Processes underlying the nutritional programming of embryonic development by iron deficiency in the rat

Peer reviewedPublisher PD

Walking for Transportation on Campus: Perspectives from Faculty and Students

Background: Walking is a recommended strategy for meeting physical activity (PA) requirements and benefiting from associated health outcomes. Walking for transportation, which is walking to get from ”Point A” to ”Point B,” may help individuals in fulfilling their weekly recommended PA, though little research has been done as it relates to walking for transportation on a college campus.Aim: To qualitatively explore attitudes and barriers toward walking for transportation and cues to action among a convenience sample of faculty, staff, and students.Methods: Through a non-experimental design, qualitative data were collected through conducting focus groups (n = 10) at a public, southeastern university with college students, staff, faculty (n = 13 students; n = 25 staff; n = 19 faculty).Results: The main themes emerging included: definitions of walking for transportation, factors that encouraged walking for transportation, barriers to walking on campus, and campaign/incentive suggestions.Conclusion: Findings support previous research which indicates situational factors prohibit individuals from walking for transportation. Further, findings indicate it would be of value for future research to determine best practices for promoting and incentivizing walking across various sub-groups not explored in this study. Lastly, point-of-decision prompt use (i.e., campus signage to promote walking) should be explored as a strategy to promote walking and active transport to determine what various groups respond most positively to

The impact of maternal protein restriction during rat pregnancy upon renal expression of angiotensin receptors and vasopressin-related aquaporins

<p>Abstract</p> <p>Background</p> <p>Maternal protein restriction during rat pregnancy is known to impact upon fetal development, growth and risk of disease in later life. It is of interest to understand how protein undernutrition influences the normal maternal adaptation to pregnancy. Here we investigated the mechanisms regulating renal haemodynamics and plasma volume during pregnancy, in the context of both normal and reduced plasma volume expansion. The study focused on expression of renal angiotensin receptors (ATR) and vasopressin-related aquaporins (AQP), hypothesising that an alteration in the balance of these proteins would be associated with pregnancy <it>per se </it>and with compromised plasma volume expansion in rats fed a low-protein diet.</p> <p>Methods</p> <p>Female Wistar rats were mated and fed a control (18% casein) or low-protein (9% casein) diet during pregnancy. Animals were anaesthetised on days 5, 10, 15 and 20 of gestation (n = 8/group/time-point) for determination of plasma volume using Evans Blue dye, prior to euthanasia and collection of tissues. Expression of the ATR subtypes and AQP2, 3 and 4 were assessed in maternal kidneys by PCR and western blotting. 24 non-pregnant Wistar rats underwent the same procedure at defined points of the oestrous cycle.</p> <p>Results</p> <p>As expected, pregnancy was associated with an increase in blood volume and haemodilution impacted upon red blood cell counts and haemoglobin concentrations. Expression of angiotensin II receptors and aquaporins 2, 3 and 4 was stable across all stages of the oestrus cycle. Interesting patterns of intra-renal protein expression were observed in response to pregnancy, including a significant down-regulation of AQP2. In contrast to previous literature and despite an apparent delay in blood volume expansion in low-protein fed rats, blood volume did not differ significantly between groups of pregnant animals. However, a significant down-regulation of AT₂R protein expression was observed in low-protein fed animals alongside a decrease in creatinine clearance.</p> <p>Conclusion</p> <p>Regulatory systems involved in the pregnancy-induced plasma volume expansion are susceptible to the effects of maternal protein restriction.</p

The effect of feeding a low iron diet prior to and during gestation on fetal and maternal iron homeostasis in two strains of rat

Background Iron deficiency anaemia during pregnancy is a global problem, with short and long term consequences for maternal and child health. Animal models have demonstrated that the developing fetus is vulnerable to maternal iron restriction, impacting on postnatal metabolic and blood pressure regulation. Whilst long-term outcomes are similar across different models, the commonality in mechanistic events across models is unknown. This study examined the impact of iron deficiency on maternal and fetal iron homeostasis in two strains of rat. Methods Wistar (n=20) and Rowett Hooded Lister (RHL, n=19) rats were fed a control or low iron diet for 4 weeks prior to and during pregnancy. Tissues were collected at day 21 of gestation for analysis of iron content and mRNA/protein expression of regulatory proteins and transporters. Results A reduction in maternal liver iron content in response to the low iron diet was associated with upregulation of transferrin receptor expression and a reduction in hepcidin expression in the liver of both strains, which would be expected to promote increased iron absorption across the gut and increased turnover of iron in the liver. Placental expression of transferrin and DMT1+IRE were also upregulated, indicating adaptive responses to ensure availability of iron to the fetus. There were considerable differences in hepatic maternal and fetal iron content between strains. The higher quantity of iron present in livers from Wistar rats was not explained by differences in expression of intestinal iron transporters, and may instead reflect greater materno-fetal transfer in RHL rats as indicated by increased expression of placental iron transporters in this strain. Conclusions Our findings demonstrate substantial differences in iron homeostasis between two strains of rat during pregnancy, with variable impact of iron deficiency on the fetus. Whilst common developmental processes and pathways have been observed across different models of nutrient restriction during pregnancy, this study demonstrates differences in maternal adaptation which may impact on the trajectory of the programmed response

Limiting antenatal weight gain improves maternal health outcomes in severely obese pregnant women: findings of a pragmatic evaluation of a midwife-led intervention

Background: Antenatal obesity in pregnancy is associated with complications of pregnancy and poor obstetric outcomes. Although most guidance on pregnancy weight is focused on the pre-pregnancy period, pregnancy is widely viewed as a period where women are open to lifestyle change to optimise their health. Method: The hospital-based Bumps and Beyond intervention invited all pregnant women with a BMI of over 35 kg/m2 to take part in a programme of health education around diet and exercise, accompanied by one-to-one guidance and monitoring of dietary change. This service evaluation compares 89 women who completed at a programme of 7 sessions with healthy lifestyle midwives and advisors (intervention) with a group of 89 women who chose not to attend (non-intervention). Results: Weight gain in the intervention group (4.5±4.6 kg) was less than in the non-intervention group (10.3±4.4 kg) between antenatal booking and 36 weeks gestation (<0.001). This was associated with a 95% reduction in the risk of gestational hypertension during pregnancy and a general reduction in pregnancy complications. There was no effect of the intervention upon gestational diabetes or complications in labour other than post-partum haemorrhage (reduced 55%). The impact of the intervention on gestational weight gain was greater in women with BMI over 40 kg/m2 at booking. There were no adverse effects of the intervention, even though 21% of the intervention group lost weight during their pregnancy. Conclusion: Intensive, personalised weight management intervention may be an effective strategy for prevention of hypertensive disorders during pregnancy

Limiting antenatal weight gain improves maternal health outcomes in severely obese pregnant women: findings of a pragmatic evaluation of a midwife-led intervention

Background: Antenatal obesity in pregnancy is associated with complications of pregnancy and poor obstetric outcomes. Although most guidance on pregnancy weight is focused on the pre-pregnancy period, pregnancy is widely viewed as a period where women are open to lifestyle change to optimise their health. Method: The hospital-based Bumps and Beyond intervention invited all pregnant women with a BMI of over 35 kg/m2 to take part in a programme of health education around diet and exercise, accompanied by one-to-one guidance and monitoring of dietary change. This service evaluation compares 89 women who completed at a programme of 7 sessions with healthy lifestyle midwives and advisors (intervention) with a group of 89 women who chose not to attend (non-intervention). Results: Weight gain in the intervention group (4.5±4.6 kg) was less than in the non-intervention group (10.3±4.4 kg) between antenatal booking and 36 weeks gestation (<0.001). This was associated with a 95% reduction in the risk of gestational hypertension during pregnancy and a general reduction in pregnancy complications. There was no effect of the intervention upon gestational diabetes or complications in labour other than post-partum haemorrhage (reduced 55%). The impact of the intervention on gestational weight gain was greater in women with BMI over 40 kg/m2 at booking. There were no adverse effects of the intervention, even though 21% of the intervention group lost weight during their pregnancy. Conclusion: Intensive, personalised weight management intervention may be an effective strategy for prevention of hypertensive disorders during pregnancy

Antenatal weight management: women’s experiences, behaviours, and expectations of weighing in early pregnancy

The current emphasis on obstetric risk management helps to frame gestational weight gain as problematic and encourages intervention by healthcare professionals. However pregnant women have reported confusion, distrust, and negative affect associated with antenatal weight management interactions. The MAGIC study (MAnaging weiGht In pregnanCy) sought to examine women’s self-reported experiences of usual-care antenatal weight management in early pregnancy, and consider these alongside weight monitoring behaviours and future expectations. 193 women (18yrs+) were recruited from routine antenatal clinics at the Nottingham University Hospital NHS Trust. Self-reported gestation was 10-27 weeks, with 41.5% (n=80) between 12-14 and 43.0% (n=83) between 20-22 weeks. At recruitment 50.3% of participants (n=97) could be classified as overweight or obese. 69.4% of highest weight women (≥30kg/m2) did not report receiving advice about weight, although they were significantly more likely to compared to women with BMI<30kg/m2. The majority of women (regardless of BMI) did not express any barriers to being weighed and 40.8% reported weighing themselves at home. Women across the BMI categories expressed a desire for more engagement from healthcare professionals on the issue of bodyweight. Women are clearly not being served appropriately in the current situation which simultaneously problematizes and fails to offer constructive dialogue

Water intake, faecal output and intestinal motility in horses moved from pasture to a stabled management regime with controlled exercise

Reasons for performing study: A change in management from pasture to stabling is a risk factor for equine colic. Objectives: To investigate the effect of a management change from pasture with no controlled exercise to stabling with light exercise on aspects of gastrointestinal function related to large colon impaction. The hypothesis was that drinking water intake, faecal output, faecal water content and large intestinal motility would be altered by a transition from a pastured to a stabled regime. Study design: Within-subject management intervention trial involving changes in feeding and exercise using noninvasive techniques. Methods: Seven normal horses were evaluated in a within-subjects study design. Horses were monitored while at pasture 24 h/day, and for 14 days following a transition to a stabling regime with light controlled exercise. Drinking water intake, faecal output and faecal dry matter were measured. Motility of the caecum, sternal flexure and left colon (contractions/min) were measured twice daily by transcutaneous ultrasound. Mean values were pooled for the pastured regime and used as a reference for comparison with stabled data (Days 1–14 post stabling) for multilevel statistical analysis. Results: Drinking water intake was significantly increased (mean ± s.d. pasture 2.4 ± 1.8 vs. stabled 6.4 ± 0.6 l/100 kg bwt/day), total faecal output was significantly decreased (pasture 4.62 ± 1.69 vs. stabled 1.81 ± 0.5 kg/100 kg bwt/day) and faecal dry matter content was significantly increased (pasture 18.7 ± 2.28 vs. stabled 27.2 ± 1.93% DM/day) on all days post stabling compared with measurements taken at pasture (P<0.05). Motility was significantly decreased in all regions of the large colon collectively on Day 2 post stabling (-0.76 contractions/min), and in the left colon only on Day 4 (-0.62 contractions/min; P<0.05). Conclusions: There were significant changes in large intestinal motility patterns and parameters relating to gastrointestinal water balance during a transition from pasture to stabled management, particularly during the first 5 days

Antenatal weight management: women’s experiences, behaviours, and expectations of weighing in early pregnancy

The current emphasis on obstetric risk management helps to frame gestational weight gain as problematic and encourages intervention by healthcare professionals. However pregnant women have reported confusion, distrust, and negative affect associated with antenatal weight management interactions. The MAGIC study (MAnaging weiGht In pregnanCy) sought to examine women’s self-reported experiences of usual-care antenatal weight management in early pregnancy, and consider these alongside weight monitoring behaviours and future expectations. 193 women (18yrs+) were recruited from routine antenatal clinics at the Nottingham University Hospital NHS Trust. Self-reported gestation was 10-27 weeks, with 41.5% (n=80) between 12-14 and 43.0% (n=83) between 20-22 weeks. At recruitment 50.3% of participants (n=97) could be classified as overweight or obese. 69.4% of highest weight women (≥30kg/m2) did not report receiving advice about weight, although they were significantly more likely to compared to women with BM