Many studies have provided evidence for the hypothesis that size at birth is related to the risk of developing disease in later life. In particular, links are well established between reduced birthweight and increased risk of coronary heart disease, diabetes, hypertension and stroke in adulthood. These relationships are modified by patterns of postnatal growth. The most widely accepted mechanisms thought to underlie these relationships are those of fetal programming by nutritional stimuli or excess fetal glucocorticoid exposure. It is suggested that the fetus makes physiological adaptations in response to changes in its environment to prepare itself for postnatal life. These changes may include epigenetic modification of gene expression. Less clear at this time are the relevance of fetal programming phenomena to twins and preterm babies, and whether any of these effects can be reversed after birth. Much current active research in this field will be of direct relevance to future obstetric practice.

The developmental origins of adult disease (Barker) hypothesis

There is now considerable evidence that elements of the heritable or familial component of disease susceptibility are transmitted by nongenomic means, and that environmental influences acting during early development shape disease risk in later life. The underlying mechanisms are thought to involve epigenetic modifications in nonimprinted genes induced by aspects of the developmental environment, which modify gene expression without altering DNA sequences. These changes result in life-long alterations in gene expression. Such nongenomic tuning of phenotype through developmental plasticity has adaptive value because it attempts to match an individual's responses to the environment predicted to be experienced. When the responses are mismatched, disease risk increases. An example of such mismatch is that arising either from inaccurate nutritional cues from the mother or placenta before birth, or from rapid environmental change through improved socioeconomic conditions, which contribute substantially to the increasing prevalence of type-2 diabetes, obesity, and cardiovascular disease. Recent evidence suggests that the effects can be transmitted to more than the immediately succeeding generation, through female and perhaps male lines. Future research into epigenetic processes may permit us to develop intervention strategies.

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Epigenetic Mechanisms and the Mismatch Concept of the Developmental Origins of Health and Disease

The primary markers of the metabolic syndrome are central obesity, insulin resistance and hypertension. In this review, we consider the effect of changes in maternal nutrition during critical windows in fetal development on an individual's subsequent predisposition to the metabolic syndrome. The fetal origins of obesity, cardiovascular disease and insulin resistance have been investigated in a wide range of epidemiological and animal studies; these investigations highlight adaptations made by the nutritionally manipulated fetus that aim to maintain energy homeostasis to ensure survival. One consequence of such developmental plasticity may be a long term re-setting of cellular energy homeostasis, most probably via epigenetic modification of genes involved in a number of key regulatory pathways. For example, reduced maternal-fetal nutrition during early gestation to midgestation affects adipose tissue development and adiposity of the fetus by setting an increased number of adipocyte precursor cells. Importantly, clinically relevant adaptations to nutritional challenges in utero may only manifest as primary components of the metabolic syndrome if followed by a period of accelerated growth early in the postnatal period and/or if offspring become obese.

Nutritional programming of the metabolic syndrome.

Context Increasing evidence suggests that adverse conditions during early prenatal life are associated with cardiometabolic dysfunction in postnatal life. In vitro fertilization (IVF) conception may be an early prenatal life event with long-term health consequences. Objective Our objective was to investigate several cardiometabolic measures in 8- to 18-yr-old IVF singletons and spontaneously conceived controls born from subfertile parents. Design and setting This follow-up study was conducted at the VU University Medical Center, Amsterdam, The Netherlands. Participants Blood pressure was examined in 225 IVF-conceived children and 225 age- and gender-matched spontaneously conceived control children. Several indicators of insulin resistance were studied in a pubertal subpopulation (131 IVF children and 131 controls). Main outcome measures Blood pressure, fasting glucose, and fasting insulin were determined. Results Systolic and diastolic blood pressure levels were higher in IVF children than controls (109 +/- 11 vs. 105 +/- 10 mm Hg, P Conclusions These findings highlight the importance of continued cardiometabolic monitoring of IVF-conceived children and might contribute to current knowledge about periconceptional influences and their consequences in later life.

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Cardiometabolic differences in children born after in vitro fertilization: follow-up study.

This study utilized maternal undernutrition from early to midgestation in the ewe to determine the impact(s) of intrauterine growth restriction on postpartum growth of male offspring and the potential mechanisms involved. Multiparous ewes were fed 50% (nutrient-restricted) or 100% (control-fed) of their nutrient requirements (NRC, 1985) between d 28 and 78 of gestation, and then all ewes were fed 100% of the NRC requirements from d 79 through lambing. Male lambs born to nutrient-restricted (n = 9) and control-fed (n = 9) ewes exhibited similar BW (5.8 vs. 6.0 +/- 0.3 kg) and crown-rump lengths (53.8 vs. 55.4 +/- 1.0 cm) at birth. At 63 and 250 d of postnatal age, wether lambs were subjected to a glucose tolerance test, in which a bolus of glucose was administered i.v. to evaluate changes in glucose and insulin concentrations. After i.v. glucose administration at 63 d of age, lambs from nutrient-restricted ewes exhibited a greater area under the curve for glucose (AUCg; 6,281 vs. 5,242 +/- 429; P < 0.05) and insulin (AUCi; 21.0 vs. 8.6 +/- 1.9; P < 0.001) than lambs from control-fed ewes. After glucose administration at 250 d of age, lambs from nutrient-restricted ewes had greater AUCg (7,147 vs. 5,823 +/- 361; P < 0.01) but a lower AUCi (6.4 vs. 10.2 +/- 1.9; P = 0.05) than lambs from control-fed ewes. Lambs from nutrient-restricted ewes were heavier (26.6 vs. 21.8 +/- 2.3 kg; P < 0.05) and had more backfat (0.30 vs. 0.21 +/- 0.03 cm, P < 0.05) by 4 mo of age than the lambs from control-fed ewes. At slaughter at 280 d of age, lambs from nutrient-restricted ewes remained heavier than lambs from control-fed ewes, had greater (P < 0.05) amounts of kidney and pelvic-area adipose tissue, and tended (P < 0.10) to have reduced LM and semitendinosus muscle weights as a percentage of HCW. These data demonstrate that a bout of maternal undernutrition during early to midgestation in sheep increased BW and fat deposition during adolescence and dysregulated glucose uptake in the absence of any change in birth weight.

Maternal undernutrition during early to mid-gestation in the ewe results in altered growth, adiposity, and glucose tolerance in male offspring.

The present study examines the effects of late vs. early gestation undernutrition on adult glucose-insulin homeostasis in sheep and investigates whether the lower birth weight of twins alters glucose-insulin handling in adult life. Pregnant sheep were fed to requirement (100% intake) from day 0 of gestation to term [ approximately 147 days of gestation (dGA), control singles (CS) n = 5; control twins (CT) n = 5] or to 50% requirement from days 0-30 dGA [nutrient restricted during early gestation (NRE); n = 5] or day 110-term [NR during late nutrition (NRL); n = 4]. At all other times, NR sheep received 100% intake. All sheep lambed naturally; offspring were weaned at 10 wk and were reared on pasture until 1 yr of age. At this time, indwelling catheters were inserted, and 2-4 days later, basal metabolic and endocrine status and responses to an intravenous glucose tolerance test (IVGTT) and feeding were assessed. Adipose and skeletal muscle were then sampled after humane euthanasia and were analyzed for expression of insulin-signaling proteins and GLUT4. Between groups, birth weight of singletons was similar and increased relative to twins. At 1 yr of age, weights were similar between groups. The areas under the curve for glucose and insulin during the IVGTT were greater in NRL vs. other groups, indicating glucose intolerance. This was associated with reduced adipose, but not muscle, GLUT4, and increased adipose tissue mass. Adult glucose-insulin homeostasis in sheep was unaffected by fetal number. In conclusion, prenatal undernutrition, specifically during late gestation, affects adult offspring intermediary metabolism, and, in particular, glucose-insulin homeostasis.

Programming of glucose-insulin metabolism in adult sheep after maternal undernutrition

Glucocorticoids are proposed to act as intermediary factors that transcribe the developmental programming sequelae of maternal nutrient restriction (NR). Periconceptional under-nutrition of sheep markedly activates fetal hypothalamic-pituitary-adrenal (HPA) axis activity leading to preterm birth, while transient undernutrition during late gestation in sheep programs adult HPA axis function. To date, no study has examined resting or stimulated HPA axis function in young adult offspring following a periconceptional nutritional challenge. In the present study, 20 ewes were either periconceptionally undernourished (50% metabolisable energy requirements from days 1 to 30 gestation; NR, n = 8) or fed to control levels (100% requirement; controls, n = 12) to term (147 days gestation). Ewes were blood sampled remotely at 2 and 30 days using automated blood sampling equipment. Thereafter, offspring (controls, n = 6/6 males/females; NR, n = 4/4 males/females) were reared to 1 year of age and on separate days received either an i.v. corticotrophin-releasing hormone (CRH; 0.5 microg/kg) and vasopressin (AVP; 0.1 microg/kg) challenge or a synthetic ACTH i.v. bolus (Synacthen; 1.25 microg/kg), and blood samples were taken (manually and remotely) at appropriate intervals for measurement of plasma ACTH and cortisol accordingly. Resting plasma cortisol, assessed remotely, was similar in ewes during undernutrition (control 18.3 +/- 1.4 vs NR 23.4 +/- 1.9 nmol/l) and in offspring at 4 months of age (control male 17.6 +/- 2.9; control female 17.2 +/- 0.4, NR male 16.5 +/- 3.1, NR female 21.7 +/- 4.0 nmol/l). At 12 months of age, however, resting plasma cortisol was significantly increased in NR females (control male 28.0 +/- 1.5, control female 32.9 +/- 9, NR male 32 +/- 7, NR female 53 +/- 10 nmol/l, F 5.7, P = 0.02) despite no difference in plasma ACTH concentration. There was an interaction between nutritional group and gender for both the pituitary and adrenal responses to CRH and AVP, i.e. for controls, females exhibited increased plasma ACTH or cortisol relative to males but for NR this trend was either not present or reversed. The adrenocortical response to synthetic ACTH was gender-dependent only, being greater in female offspring. Combined CRH and AVP provoked a transient hypertension and marked bradycardia in all animals, irrespective of dietary group or gender and could be effectively reproduced by an AVP bolus alone. In conclusion, the present study has shown that periconceptional undernutrition of sheep has only a minor influence on HPA axis function in their young adult offspring when considered alongside the effect of gender per se.

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Effect of periconceptional undernutrition and gender on hypothalamic-pituitary-adrenal axis function in young adult sheep.

You might find this additional information useful... This article cites 65 articles, 31 of which you can access free at: http://ajpregu.physiology.org/cgi/content/full/287/1/R12#BIBL This article has been cited by 5 other HighWire hosted articles: € [Abstract]€ [Full Text]€ [PDF] J. Physiol., December 1,€2004; 561€(2): 355-377. J. A Armitage, I. Y Khan, P. D Taylor, P. W Nathanielsz and L. Poston imbalance: how strong is the evidence from experimental models in mammals? Developmental programming of the metabolic syndrome by maternal nutritional€ [Full Text]€ [PDF] Am J Physiol Regulatory Integrative Comp Physiol, January 1,€2005; 288€(1): R11-R15. J. Schwartz and J. L. Morrison Impact and mechanisms of fetal physiological programming € [Abstract]€ [Full Text]€ [PDF] J. Physiol., May 15,€2005; 565€(1): 137-147. J. S. Gilbert, A. L. Lang, A. R. Grant and M. J. Nijland offspring at 9 months of age Maternal nutrient restriction in sheep: hypertension and decreased nephron number in€ [Abstract]€ [Full Text]€ [PDF] Am J Physiol Regulatory Integrative Comp Physiol, October 1,€2005; 289€(4): R1169-R1176. D. Scholz and F. S. Lamb R. D. Roghair, J. L. Segar, R. V. Sharma, M. C. Zimmerman, D. K. Jagadeesha, E. M. Segar, T.dexamethasone before the onset of systemic hypertension Newborn lamb coronary artery reactivity is programmed by early gestation€ [Abstract]€ [Full Text]€ [PDF] Am J Physiol Regulatory Integrative Comp Physiol, October 1,€2005; 289€(4): R947-R954. Keisler, T. Stephenson and M. E. Symonds D. S. Gardner, K. Tingey, B. W. M. Van Bon, S. E. Ozanne, V. Wilson, J. Dandrea, D. H.Programming of glucose-insulin metabolism in adult sheep after maternal undernutrition Updated information and services including high-resolution figures, can be found at: http://ajpregu.physiology.org/cgi/content/full/287/1/R12 and Comparative Physiology can be found at: Additional material and information about American Journal of Physiology - Regulatory, Integrativehttp://www.the-aps.org/publications/ajpregu This information is current as of December 2, 2005 . € ISSN: 0363-6119, ESSN: 1522-1490. Visit our website at http://www.the-aps.org/.

B. W. M. Van Bon

Papers

Programming of glucose-insulin metabolism in adult sheep after maternal undernutrition

Effect of periconceptional undernutrition and gender on hypothalamic-pituitary-adrenal axis function in young adult sheep.

early maternal undernutrition in sheep Programming of adult cardiovascular function after