The relation of maternal weight to the blood pressures of Gambian children

Nutrition and Health from Womb to Tomb

Fulfilment of the genetic potential of individuals is impaired by malnutrition and other environmental factors throughout life. The impact of nutritional factors in early childhood helps to explain why the known adult risk factors, demonstrable in populations, are poor predictors of cardiovascular disease in individuals. The combined findings of early and later risk factors strengthen the conclusion that the bulk of so-called degenerative diseases and many other functional impairments in adult life occur because of environmental factors, of which diet may be the most important. The apparent increased susceptibility to degenerative diseases of adults born small-for-date suggests that the increase in meat, fat, and calorie consumption with rising affluence is particularly hazardous for formerly poorly nourished populations. Articles confirming the nutritional origins of a wide range of diseases and disabilities at all ages increasingly predominate in the health-related scientific literature. Recognition that so much disease can be prevented or delayed by improved diet and related lifestyles constitutes a new paradigm applicable to the populations of both developing and industrialized countries.

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.

Persistent influence of maternal obesity on offspring health: Mechanisms from animal models and clinical studies

The consequences of excessive maternal weight and adiposity at conception for the offspring are now well recognized. Maternal obesity increases the risk of overweight and obesity even in children born with appropriate-for-gestational age (AGA) birth weights. Studies in animal models have employed both caloric excess and manipulation of macronutrients (especially high-fat) to mimic hypercaloric intake present in obesity. Findings from these studies show transmission of susceptibility to obesity, metabolic dysfunction, alterations in glucose homeostasis, hepatic steatosis, skeletal muscle metabolism and neuroendocrine changes in the offspring. This review summarizes the essential literature in this area in both experimental and clinical domains and focuses on the translatable aspects of these experimental studies. Moreover this review highlights emerging mechanisms broadly explaining maternal obesity-associated developmental programming. The roles of early developmental alterations and placental adaptations are also reviewed. Increasing evidence also points to changes in the epigenome and other emerging mechanisms such as alterations in the microbiome that may contribute to persistent changes in the offspring. Finally, we examine potential interventions that have been employed in clinical cohorts.

Programming of fetal insulin resistance in pregnancies with maternal obesity by ER stress and inflammation

The global epidemics of obesity during pregnancy and excessive gestational weight gain (GWG) are major public health problems worldwide. Obesity and excessive GWG are related to several maternal and fetal complications, including diabetes (pregestational and gestational diabetes) and intrauterine programming of insulin resistance (IR). Maternal obesity (MO) and neonatal IR are associated with long-term development of obesity, diabetes mellitus, and increased global cardiovascular risk in the offspring. Multiple mechanisms of insulin signaling pathway impairment have been described in obese individuals, involving complex interactions of chronically elevated inflammatory mediators, adipokines, and the critical role of the endoplasmic reticulum (ER) stress-dependent unfolded protein response (UPR). However, the underlying cellular processes linking MO and IR in the offspring have not been fully elucidated. Here, we summarize the state-of-the-art evidence supporting the possibility that adverse metabolic postnatal outcomes such as IR in the offspring of pregnancies with MO and/or excessive GWG may be related to intrauterine activation of ER stress response.

The impact of malaria in pregnancy on changes in blood pressure in children during their first year of life

We established a maternal birth cohort in Ibadan, Nigeria, where malaria is hyperendemic, to assess how intrauterine exposure to malaria affected infant blood pressure (BP) development. In a local maternity hospital, healthy pregnant women had regular blood films for malaria parasites from booking to delivery. Growth and BP were measured on 318 babies, all followed from birth to 3 and 12 months. Main outcomes were standardized measures of anthropometry and change in BP to 1 year. Babies exposed to maternal malaria were globally smaller at birth, and boys remained smaller at 3 months and 1 year. Change in systolic BP (SBP) during the year was greater in boys than in girls (20.9 versus 15.7 mm Hg; P=0.002) but greater in girls exposed to maternal malaria (18.7 versus 12.7 mm Hg; 95% confidence interval, 1-11 mm Hg; P=0.02). Eleven percent of boys (greater than twice than expected) had a SBP ≥95th percentile (hypertensive, US criteria), of whom 68% had maternal malaria exposure. On regression analysis (β coefficients, mm Hg), sex (boys>girls; β=4.4; 95% confidence interval, 1.1-7.7; P=0.01), maternal malaria exposure (3.64; 0.3-6.9; P=0.03), and weight change (2.4; 0.98-3.8/1 standard deviation score; P=0.001) all independently increased SBP change to 1 year, whereas increase in length decreased SBP (-1.98; -3.6 to -0.40). In conclusion, malaria-exposed boys had excess hypertension, whereas malaria-exposed girls a greater increase in SBP. Intrauterine exposure to malaria had sex-dependent effects on BP, independent of infant growth. Because infant-child-adult BP tracking is powerful, a malarial effect may contribute to the African burden of hypertension.

Randomized, placebo-controlled, calcium supplementation trial in pregnant Gambian women accustomed to a low calcium intake: effects on maternal blood pressure and infant growth

BACKGROUND

Dietary calcium intake in rural Gambian women is very low (∼350 mg/d) compared with international recommendations. Studies have suggested that calcium supplementation of women receiving low-calcium diets significantly reduces risk of pregnancy hypertension.

OBJECTIVE

We tested the effects on blood pressure (BP) of calcium carbonate supplementation (1500 mg Ca/d) in pregnant, rural Gambian women.

DESIGN

The study was a randomized, double-blind, parallel, placebo-controlled supplementation trial from 20 wk of gestation (P20) until delivery (calcium: n = 330; placebo; n = 332). BP and anthropometric measures were taken at P20 and then 4 weekly until 36 wk of gestation (P36), and infant anthropometric measures were taken at 2, 13, and 52 wk postdelivery.

RESULTS

A total of 525 (calcium: n = 260; placebo: n = 265) women had BP measured at P36 and subsequently delivered a healthy term singleton infant. Mean compliance was 97%, and urinary calcium measures confirmed the group allocation. At P20, the mean (±SD) systolic blood pressure (SBP) was 101.2 ± 9.0 and 102.1 ± 9.3 mm Hg, and diastolic blood pressure (DBP) was 54.5 ± 7.3 and 55.8 ± 7.8 mm Hg, in the calcium and placebo groups, respectively. The intention-to-treat analysis that was adjusted for confounders showed no significant effect of calcium supplementation on the change between P20 and P36 (calcium compared with placebo; mean ± SEM) in SBP (-0.64 ± 0.65%; P = 0.3) or DBP (-0.22 ± 1.15%; P = 0.8). There was no significant effect of supplementation on BP, pregnancy weight gain, weight postpartum, or infant weight, length, and other measures of growth. However, the comparability of the original randomly assigned groups may have been compromised by the exclusion of 20.7% of women from the final analysis.

CONCLUSIONS

Calcium supplementation did not affect BP in pregnancy. This result may have been because the Gambian women were adapted to a low dietary calcium intake, and/or obesity, high gestational weight gain, high underlying BP, tobacco use, alcohol consumption, and sedentary lifestyles were rare. This trial was registered at the International Standard Randomized Controlled Trial Register (www.controlled-trials.com/mrct/) as ISRCTN96502494.

The risk of maternal obesity to the long-term health of the offspring

The prevalence of maternal obesity has risen dramatically in recent years, with approximately one in five pregnant women in the UK now classed as obese (body mass index ≥ 30 kg/m(2) ) at antenatal booking. Obesity during pregnancy has been hypothesized to exert long-term health effects on the developing child through 'early life programming'. While this phenomenon has been well studied in a maternal undernutrition paradigm, the processes by which the programming effects of maternal obesity are mediated are less well understood. In humans, maternal obesity has been associated with a number of long-term adverse health outcomes in the offspring, including lifelong risk of obesity and metabolic dysregulation with increased insulin resistance, hypertension and dyslipidaemia, as well as behavioural problems and risk of asthma. The complex relationships between the maternal metabolic milieu and the developing foetus, as well as the potential influence of postnatal lifestyle and environment, have complicated efforts to study the programming effects of maternal overnutrition in humans. This review will examine the emerging evidence from human studies linking maternal obesity to adverse offspring outcomes.

Human growth and chronic disease: a memorial to Jim Tanner

CONTEXT

Memorial to Jim Tanner.

OBJECTIVE

To examine the links between early growth and chronic disease in later life.

METHODS

Literature review.

RESULTS

There is now a developmental model for the origins of chronic disease in which the causes to be identified are linked to normal variations in feto-placental, infant and childhood growth and development. These variations lead to variations in the supply of nutrients to the baby that permanently alters gene expression, a process known as 'programming'.

CONCLUSIONS

Variations in the processes of development programme the function of a few key systems that are linked to chronic disease-the immune system, anti-oxidant defences, inflammatory responses, the number and quality of stem cells, neuro-endocrine settings and the balance of the autonomic nervous system. There is not a separate cause for each different disease. Which chronic disease originates during development may depend more on timing than on qualitative differences in exposures to external influences.

Reducing excessive gestational weight gain: lessons from the weight control literature and avenues for future research

Excessive gestational weight gain is a prevalent problem and an independent predictor of future obesity in both mothers and offspring. Intervention research to prevent excessive gestational weight gain is still in its infancy but results to date have been quite modest. Research in weight control outside of pregnancy over the past 30 years has been more robust and identified several key components of effective programs, including use of caloric restriction, daily diet self-monitoring, self-weighing, behavior therapy and ongoing patient-provider contact. The aim of this article is to summarize intervention components shown to be effective in promoting successful weight control outside of pregnancy and explore potential applications in pregnancy. Available evidence suggests that the strategies shown to be effective for weight control outside of pregnancy may also promote better weight control in pregnancy, but several lines for future investigation remain.

Fetoplacental vascular endothelial dysfunction as an early phenomenon in the programming of human adult diseases in subjects born from gestational diabetes mellitus or obesity in pregnancy

Gestational diabetes mellitus (GDM) and obesity in pregnancy (OP) are pathological conditions associated with placenta vascular dysfunction coursing with metabolic changes at the fetoplacental microvascular and macrovascular endothelium. These alterations are seen as abnormal expression and activity of the cationic amino acid transporters and endothelial nitric oxide synthase isoform, that is, the "endothelial L-arginine/nitric oxide signalling pathway." Several studies suggest that the endogenous nucleoside adenosine along with insulin, and potentially arginases, are factors involved in GDM-, but much less information regards their role in OP-associated placental vascular alterations. There is convincing evidence that GDM and OP prone placental endothelium to an "altered metabolic state" leading to fetal programming evidenced at birth, a phenomenon associated with future development of chronic diseases. In this paper it is suggested that this pathological state could be considered as a metabolic marker that could predict occurrence of diseases in adulthood, such as cardiovascular disease, obesity, diabetes mellitus (including gestational diabetes), and metabolic syndrome.

Prenatal factors for childhood blood pressure mediated by intrauterine and/or childhood growth?

OBJECTIVE

Some prenatal factors may program an offspring's blood pressure, but existing evidence is inconclusive and mechanisms remain unclear. We examined the mediating roles of intrauterine and childhood growth in the associations between childhood systolic blood pressure (SBP) and 5 potentially modifiable prenatal factors: maternal smoking during pregnancy; prepregnancy BMI; pregnancy weight gain; chronic hypertension; and preeclampsia-eclampsia.

METHODS

The sample contained 30 461 mother-child pairs in the Collaborative Perinatal Project. Prenatal data were extracted from obstetric forms, and children's SBP was measured at 7 years of age. Potential mediation by intrauterine growth restriction (IUGR) and childhood growth was examined by the causal step method.

RESULTS

Heavy maternal smoking during pregnancy was significantly associated with higher offspring SBP (adjusted mean difference versus nonsmoking: 0.73 mm Hg [95% confidence interval (CI): 0.32-1.14]), which attenuated to null (0.13 [95% CI: -0.27-0.54]) after adjustment for changes in BMI from birth to 7 years of age. Prepregnancy overweight-obesity was significantly associated with higher offspring SBP (versus normal weight: 0.89 mm Hg [95% CI: 0.52-1.26]), which also attenuated to null (-0.04 mm Hg [95% CI: -0.40-0.31]) after adjustment for childhood BMI trajectory. Adjustment for BMI trajectory augmented the association between maternal pregnancy weight gain and offspring SBP. Adjustment for childhood weight trajectory similarly changed these associations. However, all these associations were independent of IUGR.

CONCLUSIONS

Childhood BMI and weight trajectory, but not IUGR, may largely mediate the associations of maternal smoking during pregnancy and prepregnancy BMI with an offspring's SBP.

Association of maternal weight gain in pregnancy with offspring obesity and metabolic and vascular traits in childhood

BACKGROUND

We sought to examine the association of gestational weight gain (GWG) and prepregnancy weight with offspring adiposity and cardiovascular risk factors.

METHODS AND RESULTS

Data from 5154 (for adiposity and blood pressure) and 3457 (for blood assays) mother-offspring pairs from a UK prospective pregnancy cohort were used. Random-effects multilevel models were used to assess incremental GWG (median and range of repeat weight measures per woman: 10 [1, 17]). Women who exceeded the 2009 Institute of Medicine-recommended GWG were more likely to have offspring with greater body mass index, waist, fat mass, leptin, systolic blood pressure, C-reactive protein, and interleukin-6 levels and lower high-density lipoprotein cholesterol and apolipoprotein A1 levels. Children of women who gained less than the recommended amounts had lower levels of adiposity, but other cardiovascular risk factors tended to be similar in this group to those of offspring of women gaining recommended amounts. When examined in more detail, greater prepregnancy weight was associated with greater offspring adiposity and more adverse cardiovascular risk factors at age 9 years. GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution but strengthened in women gaining >500 g/wk. By contrast, between 14 and 36 weeks, GWG was only associated with offspring adiposity in women gaining >500 g/wk. GWG between 14 and 36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles, with these associations largely mediated by the associations with offspring adiposity.

CONCLUSIONS

Greater maternal prepregnancy weight and GWG up to 36 weeks of gestation are associated with greater offspring adiposity and adverse cardiovascular risk factors. Before any GWG recommendations are implemented, the balance of risks and benefits of attempts to control GWG for short- and long-term outcomes in mother and child should be ascertained.

Racial Disparities in the Association between Birth Weight in the Term Infant and Blood Pressure at Age 7 Years: Results from the Collaborative Perinatal Project

BP has been inversely associated with birth weight in studies worldwide, but few studies have included black individuals. The US National Collaborative Perinatal Project followed 58,960 pregnant women and their resultant offspring for 7 yr. In this post hoc analysis, all term white or black children without kidney or heart disease were included (n = 29,710). The effect of birth weight and other risk factors on systolic (SBP) and diastolic BP (DBP) was evaluated at 7 yr. Mean birth weight and body mass index at 7 yr were slightly lower for black compared with white children (birth weight 3.14 +/- 0.48 versus 3.32 +/- 0.46 kg [P < 0.001]; body mass index 15.8 +/- 2.0 versus 16.3 +/- 2.0 [P < 0.001]). Compared with white mothers, black mothers were less likely to smoke (41 versus 52%), were more anemic (23 versus 7%), and were more likely to live in poverty (72 versus 39%). In linear regression, there was significant interaction between race and birth weight in predicting SBP (P = 0.002). In bivariate analysis, birth weight was positively associated with SBP (beta = 0.87) and DBP (beta = 1.14) in black children (P < 0.001) but not associated with either in white children. With maternal poverty, educational level, and anemia during pregnancy added to the model, birth weight remained a significant positive predictor of SBP (beta = 0.89, P < 0.001) in black but not in white children (beta = 0.02, P = 0.17). The association between birth weight and SBP differs between black and white children. The cause of intrauterine growth restriction-associated hypertension seems to be race sensitive; therefore, future studies of racial disparities in the "Barker hypothesis" may help in the understanding of the mechanism of fetal programming of hypertension.

Hypotheses on the Fetal Origins of Adult Diseases: Contributions of Epidemiological Studies

Epidemiological studies have demonstrated associations between low birth weight and cardiovascular disease, type 2 diabetes and their risk factors in adult life. These findings have led to sharp debates in the literature concerning potential methodological study flaws and the effect size and causality of the associations. More recent studies seem to have overcome most methodological flaws and suggest a small effect size of low birth weight on adult diseases for the individual. However, the effect size may still be important on a population level. Various causal pathways have been hypothesized as mechanisms underlying these associations. These hypotheses have proposed central roles for (1) fetal undernutrition, (2) increased cortisol exposure, (3) genetic susceptibility and (4) accelerated post-natal growth. These hypotheses have been studied in various epidemiological study designs. Thus far, it is still not known which mechanisms underlie the associations between low birth weight and diseases in adult life. The causal pathways linking low birth weight to diseases in later life seem to be complex and may include combined environmental and genetic mechanisms in various periods of life. Well-designed epidemiological studies are necessary to estimate the population effect size and to identify the underlying mechanisms. This knowledge is needed to develop strategies for identifying groups at risk and prevention focused on early life.

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.

Maternal body composition, offspring blood pressure and the hypothalamic-pituitary-adrenal axis

We tested the hypothesis that women who are thin or have poor pregnancy weight gain have offspring with higher blood pressure and examined whether this link is mediated by increased secretion of cortisol. We studied a cohort of 388 children born in Kingston, Jamaica. From hospital records we obtained information about their mother's body mass index (BMI) and weight gain during pregnancy. At age 8.5 years we measured the children's fasting plasma cortisol concentrations and blood pressure and assessed their mother's anthropometry. There were no relationships between the mother's BMI or weight gain during pregnancy and offspring blood pressure. However, mothers with a greater subscapular to triceps skinfold thickness ratio (SSTR) had offspring with higher blood pressure (5.6 mmHg systolic and 3.7 mmHg diastolic increase per unit change in SSTR, P = 0.002 and P = 0.008 respectively). Fasting plasma cortisol concentrations correlated with the children's systolic (r = 0.33, P < 0.0001) and diastolic pressures (r = 0.12, P = 0.02) independently of age, gender, weight or socio-economic status and were also predicted by the mother's SSTR. These findings suggest that maternal truncal obesity rather than thinness is associated with raised blood pressure in the offspring, and that this link may be mediated by increased cortisol secretion.

A review of low birth weight: predictors, precursors and morbidity outcomes

This paper reviews the global evidence concerning infant low birth weight (LBW) (2.500kg and below) in relation to suggested causative factors, such as undernutrition, stress, smoking, drug abuse and deprived living environments. In addition, health promotion strategies in place to reduce LBW incidence in both developed and underdeveloped countries are reviewed. The paper also focuses on the high incidence of LBW in the UK in comparison to other European and developed countries. Predictors of LBW are then considered comparing findings of a study conducted in the UK with findings in underdeveloped countries. In addition, LBW risk is discussed in the context of vulnerability factors, such as teen pregnancy, child abuse and domestic violence. In conclusion, the author argues for a health promotion policy in the UK to reduce incidence of LBW in areas of deprivation and suggests that the improvement of maternal health is key in improving the health of today's infants and children who will one day become the adults of tomorrow.

Maternal and child nutritional supplementation are inversely associated with fasting plasma glucose concentration in young Guatemalan adults

Cardiovascular disease and diabetes may be programmed early in life by abnormal development associated with undernutrition. We investigated whether maternal nutritional status (MNS; height, pregnancy weight gain, nonpregnant BMI, and prenatal supplementation) or childhood nutritional status (CNS; birth weight, length, ponderal index, height-for-age Z-score at 24 mo, and supplementation from 0 to 24 mo) were related to fasting plasma glucose levels in rural-born Guatemalan adults. We studied 209 men and 220 women (mean age 24.4 y) who were involved in a randomized trial of nutritional supplementation of their mothers during pregnancy and during their early childhoods, conducted from 1969 to 1977. In 2 villages, residents were offered Atole (3.8 MJ and 64 g protein/L); 2 other villages were offered Fresco (1.4 MJ/L, no protein). No associations were observed between anthropometric measures of MNS or CNS and fasting plasma glucose levels. In subgroup analyses, inverse associations (all P < 0.15) with birth size were found among women born to fatter mothers, women with low supplement intake, men born to short mothers, and men more severely stunted at 24 mo. Prenatal supplementation was inversely associated with fasting plasma glucose among women [-0.40 +/- 0.17 mmol/(L. MJ. d), P = 0.02]. Among men, postnatal intake of supplementation of 0.10 to 0.20 MJ/d was associated with up to a 0.56 mmol/L reduction in fasting plasma glucose (P = 0.03), but intake in excess of 0.20 MJ/d provided no added benefit. Among women, the benefit of postnatal supplementation was restricted to those born thin (test for interaction P = 0.10). Improving the nutritional status of undernourished women and children may have positive long-term consequences.

Nutrition before birth, programming and the perpetuation of social inequalities in health

The need to explain social inequalities in health has led to the theory that chronic disease is due, in part, to a legacy of adverse experiences in early life. Epidemiological studies show consistently that individuals who are small at birth have an increased risk of cardiovascular disease in adulthood. There is growing consensus that this association reflects a causal relationship and is not simply the product of bias or confounding. The concept of programming is invoked as the biological mechanism; birth size is thus a proxy for fetal programming. Recent findings suggest that fetal programming interacts with the post-birth environment. The adverse exposures that are thought to underlie and potentiate programming cluster in socially patterned ways, thus creating substantial inequalities in health. Experiments in animals demonstrate that nutritional interventions before or during pregnancy can produce programming phenomena in the offspring, sometimes without an impact on birth size. However, the extent to which maternal nutrition contributes to programming in contemporary developed countries is uncertain.

Cardiovascular disease risk factors are related to adult adiposity but not birth weight in young guatemalan adults

Fetal undernutrition has been hypothesized to program inappropriate metabolic responses to nutritional abundance in later life. Most studies have been conducted in industrialized countries. We studied the relationship between birth weight and risk factors for cardiovascular disease (CVD) among 187 men and 198 women age 20-29 y (mean age 24 y) who had participated in a longitudinal study conducted in Guatemala between 1969 and 1977. In women, birth weight was positively associated with adult body mass index (BMI; P < 0.01), systolic (P < 0.001) and diastolic blood pressure (P < 0.05), but not with glucose or any lipid measure. In men, birth weight was not associated with adult BMI, blood pressure or glucose, and was weakly and inversely related to total cholesterol and LDL cholesterol (test for trend: P = 0.06 and P = 0.09, respectively). Adult BMI was associated with increased prevalence of CVD risk factors in both men and women. Our data offer no support for the fetal programming of cardiovascular disease risk hypothesis in young adult women, and weak support in young adult men. Overweight in adults is a strong determinant of variance in CVD risk factor prevalence.

The role of the placenta in fetal programming-a review

The fetal origins hypothesis proposes that adult cardiovascular and metabolic disease originate through developmental plasticity and fetal adaptations arising from failure of the materno-placental supply of nutrients to match fetal requirements. The hypothesis is supported by experimental data in animals indicating that maternal nutrition can programme long term effects on the offspring without necessarily affecting size at birth. There is now evidence linking body composition in pregnant women and the balance of nutrient intake during pregnancy with raised levels of cardiovascular risk factors in the offspring. Maternal body composition and diet are thought to affect fetal development and programming as a result of both direct effects on substrate availability to the fetus and indirectly through changes in placental function and structure. Alterations in placental growth and vascular resistance, altered nutrient and hormone metabolism in the placenta, and changes in nutrient transfer and partitioning between mother, placenta and fetus all have important effects on the fetal adaptations thought to be central to programming. Future interventions to improve placental function are likely to have lifelong health benefits for the offspring.

The "fetal origins" hypothesis: challenges and opportunities for maternal and child nutrition

The "fetal origins" hypothesis postulates that conditions, most likely nutritional, "program" the fetus for the development of chronic diseases in adulthood. Associations between the newborn's size at birth and various determinants or consequences of chronic diseases have been identified in many, but not all, of the available studies. It remains to be established whether these associations are causal. Remarkably little information is available on the specific role of maternal nutritional status. The role of birth weight remains difficult to interpret except as a proxy for events in intrauterine life. Unfortunately, birth weight does not make an important contribution to the population attributable risk of cardiovascular disease; lifestyle factors during adulthood make much greater contributions. Data from experimental species suggest possible mechanisms for the origin of chronic disease early in life. It is too soon to use this research as a basis for new interventions directed at pregnant women for the purpose of reducing chronic disease in their offspring.

High-meat, low-carbohydrate diet in pregnancy: relation to adult blood pressure in the offspring

To examine the hypothesis that a high-animal protein, low-carbohydrate diet in pregnancy is associated with raised blood pressure in the adult offspring, we performed a follow-up study of 626 men and women in Motherwell, Scotland, whose mothers' food intake had been recorded during pregnancy. The mothers had taken part in a dietary intervention in which they were advised to eat 1 lb (0.45 kg) of red meat per day and to avoid carbohydrate-rich foods during pregnancy. The offspring were followed up at age 27 to 30 years, and their systolic and diastolic blood pressures were measured. Women who reported greater consumption of meat and fish in the second half of pregnancy had offspring with higher systolic blood pressure in adult life (regression coefficient, 0.19 mm Hg per portion per week; 95% confidence interval, 0.04 to 0.35; P=0.02). High maternal consumption of fish, but not meat, was associated with higher diastolic blood pressure in the offspring (regression coefficient, 1.00 mm Hg per portion per week; 95% confidence interval, 0.18 to 1.82; P=0.02). These associations were independent of maternal blood pressure, body size, and smoking habits during pregnancy. Although we cannot exclude confounding by maternal saturated fat or salt intake, the findings support those of a study in Aberdeen showing higher blood pressure in men and women whose mothers had eaten a high-animal protein, low-carbohydrate diet in late pregnancy. These associations may reflect the metabolic stress imposed on the mother by an unbalanced diet in which high intakes of essential amino acids are not accompanied by the nutrients required to utilize them.

Body size at birth and blood pressure among children in developing countries

BACKGROUND

Studies in developed countries have shown that reduced fetal growth is related to raised blood pressure in childhood and adult life. Little is known about this association in developing countries, where fetal growth retardation is common.

METHODS

In 1994-1995, we measured blood pressure in 1570 3-6-year-old children living in China, Guatemala, Chile, Nigeria and Sweden. We related their blood pressure to patterns of fetal growth, as measured by body proportions at birth. The children were all born after 37 weeks gestation and weighed more than 2.5 kg at birth.

RESULTS

In each country, blood pressure was positively related to the child's current weight. After adjusting for this and gender, systolic pressure was inversely related to size at birth in all countries except Nigeria. In Chile, China and Guatemala, children who were proportionately small at birth had raised systolic pressure. For example, in Chile, systolic pressure adjusted for current weight increased by 4.9 mmHg (95% CI : 2.1, 7.7) for every kilogram decrease in birthweight, by 1 mmHg (95% CI : 0.4, 1.6) for every centimetre decrease in birth length, and by 1.3 mmHg (95% CI : 0.4, 2.2) for every centimetre decrease in head circumference at birth. In Sweden, systolic pressure was higher in children who were disproportionately small, that is thin, at birth. Systolic pressure increased by 0.3 mmHg (95% CI : 0.0, 0.6) for every unit (kg/m3) decrease in ponderal index at birth. These associations were independent of the duration of gestation.

CONCLUSIONS

Raised blood pressure among children in three samples from China, Central and South America is related to proportionate reduction in body size at birth, which results from reduced growth throughout gestation. The relation between fetal growth and blood pressure may be different in African populations. Proportionately reduced fetal growth is the prevalent pattern of fetal growth retardation in developing countries, and is associated with chronic undernutrition among women. Improvement in the nutrition and health of girls and young women may be important in preventing cardiovascular disease in developing countries.

Fetal growth and blood pressure in a Danish population aged 31-51 years

During the past decade, studies have shown an inverse association between birth weight and blood pressure and risk of coronary heart disease in adult life. From old public archives we were able to trace the birth records of 545 out of 905 persons (60.2%) aged 31-51 years who participated in the Ebeltoft Health Promotion Project in Denmark. We examined the associations between birth weight, length at birth, Ponderal Index and systolic and diastolic blood pressure. No associations were found for women. For men, the mean systolic blood pressure fell from 131.1 mmHg with a birth weight of less than 3300 g to 129.6 mmHg with a birth weight of more than 4000 g, and for diastolic blood pressure 81.6 mmHg to 80.3 mmHg, respectively. For men, the mean systolic blood pressure fell from 135.7 mm Hg with a birth length of 30-51 cm to 131.6 with a birth length of 55-62 cm, and for diastolic blood pressure 83.0 mmHg to 78.8 mmHg, respectively. The associations may reflect organ programming in fetal life.

In utero programming of cardiovascular disease

Low birth weight, thinness and short body length at birth are now known to be associated with increased rates of cardiovascular disease and non-insulin dependent diabetes in adult life. The fetal origins hypothesis proposes that these diseases originate through adaptations which the fetus makes when it is undernourished. These adaptations may be cardiovascular, metabolic or endocrine. They permanently change the structure and function of the body. Prevention of the diseases may depend on prevention of imbalances in fetal growth or imbalances between pre- and post-natal growth, or imbalances in nutrient supply to the fetus.

An inverse relation between blood pressure and birth weight among 5 year old children from Soweto, South Africa

STUDY OBJECTIVE

To examine the relation between birth weight and blood pressure at 5 years in a cohort of South African children.

DESIGN

Prospective cohort study.

PARTICIPANTS

849 five year old children.

SETTING

Soweto, a sprawling urban area close to Johannesburg, South Africa, which was a designated residential area for people classified as "black" under apartheid legislation.

MAIN RESULTS

Systolic blood pressure at 5 years was inversely related to birthweight (r = -0.05, p = 0.0007), independent of current weight, height, gestational age, maternal age or socioeconomic status at 5 years. There was no relation between birth weight and diastolic blood pressure. After adjusting for current weight and height, there was a mean decline in systolic blood pressure of 3.4 mm Hg (95% confidence intervals 1.4, 5.3 mm Hg) for every 1000 g increase in birth weight.

CONCLUSIONS

These data from a disadvantaged urbanised community in Southern Africa extend the reported observations of an inverse relation between birth weight and systolic blood pressure. The study adds to the evidence that influences in fetal life and early childhood influence systolic blood pressure. Further research is required to assess whether efforts to reduce the incidence of low birthweight babies will attenuate the prevalence of hypertension in future generations.

Relationship between birthweight and blood pressure in childhood

Studies have shown an inverse relationship between birthweight and blood pressure in later life. The objective of this study is to analyze the relationship between birthweight and blood pressure in childhood in a North American-based population. Data on 2,958 births with follow-up at 7 years of age from the Providence, RI, cohort of the Collaborative Perinatal Project of the National Institute of Neurological Diseases and Stroke were retrospectively analyzed using univariate and multivariate analytic methods. Bivariate analysis of the total cohort showed a direct relationship between follow-up weight at age 7 years and birthweight (r = 0.24; P < 0.001) and follow-up weight with systolic (SBP) and diastolic blood pressure (DBP; r = 0.33; P < 0.001 and r = 0.22; P < 0.001, respectively). On multivariate analysis, follow-up weight and height were the strongest predictors of SBP and DBP. There was also a significant inverse relationship between birthweight and SBP. A cohort of term infants (n = 2,561) was subdivided into birthweight-for-gestational-age groupings to further evaluate the effects of birthweight on blood pressure. Small-for-gestational-age (SGA) infants were markedly smaller at age 7 years than those large-for-gestational-age (LGA; 21 +/- 4 kg v 26 +/- 4 kg; P < 0.01). Despite the direct association between follow-up weight and blood pressure, the mean blood pressure did not differ between SGA (103/58 mm Hg) and LGA patients (103/59 mm Hg). To assess whether birthweight was an independent predictor of blood pressure, blood pressures were predicted using linear regression equations. For every 1-kg decrease in birthweight in term infants, SBP at 7 years increased by 1.3 mm Hg and DBP by 0.6 mm Hg. In conclusion, controlling for weight and height in term infants at 7 years of age has an inverse linear effect on blood pressure. This suggests that birthweight in relation to gestation may be a contributor to the multifactorial cause of essential hypertension.

Placental weight, birth measurements, and blood pressure at age 8 years

OBJECTIVE

To examine relationships between blood pressure during childhood and both placental weight and body size at birth, in an Australian population.

DESIGN

A follow up study of a birth cohort, undertaken when cohort members were aged 8 years.

SETTING

Adelaide, South Australia.

SUBJECTS

830 children born in the Queen Victoria Hospital in Adelaide, South Australia, during 1975-6.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure measured when the children were aged 8 years.

RESULTS

Blood pressure at 8 years was positively related to placental weight and inversely related to birth weight, after adjusting for the child's current weight. For diastolic pressure there was a decrease of 1.0 mm Hg for each 1 kg increase in birth weight (95% confidence interval (CI) = -0.4 to 2.4) and an increase of 0.7 mm Hg for each 100 g increase in placental weight (95% CI = 0.1 to 1.3). Diastolic pressure was also inversely related to chest circumference at birth, independently of placental weight, with a decrease of 0.3 mm Hg for each 1 cm increase in chest circumference (95% CI = 0.2 to 0.5).

CONCLUSIONS

These findings are further evidence that birth characteristics, indicative of fetal growth patterns, are related to blood pressure in later life.

Fetal growth and cardiovascular risk factors in Jamaican schoolchildren

OBJECTIVE

To determine relation between schoolchildren's blood pressure, glycated haemoglobin level, and cholesterol concentration and their anthropometry, socioeconomic status, and birth measurements.

DESIGN

Retrospective cohort study.

SETTING

27 schools closest to University Hospital of the West Indies, Kingston, Jamaica.

SUBJECTS

2337 children aged 6-16 years who were born at university hospital were recruited, and their birth records were recovered: 1610 had suitable records, 659 had records including birth length, and 610 of these were prepubertal.

MAIN OUTCOME MEASURES

Blood pressure, glycated haemoglobin level, serum cholesterol concentration, anthropometry at birth, current anthropometry, and socioeconomic status.

RESULTS

Multiple regression analysis showed that children's systolic blood pressure was inversely related to their birth weight (P < 0.0001) and directly related to their current weight. Glycated haemoglobin level was higher in children with thicker triceps skinfolds (P < 0.001) and who had been shorter at birth (P = 0.003). Serum cholesterol concentration was inversely related to current height (P = 0.001) and to length at birth (P = 0.09) and was directly related to triceps skinfold thickness and higher socioeconomic status (P < 0.001).

CONCLUSIONS

Blood pressure in childhood was inversely related to birth weight and directly to current weight. Glycaemic control and serum cholesterol were related to short length at birth, height deficit in childhood, and childhood obesity.

Catch up growth and pancreatic function in growth retarded neonates

To test the hypothesis that relative pancreatic dysfunction is a determinant of catch up growth in small for gestational age (SGA) babies, 47 such babies (median gestation 38 weeks; range 27-41) and 41 appropriate for gestational age (AGA) babies matched for sex, race, and gestational age were recruited. Anthropometry was performed within 48 hours of birth and at 6 months. Faecal chymotrypsin activities were measured at 0-2 days, 14 days, 6 weeks and 6 months. At 6 months 30 SGA infants and 25 AGA infants were remeasured. In each group, median stool chymotrypsin activities doubled between 0-2 days and 6 months (9.0-25.5 IU/g SGA group; 11.6-25.3 IU/g AGA group). SGA babies had significantly lower chymotrypsin activities at 14 days (10.9 U/g) than AGA babies (15.5 U/g). In the SGA group faecal chymotrypsin activities at 0-2 days were strongly correlated with both catch up weight and with catch up length when corrected for the effects of birthweight. These data show that impaired pancreatic exocrine function at birth is associated with severe intrauterine malnutrition and with impaired catch up growth during the first 6 months of life.

Maternal nutrition in relation to fetal and placental growth

Babies who are small or disproportionate at birth, or who have altered placental growth are now known to be at an increased risk of developing coronary heart disease, hypertension and diabetes during adult life. This has led to the suggestion that these diseases are 'programmed' by an inadequate supply of nutrients to the developing fetus. The phenomenon of 'programming', whereby undernutrition in early life permanently changes body structure and function, is well documented in animals. As yet, relatively little is known about the maternal influences that alter fetal and placental growth, and underlie the programming of adult cardiovascular disease during fetal development. There are, however, interesting indications that maternal nutrition may be important.

Maternal and fetal determinants of adult diseases

Recent epidemiologic studies in the United Kingdom have led to the hypothesis that adverse nutritional experiences in utero have a powerful influence on the development of degenerative diseases in adulthood. Poor fetal growth as measured by weight, length, head, chest, and abdominal circumferences is a strong predictor of hypertension, diabetes, hyperlipidemia, alteration in clotting factors, Syndrome X,* and mortality from cardiovascular and chronic obstructive airways disease. The theory of fetal origins of adult disease proposes that early defects in the development, structure, and function of organs lead to a programmed susceptibility, which interacts with later diet and environmental stresses to cause overt disease many decades after the original insult.

Maternal nutritional status in pregnancy and blood pressure in childhood

OBJECTIVE

To examine the relation between indices of maternal nutrition during pregnancy, including haemoglobin concentration, skinfold thickness and body weight, and the child's blood pressure at 10 to 12 years of age.

DESIGN

Follow up study of children whose mothers had haemoglobin estimations, weights and skinfold thicknesses recorded during pregnancy.

SETTING

Kingston, Jamaica.

SUBJECTS

Seventy-seven children whose mothers took part in a prospective study of nutrition during pregnancy in relation to fetal growth.

MAIN OUTCOME MEASURE

Blood pressure at 10 to 12 years of age.

RESULTS

The child's mean systolic pressure adjusted for current weight rose by 2.6 mmHg (95% CI 0.5-4.6, P = 0.01) for each 1 g/dl fall in the mother's lowest haemoglobin during pregnancy. Mothers with a lower haemoglobin had thinner skinfold thicknesses, especially over the triceps (P = 0.005). In multiple regression analyses, taking account of the child's sex and current weight, there was a strong association between thin maternal triceps skinfold thickness at 15 weeks of gestation and raised blood pressure in the offspring. Taking account of the mother's triceps skinfold thickness abolished the relation between lower haemoglobin and raised blood pressure in the child. Lower weight gain between 15 and 35 weeks of gestation was independently associated with raised children's blood pressure. Systolic pressure rose by 10.7 mmHg (95% CI 5.7 to 15.6, P = 0.0001) for each log mm decrease in the mother's triceps skinfold thickness, and by 0.6 mmHg (95% CI 0.1 to 1.0, P = 0.02) for each 1 kg decrease in the mother's weight gain during pregnancy.

CONCLUSIONS

These results parallel animal experiments suggesting that impaired maternal nutrition may underlie the programming of adult hypertension during fetal life.