73µm) wider venules. Children living 100m closer to a major road had 0.30µm (0.05-0.54µm) narrower arterioles.

CONCLUSIONS

Blood vessel diameters of the retinal microcirculation of healthy school-aged children respond to same-day PM_2.5 exposure. Furthermore, children living closer to major roads had smaller arteriolar diameters. Our results suggest that the microcirculation, with retinal microvasculature as a proxy in this study, is a pathophysiological target for air pollution in children.

Gestational age-related patterns of AMOT methylation are revealed in preterm infant endothelial progenitors

Objective

Preterm birth is associated with altered angiogenesis and with increased risk of cardiovascular dysfunction and hypertension at adulthood. We previously demonstrated that in preterm newborns circulating cord blood endothelial progenitor cells (ECFC), responsible for angio/vasculogenesis, are reduced in number and display altered angiogenic properties. Altered angiogenic function was associated with a decreased expression of pro-angiogenic genes, among which the AMOT gene which is a strong positive regulator of angiogenesis. Such dysregulation may be related to epigenetic factors. In this study we analyse the methylation profiling of the AMOT gene during development, through a comparative analysis of the cord blood ECFC of preterm newborns and their term counterpart.

Methods

We used both cloning-sequencing and pyrosequencing experiments to perform a comparative analysis of the DNA methylation profile of the promoter CpG island of AMOT gene in the cord blood ECFC of 16 preterm newborns (28–35 weeks gestational age-GA) and 15 term newborns (>37 weeks GA).

Results

Twenty nine clones (obtained from 2 term newborns) and forty clones (obtained from 3 preterm newborns) were sequenced. The AMOT gene methylation rate was significantly higher in preterm compared to term newborns (4.5% versus 2.5% respectively: χ2 = 3.84; P = 1.8 10⁻⁰²). Bisulfite pyrosequencing identified four CpG dinucleotides with significantly higher methylation levels in preterm newborns. This CpG-targeted methylation significantly decreased with increasing gestational age.

Conclusions

These findings highlight importance of pro-angiogenic AMOT gene methylation in ECFC, suggesting that epigenetic mechanisms may control the regulation of angiogenesis during development. Therefore they pave the way to specific short term and long term complications of preterm birth by altered angiogenesis.

Neonatal Arterial Morphology Is Related to Body Size in Abnormal Human Fetal Growth

BACKGROUND

Restriction in fetal growth is associated with cardiovascular disease in adulthood. It is unclear whether abnormal intrauterine growth influences arterial morphology during the fetal or neonatal stage. The objective was to study the regional arterial morphology with respect to gestational age and abnormal fetal body size.

METHODS AND RESULTS

We studied body anthropometrics and arterial morphology and physiology in 174 neonates born between 31 and 42 weeks of gestation, including neonates with birth weights appropriate, small, and large for age, with very high resolution vascular ultrasound (35-55 MHz). In simple linear regressions, parameters of body size (body weight, body surface area, and organ circumference) and gestational age were statistically significantly associated with common carotid, brachial, femoral arterial parameters (lumen diameter [LD], wall layer thickness [intima-media thickness and intima-media-adventitia thickness], and carotid artery wall stress [CAWS]). Male sex was statistically significantly associated with LD and CAWS. In multiple linear regression models, body size, gestational age, and sex explained a large proportion of the arterial variance (R( 2) range, 0.37-0.47 for LD; 0.09-0.35 for intima-media thickness; 0.21-0.41 for intima-media-adventitia thickness; and 0.23 for CAWS; all models P<0.001). Arterial wall layer thickness, LDs, and CAWS were independently and strongly predicted by body size, and no effect of maternal disease was observed when added to the models. Gestational age and male sex were also independently but more weakly associated with arterial LDs and CAWS (P<0.01), but not with arterial wall layers.

CONCLUSIONS

These results indicate that the intrauterine growth of fetal arterial LD and wall layer thickness are primarily attributed to body growth overall. LD and CAWS show weaker association with gestational age and sex.

Vascular risk factors are associated with retinal arteriolar narrowing and venular widening in children and adolescents with type 1 diabetes

BACKGROUND

The aim of the study was to describe the relationship of retinal arteriolar and venular calibre with vascular risk factors in children and adolescents with type 1 diabetes.

METHODS

In this hospital-based cross-sectional study, the medical files of 483 children and adolescents with type 1 diabetes were audited to collect retinal images and relevant clinical data. Retinal vascular calibre was measured using standardised protocols.

RESULTS

After multivariable adjustments, a vascular risk profile that included: older age, higher serum creatinine, higher systolic blood pressure (SBP), higher body mass index (BMI), abnormal estimated glomerular filtration rate (eGFR), lower high-density lipoproteins (HDL) cholesterol, longer duration of diabetes and higher serum sodium was associated with narrower central retinal artery equivalent (CRAE) (95% CI=-4.10/-0.76, p=0.004). A specific risk profile, including higher total cholesterol level, higher BMI, lower physical activity level, higher HbA1c, higher triglyceride levels, female gender and lower socio-economic status, was associated with wider central retinal vein equivalent (CRVE) (95% CI=1.14/5.62, p=0.003).

CONCLUSIONS

In summary, these findings support evidence that cardiovascular disease may have its origins early in life. Prospective and/or intervention studies are required to confirm whether the observed associations are involved in the causal pathway for retinal vascular calibre.

Influence of Maternal Gestational Hypertensive Disorders on Microvasculature in School-Age Children: The Generation R Study

Gestational hypertensive disorders may lead to vascular changes in the offspring. We examined the associations of maternal blood pressure development and hypertensive disorders during pregnancy with microvasculature adaptations in the offspring in childhood. This study was performed as part of the Generation R Study in Rotterdam, the Netherlands (2002-2012), among 3,748 pregnant mothers and their children for whom information was available on maternal blood pressure in different periods of pregnancy and gestational hypertensive disorders. Childhood retinal arteriolar and venular calibers were assessed at the age of 6 years. We found that higher maternal systolic and diastolic blood pressures in early pregnancy were associated with childhood retinal arteriolar narrowing (P < 0.05). Higher maternal systolic blood pressure in late pregnancy, but not in middle pregnancy, was associated with childhood narrower retinal venular caliber (standard deviation score per standardized residual increase in systolic blood pressure: -0.05; 95% confidence interval: -0.08, -0.01). Paternal blood pressure was not associated with childhood retinal vessel calibers. Children of mothers with gestational hypertensive disorders tended to have narrower retinal arteriolar caliber (standard deviation score: -0.13, 95% confidence interval: -0.27, 0.01). Our results suggest that higher maternal blood pressure during pregnancy is associated with persistent microvasculature adaptations in their children. Further studies are needed to replicate these observations.

Body composition and the monitoring of non-communicable chronic disease risk

There is a need for simple proxies of health status, in order to improve monitoring of chronic disease risk within and between populations, and to assess the efficacy of public health interventions as well as clinical management. This review discusses how, building on recent research findings, body composition outcomes may contribute to this effort. Traditionally, body mass index has been widely used as the primary index of nutritional status in children and adults, but it has several limitations. We propose that combining information on two generic traits, indexing both the ‘metabolic load’ that increases chronic non-communicable disease risk, and the homeostatic ‘metabolic capacity’ that protects against these diseases, offers a new opportunity to improve assessment of disease risk. Importantly, this approach may improve the ability to take into account ethnic variability in chronic disease risk. This approach could be applied using simple measurements readily carried out in the home or community, making it ideal for M-health and E-health monitoring strategies.

Association of body composition and blood pressure categories with retinal vessel diameters in primary school children

Alterations in retinal vessel diameters have been shown to be predictive of cardiovascular risk in adults and children. The aim of our study was to examine the association of body composition and blood pressure (BP) categories with retinal vessel diameters in school children. We examined anthropometric parameters, BP and retinal arteriolar (CRAE) and venular (CRVE) diameters as well as the arteriolar-to-venular diameter ratio (AVR) in 391 children (age: 7.3, s.d. 0.4). Differences between the lowest and highest BP quartiles indicated that higher systolic and diastolic BP were associated with narrower CRAE (P<0.001 for both). Children in the highest weight quartile had narrower CRAE compared with the lowest quartile (P=0.05). In the regression analysis, systolic and diastolic BP were associated with arteriolar narrowing (-0.4 measuring units (mu) per mm Hg, 95% confidence interval: [-0.6; -0.3] and -0.6 mu per mm Hg [-0.7; -0.4], respectively; P<0.001 for both). An independent association was found for diastolic BP only. Compared with normotensives (NT; 74.4% of cohort), arteriolar narrowing was already seen in children categorized as pre-hypertensive (PHT) (11.5% of cohort), which was similar to HT children (14.1% of cohort) (NT: mean 207.2 [205.6; 208.7] mu; PHT: 201.7 [197.8; 205.7] mu; HT: 199.7 [196.2; 203.3] mu; P=0.01 for PHT vs. NT and P<0.001 for HT vs. NT in systolic BP). Our results suggest that systolic and diastolic BP are main determinants of retinal arteriolar diameters; and therefore, microvascular health in young children. Pre-hypertension seems to be associated with retinal microvascular alterations early in life.

Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non-invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low-fibre and high-sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre-clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood.

Perinatal inflammation: a common factor in the early origins of cardiovascular disease?

Cardiovascular disease continues to be the leading cause of global morbidity and mortality. Traditional risk factors account for only part of the attributable risk. The origins of atherosclerosis are in early life, a potential albeit largely unrecognized window of opportunity for early detection and treatment of subclinical cardiovascular disease. There are robust epidemiological data indicating that poor intrauterine growth and/or prematurity, and perinatal factors such as maternal hypercholesterolaemia, smoking, diabetes and obesity, are associated with adverse cardiovascular intermediate phenotypes in childhood and adulthood. Many of these early-life risk factors result in a heightened inflammatory state. Inflammation is a central mechanism in the development of atherosclerosis and cardiovascular disease, but few studies have investigated the role of overt perinatal infection and inflammation (chorioamnionitis) as a potential contributor to cardiovascular risk. Limited evidence from human and experimental models suggests an association between chorioamnionitis and cardiac and vascular dysfunction. Early life inflammatory events may be an important mechanism in the early development of cardiovascular risk and may provide insights into the associations between perinatal factors and adult cardiovascular disease. This review aims to summarise current data on the early life origins of atherosclerosis and cardiovascular disease, with particular focus on perinatal inflammation.

Impact of maternal smoking during pregnancy on microvasculature in childhood. The Generation R Study

BACKGROUND

Fetal exposure to maternal smoking is associated with an adverse cardiovascular risk profile in later life. Early microvasculature adaptations might be part of the underlying mechanisms for these associations.

AIMS

The aim of this study was to examine the influence of maternal smoking during pregnancy on retinal vessel calibers in children.

STUDY DESIGN

We performed a population-based prospective cohort study among 3564 school-age children. Maternal smoking patterns during pregnancy were assessed by questionnaires.

OUTCOME MEASURES

At the median age of 6.0 years (95% range 5.8, 8.0 years), we measured childhood retinal vessel calibers from retinal photographs.

RESULTS

No differences were observed in childhood retinal arteriolar and venular calibers among offspring from mothers who smoked in the first trimester and mothers who continued smoking throughout pregnancy, as compared to mothers who did not smoke during pregnancy. Also, no dose-dependent associations of the number of cigarettes smoked during pregnancy with childhood retinal vessel calibers were present.

CONCLUSION

Maternal smoking during pregnancy did not influence childhood retinal arteriolar and venular calibers. The mechanisms linking fetal smoke exposure with cardiovascular risk factors in later life may include other mechanisms than structural microvasculature adaptations.

Retinal nerve fiber layer thickness in prematurity is correlated with stage of retinopathy of prematurity

PURPOSE

To compare retinal nerve fiber layer (RNFL) thickness profiles between preterm and full-term children and to investigate factors affecting the RNFL distribution in preterm children.

METHODS

We performed Spectral domain optical coherence tomography (SD-OCT) peripapillary RNFL circular scan centered on the optic disc in 50 premature and 58 full-term children. RNFL thickness profiles were compared between preterm and full-term children using a linear regression model. Among preterm patients in this study, 20 patients previously received laser treatment for severe retinopathy of prematurity (ROP).

RESULTS

Global average, nasal, and superior disc RNFL thickness profiles were significantly smaller in preterm children (92.70±16.57 μm, 56.02±17.04 μm, and 108.74±27.36 μm, respectively) compared with full-term children (101.63±9.21 μm, P=0.006, 69.14±14.15 μm, P<0.001, and superior, 129.11±18.14 μm, P<0.001, respectively). Multivariable analysis revealed that ROP stage was inversely correlated with nasal RNFL thickness (P=0.010).

CONCLUSIONS

Our SD-OCT data demonstrate decreased global average, nasal, and superior disc RNFL thicknesses in preterm children. ROP stage was inversely correlated with nasal RNFL thickness. Further studies are needed to better understand the association between these structural changes and visual functions in preterm children.

Design and feasibility of "PREMATurity as predictor of children's Cardiovascular-renal Health" (PREMATCH): A pilot study

The microvasculature and macrovasculature undergo extensive, organ-specific perinatal maturation. Multiple studies show associations between low birth weight and subsequent cardiovascular dysfunction in adulthood, suggesting that extreme preterm birth interferes with this maturation process. Therefore, we designed PREMATCH (PREMATurity as predictor of Cardiovascular–renal Health) to phenotype the microcirculation and macrocirculation during childhood in former preterm infants. A well-characterized cohort of former extreme preterm birth survivors and gender- and age-matched controls (aged 8–13 years) will be investigated for microvascular and macrovascular structure and function. In addition to cognitive performance and anthropometrics, we will investigate (i) the microvascular structure and function by endothelial function (photoplethysmography), sublingual capillary glycocalyx function (sidestream dark field imaging) and retinal structure (diameters of arterioles and venules); and (ii) the macrovascular phenotype by cardiac and renal ultrasound, repeated blood pressure measurements and arterial pulse-wave recordings. The PREMATCH study is unique in its design, and ongoing recruitment demonstrates excellent feasibility. The expectation is that the results of this study will identify risk factors during childhood for subsequent cardiovascular–renal disease in the adult life of former preterm infants, while further analysis on mediators in neonatal life of this cardiovascular–renal outcome may provide new information on perinatal risk factors.

Retinal microvasculature and cardiovascular health in childhood

BACKGROUND AND OBJECTIVE

Alterations in retinal microvasculature are associated with increased risk of cardiovascular disease. We examined the associations of retinal vessel caliber with cardiovascular markers in school-age children.

METHODS

Among 4007 school-age children (median age of 6.0 years), we measured cardiovascular markers and retinal vessel calibers from digitized retinal photographs.

RESULTS

Narrower retinal arteriolar caliber was associated with higher systolic and diastolic blood pressure (-0.20 SD score [SDS] [95% confidence interval (CI) -0.24 to -0.18] and -0.14 SDS [-0.17 to -0.11], respectively, per SDS increase in retinal arteriolar caliber), mean arterial pressure, and pulse pressure, but not with carotid-femoral pulse wave velocity, heart rate, cardiac output, or left ventricular mass. A wider retinal venular caliber was associated with lower systolic blood pressure, mean arterial pressure, and pulse pressure and higher carotid-femoral pulse wave velocity (carotid-femoral pulse wave velocity difference = 0.04 SDS [95% CI 0.01 to 0.07] per SDS increase in retinal venular caliber). Both narrower retinal arteriolar and venular calibers were associated with higher risk of hypertension at the age of 6 years, with the strongest association for retinal arteriolar caliber (odds ratio 1.35 [95% CI 1.21 to 1.45] per SDS decrease in arteriolar caliber). Adjustment for parental and infant sociodemographic factors did not influence the observed associations.

CONCLUSIONS

Both retinal arteriolar and venular calibers are associated with blood pressure in school-age children, whereas retinal venular caliber is associated with carotid-femoral pulse wave velocity. Microvascular adaptations in childhood might influence cardiovascular health and disease from childhood onward.

Association of parental blood pressure with retinal microcirculatory abnormalities indicative of endothelial dysfunction in children

OBJECTIVE

Microcirculatory abnormalities precede the onset of hypertension and may explain its familial nature. We examined the relationship between parental blood pressure (BP) and offspring retinal microvasculature in Pakistani trios [father, mother, and child (aged 9-14 years)].

METHODS

This is a substudy of a population-based trial of BP reduction. Data were available on 358 normotensive, and 410 offspring of at least one hypertensive parent. Retinal vessel characteristics were measured from digital images. Multivariable linear regression models were built to assess the associations between maternal and paternal BP and offspring retinal microvasculature.

RESULTS

Optimality deviation was greatest in offspring of two hypertensive parents, compared with those with one or no hypertensive parent (P=0.030 for trend). Paternal SBP and DBP were each significantly associated with optimality deviation in offspring (P=0.023 and P=0.006, respectively). This relationship persisted after accounting for offspring cardiovascular risk factors [increase in optimality deviation (95% confidence interval, CI) 0.0053 (0.0001-0.0106, P=0.047) and 0.0109 (0.0025-0.0193, P=0.011), for each 10 mmHg increase in paternal SBP and DBP, respectively]. Maternal DBP was inversely associated with offspring arteriovenous ratio -0.0102 (-0.0198 to -0.0007, P=0.035).

CONCLUSION

Microvascular endothelial dysfunction in children is associated with increasing levels of parental hypertension. The association with paternal BP is independent of other cardiovascular risk factors, including the child's BP. Higher maternal DBP is associated with evidence of arteriolar narrowing in offspring. These early microcirculatory changes may help explain familial predisposition to hypertension in people of Pakistani origin at an early age.

VIDEO ABSTRACT

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Skin capillary density in infants born to normotensive mothers: a comparison between singleton and twin infants

OBJECTIVE

Twin infants tend to have LBW and microvascular alterations but do not appear to have an increase in cardiovascular mortality later in life as singleton infants. We hypothesized that twin infants born to normotensive mothers would not have capillary rarefaction at birth.

METHODS

We studied 26 dizygotic twin infants and compared them with 115 consecutive singleton infants to normotensive mothers. We used orthogonal polarized spectroscopy to measure basal (i.e., functional) and maximal (i.e., structural) skin capillary density according to a well-standardized protocol.

RESULTS

Twin infants have significantly higher BCD (mean difference 4.3 capillaries/mm(2) , 95% CI: 0.4, 8.1, p = 0.03) and have marginally significantly higher MCD (mean difference 3.9 capillaries/mm(2) , 95% CI: -0.6, 8.3, p = 0.086) compared to singleton infants. Birth weight was significantly associated with BCD and MCD (p = 0.003 and 0.006).

CONCLUSIONS

Twin infants with low and NBWs tend to have higher functional and structural capillary densities compared to singleton infants. Further longitudinal studies of skin capillary density and of retinal vascular parameters commencing from birth to various stages in early childhood are essential to identify the dynamics and the exact timing, if any, of the remodeling of microcirculation in these individuals.

Aortic growth arrest after preterm birth: a lasting structural change of the vascular tree

Young people who are born very preterm exhibit a narrower arterial tree as compared with people born at term. We hypothesized that such arterial narrowing occurs as a direct result of premature birth. The aim of this study was to compare aortic and carotid artery growth in infants born preterm and at term. Observational and longitudinal cohort study of 50 infants (21 born very preterm, all appropriate for gestational age, 29 controls born at term) was conducted. Diameters of the upper abdominal aorta and common carotid artery were measured with ultrasonography at three months before term, at term and three months after term-equivalent age. At the first assessment, the aortic end-diastolic diameter (aEDD) was slightly larger in very preterm infants as compared with fetal dimensions. Fetal aortic EDD increased by 2.6 mm during the third trimester, whereas very preterm infants exhibited 0.9 mm increase in aEDD during the same developmental period (P < 0.001 for group difference). During the following 3-month period, aortic growth continued unchanged (+0.9 mm) in very preterm infants, whereas postnatal growth in term controls slowed down to +1.3 mm (P < 0.001 v. fetal aortic growth). At the final examination, aEDD was 22% and carotid artery EDD was 14% narrower in infants born preterm compared with controls, also after adjusting for current weight (P < 0.01). Aortic and carotid artery growth is impaired after very preterm birth, resulting in arterial narrowing. Arterial growth failure may be a generalized vascular phenomenon after preterm birth, with implications for cardiovascular morbidity in later life.

Birth weight is the most important predictor of abnormal retinal vascularisation in moderately preterm infants

AIM

To find predictors of abnormal retinal vascularisation in moderately to late preterm newborn infants considered to have no risk of developing retinopathy of prematurity.

METHODS

Seventy-eight infants (34 girls) were recruited from a longitudinal study of otherwise healthy premature children born at a gestational age of 32 + 0-36 + 6 weeks. Retinal vessel morphology was evaluated at mean postnatal age 7 days. Insulin-like growth factor-I (IGF-I) levels were analysed in umbilical cord blood.

RESULTS

Of the 78 infants, 21 (27%) had abnormal retinal vessel morphology; they had significantly lower median (range) birth weight [1850 g, (1190-3260), vs. 2320, (1330-3580), p < 0.0001], shorter birth length [43.0 cm, (38-49), vs. 46.0, (40-50), p < 0.0001] and smaller head circumference [31.0 cm, (27.7-34.0), vs. 32.0, (27.5-36.5), p = 0.003]. They also had significantly lower gestational age [34 + 1 weeks, (32 + 2-35 + 3), vs. 34 + 6, (32 + 2-36 + 6), p = 0.004] and mean ± SD IGF-I levels (24.6 ± 17.0 μg/L vs. 46.7 ± 21.5, p < 0.0001). A higher percentage of these infants were small for gestational age (57.1% vs. 15.8%, p = 0.001), and maternal hypertension/preeclampsia rates were also higher (47.6% vs. 19.3%, p = 0.03). Step-wise logistic regression showed that birth weight was the strongest predictor of abnormal retinal vascularisation (p < 0.0001, odds ratio 0.040, 95% confidence interval 0.007-0.216).

CONCLUSION

In this population of moderately to late preterm newborns, birth weight appeared to affect the retinal vascular system.

Retinal vessel abnormalities as a possible biomarker of brain volume loss in obese adolescents

OBJECTIVE

Endothelial dysfunction in childhood obesity may precede cerebrovascular damage and cognitive impairment in adulthood. A noninvasive proxy of microvascular health is required to identify the risk for microvascular damage in obese children.

DESIGN AND METHODS

The associations of hippocampal volumes and global cerebral atrophy were assessed with retinal vessel caliber in 40 normal BMI controls and 62 obese age-matched nondiabetic adolescents and the contribution of inflammation, obesity, and insulin resistance to retinal vessel caliber was evaluated.

RESULTS

Compared to controls, obese adolescents had smaller retinal arterioles (8.3% decrease, P < 0.05) and wider venules (5.4% increase, P < 0.01). Larger retinal arteriole diameters were associated with less global cerebral atrophy (B = -0.24 [95% confidence interval, CI: -0.48, -0.002]) and larger hippocampal volumes (B = 0.01 [95% CI: 0, 0.02]). Venule diameters (B = 84.2 [95% CI: 30.3, 138.1]) were predicted by inflammation (fibrinogen). Arteriolar diameters were predicted by insulin resistance, indicated by logHOMA (homeostatic model assessment, HOMA) values (B = -17.03 [95% CI: -28.25, -5.81)] and body mass index (BMI) (B = -.67 [95% CI: -1.09, -0.24)]. All analyses were adjusted for mean arterial pressure, sleep apnea, and vessel diameter.

CONCLUSIONS

Measures of brain health, BMI, and insulin resistance are associated with retinal vessel caliber. If confirmed in larger studies, retinal arteriolar caliber may serve as a possible noninvasive proxy for brain atrophy in obese adolescents, and the identification of elevated risk for cerebral microvascular disease in adulthood.

Can the retinal microvasculature offer clues to cardiovascular risk factors in early life?

Adulthood cardiovascular diseases (CVD) burdening in adulthood have been suggested to have possible predisposition early in life. We aimed to systematically review the literatures on retinal microvasculature among paediatric population in relation to a range of environmental and systemic changes. Papers with quantitative retinal vascular assessment and epidemiological design were reviewed.

CONCLUSION

This review supports the theory that major vascular diseases have pathological predisposition early in life by providing morphological evidence on retinal microcirculation in vivo.

Birth weight and time spent in outdoor physical activity during adolescence

PURPOSE

We investigated the association between birth parameters (weight, length, and head circumference) and time spent in physical activity (outdoor and indoor) and screen time (TV viewing, computer, and videogame usage) among adolescents.

METHODS

A longitudinal cohort study surveyed 1794 children in 2004-2005 (median age = 12.7 yr), and 752 were resurveyed 5 yr later in 2009-2010 (age = 17-18 yr). Adolescents completed detailed activity questionnaires. Parents extracted birth parameter data from their child's health record booklet.

RESULTS

After adjusting for age, sex, ethnicity, gestational age, parental education, home ownership, exposure to passive smoking, and body mass index, 12-yr-old children in the highest compared with the lowest quartile of birth weight spent on average approximately 56 and 62 min more in total (Ptrend = 0.02) and outdoor physical activity (Ptrend = 0.02) per week, respectively. Similarly, 12-yr-old children in the high (>4000 g) versus very low (<2000 g) birth weight group spent approximately 1.3 h·wk more in outdoor activity (Ptrend = 0.02). Among those age 17-18 yr, increasing birth weight (lowest to highest quartile) was associated with greater time spent in outdoor physical activity (∼1 h·wk-1, Ptrend = 0.04). Significant associations were not observed between all birth parameters and recreational screen time. Also, no associations were observed between head circumference or birth length with physical activity and screen time.

CONCLUSIONS

Birth weight could be a potential determinant of physical activity, but not of screen time during adolescence. Hence, this could be part of the underlying mechanism between prenatal influences and future disease risk and could have possible clinical implications.