Conference on "Multidisciplinary approaches to nutritional problems". Postgraduate Symposium. Exploiting dietary supplementation trials to assess the impact of the prenatal environment on CVD risk

Early-Life Nutrition Interventions and Associated Long-Term Cardiometabolic Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Early-life nutrition interventions can have lifelong cardiometabolic benefits. Most evidence on this topic is derived from observational studies. We evaluated the association of randomized controlled nutritional trials in early life and long-term cardiometabolic outcomes. Through literature search of PubMed, CABI Global Health, Embase, and Cochrane, with manual reference check and weekly alert from PubMed, we identified 8312 records, and included 53 records from 40 cohorts in 21 countries. The total number of participants was 33,551. Interventions were initiated as early as conception, and the longest until 7 y (except 1 study from infancy to 20 y). The cohorts were followed up for between 3 and 73 y. We identified 7 types of interventions (protein-energy supplements, long-chain PUFAs, single micronutrient, multiple micronutrients, infant and young child feeding, dietary counseling, and other) and 4 categories of cardiometabolic outcomes (biomarkers, cardiovascular, body size and composition, and subclinical/clinical outcomes). Most findings were null. Fasting glucose concentration was 0.04 mmol/L lower (95% CI: -0.05, -0.02 mmol/L; I2 = 0%) in the intervention groups than in the control groups (15 studies). BMI (kg/m2) was 0.20 higher (95% CI: 0.12, 0.28; I2 = 54%) in the intervention groups than control groups (14 studies). No significant effect was observed for total cholesterol (12 studies) or blood pressure (17 studies). Ongoing and personalized dietary counseling was associated with lower glucose and cholesterol, better endothelial function, and reduced risk of metabolic syndrome. The timing of intervention mattered, with earlier initiation conferring greater benefit (improved lipid profile and marginally lower glucose concentration) based on 2 studies. In sum, glucose concentration was lower following early-life nutrition interventions, but there is a risk of unintended consequences, including higher BMI. Maternal and child nutrition interventions must be evidence-based and tailored to each population to promote long-term cardiometabolic health.

Early Life Origins of Obesity and Related Complications

The idea that nutrition in early life (such as before conception, during pregnancy and in infancy) can influence, or programme, long-term health, known as the 'Developmental Origins of Health and Disease Hypothesis', has generated great scientific interest. This concept is particularly relevant for the development of obesity and its complications, arguably the most important public health issue of the twenty-first century worldwide. The concept is strongly supported by evidence from animal studies, both observational and experimental (randomised) studies in humans, and is highly relevant for population health in both low-income and high-incomes countries. For instance, optimising nutrition in pregnancy (both in terms of under-nutrition and over-nutrition) and preventing too fast infant weight gain have been shown to reduce the risk of future obesity. Proposed mechanisms have included effects of early nutrition on the epigenome, hormones such as insulin, and regulation of appetite, that effect long-term risk of obesity. Although further data from experimental studies is required to support a causal link between early nutrition and future adiposity, the developmental origins hypothesis is already changing health policy and practice globally. The present review considers the evidence for the developmental origins of obesity, the mechanisms involved, and the implications for public health.

The Impact of Kidney Development on the Life Course: A Consensus Document for Action

Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world.

Maternal supplementation with vitamin A or β-carotene and cardiovascular risk factors among pre-adolescent children in rural Nepal

Vitamin A plays an important role in fetal renal and cardiovascular development, yet there has been little research on its effects on cardiovascular risk factors later in childhood. To examine this question, we followed the children of women who had been participants in a cluster-randomized, double blind, placebo-controlled trial of weekly supplementation with 7000 μg retinol equivalents of preformed vitamin A or 42 mg of β-carotene from 1994 to 1997 in rural Nepal. Women received their assigned supplements before, during and after pregnancy. Over a study period of 3 years, 17,531 infants were born to women enrolled in the trial. In 2006-2008, we revisited and assessed 13,118 children aged 9-13 years to examine the impact of maternal supplementation on early biomarkers of chronic disease. Blood pressure was measured in the entire sample of children. In a subsample of 1390 children, venous blood was collected for plasma glucose, Hb1Ac and lipids and a morning urine specimen was collected to measure the ratio of microalbumin/creatinine. Detailed anthropometry was also conducted in the subsample. The mean ± s.d. systolic and diastolic blood pressure was 97.2 ± 8.2 and 64.6 ± 8.5 mm Hg, respectively, and about 5.0% had high-blood pressure (⩾120/80 mm Hg). The prevalence of microalbuminuria (⩾30 mg/g creatinine) was also low at 4.8%. There were no differences in blood pressure or the risk of microalbuminuria between supplement groups. There were also no group differences in fasting glucose, glycated hemoglobin, triglycerides or cholesterol. Maternal supplementation with vitamin A or β-carotene had no overall impact on cardiovascular risk factors in this population at pre-adolescent age in rural Nepal.

Intrauterine nutrition: long-term consequences for vascular health

There is a growing body of evidence that improper intrauterine nutrition may negatively influence vascular health in later life. Maternal malnutrition may result in intrauterine growth retardation and, in turn, metabolic disorders such as insulin resistance, diabetes, hypertension, and dyslipidemia, and also enhanced risk of atherosclerosis and cardiovascular death in the offspring. Energy and/or protein restriction is the most critical determinant for fetal programming. However, it has also been proposed that intrauterine n-3 fatty acid deficiency may be linked to later higher blood pressure levels and reduced insulin sensitivity. Moreover, it has been shown that inadequate supply of micronutrients such as folate, vitamin B12, vitamin A, iron, magnesium, zinc, and calcium may contribute to impaired vascular health in the progeny. In addition, hypertensive disorders of pregnancy that are linked to impaired placental blood flow and suboptimal fetal nutrition may also contribute to intrauterine growth retardation and aggravated cardiovascular risk in the offspring. On the other hand, maternal overnutrition, which often contributes to obesity and/or diabetes, may result in macrosomia and enhanced cardiometabolic risk in the offspring. Progeny of obese and/or diabetic mothers are relatively more prone to develop obesity, insulin resistance, diabetes, and hypertension. It was demonstrated that they may have permanently enhanced appetites. Their atheromatous lesions are usually more pronounced. It seems that, particularly, a maternal high-fat/junk food diet may be detrimental for vascular health in the offspring. Fetal exposure to excessive levels of saturated fatty and/or n-6 fatty acids, sucrose, fructose and salt, as well as a maternal high glycemic index diet, may also contribute to later enhanced cardiometabolic risk.

Metabolic syndrome: role of maternal undernutrition and fetal programming

Development of metabolic syndrome is attributed to genes, dietary intake, physical activity and environmental factors. Fetal programming due to maternal nutrition is also an important factor especially in developing countries where intrauterine growth retardation followed by excess nutrition postnatally is causing mismatch predisposing individuals to development of metabolic syndrome and its components. Several epidemiological and animal studies have provided evidence for the link between intrauterine growth retardation and adult metabolic diseases. Deficiency of macronutrients, protein and carbohydrates, during pregnancy and gestation results in lower infant birth weight, a surrogate marker of fetal growth and subsequently insulin resistance, glucose intolerance, hypertension and adiposity in adulthood. The role of micronutrients is less extensively studied but however gaining attention with several recent studies focusing on this aspect. Several mechanisms have been proposed to explain the developmental origin of adult diseases important among them being alteration of hypothalamic pituitary axis, epigenetic regulation of gene expression and oxidative stress. All of these mechanisms may be acting at different time during gestation and contributing to development of metabolic syndrome in adulthood.

Effects of exclusive breastfeeding intervention on child growth and body composition: the MINIMat trial, Bangladesh

AIM

Exclusive breastfeeding (EBF) for 6 months is recommended for optimal infant health, but the evidence for longer-term impacts is weak. We examined whether randomization to receive EBF counselling (BFC) in rural Bangladeshi women had an impact on childhood growth trajectories and body composition.

METHODS

In the Maternal and Infant Nutrition Interventions in Matlab trial, 4436 pregnant women were randomized to six equally sized, food and micronutrient groups. Of these, 3214 were randomized during the last trimester of pregnancy to receive either BFC or the usual/standard health message (UHM). Their infants were extensively followed up, with anthropometric measurements between 0 and 54 months and assessment of body composition at 54 months.

RESULTS

The mean duration of EBF in the BFC group was 111 days compared to 76 days in the UHM group (mean difference: 35.0 days, 95% CI 30.6-39.5, p < 0.001). There was no difference in growth trajectories between the BFC and UHM groups and no difference in body composition at 54 months. Children exposed to prenatal multiple micronutrients (vs 60 mg iron and folate) combined with BFC (vs UHM), however, had slower linear growth (mean difference -0.17 SD score, p < 0.01).

CONCLUSION

Exclusive breastfeeding counselling resulted in neither differential growth trajectories in infancy and childhood, nor body composition differences at 54 months. The combination of prenatal multiple micronutrient supplementation (MMS) and BFC was unfavourable for linear growth during 0-54 months, which raises questions about possible negative effects of MMS.

Combined food and micronutrient supplements during pregnancy have limited impact on child blood pressure and kidney function in rural Bangladesh

Observational evidence suggests nutritional exposures during in utero development may have long-lasting consequences for health; data from interventions are scarce. Here, we present a trial follow-up study to assess the association between prenatal food and micronutrient supplementation and childhood blood pressure and kidney function. During the MINIMat Trial in rural Bangladesh, women were randomly assigned early in pregnancy to receive an early or later invitation to attend a food supplementation program and additionally to receive either iron and folate or multiple micronutrient tablets daily. The 3267 singleton birth individuals with measured anthropometry born during the trial were eligible for a follow-up study at 4.5 y old. A total of 77% of eligible individuals were recruited and blood pressure, kidney size by ultrasound, and glomerular filtration rate (GFR; calculated from plasma cystatin c) were assessed. In adjusted analysis, early invitation to food supplementation was associated with a 0.72-mm Hg [(95% CI: 0.16, 1.28); P = 0.01] lower childhood diastolic blood pressure and maternal MMS supplementation was associated with a marginally higher [0.87 mm Hg (95% CI: 0.18, 1.56); P = 0.01] childhood diastolic blood pressure. There was also some evidence that a supplement higher in iron was associated with a higher offspring GFR. No other effects of the food or micronutrient interventions were observed and there was no interaction between the interventions on the outcomes studied. These marginal associations and small effect sizes suggest limited public health importance in early childhood.

Nutritional supplementation during pregnancy and offspring cardiovascular disease risk in The Gambia

BACKGROUND

Maternal nutritional intake during pregnancy may have important consequences for long-term health in offspring.

OBJECTIVE

The objective was to follow up the offspring in 2 randomized trials of nutrient supplementation during pregnancy to investigate the effect on cardiovascular disease (CVD) risk in offspring.

DESIGN

We recruited offspring born during 2 trials in The Gambia, West Africa. One trial provided protein-energy-dense food supplements (1015 kcal and 22 g protein/d) to pregnant (intervention, from 20 wk gestation until delivery) or lactating (control, for 20 wk from birth) women and was randomized at the village level. The second was a double-blind, individually randomized, placebo-controlled trial of calcium supplementation (1.5 g/d), which was also provided from 20 wk gestation until delivery.

RESULTS

Sixty-two percent (n = 1267) of children (aged 11-17 y) born during the protein-energy trial were recruited and included in the analysis, and 64% (n = 350) of children (aged 5-10 y) born during the calcium trial were recruited and included in the analysis. Fasted plasma glucose was marginally lower in children born to mothers receiving protein-energy supplements during pregnancy than in those children of the lactating group (adjusted mean difference: -0.05 mmol/L; 95% CI: -0.10, -0.001 mmol/L). There were no other differences in CVD risk factors, including blood pressure, body composition, and cholesterol, between children born to intervention and control women from the protein-energy trial. Maternal calcium supplementation during pregnancy was unrelated to offspring blood pressure.

CONCLUSION

These data suggest that providing supplements to pregnant women in the second half of pregnancy may have little effect on the CVD risk of their offspring, at least in this setting and at the ages studied here. This trial was registered at www.controlled-trials.com as ISRCTN96502494.

Maternal nutritional status, C(1) metabolism and offspring DNA methylation: a review of current evidence in human subjects

Evidence is growing for the long-term effects of environmental factors during early-life on later disease susceptibility. It is believed that epigenetic mechanisms (changes in gene function not mediated by DNA sequence alteration), particularly DNA methylation, play a role in these processes. This paper reviews the current state of knowledge of the involvement of C₁ metabolism and methyl donors and cofactors in maternal diet-induced DNA methylation changes in utero as an epigenetic mechanism. Methyl groups for DNA methylation are mostly derived from the diet and supplied through C₁ metabolism by way of choline, betaine, methionine or folate, with involvement of riboflavin and vitamins B₆ and B₁₂ as cofactors. Mouse models have shown that epigenetic features, for example DNA methylation, can be altered by periconceptional nutritional interventions such as folate supplementation, thereby changing offspring phenotype. Evidence of early nutrient-induced epigenetic change in human subjects is scant, but it is known that during pregnancy C₁ metabolism has to cope with high fetal demands for folate and choline needed for neural tube closure and normal development. Retrospective studies investigating the effect of famine or season during pregnancy indicate that variation in early environmental exposure in utero leads to differences in DNA methylation of offspring. This may affect gene expression in the offspring. Further research is needed to examine the real impact of maternal nutrient availability on DNA methylation in the developing fetus.

Estimated birth weight and adult cardiovascular risk factors in a developing southern Chinese population: a cross sectional study

Background

Birth weight is negatively associated with cardiovascular diseases and diabetes, but the associations are less well-established in developing populations where birth weight is often unavailable. We studied the association of birth weight and cardiovascular risk, using birth rank as an instrumental variable, in Southern China.

Methods

We used published data on birth weight by birth rank from an appropriate population and baseline data from the Guangzhou Biobank Cohort Study phases 2 & 3 (2005-8) to examine the adjusted associations, using instrumental variable analysis, of birth weight with clinically measured cardiovascular risk factors and the metabolic syndrome in older (≥ 50 years) men (n = 5,051) and women (n = 13,907).

Results

Estimated birth weight was associated with lower blood pressure (systolic -0.25 mm Hg 95% confidence interval (CI), -0.53 to 0.03 and diastolic -0.33 mm Hg 95% CI -0.48 to -0.18 per standard deviation higher birth weight), but had little association with glucose, lipids, waist-hip ratio, body mass index or the metabolic syndrome, adjusted for age, sex, early environment and number of offspring.

Conclusion

Birth weight may impact blood pressure; however associations of birth weight with other cardiovascular risk factors may not be related to foetal exposures, but speculatively could be an historical co-incidence, with corresponding implications for prevention.

Maternal micronutrient deficiency, fetal development, and the risk of chronic disease

Early life nutritional exposures, combined with changes in lifestyle in adult life, can result in increased risk of chronic diseases. Although much of the focus on the developmental origins of disease has been on birth size and growth in postnatal life and the availability of energy and protein during these critical developmental periods, micronutrient deficiencies may also play an important role in fetal growth and development. Micronutrient status in fetal and early life may alter metabolism, vasculature, and organ growth and function, leading to increased risk of cardiometabolic disorders, adiposity, altered kidney function, and, ultimately, to type 2 diabetes and cardiovascular diseases. This review elucidates pathways through which micronutrient deficiencies lead to developmental impairment and describes the research to date on the evidence that micronutrient deficiencies in utero influence the development of chronic disease risk. Animal studies, observational human studies examining maternal diet or micronutrient status, and limited data from intervention studies are reviewed. Where data are lacking, plausible mechanisms and pathways of action have been derived from the existing animal and in vitro models. This review fills a critical gap in the literature related to the seminal role of micronutrients in early life and extends the discussion on the developmental origins of health and disease beyond birth size and energy and protein deficiency.