Blood pressure in relation to relative weight at birth through childhood and youth in obese and non-obese adult men

Changes and correlations in height from 7 to 69 years of age across the birth years of 1930 to 1989

OBJECTIVES

The aims of this study were to describe changes in height during childhood and to investigate potential changes in the proportion of children attaining final height in childhood and in correlations between child and adult height across birth cohorts.

METHODS

We included 363 059 children (179 906 girls) from the Copenhagen School Health Records Register, who were born between 1930 and 1989, with height measurements at ages 7, 10, or 13 years. Linkages to data resources containing adult height values between ages 18 and 69 years were possible for a subpopulation of 96 133 individuals (23 051 women). Birth years were categorized as 1930 to 1939, 1940 to 1949, and 1950 to 1989. Descriptive height statistics were estimated by birth years and birth cohorts. Height correlations were examined using sex- and age-specific partial Pearson correlation analyses and meta-regression techniques.

RESULTS

Across 60 birth years, mean child heights at age 7 increased by 2.9 cm in girls and 3.0 cm in boys, and adult heights increased as well. The proportions of children attaining final height by age 13 remained low across the birth cohorts; nonetheless, there was a significant increase from 0.7% to 1.5% in girls only (P < .0001). Both child-child and child-adult height correlations were strong and remained relatively stable across birth cohorts.

CONCLUSIONS

Mean child and adult height increased during the study period, but the proportion of children attaining final height at age 13 remained low. Child-child and child-adult height correlations were largely unchanged across birth cohorts.

Birth weight and adolescent blood pressure measured at age 12 years in the Gateshead Millennium Study

Birth weight and early growth have been associated with later blood pressure. However, not all studies consistently find a significant reduction in blood pressure with an increase in birth weight. In addition, the relative importance of birth weight and of other lifestyle and environmental factors is often overlooked and the association is rarely studied in adolescents. We investigated early life predictors, including birth weight, of adolescent blood pressure in the Gateshead Millennium Study (GMS). The GMS is a cohort of 1029 individuals born in 1999-2000 in Gateshead in Northern England. Throughout infancy and early childhood, detailed information were collected, including birth weight and measures of height and weight. Assessments of 491 returning participants at age 12 years included measures of body mass and blood pressure. Linear regression and path analysis were used to determine predictors and their relative importance on blood pressure. Birth weight was not directly associated with blood pressure at the age of 12. However, after adjustment for contemporaneous body mass index (BMI), an inverse association of standardized birth weight on systolic blood pressure was significant. The relative importance of birth weight on later systolic blood pressure was smaller than other contemporaneous body measures (height and BMI). There was no independent association of birth weight on blood pressure seen in this adolescent population. Contemporaneous body measures have an important role to play. Lifestyle factors that influence body mass or size, such as diet and physical activity, where interventions are directed at early prevention of hypertension should be targeted.

Effect of early postnatal nutrition on chronic kidney disease and arterial hypertension in adulthood: a narrative review

Intrauterine growth restriction (IUGR) has been identified as a risk factor for adult chronic kidney disease (CKD), including hypertension (HTN). Accelerated postnatal catch-up growth superimposed to IUGR has been shown to further increase the risk of CKD and HTN. Although the impact of excessive postnatal growth without previous IUGR is less clear, excessive postnatal overfeeding in experimental animals shows a strong impact on the risk of CKD and HTN in adulthood. On the other hand, food restriction in the postnatal period seems to have a protective effect on CKD programming. All these effects are mediated at least partially by the activation of the renin-angiotensin system, leptin and neuropeptide Y (NPY) signaling and profibrotic pathways. Early nutrition, especially in the postnatal period has a significant impact on the risk of CKD and HTN at adulthood and should receive specific attention in the prevention of CKD and HTN.

Is birth weight associated with blood pressure among African children and adolescents? A systematic review

There is substantial evidence of an inverse association between birth weight and later blood pressure (BP) in populations from high-income countries, but whether this applies in low-income countries, where causes of low birth weight are different, is not certain.

OBJECTIVE

We conducted a review of the evidence on the relationship between birth weight and BP among African children and adolescents. Medline, EMBASE, Global Health and Web of Science databases were searched for publications to October 2016. Papers reporting the relationship between birth weight and BP among African children and adolescents were assessed. Bibliographies were searched for further relevant publications. Selected papers were summarized following the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. In total, 16 papers from 13 studies conducted in nine African countries (Nigeria, Republic of Seychelles, Gambia, Democratic Republic of Congo, Cameroon, South Africa, Algeria, Zimbabwe and Angola) were reviewed. Eight studies were cohorts, while five were cross-sectional. The relationship between birth weight and later BP varied with age of the participants. Studies in neonates showed a consistently positive association, while predominantly inverse associations were seen among children, and studies in adolescents were inconsistent. Based on the limited number of studies identified, the relationship between birth weight and later BP may vary with age in African children and adolescents. Not all studies adequately controlled for confounding, notably gender or age. Whether the inverse relationship between birth weight and BP in later life observed in Western settings is also seen in Africa remains unclear.

Association of Breast Feeding and Birth Weight with Anthropometric Measures and Blood Pressure in Children and Adolescents: The CASPIAN-IV Study

BACKGROUND

Noncommunicable diseases (NCDs) and their risk factors are major health threats especially for developing countries. The aim of this study was to assess the association between breast feeding (BF) and birth weight (BW) with anthropometric measures and blood pressure (BP) in a nationally-representative sample of Iranian children and adolescents.

METHODS

In this national survey, 14,880 children and adolescents, aged 6-18 years, were selected using a multistage, cluster sampling method from rural and urban areas of 30 provinces of Iran. BF duration and BW were assessed by validated questionnaires completed by parents.

RESULTS

The study participants were 13,486 students (participation rate of 90.6%). They consisted of 49.24% girls, 75.6% urban residents, with a mean age of 12.5 years (95% confidence interval: 12.3-12.6). The family history of obesity had a significant association with BW (p < 0.001). A substantial association was found between BF duration and the order of children in the family, both in boys (p < 0.001) and girls (p < 0.001). The mean values for height, weight, body mass index, as well as waist, wrist, and hip circumferences were higher in those with higher BW categories (p for trend < 0.001). As BW increased, there was a linear decrease in underweight (p for trend < 0.001) and a linear increase in the prevalence of generalized obesity (p for trend < 0.001) was documented.

CONCLUSION

BW was associated with a higher prevalence in general obesity and a lower prevalence of being underweight. Duration of BF had no significant association with anthropometric measures and BP. Future longitudinal studies are necessary to determine the clinical implications of these findings.

Obesity research based on the Copenhagen School Health Records Register

INTRODUCTION

To summarise key findings from research performed using data from the Copenhagen School Health Records Register over the last 30 years with a main focus on obesity-related research. The register contains computerised anthropometric information on 372,636 schoolchildren from the capital city of Denmark. Additional information on the cohort members has been obtained via linkages with population studies and national registers.

RESEARCH TOPICS

Studies using data from the register have made important contributions in the areas of the aetiology of obesity, the development of the obesity epidemic, and the long-term health consequences of birth weight as well as body size and growth in childhood.

CONCLUSION

Research using this unique register is ongoing, and its contributions to the study of obesity as well as other topics will continue for years to come.

Life course path analysis of birth weight, childhood growth, and adult systolic blood pressure

The inverse associations between birth weight and later adverse health outcomes and the positive associations between adult body size and poor health imply that increases in relative body size between birth and adulthood may be undesirable. In this paper, the authors describe life course path analysis, a method that can be used to jointly estimate associations between body sizes at different time points and associations of body sizes throughout life with health outcomes. Additionally, this method makes it possible to assess both the direct effect and the indirect effect mediated through later body size, and thereby the total effect, of size and changes in size on later outcomes. Using data on childhood body size and adult systolic blood pressure from a sample of 1,284 Danish men born between 1936 and 1970, the authors compared results from path analysis with results from 3 standard regression methods. Path analysis produced easily interpretable results, and compared with standard regression methods it produced a noteworthy gain in statistical power. The effect of change in relative body size on adult blood pressure was more pronounced after age 11 years than in earlier childhood. These results suggest that increases in body size prior to age 11 years are less harmful to adult blood pressure than increases occurring after this age.

Risks and causes of mortality among low-birthweight infants in childhood and adolescence

The purpose of the study was to estimate the risks of mortality among infants with low birthweight (LBW, <2500 g) during their childhood and adolescence using a prospective cohort design. A total of 341 249 livebirths were registered in the 1985 Taiwan Birth Registry. We identified the 11 701 LBW singletons and randomly selected the same number of normal-birthweight (NBW) singletons. Study subjects of both LBW and NBW groups were linked, through the individual's unique personal identification number, to the Taiwan Death Registry to identify those who died between 1985 and 2003. Using the life-table method, we calculated the age-specific and cumulative survival rate for both LBW and NBW groups. We used Cox's proportional hazard model with adjustment for potential confounders to estimate the age-specific hazard ratio (HR) of mortality. Age-specific causes of mortality were presented for both groups. The result showed that the cumulative survival rate over an 18-year period for the LBW and NBW subjects was estimated at 95.83% and 99.37%, respectively. Significantly increased adjusted HR of mortality associated with LBW was limited to ages <1 year (boys: 8.99; girls: 8.29) and 1-4 years (boys: 2.19; girls: 2.25). Conditions originating in the perinatal period and congenital anomalies were the most prevalent cause of death among LBW and NBW, respectively. Between ages 1 and 18 years, injury and poisoning became the top ranked causes of death irrespective of birthweight and gender. Although there were small numbers of congenital anomalies, they were still a leading cause of death for LBW subjects, but not for NBW subjects, at ages 5-18 years. The LBW subjects were also likely to suffer from respiratory causes at 5-18 years. This study suggested, therefore, that LBW infants tended to have significantly elevated mortality rates under the age of 5 years, and were vulnerable to more non-injury deaths in their childhood and adolescence.

What evidence is there that adjustment for adult height influences the relationship between birth weight and blood pressure?

BACKGROUND

The inverse association between birth weight and blood pressure may partly be the result of inappropriate adjustment for adult body size, but it remains unclear whether adjustment for adult height elicits this effect.

AIM

The study investigated the impact of adjustment for adult height on the relationship between birth weight and blood pressure.

METHODS

A systematic search of Medline from 1996 to 2006 was conducted using the terms 'birth weight', 'blood pressure' and 'hypertension', and any papers containing linear regression analyses of blood pressure on birth weight for populations with an average age of 25+ were eligible for inclusion in comparative meta-analyses.

RESULTS

None of the 30 studies identified had published regression coefficients for blood pressure on birth weight before and after adjustment for adult height, and only two studies were found to adjust for adult height at all. Data from these studies were obtained, and it was found that adjustment for height made the association between birth weight and systolic blood pressure (SBP) more negative in one study but less negative in the other. When compared with meta-analyses of comparable models, it was found that both studies were substantially different from the combined estimate of the relationship between birth weight and SBP.

CONCLUSIONS

Both the differences between the two selected studies and their differences from the combined estimates obtained by meta-analysis are likely to be due to differences in the age of the participants. The relationship between birth weight and SBP tended to become more strongly inverse in studies with older participants. Additionally, the correlations between height and SBP were found to change from positive to negative with increasing age, which explained the differential impact of adjustment for height in the two selected studies. It therefore appears that adjustment for height may have little effect for older participants, but more so for younger participants.

Effect of postnatal catch-up growth on blood pressure in children at 3 years of age

Size at birth and early postnatal growth rates appear to be important determinants of cardiovascular diseases. We examined whether intrauterine growth restriction or the subsequent catch-up postnatal weight gain leads to higher blood pressure in early life to confirm that size at birth and early postnatal growth rates appear to be important determinants of blood pressure changes in early life. Of 407 children born between December 2001 and November 2002 in hospital based-birth cohorts, 102 were followed up at 3 years of age (24.2%) at Ewha Womans University Hospital in Seoul, Korea. At 3 years of age, those who had a low birth weight still belonged in the lower-weight group than the others. The subjects' systolic blood pressure was correlated with their current weight (r=0.41) and weight gain (r=0.39), but not with their birth weight. Those with a higher current weight and higher weight gain based on birth weight (conditional weight gain) had the highest blood pressure. Systolic blood pressure increased by 0.2 mm Hg for every 100-g increase in weight at 3 years and, independently, by 1.5 mm Hg for every 100-unit increase in conditional weight gain. This study suggests that birth weight is not directly associated with blood pressure, but accelerated growth, which occurs mostly in those born with a low birth weight, seems to affect blood pressure in early life.

The association between intrauterine growth restriction in the full-term infant and high blood pressure at age 7 years: results from the Collaborative Perinatal Project

OBJECTIVE

To use neonatal and placental anthropometry as proxy measures of intrauterine growth restriction (IUGR) and to relate these to blood pressure later in childhood.

STUDY DESIGN

A post hoc analysis of full-term white and black children from the Collaborative Perinatal Project, followed from birth until age 7 years (n = 29,710). Blood pressure above the 90th percentile by gender and race was considered high blood pressure. Anthropometric measures at birth included birth weight, ponderal index (PI, birth weight/birth length(3)), head to chest circumference (HCC) ratio, and placental ratio percentage (PRP, placental weight(*)100/birth weight).

RESULTS

Among anthropometric measures, PI, HCC, and birth weight were not associated with high systolic blood pressure at age 7 years, but PRP was. In multiple logistic regression, high systolic blood pressure and widened pulse pressure were both predicted by increased PRP [odds ratio (OR) 1.03 and 1.04, P < 0.001] but not by birth weight, when adjusted for gender, race, and maternal education. High diastolic blood pressure was weakly predicted by birth weight (OR 1.10, P = 0.05) but not by PRP.

CONCLUSIONS

PRP is associated with an increased risk for high systolic blood pressure and pulse pressure later in childhood, whereas birth weight, PI, and HCC are not. The proportion of placental weight to birth weight is a useful marker of IUGR for studying the developmental origins of adult disease hypothesis.

Sex-specific effects of prenatal low-protein and carbenoxolone exposure on renal angiotensin receptor expression in rats

Experimental models have shown the developing cardiovascular and renal systems to be sensitive to mild shifts in maternal nutrition, leading to altered function and risk of disease in adult life. The offspring of Wistar rats fed a low-protein diet during pregnancy exhibit a reduced nephron number and hypertension in postnatal life, providing a useful tool to examine the mechanistic basis of programming. Evidence indicates that upregulation of the renin-angiotensin system plays an important role, in particular through receptor-mediated changes in angiotensin II activity. However, although programmed hypertension has proven dependent on maternal glucocorticoids, there appear to be conflicting effects of prenatal low-protein and glucocorticoid exposure on postnatal angiotensin receptor expression. This study aimed to resolve this issue by comparing the effects of low-protein and glucocorticoid exposures on postnatal nephron number and angiotensin receptor expression. In addition, this study examined the modulation of prenatal treatment effects by postnatal inhibition of type 1 angiotensin receptor. The data demonstrates that whereas prenatal low-protein and glucocorticoid exposure have a similar effect in reducing nephron number, there are age- and gender-related differences in their effects on postnatal angiotensin receptor expression. In addition, this study provides novel evidence of a substantial upregulation of type 2 angiotensin receptor expression in low-protein- and glucocorticoid-exposed female offspring at 20 weeks of age, with implications for subsequent renal remodeling and function. Despite being targeted to the postnephrogenic period, inhibition of type 1 angiotensin receptor had an inhibitory effect on renal and somatic growth, additionally indicating its unsuitability during early life.

Developmental determinants of blood pressure in adults

Over the past 20 years a large and varied body of research has attempted to make the case for the developmental origins of elevated adult blood pressure (BP). Experimental animal research has identified plausible biological mechanisms through which fetal nutritional insufficiency may affect adult BP. The majority of human epidemiologic studies demonstrate an inverse association of birth weight (the most commonly used marker of fetal nutrition) with adult BP and higher risk of hypertension among individuals with lower weight at birth. The most adverse BP outcomes occur among individuals who were small at birth but relatively large as adults, a finding that suggests a role for postnatal growth. We critically review the literature on proposed mechanisms and epidemiologic evidence for developmental origins of adult BP and hypertension, considering associations with birth weight, maternal nutrition during pregnancy, child growth patterns, and infant feeding.

Developmental origins of the metabolic syndrome: prediction, plasticity, and programming

The "fetal" or "early" origins of adult disease hypothesis was originally put forward by David Barker and colleagues and stated that environmental factors, particularly nutrition, act in early life to program the risks for adverse health outcomes in adult life. This hypothesis has been supported by a worldwide series of epidemiological studies that have provided evidence for the association between the perturbation of the early nutritional environment and the major risk factors (hypertension, insulin resistance, and obesity) for cardiovascular disease, diabetes, and the metabolic syndrome in adult life. It is also clear from experimental studies that a range of molecular, cellular, metabolic, neuroendocrine, and physiological adaptations to changes in the early nutritional environment result in a permanent alteration of the developmental pattern of cellular proliferation and differentiation in key tissue and organ systems that result in pathological consequences in adult life. This review focuses on those experimental studies that have investigated the critical windows during which perturbations of the intrauterine environment have major effects, the nature of the epigenetic, structural, and functional adaptive responses which result in a permanent programming of cardiovascular and metabolic function, and the role of the interaction between the pre- and postnatal environment in determining final health outcomes.

Birth weight and blood pressure in childhood: results from the Health Survey for England

Findings of previous reports relating low birth weight with raised blood pressure in childhood and adolescence have been inconsistent. The present study uses cross-sectional data from a series of nationally representative annual surveys--the Health Survey for England--between 1995 and 2002, totaling a sample of 15 629 children aged 5 to 15. A significant negative relationship between birth weight, in quartiles or dichotomized as low (<2.5 kg) and normal (> or =2.5 kg) and systolic blood pressure was apparent. Linear regression analyses confirmed these findings. When current weight was included in the model, the strength of the relationship increased. An interaction term between birth weight and current weight was not significant. A life-course plot for those aged 13 to 15 (n=3900), converting the weight measurements at birth and as a teenager to standard deviation scores to make the regression coefficients comparable, showed the importance of weight gain on blood pressure (1 standard deviation increase in weight from birth to age 13 to 15 was associated with an increase in systolic blood pressure of 0.8 mm Hg). Separating those with low and normal birth weight demonstrated that the increase in weight from birth to adolescence had an effect on blood pressure in both those with low and normal birth weight. Postnatal changes in size have a more important effect on blood pressure in childhood and adolescence than birth weight. Reducing the prevalence of overweight among children may reduce their systolic blood pressure importantly and, particularly among children with lower birth weight, the prevalence of hypertension later in life.

Effect of Birth Weight on Blood Pressure and Body Size in Early Adolescence

The fetal programming theory that birth weight contributes to blood pressure or body size in later life is examined in this study. A prospective longitudinal study was conducted on subjects who were examined as newborns and prospectively interviewed and re-examined at 11 to 14 years old. Low birth weight (<2500 g) was present in 36% of the sample. The adolescent examination included measurements of blood pressure (BP), both auscultation and oscillometric methods; anthropometrics (height, weight, and body mass index [BMI]); health status; and health behaviors. Data were analyzed on 250 subjects. Correlation coefficients of birth weight with all BP measures were nonsignificant, except for the last auscultated diastolic BP ( r =0.19, P <0.01), which had a positive relationship. The simple correlation coefficients of birth weight with adolescent body size were significant and positive for weight and BMI. After multiple linear regression analyses with adjustments for age, Tanner stage, and gestational age, there was no significant effect of birth weight on adolescent weight or BMI. No significant correlations were detected for ponderal index at birth with adolescent measures. This study, which includes a substantial portion of low-birth-weight cases (36%), indicates that birth weight does not correlate negatively with later BP. These results do not support the low-birth-weight theory and indicate that childhood factors that are more proximal have a greater effect on adolescent BP than intrauterine factors.