Abstract-Maternal obesity is increasingly prevalent and may affect the long-term health of the child. We investigated the effects of maternal diet-induced obesity in mice on offspring metabolic and cardiovascular function. Female C57BL/6J mice were fed either a standard chow (3% fat, 7% sugar) or a palatable obesogenic diet (16% fat, 33% sugar) for 6 weeks before mating and throughout pregnancy and lactation. Offspring of control (OC) and obese dams (OO) were weaned onto standard chow and studied at 3 and 6 months of age. OO were hyperphagic from 4 to 6 weeks of age compared with OC and at 3 months locomotor activity was reduced and adiposity increased (abdominal fat pad mass; PϽ0.01). OO were heavier than OC at 6 months (body weight, PϽ0.05). OO abdominal obesity was associated with adipocyte hypertrophy and altered mRNA expression of ␤-adrenoceptor 2 and 3, 11␤HSD-1, and PPAR-␥ 2. OO showed resistance artery endothelial dysfunction at 3 months, and were hypertensive, as assessed by radiotelemetry (nighttime systolic blood pressure at 6 months [ Key Words: obesity Ⅲ pregnancy Ⅲ developmental programming Ⅲ metabolic syndrome Ⅲ appetite Ⅲ blood pressure Ⅲ mouse O besity among women of reproductive age is presenting a critical challenge to health care. 29% of USA women aged 20 to 39 years are reported to be clinically obese 1 and there is serious concern in many European countries over the increasing obesity among young women. 2 While obesity is associated with increased risk of almost every common complication of pregnancy, obesity in the mother may play a direct role in transmission of an obesogenic and diabetogenic trait from generation to generation. Increasing evidence suggests that children born of pregnancies complicated by either obesity or related gestational diabetes mellitus (GDM) are at increased risk of obesity, impaired glucose tolerance, and other facets of the metabolic syndrome. 3 Animal models have proven invaluable in interrogation of associations between maternal diet and body composition and offspring phenotype. 4 Those studies which have addressed effects of maternal calorific excess, including several from our laboratory, have generally fed rats diets rich in animal fat. 4 -7 Because young women of reproductive age often consume excessive amounts of sugars as well as fats, 8 the relevance of a diet rich in fat alone is limited. In this study, we induced obesity by feeding mice a highly palatable diet rich in sugars and animal fat, and addressed the hypothesis that diet-induced obesity during pregnancy can transmit a propensity for adiposity, glucose intolerance, and cardiovascular dysfunction to the offspring. Obesity was induced in female mice and offspring cardiovascular and metabolic function

Maternal obesity requires the development of effective interventions to improve pregnancy outcome. Strategies that incorporate a detailed understanding of the maternal metabolic environment and its consequences for the health of the mother and the growth of the child are likely to identify the best approach.

Eating an unbalanced diet during pregnancy may induce long-term health consequences in offspring, in particular obesity, insulin resistance, and hypertension. We tested the hypothesis that a maternal diet rich in simple sugars predispose mouse offspring to obesity, glucose intolerance, and cardiovascular diseases in adulthood. Female C57BL/6J mice were fed either a standard chow or a sucrose-rich diet (26% of total energy) 6 weeks prior to mating, throughout pregnancy and lactation. Offspring of control dams (OC) and high sucrose fed dams (OSF) were weaned onto standard control chow, and metabolic and cardiovascular parameters determined at 3 months of age. Both male and female OSF were hyperphagic by 4 weeks of age and females were heavier than OC at 6 weeks. At 3 months, female OSF showed a significant increase in inguinal fat pad mass, whereas skeletal muscle mass (tibialis anterior) and locomotor activity were decreased relative to OC. A 10-fold increase in fasting serum insulin in female OSF vs. OC at 3 months (Insulin [pmol/L] mean ± SEM, OSF, 200.3 ± 16.1, vs. OC, 20.3 ± 1.8, n = 6 P < 0.001), was associated with impaired glucose tolerance (AUC [mmol/L min] mean ± SEM, OSF 1437.4 ± 124.2 vs. OC, 1076.8 ± 83.9, n = 6, P < 0.05). Both male and female OSF were hypertensive as assessed by radiotelemetry (night-time systolic arterial pressure (SAP) [mmHg] mean ± SEM, male OSF, 128 ± 1 vs. OC, 109 ± 1, n = 6, P < 0.01; female OSF, 130 ± 1 vs. OC, 118 ± 1, n = 6, P < 0.05). Analysis of heart rate variability (HRV) demonstrated an increased low:high frequency ratio in male and female OSF (P < 0.05), indicative of heightened sympathetic efferent tone. Renal tissue noradrenaline (NA) content was markedly raised in the OSF vs. OC (NA [pg/ml/mg tissue] mean ± SEM, male OSF, 2.28 ± 0.19 vs. OC 0.84 ± 0.09, n = 6, P < 0.01). Exposure to a maternal diet rich in sucrose led to obesity and glucose intolerance in female mice offspring, and hypertension in both sexes.

Non-technical summary Cross-fostering of newborn pups to different dams is a method widely used in rodent studies of developmental 'programming' to determine whether pregnancy or the suckling period is more important in determining adult characteristics following changes to the maternal environment. We have investigated whether the process of fostering per se influences cardiovascular and metabolic development in mice. Compared with mice reared by their biological mother, fostered mice showed increased appetite, body weight, abdominal fatness and altered blood sugar metabolism. A marked increase in blood pressure was also apparent. This study demonstrates that the process of fostering can lead to profound effects in cardiovascular and metabolic function in otherwise normal mice. The findings have implications both for the interpretation of previous cross-fostering studies in mice and for studies investigating the hypothesis of developmental programming, in which early postnatal manipulation of litters is common practice.Abstract Cross-fostering is widely used in developmental programming studies to determine the relative contribution of the in utero and suckling periods in establishing the adult offspring phenotype in response to an environmental challenge. We have investigated whether the process of fostering per se influences cardiovascular and metabolic function in adult offspring of C57BL/6J mice in comparison with animals suckled by their biological dams. Cross-fostered (CF) mice demonstrated juvenile onset hyperphagia and significantly higher body weight (from weaning to 12 weeks: male control (CON) vs. CF: P < 0.01, female CON vs. CF: P < 0.001; RM ANOVA) accompanied by increased abdominal adiposity in males only (white adipose tissue mass (mg): CON 280.5 ± 13.4 [mean ± SEM] (n = 7) vs. CF, 549.8 ± 99.3 (n = 8), P < 0.01). Both male and female CF mice demonstrated significantly enhanced glucose tolerance. A marked increase in systolic blood pressure (SBP) was observed in male CF mice (SBP (mmHg), day: CON 100.5 ± 1.4 (n = 6) vs. CF 114.3 ± 0.7 (n = 6), P < 0.001; night: CON 108.0 ± 2.0 (n = 6) vs. CF 123.2 ± 1.1 (n = 6), P < 0.001). Endothelium-dependent relaxation was enhanced in male CF mice, and renal noradrenaline was increased in female CF mice. Concentration of serum triglycerides, cholesterol, insulin and leptin were increased in CF vs. CON. The process of cross-fostering profoundly affects cardiovascular and metabolic phenotype in mice. The findings have implications for the inclusion of appropriate controls in the design of future studies and in the interpretation of previous cross-fostering studies in mice.

Background and aimsThe prevalence of pancreatic adenocarcinoma (PAC) parallels rising rates of obesity and dysmetabolism, a possible link being non-alcoholic fatty pancreas disease (NAFPD). We have recently shown that maternal obesity programmes the development of a dysmetabolic and fatty liver (non-alcoholic fatty liver disease, NAFLD) phenotype in adult offspring. Since the pancreas and liver originate from the same embryonic bud, it is plausible that maternal obesity may similarly programme the development of NAFPD. Our objective was to determine the effect of maternal obesity on development of NAFPD in offspring and ascertain contributions of the intra/extra-uterine periods.MethodsFemale C57BL/6J mice were fed either a standard chow (3% fat, 7% sugar) or a hypercalorific diet (16% fat, 33% sugar) for six weeks prior to mating and throughout pregnancy and lactation. Female offspring were cross-fostered for suckling to dams on the same or opposite diet to yield four groups: offspring of lean suckled by lean dams (n = 6), offspring of obese suckled by obese dams (n = 6), offspring of lean suckled by obese dams (n = 5) and offspring of obese suckled by lean dams (n = 6). All offspring were weaned onto a standard chow diet at 21 days and sacrificed at 3 months post-partum for tissue collection.ResultsOffspring subjected to an adverse suckling environment showed significant increases in body weight, pancreatic triglyceride content, TGF-β, collagen gene expression and SBP at rest along with an enhanced restraint stress response, indicating a dysmetabolic and NAFPD phenotype.ConclusionsDevelopmental programming is involved in the pathogenesis of NAFPD and appears to be largely dependent on an adverse extra-uterine environment.