Low birth weight as a risk factor for hypertension

No relationship found between dental fluctuating asymmetry, birthweight, and birth term in two modern North American samples

OBJECTIVE

Deciduous dental crowns primarily develop during gestation and early infancy and embody early life stress exposures. Composite measures of dental fluctuating asymmetry (DFA) generated from the deciduous teeth may therefore indicate cumulative gestational stress in developmental origins of health and disease (DOHaD) studies. This study examines whether higher composite measures of deciduous DFA are associated with low birthweight and prematurity, two aspects of birth phenotype consistently associated with increased morbidity and mortality risks in adulthood.

SUBJECTS AND METHODS

We evaluated associations between composite deciduous DFA, birthweight, and birth term in two contemporary North American samples: an autopsy sample from New Mexico (n = 94), and sample from a growth cohort study in Burlington, Ontario (n = 304). Dental metric data for each sample was collected from postmortem CT scans and dental casts, respectively. Composite DFA was estimated using buccolingual (BL) and mesiodistal (MD) crown diameters from paired deciduous teeth.

RESULTS

Contrary to expectations, the results of linear regression indicated no significant relationship between birthweight and DFA, or birth term and DFA, in either sample.

CONCLUSIONS

Deciduous DFA does not predict aspects of birth phenotype associated with gestational stress. Birthweight and birth term are plastic relative to the more developmentally stable deciduous dentition, which may only subtly embody early life stress. We suggest that deciduous DFA should be utilized with caution in DOHaD studies until its relationship with gestational stress is clarified.

The fascinating theory of fetal programming of adult diseases: A review of the fundamentals of the Barker hypothesis

The theory of fetal programming of adult diseases was first proposed by David J.P. Barker in the eighties of the previous century, to explain the higher susceptibility of some people toward the development of ischemic heart disease. According to his hypothesis, poor maternal living conditions during gestation represent an important risk factor for the onset of atherosclerotic heart disease later in life. The analysis of the early phases of fetal development is a fundamental tool for the risk stratification of children and adults, allowing the identification of susceptible or resistant subjects to multiple diseases later in life. Here, we provide a narrative summary of the most relevant evidence supporting the Barker hypothesis in multiple fields of medicine, including neuropsychiatric disorders, such as Parkinson disease and Alzheimer disease, kidney failure, atherosclerosis, coronary heart disease, stroke, diabetes, cancer onset and progression, metabolic syndrome, and infectious diseases including COVID-19. Given the consensus on the role of body weight at birth as a practical indicator of the fetal nutritional status during gestation, every subject with a low birth weight should be considered an "at risk" subject for the development of multiple diseases later in life. The hypothesis of the "physiological regenerative medicine," able to improve fetal organs' development in the perinatal period is discussed, in the light of recent experimental data indicating Thymosin Beta-4 as a powerful growth promoter when administered to pregnant mothers before birth.

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.

Kidney glomerular filtration rate plasticity after transplantation

Since the first living donor kidney transplantation about six decades ago, significant progress has been made in terms of extending allograft survival. However, to date, only a small number of studies have compared the functional changes of the donated kidney to that of the remaining kidney. Although relatively small, the study by Gonzalez Rinne et al. demonstrated the adaptive capacity of the transplanted kidney in 30 donor-recipient pairs. The glomerular filtration rate (GFR) in both donors and recipients was obtained 12 months after transplantation and the authors identified three scenarios: (i) where donors had a higher GFR than recipients; (ii) where donors had a lower GFR than recipients; and (iii) where donors had a similar GFR to recipients. The mechanisms mediating GFR adaptability after kidney transplantation seem to be associated with body surface area (including sex differences in body surface area). Microstructural analysis of human and animal models of renal physiology provides some clues to the physiological adaptation of the transplanted organ. The nephron number from endowment and age-related loss and the adaptive ability for compensatory glomerular hyperfiltration likely play a major role.

Insights into the Mechanisms of Fetal Growth Restriction-Induced Programming of Hypertension

In recent decades, both clinical and animal studies have shown that fetal growth restriction (FGR), caused by exposure to adverse uterine environments, is a risk factor for hypertension as well as for a variety of adult diseases. This observation has shaped and informed the now widely accepted theory of developmental origins of health and disease (DOHaD). There is a plethora of evidence supporting the association of FGR with increased risk of adult hypertension; however, the underlying mechanisms responsible for this correlation remain unclear. This review aims to explain the current advances in the field of fetal programming of hypertension and a brief narration of the underlying mechanisms that may link FGR to increased risk of adult hypertension. We explain the theory of DOHaD and then provide evidence from both clinical and basic science research which support the theory of fetal programming of adult hypertension. In addition, we have explored the underlying mechanisms that may link FGR to an increased risk of adult hypertension. These mechanisms include epigenetic changes, metabolic disorders, vascular dysfunction, neurohormonal impairment, and alterations in renal physiology and function. We further describe sex differences seen in the developmental origins of hypertension and provide insights into the opportunities and challenges present in this field.

Long-term kidney function and survival in recipients of allografts from living kidney donors with hypertension: a national cohort study

Allografts from living kidney donors with hypertension may carry subclinical kidney disease from the donor to the recipient and, thus, lead to adverse recipient outcomes. We examined eGFR trajectories and all-cause allograft failure in recipients from donors with versus without hypertension, using mixed-linear and Cox regression models stratified by donor age. We studied a US cohort from 1/1/2005 to 6/30/2017; 49 990 recipients of allografts from younger (<50 years old) donors including 597 with donor hypertension and 21 130 recipients of allografts from older (≥50 years old) donors including 1441 with donor hypertension. Donor hypertension was defined as documented predonation use of antihypertensive therapy. Among recipients from younger donors with versus without hypertension, the annual eGFR decline was -1.03 versus -0.53 ml/min/m² (P = 0.002); 13-year allograft survival was 49.7% vs. 59.0% (adjusted allograft failure hazard ratio [aHR] 1.23; 95% CI 1.05-1.43; P = 0.009). Among recipients from older donors with versus without hypertension, the annual eGFR decline was -0.67 versus -0.66 ml/min/m² (P = 0.9); 13-year allograft survival was 48.6% versus 52.6% (aHR 1.05; 95% CI 0.94-1.17; P = 0.4). In secondary analyses, our inferences remained similar for risk of death-censored allograft failure and mortality. Hypertension in younger, but not older, living kidney donors is associated with worse recipient outcomes.

A cohort study of dysmenorrhea and risk of low birth weight

OBJECTIVE

Little is known about the association between maternal history of dysmenorrhea and perinatal outcomes. The aim of this study was to investigate the association between maternal history of dysmenorrhea and low birth weight (LBW).

METHODS

A total of 6754 pregnant women were recruited from the ongoing prospective cohort study in Guangxi, China, in 2015-2018. Information on the maternal history of dysmenorrhea was obtained by questionnaires including visual analog scale (VAS) questions during the first antenatal care visit. The association of maternal history of dysmenorrhea and LBW was evaluated using logistic regression analyses adjusted for confounding factors (infant sex, maternal age, parity, pre-pregnancy body mass index (BMI) (kg/m²), gestational age, alcohol use during pregnancy, passive smoking, and occupational status).

RESULTS

Mothers with a history of dysmenorrhea were more likely to give birth to LBW infants (adjusted odds ratio (OR)=1.44; 95% confidence interval (CI): 1.12, 1.83). Among women with a history of dysmenorrhea, women ≥29 years old (adjusted OR 1.46; 95% CI 1.02, 2.10), multiparous (adjusted OR 1.59, 95% CI 1.12, 2.25), and women gave birth to female infant (adjusted OR = 1.53, 95% CI = 1.11, 2.11) had a higher risk of LBW.

CONCLUSIONS

As the first cohort study to investigate the association between maternal history of dysmenorrhea and LBW, our study shows that dysmenorrhea may increase the risk of LBW.

Time-to-event modeling of hypertension reveals the nonexistence of true controls

Given a lifetime risk of ~90% by the ninth decade of life, it is unknown if there are true controls for hypertension in epidemiological and genetic studies. Here, we compared Bayesian logistic and time-to-event approaches to modeling hypertension. The median age at hypertension was approximately a decade earlier in African Americans than in European Americans or Mexican Americans. The probability of being free of hypertension at 85 years of age in African Americans was less than half that in European Americans or Mexican Americans. In all groups, baseline hazard rates increased until nearly 60 years of age and then decreased but did not reach zero. Taken together, modeling of the baseline hazard function of hypertension suggests that there are no true controls and that controls in logistic regression are cases with a late age of onset.

Impact of in vitro embryo culture and transfer on blood pressure regulation in the adolescent lamb

Nutrition during the periconceptional period influences postnatal cardiovascular health. We determined whether in vitro embryo culture and transfer, which are manipulations of the nutritional environment during the periconceptional period, dysregulate postnatal blood pressure and blood pressure regulatory mechanisms. Embryos were either transferred to an intermediate recipient ewe (ET) or cultured in vitro in the absence (IVC) or presence of human serum (IVCHS) and a methyl donor (IVCHS+M) for 6 days. Basal blood pressure was recorded at 19-20 weeks after birth. Mean arterial pressure (MAP) and heart rate (HR) were measured before and after varying doses of phenylephrine (PE). mRNA expression of signaling molecules involved in blood pressure regulation was measured in the renal artery. Basal MAP did not differ between groups. Baroreflex sensitivity, set point, and upper plateau were also maintained in all groups after PE stimulation. Adrenergic receptors alpha-1A (αAR1A), alpha-1B (αAR1B), and angiotensin II receptor type 1 (AT1R) mRNA expression were not different from controls in the renal artery. These results suggest there is no programmed effect of ET or IVC on basal blood pressure or the baroreflex control mechanisms in adolescence, but future studies are required to determine the impact of ET and IVC on these mechanisms later in the life course when developmental programming effects may be unmasked by age.

Impact of Maternal Demographic and Socioeconomic Factors on the Association Between Particulate Matter and Adverse Birth Outcomes: a Systematic Review and Meta-analysis

BACKGROUND

Numerous studies conducted in the United States found associations between prenatal exposure to particulate matter (PM) and adverse birth outcomes, and some studies identified vulnerable populations, including certain racial/ethnic groups and people with low-socioeconomic status. However, their findings are not always consistent. In this review, we compared the risk of adverse birth outcomes due to PM exposures among subpopulations and investigated whether any particular population is more vulnerable.

METHODS

We selected U.S. studies examining associations between PM exposure during pregnancy and birth outcomes that included results for effect modification by race/ethnicity and/or maternal education. We summarized the findings for various sizes of PM and birth outcomes. Meta-analysis was conducted to quantify vulnerable race/ethnicity for the association between fine PM (PM_2.5) and birthweight.

RESULTS

In total, 19 studies were assessed, and PM-related risks of adverse birth outcomes, particularly those related to fetal growth, likely differ across subpopulations. A meta-analysis from five studies showed that a 10 μg/m³ increase of PM_2.5 during the full-gestation reduced birthweight by 21.9 g (95% confidence interval 11.7, 32.0), 15.7 g (10.1, 21.4), 9.3 g (2.7, 15.8), and 5.8 g (- 9.0, 20.7) for Black, White, Hispanic, and Asian mothers, respectively.

CONCLUSION

Our review indicated that Black mothers and mothers with low educational attainment are more vulnerable subpopulations. More investigation is needed for effect modification by other maternal factors, such as household income. Characterizing and quantifying vulnerable subpopulations are essential for addressing environmental justice since it can help regulatory agencies allocate resources and design policy interventions.

In-vivo techniques for determining nephron number

PURPOSE OF REVIEW

Many studies have suggested low nephron endowment at birth contributes to the risk of developing hypertension and chronic kidney disease (CKD) later in life. Loss of nephrons with age and disease is largely a subclinical process. New technologies are needed to count nephrons as glomerular filtration rate (GFR) is a poor surrogate for nephron number.

RECENT FINDINGS

Cortical volume, glomerular density, and percent globally sclerotic glomeruli are imperfect surrogates for nephron number. The disector-fractionator method is the most accurate method to count nephrons but is limited to autopsy settings. Glomerular density combined with kidney imaging and ultrafiltration coefficient-based methods require a kidney biopsy, and have been applied in living humans (kidney donors). Low nephron number predicts a higher postdonation urine albumin. Contrast-enhanced MRI has detected glomeruli without a biopsy, but so far, not in living humans.

SUMMARY

Currently, there is no accurate and well tolerated method for determining nephron number in living humans. A clinically useful method may allow GFR to be replaced by its more relevant determinants: nephron number and single nephron GFR. This could revolutionize nephrology by separating the measurement of chronic disease (nephron loss) from more reversible hemodynamic effects (nephron hyperfiltration/hypofiltration).

Association between High-Sensitivity C-Reactive Protein and Blood Pressure among Children with History of Low Birth Weight Appropriate for Gestational Age, Low Birth Weight Small for Gestational Age, and Normal Birth Weight in Manado, North Sulawesi

Over the past years, low birth weight (LBW) has been proven to be attributed to a wide variety of long-term morbidities, including hypertension. This study aimed to investigate the association between high-sensitivity C-reactive protein (hs-CRP) and blood pressure (BP) in children with a history of LBW appropriate for gestational age (LBW AGA), LBW small for gestational age (LBW SGA), and normal birth weight appropriate for gestational age (NBW AGA). The study cohort comprised children aged 9-12 years who were born in 2007-2010 at Prof. Dr. R. D. Kandou General Hospital Manado and resided in the city of Manado from March to August 2019. The children who met the inclusion criteria were evaluated for BP and hs-CRP level. A total of 120 children who met the inclusion criteria were enrolled in this study. Analysis for the association between LBW and NBW with systolic blood pressure (SBP) showed statistical significance (p=0.007). Linear regression analysis indicated a strongly significant influence of BW on serum hs-CRP level and SBP. Every 1 g increase in BW results in a decrease of serum hs-CRP level of 0.001 mg/L. Every 1 g increase in BW is attributed to 0.004 mmHg decrease in SBP. An increase in hs-CRP by 1 mg/L increases the SBP by 4.99 mmHg and DBP by 2.88 mmHg. LBW significantly correlates with hs-CRP level and higher SBP. A comprehensive education must be undertaken for the families who have children with LBW to reduce the risk of developing hypertension later in their life.

Clinical consequences of developmental programming of low nephron number

Nephron number in humans varies up to 13-fold, likely reflecting the impact of multiple factors on kidney development, including inherited body size and ethnicity, as well as maternal health and nutrition, fetal exposure to gestational diabetes or preeclampsia and other environmental factors, which may potentially be modifiable. Such conditions predispose to low or high offspring birth weight, growth restriction or preterm birth, which have all been associated with increased risks of higher blood pressures and/or kidney dysfunction in later life. Low birth weight, preterm birth, and intrauterine growth restriction are associated with reduced nephron numbers. Humans with hypertension and chronic kidney disease tend to have fewer nephrons than their counterparts with normal blood pressures or kidney function. A developmentally programmed reduction in nephron number therefore enhances an individual's susceptibility to hypertension and kidney disease in later life. A low nephron number at birth may not lead to kidney dysfunction alone except when severe, but in the face of superimposed acute or chronic kidney injury, a kidney endowed with fewer nephrons may be less able to adapt, and overt kidney disease may develop. Given that millions of babies are born either too small, too big or too soon each year, the population impact of altered renal programming is likely to be significant. Many gestational exposures are modifiable, therefore urgent attention is required to implement public health measures to optimize maternal, fetal, and child health, to prevent or mitigate the consequences of developmental programming, to improve the health future generations.

Chronic Estrogen Supplementation Prevents the Increase in Blood Pressure in Female Intrauterine Growth-Restricted Offspring at 12 Months of Age

Low birth weight is associated with a greater prevalence of hypertension and an earlier age at menopause in women in later life. Yet, the association between birth weight and blood pressure (BP) in women as they age is not well defined. In a rodent model of low birth weight induced by placental insufficiency, intrauterine growth restriction programs a significant increase in BP by 12 months of age in female growth-restricted offspring that is associated with early reproductive senescence, increased testosterone, and a shift in the hormonal milieu. Thus, this study tested the hypothesis that increased BP in female growth-restricted offspring is abolished by chronic estradiol supplementation. Placebo or 17β-estradiol valerate mini pellets (1.5 mg for 60-day release) were administered at 12 months of age for 6 weeks. BP, measured in conscious catheterized rats, was significantly increased in placebo-treated growth-restricted relative to placebo-treated control. However, BP was not elevated in estradiol-treated growth-restricted relative to placebo-treated growth-restricted. Estradiol mediates its effects on BP via its receptors and the renin-angiotensin system. BP was decreased in growth-restricted offspring treated with a G-protein coupled receptor agonist, G1 (400 mg/kg for 2 weeks). Renal AT1aR (angiotensin type 1a receptor) and AT1bR (angiotensin type 1b receptor) and renal AR (androgen receptor) mRNA expression were elevated in vehicle-treated growth-restricted offspring, but not in G1-treated growth-restricted. Therefore, these data suggest that chronic estradiol supplementation prevents the increase in BP that develops in female growth-restricted offspring via actions that may involve its G-protein coupled receptor and the renin-angiotensin system.

The Effect of Maternal Intact Protein- and Amino Acid-Based Diets on Development of Food Intake Regulatory Systems and Body Weight in Dams and Male Offspring of Wistar Rats

The objective of this study is to examine the effect of maternal and weaning intact protein- and amino acid-based diets on regulation of food intake, intake regulatory hormones, and body weight in dams and their male offspring. Pregnant Wistar rats were allocated to two groups (n = 12) and were fed either an intact protein diet (IPD) or mixed amino acid diet (AAD) from day 3 of gestation throughout gestation and lactation. Male offspring were weaned to either an IPD or AAD for 18 weeks. Food intake (FI) and body weight (BW) were measured weekly. Results: In dams, the AAD group had lower FI and BW in the post-partum period compared with the IPD group. In pups born to AAD dams, birth weight and BW were lower. However, the percentage of fat and lean mass were not affected. Food intake was influenced by maternal diet and was higher in pups born to IPD dams throughout post-weaning. Short-term FI in response to protein preloads was lower in pups born to AAD dams in 1 h. Fasting plasma concentrations of glucose, insulin, and ghrelin were not influenced by either maternal or weaning diet. However, peptide YY (PYY) was higher in pups born to IPD dams at weaning. Conclusions: The physicochemical properties of proteins fed during pregnancy and lactation had determining effects on the body weight and development of food intake regulatory systems in offspring. Maternal AAD resulted in lower BW in dams and lower birth weight and post-weaning BWs in pups compared with maternal IPD which was consistent with their lower FI.

The relationship between maternal anxiety and cortisol during pregnancy and birth weight of chinese neonates

BACKGROUND

To determine the relationship between maternal anxiety and cortisol values and birth weight at various stages of pregnancy.

METHODS

Two hundred sixteen pregnant Chinese women were assessed for anxiety and depression and had measurement of morning fasting serum cortisol. Women were assessed either in the first (71), second (72) or third (73) trimester. Birth weights of all children were recorded.

RESULTS

There were significant negative correlations between anxiety level and birth weight of - 0.507 (p < 0.01) and - 0.275 (p < 0.05) in trimesters 1and 2. In trimester 3 the negative relation between anxiety and birth weight of -.209 failed to reach significance (p = 0.070). There was no relation between depression and birth weight in any trimester (p > 0.5 for all). Maternal cortisol was significantly inversely related to birth weight in trimester 1 (r = - 0.322) and with borderline significance in trimester 2 (r = - 0.229). Anxiety score and maternal cortisol were significantly correlated in each trimester (r = 0.551, 0.650, 0.537). When both anxiety score and maternal cortisol were simultaneously included in multiple regression analyses only anxiety score remained significant.

CONCLUSION

Whilst both maternal anxiety score and maternal cortisol are inversely related to birth weight the associations with anxiety score were more robust perhaps indicating the importance of mechanisms other than, or in addition to, maternal cortisol in mediating the effects of anxiety. The findings indicate the importance of measures to reduce maternal anxiety, particularly of a severe degree, at all stages of pregnancy.

TRIAL REGISTRATION

The study was approved by the Ethics Committee of the 1st Affiliated Hospital of Xi'an Jiaotong University.

The Joint Association of Small for Gestational Age and Nighttime Sleep with Blood Pressure in Childhood

Children born small for gestational age (SGA) are more likely to develop high blood pressure. In prior studies, longer sleep duration is associated with lower BP, and SGA is associated with shorter sleep duration in childhood. We investigated whether sleep duration in early childhood modifies the association between SGA and higher childhood SBP in 1178 children recruited at birth and followed up to age 9 years. We ascertained birthweight and gestational age from medical records. We derived child sleep duration from maternal questionnaire interview. We calculated child SBP percentile according to U.S. reference data. We defined elevated SBP as SBP ≥75^th percentile. In this sample, 154 (13.1%) children were born SGA. Children born SGA had higher SBP percentiles and higher risk of elevated SBP. Among children born SGA, those in the highest compared to the lowest tertile for sleep had a 12.28 lower (−22.00, −2.57) SBP percentile and 0.44 (0.25 to 0.79) times lower risk of developing elevated SBP. Our data are consistent with an interaction between SGA and sleep duration on childhood elevated SBP (P_interaction = 0.0056). In conclusion, in this prospective birth cohort, longer sleep duration in early childhood may mitigate the blood pressure-raising effect of being born small.

Cardiotocography and the evolution into computerised cardiotocography in the management of intrauterine growth restriction

Timely recognition and appropriate management of high-risk pregnancies, such as intrauterine growth restriction (IUGR), are of paramount importance for every obstetrician. After the initial screening of IUGR fetuses through sonographic fetometry and Doppler, the focus is shifted to the appropriate monitoring and timing of delivery. This can, especially in cases of early IUGR, become a very difficult task. At this point, cardiotocography (CTG) is introduced as a major tool in the day-to-day monitoring of the antenatal well-being of the IUGR fetus. Since the first introduction of CTG up to the nowadays widely spreading implementation of computerised CTG in the clinical practice, there has been great progress in the recording of the fetal heart rate, as well as its interpretation. Focus of this review is to offer an understanding of the evolution of CTG from its early development to modern computerised methods and to provide an insight as to where the future of CTG is leading, especially in the monitoring of IUGR.

The future of preconception care in the United States: multigenerational impact on reproductive outcomes

The future of preconception care will require an innovative multigenerational approach to health promotion for women and men to achieve optimal reproductive health outcomes. In this paper we provide a summary of historical trends in perinatal interventions in the United States that have effectively reduced adverse perinatal outcomes but have not improved disparities among ethnic/racial groups. We describe evidence pointing to an enhanced preconception care paradigm that spans the time periods before, during, and between pregnancies and across generations for all women and men. We describe how the weathering, Barker, and life course theories point to stress and non-chromosomal inheritance as key mediators in racial disparities. Finally, we provide evidence that indicates that humans exposed to toxic stress can be impacted in future generations and that these phenomena are potentially related to epigenetic inheritance, resulting in perinatal disparities. We believe that this expanded view will define preconception care as a critical area for research in the years ahead.

Birth weight was longitudinally associated with cardiometabolic risk markers in mid-adulthood

PURPOSE

Birth weight (BW) is associated with risk of cardiovascular (CV) disease. The findings from studies examined the association of BW with metabolic markers of CV risk were inconsistent and controversial. We examined the association of BW with insulin resistance and blood lipids using repeated measures up to mid-adulthood.

METHODS

Data from seven screenings of the Bogalusa Heart Study-a longitudinal study of cardiovascular risk factors in Bogalusa, LA-are analyzed using generalized estimation equations method. Participants with birth data and at least one measurement of study outcomes between 18 and 44 years (n = 2,034) were included.

RESULTS

BW is inversely associated with insulin resistance, triglycerides, and total cholesterol (P < .01 for all). For 1-kg decrease in BW, insulin resistance increased by 2.3 units, 95% confidence interval (CI) = 0.7-3.9; triglycerides by 8.7 mg per dL, 95% CI = 4.9-12.4, and total cholesterol by 5.4 mg per dL, 95% CI = 1.8-9.1. The association of body mass with adult blood lipids levels is weaker in persons with low versus normal BW.

CONCLUSIONS

The study provides strong evidence of an inverse relationship of BW with adulthood cardiometabolic risk profile. Persons born with low BW are maybe less responsive to preventive interventions aiming at weight reduction.

The Substantial Loss of Nephrons in Healthy Human Kidneys with Aging

Nephron number may be an important determinant of kidney health but has been difficult to study in living humans. We evaluated 1638 living kidney donors at Mayo Clinic (MN and AZ sites) and Cleveland Clinic. We obtained cortical volumes of both kidneys from predonation computed tomography scans. At the time of kidney transplant, we obtained and analyzed the sections of a biopsy specimen of the cortex to determine the density of both nonsclerotic and globally sclerotic glomeruli; the total number of glomeruli was estimated from cortical volume×glomerular density. Donors 18-29 years old had a mean 990,661 nonsclerotic glomeruli and 16,614 globally sclerotic glomeruli per kidney, which progressively decreased to 520,410 nonsclerotic glomeruli per kidney and increased to 141,714 globally sclerotic glomeruli per kidney in donors 70-75 years old. Between the youngest and oldest age groups, the number of nonsclerotic glomeruli decreased by 48%, whereas cortical volume decreased by only 16% and the proportion of globally sclerotic glomeruli on biopsy increased by only 15%. Clinical characteristics that independently associated with fewer nonsclerotic glomeruli were older age, shorter height, family history of ESRD, higher serum uric acid level, and lower measured GFR. The incomplete representation of nephron loss with aging by either increased glomerulosclerosis or by cortical volume decline is consistent with atrophy and reabsorption of globally sclerotic glomeruli and hypertrophy of remaining nephrons. In conclusion, lower nephron number in healthy adults associates with characteristics reflective of both lower nephron endowment at birth and subsequent loss of nephrons.

The Substantial Loss of Nephrons in Healthy Human Kidneys with Aging

Nephron number may be an important determinant of kidney health but has been difficult to study in living humans. We evaluated 1638 living kidney donors at Mayo Clinic (MN and AZ sites) and Cleveland Clinic. We obtained cortical volumes of both kidneys from predonation computed tomography scans. At the time of kidney transplant, we obtained and analyzed the sections of a biopsy specimen of the cortex to determine the density of both nonsclerotic and globally sclerotic glomeruli; the total number of glomeruli was estimated from cortical volume×glomerular density. Donors 18-29 years old had a mean 990,661 nonsclerotic glomeruli and 16,614 globally sclerotic glomeruli per kidney, which progressively decreased to 520,410 nonsclerotic glomeruli per kidney and increased to 141,714 globally sclerotic glomeruli per kidney in donors 70-75 years old. Between the youngest and oldest age groups, the number of nonsclerotic glomeruli decreased by 48%, whereas cortical volume decreased by only 16% and the proportion of globally sclerotic glomeruli on biopsy increased by only 15%. Clinical characteristics that independently associated with fewer nonsclerotic glomeruli were older age, shorter height, family history of ESRD, higher serum uric acid level, and lower measured GFR. The incomplete representation of nephron loss with aging by either increased glomerulosclerosis or by cortical volume decline is consistent with atrophy and reabsorption of globally sclerotic glomeruli and hypertrophy of remaining nephrons. In conclusion, lower nephron number in healthy adults associates with characteristics reflective of both lower nephron endowment at birth and subsequent loss of nephrons.

Innovating healthcare delivery to address noncommunicable diseases in low-income settings: the example of hypertension

London Dialogue event, The Hospital Club, 24 Endell St, London, WC2H 9HQ, London, UK, 1 December 2015 Hypertension is a global health issue causing almost 10 million deaths annually, with a disproportionate number occurring in low- and middle-income countries. The condition can be managed effectively, but there is a need for innovation in healthcare delivery to alleviate its burden. This paper presents a number of innovative delivery models from a number of different countries, including Kenya, Ghana, Barbados and India. These models were presented at the London Dialogue event, which was cohosted by the Novartis Foundation and the London School of Hygiene & Tropical Medicine Centre for Global Noncommunicable Diseases on 1 December 2015. It is argued that these models are applicable not only to hypertension, but provide valuable lessons to address other noncommunicable diseases.

Association of socioeconomic status change between infancy and adolescence, and blood pressure, in South African young adults: Birth to Twenty Cohort

OBJECTIVE

Social epidemiology models suggest that socioeconomic status (SES) mobility across the life course affects blood pressure. The aim of this study was to investigate the association between SES change between infancy and adolescence, and blood pressure, in young adults, and the impact of early growth on this relationship.

SETTING

Data for this study were obtained from a 'Birth to Twenty' cohort in Soweto, Johannesburg, in South Africa.

PARTICIPANTS

The study included 838 Black participants aged 18 years who had household SES measures in infancy and at adolescence, anthropometry at 0, 2, 4 and 18 years of age and blood pressure at the age of 18 years.

METHODS

We computed SES change using asset-based household SES in infancy and during adolescence as an exposure variable, and blood pressure and hypertension status as outcomes. Multivariate linear and logistic regressions were used to investigate the associations between SES change from infancy to adolescence, and age, height and sex-specific blood pressure and hypertension prevalence after adjusting for confounders.

RESULTS

Compared to a persistent low SES, an upward SES change from low to high SES tertile between infancy and adolescence was significantly associated with lower systolic blood pressure (SBP) at the age of 18 years (β=-4.85; 95% CI -8.22 to -1.48; p<0.01; r(2)=0.1804) after adjusting for SES in infancy, small-for-gestational-age (SGA) and weight gain. Associations between SES change and SBP were partly explained by weight gain between birth and the age of 18 years. There was no association between SES mobility and diastolic blood pressure, mean arterial pressure or hypertension status.

CONCLUSIONS

Our study confirms that upward SES change has a protective effect on SBP by the time participants reach young adulthood. Socioeconomic policies and interventions that address inequality may have the potential to reduce cardiovascular disease burden related to BP in later life.

Effects of maternal anxiety and depression during pregnancy in Chinese women on children's heart rate and blood pressure response to stress

Psychological disturbances, including anxiety and depression, are common during human pregnancy. Our objective was to determine whether these maternal disturbances influence cardiovascular responses of the offspring. The psychological status of 231 pregnant women was determined. Offspring (216) of these women were subsequently exposed to a video challenge stress when aged 7-9 years. Heart rate (HR) and blood pressure (BP) of the children were determined at rest, in response to video stress and during subsequent recovery. Children's resting and stress-induced increases in HR (bpm), systolic (SBP, mm Hg) and diastolic (DBP, mm Hg) BP were all greater in children whose mothers reported anxiety during pregnancy. Values (mean±s.d.) for resting HR, SBP and DBP were 75.15±5.87, 95.37±2.72 and 66.39±4.74 for children whose mothers reported no anxiety and an average of 81.62±6.71, 97.26±2.90 and 68.86±2.82 for children whose mothers reported anxiety at any level. Respective values for stress-induced increments in HR, SBP and DBP were 14.83.±2.14, 16.41±1.97 and 12.72±2.69 for children whose mothers reported no anxiety and 17.95±3.46, 18.74±2.46 and 14.86±2.02 for children whose mothers reported any level of anxiety. Effects of maternal depression were less consistent. The effects of maternal anxiety remained in multivariate analyses, which also included children's birth weight. The results indicate a long-term influence of maternal psychological status during pregnancy on the cardiovascular responses to stress among offspring. These effects may contribute to prenatal influences on subsequent health of the offspring.

Recommendations for the evaluation and management of observation services: a consensus white paper: the Society of Cardiovascular Patient Care

Observation Services (OS) was founded by emergency physicians in an attempt to manage "boarding" issues faced by emergency departments throughout the United States. As a result, OS have proven to be an effective strategy in reducing costs and decreasing lengths of stay while improving patient outcomes. When OS are appropriately leveraged for maximum efficiency, patients presenting to emergency departments with common disease processes can be effectively treated in a timely manner. A well-structured observation program will help hospitals reduce the number of inappropriate, costly inpatient admissions while avoiding the potential of inappropriate discharges. Observation medicine is a complicated multidimensional issue that has generated much confusion. This service is designed to provide the best possible patient care in a value-based purchasing environment where quality, cost, and patient satisfaction must continually be addressed. Observation medicine is a service not a status. Therefore, patients are admitted to the service as outpatients no matter whether they are placed in a virtual or dedicated observation unit. The key to a successful observation program is to determine how to maximize efficiencies. This white paper provides the reader with the foundational guidance for observational services. It defines how to set up an observational service program, which diagnoses are most appropriate for admission, and what the future holds. The goal is to help care providers from any hospital deliver the most appropriate level of treatment, to the most appropriate patient, in the most appropriate location while controlling costs.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

The association of season and temperature with adverse pregnancy outcome in two German states, a time-series analysis

Background

A seasonality of low birth weight (LBW) and preterm birth (PTB) has been described for most regions and there is evidence that this pattern is caused by ambient outdoor temperature. However, the association as such, the direction of effect and the critical time of exposure remain controversial.

Methods

Logistic, time-series regression was performed on nearly 300,000 births from two German states to study the association between season and daily mean temperature and changes in daily proportions of term LBW (tLBW) or PTB. Analyses were adjusted for time-varying factors. Temperature exposures were examined during different periods of pregnancy.

Results

Weak evidence for an association between season of conception, season of birth or ambient outdoor temperature and tLBW or PTB was found. Results of analyses of temperature were not consistent between the two states. Different sources of bias which would have artificially led to stronger findings were detected and are described.

Conclusions

No clear evidence for an association between season of conception, season of birth or temperature and tLBW or PTB was found. In the study of pregnancy outcome different sources of bias can be identified which can potentially explain heterogeneous findings of the past.

Birth measurements, family history, and environmental factors associated with later-life hypertensive status

BACKGROUND

This birth cohort study was conducted to investigate the contribution of prenatal and antenatal environmental exposures to later-life hypertensive status.

METHODS

Two thousand five hundred and three individuals born in 1921-1954 at the Peking Union Medical College Hospital (PUMCH) were targeted; 2,081 (83.1%) participated. Clinical examinations included an interview, blood pressure (BP) measurements, and laboratory assays. Statistical analyses were performed using ordinal regression models with later-life hypertensive status as the dependent variable. Similar analyses were for subpopulations divided by family history of hypertension.

RESULTS

In the 2,081 subjects, 449 were normotensive, 531 were prehypertensive, and 1,101 had hypertension. Three hundred and forty two hypertensive patients were classified as high-risk (BP ≥180/110 mm Hg, or accompanied with diabetes or three well-established cardiovascular risk factors); the other 759 patients were at mid-to-low risks. Lower birth weight (<2,500 g: odds ratio (OR) = 1.67, P = 0.02; 2,500- <3,000 g: OR = 1.64, P < 0.01; 3,000- <3,500 g, OR = 1.40, P = 0.01), family history of hypertension (OR = 1.73, P < 0.01), poor education (OR = 1.76, P < 0.01), and alcoholism (OR = 3.05, P < 0.01) significantly predicted later-life high-risk hypertension. For participants with hypertensive family history (57.7%), the association with birth weight became nonsignificant, but poor education (OR = 2.33, P < 0.01) and alcoholism (OR = 3.10, P = 0.01) remained important. For participants without hypertensive family history (42.3%), the effects of lower birth weight (<2,500 g: OR = 2.26, P = 0.02; 2,500- <3,000 g: OR = 1.91, P = 0.01; 3,000- <3,500 g, OR = 1.78, P = 0.01) and alcoholism (OR = 3.23, P < 0.01) remained significant.

CONCLUSION

Low birth weight, low education, alcoholism, and hypertensive family history are linked to later-life hypertensive status. Low birth weight is also partly associated with one's genetic background; whereas the association with education and alcoholism are independent from hypertensive family history.

How the Newcastle Thousand Families birth cohort study has contributed to the understanding of the impact of birth weight and early life socioeconomic position on disease in later life

Much has been made of the potential influence of birth weight and early socioeconomic disadvantage in influencing adult health, but little has been published in terms of how important these associations may be with respect to exposures throughout the lifecourse. The objective of this review is to describe the contributions of the Newcastle Thousand Families Study in understanding the relative impacts of factors in early life, particularly birth weight and socio-economic position at birth, in influencing health in later life. The Newcastle Thousand Families Study is a prospective birth cohort established in 1947. It originally included all births to mothers resident in Newcastle upon Tyne, in northern England, in May and June of that year. Study members were followed extensively throughout childhood and intermittently in adulthood. At the age of 49-51 years, study members underwent a large-scale follow-up phase enabling an assessment of how early life may influence their later health, and also incorporating adult risk factors which enabled the relative contributions of factors at different stages of life to be assessed. While some findings from the study do support birth weight and early socio-economic position having influences on adult health status, the associations are generally small when compared to risk factors later in life. Using path analyses on longitudinal data of this nature enables mediating pathways between early life and later health to be assessed and if more studies were to take this approach, the relative importance of early life on adult disease risk could be better understood.

Birth weight and subsequent risk of obesity: a systematic review and meta-analysis

This report describes the association between birth weight (BW) and obesity. Screening of 478 citations from five electronic databases resulted in the inclusion of 33 studies, most of medium quality. The meta-analysis included 20 of these published studies. The 13 remaining articles did not provide sufficient dichotomous data and were systematically reviewed, revealing results consistent with the meta-analysis. Our results revealed that high BW (>4000 g) was associated with increased risk of obesity (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.91-2.24) compared with subjects with BW ≤ 4000 g. Low BW (<2500 g) was associated with decreased risk of obesity (OR, 0.61; 95% CI, 0.46-0.80) compared with subjects with BW ≥ 2500 g. However, when two studies exhibited selection bias were removed, the results indicated no significant association between low BW and obesity (OR, 0.77; 95% CI, 0.58-1.04). Sensitivity analyses showed that differences in the study design, sample size and quality grade of the study had an effect on the low BW/obesity association, which low BW was not associated with the risk of obesity in cohort studies, studies with large sample sizes and studies with high quality grades. Pooled results were similar when normal birth weight (2500-4000 g) was used as the reference category. Subgroup analyses based on different growth and developmental stages (pre-school children, school children and adolescents) also revealed that high BW was associated with increased risk of obesity from childhood to early adulthood. No significant evidence of publication bias was present. These results suggest that high BW is associated with increased risk of obesity and may serve as a mediator between prenatal influences and later disease risk.

Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

Periodic limb movement during sleep is associated with nocturnal hypertension in children

BACKGROUND

Increasing evidence suggests that blood pressure (BP) is significantly influenced by sleep problems in children, but the association between periodic limb movement during sleep (PLMS) and BP is still unclear. This study aims to compare ambulatory blood pressure (ABP) in children with and without PLMS.

METHODS AND RESULTS

A cross-sectional study involving 314 children (mean (SD) age of 10.4 (1.7) years, boys 62.4%). Participants underwent an overnight polysomnographic study and ABP monitoring. Subjects were hypertensive if mean SBP or DBP > 95th percentile and prehypertensive if mean SBP or DBP > 90th percentile of reference. Children with PLMS (n = 17) were at significantly higher risk for nocturnal systolic (adjusted OR (95%CI) = 6.25 [1.87-20.88]) and diastolic (OR (95%CI) = 4.83 [1.66-14.07]) hypertension. However, mean nocturnal BP did not differ between children with and without PLMS. There was a trend for higher daytime BP in patients with PLMS than those children without PLMS (P = 0.084 for systolic BP z score; P = 0.051 for diastolic BP z score; P = 0.067 for systolic prehypertension). There were significant associations between log transformed PLM index and daytime systolic and mean BP z scores (P = 0.03 and 0.033 respectively) as well as that between log transformed PLM related arousal index (PLMSArI) and nocturnal diastolic and mean BP (P = 0.008 and 0.038 respectively).

CONCLUSIONS

PLMS was independently associated with a wide range of BP elevations, especially nocturnal indices. Future studies should examine the underlying pathophysiologic mechanisms and effects of PLMS treatment on BP.

Assessing the role of placental trisomy in preeclampsia and intrauterine growth restriction

OBJECTIVE

Prenatally diagnosed confined placental trisomy is associated with increased risk for intrauterine growth restriction (IUGR) and preeclampsia. However, it is unclear how often this might underlie pregnancy complications. Our objective was to evaluate the frequency and distribution of trisomic cells in placentae ascertained for IUGR and/or preeclampsia.

METHOD

Comparative genomic hybridization was applied to two uncultured biopsies from each of 61 placentae referred with maternal preeclampsia and/or IUGR, 11 cases with elevated maternal serum hCG and/or AFP but no IUGR or preeclampsia, and 85 control placentae.

RESULTS

Trisomy was observed in four placentae among the IUGR group (N = 43) but in no case of preeclampsia in the absence of IUGR (N = 18). Trisomy was observed in 1 of the 11 cases ascertained for abnormal maternal serum screen. Each of these five cases was mosaic and not all sampled sites showed the presence of trisomy. None of the 84 control placentas showed mosaic trisomy, although 1 case of nonmosaic 47,XXX was identified in this group.

CONCLUSION

In cases in which diagnosis of the cause of IUGR may provide some benefit, testing should be performed using uncultured cells from multiple placental biopsies for the accurate diagnosis of trisomy mosaicism.

The clinical importance of nephron mass

Abundant evidence supports the association between low birth weight (LBW) and renal dysfunction in humans. Anatomic measurements of infants, children, and adults show significant inverse correlation between LBW and nephron number. Nephron numbers are also lower in individuals with hypertension compared with normotension among white and Australian Aboriginal populations. The relationship between nephron number and hypertension among black individuals is still unclear, although the high incidence of LBW predicts low nephron number in this population as well. LBW, a surrogate for low nephron number, also associates with increasing BP from childhood to adulthood and increasing risk for chronic kidney disease in later life. Because nephron numbers can be counted only postmortem, surrogate markers such as birth weight, prematurity, adult height, reduced renal size, and glomerulomegaly are potentially useful for risk stratification, for example, during living-donor assessment. Because early postnatal growth also affects subsequent risk for higher BP or reduced renal function, postnatal nutrition, a potentially modifiable factor, in addition to intrauterine effects, has significant influence on long-term cardiovascular and renal health.

Abnormal vessel morphology in boys born after intracytoplasmic sperm injection

AIM

Children born after intracytoplasmic sperm injection (ICSI) are at risk of preterm birth, low birth weight and perinatal morbidity which may predispose for diseases of the central nervous and vascular systems. Our aim was to investigate the ocular fundus morphology in children born after ICSI.

METHOD

Children born after ICSI (n = 82) had ocular fundus photographs taken at the age of 5 years and results were compared with those of a control group (n = 203). The ocular fundus morphology with the central retinal vessels was evaluated by digital image analysis.

RESULTS

Children born after ICSI (n = 57) had abnormal retinal vascularization as evidenced by a lower number of vascular branching points compared with the control group (n = 181) (p = 0.0002). A gender difference was found whereby the ICSI boys (n = 35) had significantly fewer retinal branching points (median 24, range 19-29.5) compared with the control boys (median 27.5, range 20-37) (p < 0.0001).

CONCLUSION

Our findings showed that ICSI boys have abnormal vessel morphology as demonstrated by a reduced number of central retinal branching points. The difference still remained after elimination of factors earlier shown to be associated with a low number of vascular branching points, i.e. low birth weight and preterm, suggesting other mechanisms responsible for the low number of vascular branching points.

Is schizophrenia a syndrome of accelerated aging?

Schizophrenia is associated with a number of anatomical and physiological abnormalities outside of the brain, as well as with a decrease in average life span estimated at 20% in the United States. Some studies suggest that this increased mortality is not entirely due to associated causes such as suicide and the use of psychotropic medications. In this article, in order to focus greater attention on the increased mortality associated with schizophrenia, we present a special case of the hypothesis that physiological abnormalities associated with schizophrenia make a contribution to the increased mortality of schizophrenia: specifically, the hypothesis that schizophrenia is a syndrome of accelerated aging. Evidence consistent with this hypothesis comes from several areas. The biological plausibility of the hypothesis is supported by the existence of established syndromes of accelerated aging and by the sharing of risk factors between schizophrenia and other age-related conditions. We propose methods for testing the hypothesis.

Role of epigenetics in mental disorders

The purpose of this paper was to selectively review the literature on the role of epigenetics in mental illnesses. Aberrant epigenetic regulation has been clearly implicated in the aetiology of some human illnesses. In recent years a growing body of evidence has highlighted the possibility that epigenetics may also play a key role in the origins and expression of mental disorders. Epigenetic phenomena may help explain some of the complexity of mental illnesses and provide a basis for discovering novel pharmacological targets to treat these disorders.

Differences in hypertension between blacks and whites: an overview

Hypertension is more prevalent and severe in urban black populations compared to whites, and is associated with a greater degree of target-organ damage for any given blood pressure level. In general, compared to whites, blacks respond well to diuretics and calcium channel blockers and less well to beta-blockers and ACE inhibitors. The exact mechanisms that contribute to differences in blood pressure between blacks and whites are still not fully understood, given the multi-factorial aetiology of essential hypertension. Various lines of evidence suggest black patients are more salt sensitive than whites, which is due to a tendency to retain sodium in the kidney. Inherent differences in ionic transport mechanisms, the renal epithelial sodium channel, the reninangiotensin-aldosterone system and vasoactive substances may be a partial explanation, but analysis is compounded by disparate socio-economic conditions between blacks and whites. At present, there is no complete explanation for these differences and further research is required.

Developmental exposure to terbutaline and chlorpyrifos, separately or sequentially, elicits presynaptic serotonergic hyperactivity in juvenile and adolescent rats

Developmental exposure to unrelated neurotoxicants can nevertheless converge on common final targets so as to exacerbate damage or functional deficits. We examined the effects of developmental exposure to terbutaline, a beta2-adrenergic receptor agonist used to arrest preterm labor, and chlorpyrifos, a widely used organophosphate pesticide, on serotonin (5HT) systems. Treatments were chosen to parallel periods typical of human developmental exposures, terbutaline (10 mg/kg) on postnatal days (PN) 2-5 and chlorpyrifos (5 mg/kg) on PN11-14, with assessments conducted in juvenile and adolescent stages (PN21, PN30 and PN45), comparing each agent alone as well as sequential administration of both. By itself, terbutaline produced persistent 5HT presynaptic hyperactivity as evidenced by increased 5HT turnover in brain regions containing 5HT terminal zones; this effect was similar to that seen in earlier studies with chlorpyrifos administration during the same early postnatal period. Later administration of chlorpyrifos (PN11-14) produced a transient increase in 5HT turnover during the juvenile stage, and the sequential exposure paradigm, terbutaline followed by chlorpyrifos, showed a corresponding increase in effect over either agent alone. In combination with our earlier work on 5HT receptors, these results indicate that terbutaline is a developmental neurotoxicant that targets the 5HT system, findings that lend a mechanistic underpinning to clinical indications of elevated childhood psychiatric disorders in the offspring of women treated with beta-agonist tocolytics. Equally importantly, the interaction between terbutaline and chlorpyrifos suggests that tocolytic therapy may alter the subsequent susceptibility to common environmental toxicants.

Young adults born small for gestational age: is reduced baroreceptor sensitivity a risk factor for hypertension?

BACKGROUND. Adults born small for gestational age (SGA) are at increased risk for the metabolic syndrome and cardiovascular disease.

HYPOTHESIS

Impaired short-term blood pressure regulation may contribute to the development of hypertension in patients born SGA.

METHODS

In all, 43 patients born SGA (18 female, age 19.4 +/- 0.3 years) were evaluated by beat-to-beat blood pressure and heart rate registration during rest and mental and orthostatic stress. The study group was divided into Group 1 with normal resting blood pressure (n=32) and Group 2 with slightly elevated blood pressure (n=11). Baroreceptor sensitivity (BRS) was calculated. Fasting insulin as well as lipid levels were correlated with hemodynamic parameters.

RESULTS

Eleven of the 43 study patients (25%) had a slightly elevated resting systolic blood pressure (SBP) rising during mental and orthostatic stress. Body mass index (BMI) and fasting insulin levels correlated strongly with SBP in Group 2. Baroreceptor sensitivity was lower in Group 2 at rest (p < 0.05).

CONCLUSIONS

Three components of metabolic syndrome (elevated BP, high BMI, elevated insulin levels) correlate strongly in young adolescents born SGA; BRS is reduced in prehypertensive patients. Close follow-up is warranted during adult life as they are predisposed for developing a metabolic syndrome with elevated cardiovascular risk.

Primary Prevention of Ischemic Stroke

Background and Purpose— This guideline provides an overview of the evidence on various established and potential stroke risk factors and provides recommendations for the reduction of stroke risk.

Methods— Writing group members were nominated by the committee chair on the basis of each writer’s previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee. The writers used systematic literature reviews (covering the time period since the last review published in 2001 up to January 2005), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations based on standard American Heart Association criteria. All members of the writing group had numerous opportunities to comment in writing on the recommendations and approved the final version of this document. The guideline underwent extensive peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

Results— Schemes for assessing a person’s risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to their potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic factors. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, alcohol abuse, drug abuse, oral contraceptive use, sleep-disordered breathing, migraine headache, hyperhomocysteinemia, elevated lipoprotein(a), elevated lipoprotein-associated phospholipase, hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

Conclusion— Extensive evidence is available identifying a variety of specific factors that increase the risk of a first stroke and providing strategies for reducing that risk.

Birth weight, puberty, and systolic blood pressure in children and adolescents: a longitudinal analysis

We examined the association between birth weight and systolic blood pressure (SBP) from pre-puberty to late puberty in a cohort of American children. Ninety-eight children aged 4-12 years at baseline were followed annually for 2-6 years with at least two Tanner stages. Annual measures included SBP, age, gender, race, birth weight, Tanner stage, and body composition using dual-energy X-ray absorptiometry and computed tomography. Birth weight was inversely correlated with SBP in pre-pubertal children (r=-0.23, P<0.05), especially in white children. SBP persisted at a higher level from pre-puberty through late puberty among children with low birth weight (<2500 g). However, SBP significantly increased from pre-puberty to early or late puberty among children with high birth weight (>or=4000 g). After adjusting for visceral fat, one unit change of birth weight category was associated with a 2.6 mm Hg reduction in SBP (P<0.05), but this association was attenuated as puberty progressed. The changes in SBP across puberty followed different trajectories in children with low vs high birth weight. Attenuation in the association between birth weight and SBP from pre-puberty to late puberty may be influenced by sexual maturation.

Early cardiovascular changes in 10- to 15-year-old stunted children: the Transition and Health during Urbanization in South Africa in Children study

OBJECTIVE

Early changes in vascular function could be associated with stunting, which may contribute to the development of cardiovascular diseases in later life. In this study we tested the hypothesis that stunting may be related to changes in cardiovascular function in African children ages 10 to 15 y.

METHODS

In the Transition and Health during Urbanization in South Africa in Children study, the health status of children in the North-West Province of South Africa was studied. It was an epidemiologic, cross-sectional study in which 583 black non-stunted and 192 stunted children (stature below the fifth percentile for age) of both sexes ages 10 to 15 y were recruited from 44 schools. Blood pressure was monitored with the Finapres (finger-arterial pressure) apparatus and by means of the Fast Modelflo software program; measurements for systolic and diastolic blood pressure, mean arterial pressure, pulse pressure, heart rate, cardiac output, stroke volume, total peripheral resistance, and arterial compliance were obtained. Dietary intake data were collected with a 24-h dietary recall questionnaire. Nutrient coding was the same for all recalls and macro- and micronutrients were calculated. Anthropometric measurements were done according to standard methods.

RESULTS

There were no significant differences in systolic blood pressure and diastolic blood pressure between stunted and non-stunted children after correction for body mass index and heart rate. Stroke volume, arterial compliance, and cardiac output were significantly lower and total peripheral resistance was significantly higher in stunted children than in non-stunted children. No significant differences in dietary intake could be detected, although dietary intakes were slightly lower in the stunted children.

CONCLUSIONS

We found that compliance, a marker of vascular function, is significantly lower in stunted children. Stunting was related to early changes in cardiovascular function in African children ages 10 to 15 y.

Low birth weight, nephron number, and kidney disease

More and more evidence is emerging that highlights the far-reaching consequences of prenatal (intrauterine) programming on organ function and adult disease. In humans, low birth weight (LBW) occurs more frequently in disadvantaged communities among whom there is often a disproportionately high incidence of adult cardiovascular disease, hypertension, diabetes mellitus, and kidney disease. Indeed, many epidemiologic studies have found an inverse association between LBW and higher blood pressures in infancy and childhood, and overt hypertension in adulthood. Multiple animal models have demonstrated the association of LBW with later hypertension, mediated, at least in part, by an associated congenital nephron deficit. Although no direct correlation has been shown between nephron number and birth weight in humans with hypertension, nephron numbers were found to be lower in adults with essential hypertension, and glomeruli tend to be larger in humans of lower birth weight. An increase in glomerular size is consistent with hyperfiltration necessitated by a reduction in total filtration surface area, which suggests a congenital nephron deficit. Hyperfiltration manifests clinically as microalbuminuria and accelerated loss of renal function, the prevalence of which are higher among adults who had been of LBW. A kidney with a reduced nephron number has less renal reserve to adapt to dietary excesses or to compensate for renal injury, as is highlighted in the setting of renal transplantation, where smaller kidney to recipient body-weight ratios are associated with poorer outcomes, independent of immunologic factors. Both hypertension and diabetes are leading causes of end-stage renal disease worldwide, and their incidences are increasing, especially in underdeveloped communities. Perinatal programming of these 2 diseases, as well as of nephron number, may therefore have a synergistic impact on the development of hypertension and kidney disease in later life. Existing evidence suggests that birth weight should be used as a surrogate marker for future risk of adult disease. Although the ideal solution to minimize morbidity would be to eradicate LBW, until this panacea is realized, it is imperative to raise awareness of its prognostic implications and to focus special attention toward early modification of risk factors for cardiovascular and renal disease in individuals of LBW.

Disruption of rat forebrain development by glucocorticoids: critical perinatal periods for effects on neural cell acquisition and on cell signaling cascades mediating noradrenergic and cholinergic neurotransmitter/neurotrophic responses

Glucocorticoids are the consensus treatment for the prevention of respiratory distress in preterm infants, but there is evidence for increased incidence of neurodevelopmental disorders as a result of their administration. We administered dexamethasone (Dex) to developing rats at doses below or within the range of those used clinically, evaluating the effects on forebrain development with exposure in three different stages: gestational days 17-19, postnatal days 1-3, or postnatal days 7-9. At 24 h after the last dose, we evaluated biomarkers of neural cell acquisition and growth, synaptic development, neurotransmitter receptor expression, and synaptic signaling mediated by adenylyl cyclase (AC). Dex impaired the acquisition of neural cells, with a peak effect when given in the immediate postnatal period. In association with this defect, Dex also elicited biphasic effects on cholinergic presynaptic development, promoting synaptic maturation at a dose (0.05 mg/kg) well below those used therapeutically, whereas the effect was diminished or lost when doses were increased to 0.2 or 0.8 mg/kg. Dex given postnatally also disrupted the expression of adrenergic receptors known to participate in neurotrophic modeling of the developing brain and evoked massive induction of AC activity. As a consequence, disparate receptor inputs all produced cyclic AMP overproduction, a likely contributor to disrupted patterns of cell replication, differentiation, and apoptosis. Superimposed on the heterologous AC induction, Dex impaired specific receptor-mediated cholinergic and adrenergic signals. These results indicate that, during a critical developmental period, Dex administration leads to widespread interference with forebrain development, likely contributing to eventual, adverse neurobehavioral outcomes.

Embodiment: a conceptual glossary for epidemiology

This construct and process are central to ecosocial theory and epidemiological inquiry. Recognising that we, as humans, are simultaneously social beings and biological organisms, the notion of "embodiment" advances three critical claims: (1) bodies tell stories about-and cannot be studied divorced from--the conditions of our existence; (2) bodies tell stories that often--but not always--match people's stated accounts; and (3) bodies tell stories that people cannot or will not tell, either because they are unable, forbidden, or choose not to tell. Just as the proverbial "dead man's bones" do in fact tell tales, via forensic pathology and historical anthropometry, so too do our living bodies tell stories about our lives, whether or not these are ever consciously expressed. This glossary sketches some key concepts, definitions, and hypotheses relevant for using the construct of "embodiment" in epidemiological research, so as to promote not only rigorous science but also social equity in health.