SCAMP:standardised, concentrated, additional macronutrients, parenteral nutrition in very preterm infants: a phase IV randomised, controlled exploratory study of macronutrient intake, growth and other aspects of neonatal care

<p>Abstract</p> <p>Background</p> <p>Infants born <29 weeks gestation are at high risk of neurocognitive disability. Early postnatal growth failure, particularly head growth, is an important and potentially reversible risk factor for impaired neurodevelopmental outcome. Inadequate nutrition is a major factor in this postnatal growth failure, optimal protein and calorie (macronutrient) intakes are rarely achieved, especially in the first week. Infants <29 weeks are dependent on parenteral nutrition for the bulk of their nutrient needs for the first 2-3 weeks of life to allow gut adaptation to milk digestion. The prescription, formulation and administration of neonatal parenteral nutrition is critical to achieving optimal protein and calorie intake but has received little scientific evaluation. Current neonatal parenteral nutrition regimens often rely on individualised prescription to manage the labile, unpredictable biochemical and metabolic control characteristic of the early neonatal period. Individualised prescription frequently fails to translate into optimal macronutrient delivery. We have previously shown that a standardised, concentrated neonatal parenteral nutrition regimen can optimise macronutrient intake.</p> <p>Methods</p> <p>We propose a single centre, randomised controlled exploratory trial of two standardised, concentrated neonatal parenteral nutrition regimens comparing a standard macronutrient content (maximum protein 2.8 g/kg/day; lipid 2.8 g/kg/day, dextrose 10%) with a higher macronutrient content (maximum protein 3.8 g/kg/day; lipid 3.8 g/kg/day, dextrose 12%) over the first 28 days of life. 150 infants 24-28 completed weeks gestation and birthweight <1200 g will be recruited. The primary outcome will be head growth velocity in the first 28 days of life. Secondary outcomes will include a) auxological data between birth and 36 weeks corrected gestational age b) actual macronutrient intake in first 28 days c) biomarkers of biochemical and metabolic tolerance d) infection biomarkers and other intravascular line complications e) incidence of major complications of prematurity including mortality f) neurodevelopmental outcome at 2 years corrected gestational age</p> <p>Trial registration</p> <p>Current controlled trials: <a href="http://www.controlled-trials.com/ISRCTN76597892">ISRCTN76597892</a>; EudraCT Number: 2008-008899-14</p

Macronutrient cycling in surface waters

The levels and relative proportions of macronutrients set the conditions for life in surface waters. Man-made disturbances to macronutrient cycling have caused environmental problems such as eutrophication, acidification and global change. In this thesis, macronutrient cycling was studied by performing spatial and temporal large-scale studies of aquatic, terrestrial and atmospheric national monitoring data. Trophic status was found to have a profound impact on nitrate-nitrogen (NO₃-N) concentrations in surface waters. Lakes and streams of the same trophic status displayed opposite NO₃-N patterns. These findings are of great importance when dealing with environmental assessment on the landscape scale, and an awareness of these patterns may also facilitate the design of sampling programs. Trophic status also seems important for trends in total phosphorus (TP) and total organic carbon (TOC) concentrations in boreal and alpine catchments. A temporal study of TP and TOC concentrations showed decreases in nutrient-poor catchments and increases in more nutrient-rich surface waters. Different responses of terrestrial organic matter production and decomposition to temperature increases may be responsible for the observed patterns. Consequently, continued global warming may lead to a stronger polarization between the nutrient-poor northern and the more nutrient-rich southern catchments. Further studies showed that nutrient conditions in soils and surface waters were strongly affected by atmospheric deposition. By using large data-sets on nutrient content in soils and nutrient concentrations in lakes, it was found that carbon to nitrogen ratios (C:N) in the organic soil layer and in lakes increased from the southern to the northern parts of Sweden, resulting in a strong relationship between soil and lake water C:N. The strong relationship was primarily due to the high correlation between nitrogen (N) in organic soil layer and lake N. Large-scale variations in soil C content were not strongly linked to lake C concentrations whereas soil N seemed to leach in the form of NO₃-N to lakes. By calculating catchment soil, lake and river mouth C stocks, it was estimated that about 10 % of Sweden's total terrestrial net ecosystem production is transported through lakes annually. This indicates that the amount of C exported from soils is substantial and that boreal soils maybe less important as a C sink as previously thought. Furthermore, it was found that the colored portion of C was selectively lost and that the decrease in water color was dependent on water retention time. This implies that under conditions predicted in future climate scenarios of increased precipitation, water reaching the seas will be more colored than today. The results from this thesis highlight the importance of atmospheric N deposition and trophic status to macronutrient cycling in both terrestrial and aquatic ecosystems

Central oxytocin and food intake: focus on macronutrient-driven reward

Centrally acting oxytocin (OT) is known to terminate food consumption in response to excessive stomach distension, increase in salt loading, and presence of toxins. Hypothalamic-hindbrain OT pathways facilitate these aspects of OT-induced hypophagia. However, recent discoveries have implicated OT in modifications of feeding via reward circuits: OT has been found to differentially affect consumption of individual macronutrients in choice and no-choice paradigms. In this mini-review, we focus on presenting and interpreting evidence that defines OT as a key component of mechanisms that reduce eating for pleasure and shape macronutrient preferences. We also provide remarks on challenges in integrating the knowledge on physiological and pathophysiological states in which both OT activity and macronutrient preferences are affected

Sleeve Gastrectomy Leads to Weight Loss in the Magel2 Knockout Mouse

Background Prader-Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia, obesity, cardiopulmonary diseases, and increased mortality. Although successful weight loss improves health in PWS, few treatments cause sustained weight loss in obese patients let alone obese individuals with PWS. Objectives The present study uses the Magel2 knockout (KO) mouse, an animal model of PWS, to conduct a preclinical study on the efficacy of sleeve gastrectomy(SG) in PWS. Setting Academic research laboratory, United States. Methods We performed sham or SG surgeries in 24- to 28-week-old male Magel2 KO and wild-type littermate control mice (WT) who had been maintained on a high-fat diet for 10 weeks. We monitored weight, food intake, and fat and lean mass pre- and postoperatively. Fasting glucose, glucose tolerance, and counter-regulation were measured postoperatively. Results Magel2 KO animals had similar recovery and mortality rates compared with WT. SG resulted in similar weight loss, specifically loss of fat but not lean mass, in both Magel2 KO and WT mice. SG also resulted in significantly lower fasting glucose levels and a reduction in fat intake in both Magel2 KO and WT mice. We also found that Magel2 KO mice failed to increase their food intake in response to the glucoprivic agent 2-deoxy-D-glucose, suggesting impaired glucose counter-regulation, but this occurred regardless of surgical status. All results were considered significant when P\u3c .05. Conclusion We find in this mouse model of PWS, SG is a well-tolerated, effective strategy for weight and fat loss

Childhood energy intake is associated with nonalcoholic fatty liver disease in adolescents

Background: Greater adiposity is an important risk factor for nonalcoholic fatty liver disease (NAFLD). Thus, it is likely that dietary intake is involved in the development of the disease. Prospective studies assessing the relation between childhood dietary intake and risk of NAFLD are lacking. Objective: This study was designed to explore associations between energy, carbohydrate, sugar, starch, protein, monounsaturated fat, polyunsaturated fat, saturated fat, and total fat intake by youth at ages 3, 7, and 13 y and subsequent (mean age: 17.8 y) ultrasound scan (USS)–measured liver fat and stiffness and serum alanine aminotransferase, aspartate aminotransferase, and γ-glutamyltransferase. We assessed whether observed associations were mediated through fat mass at the time of outcome assessment. Methods: Participants were from the Avon Longitudinal Study of Parents and Children. Trajectories of energy and macronutrient intake from ages 3–13 y were obtained with linear-spline multilevel models. Linear and logistic regression models examined whether energy intake and absolute and energy-adjusted macronutrient intake at ages 3, 7, and 13 y were associated with liver outcomes. Results: Energy intake at all ages was positively associated with liver outcomes; for example, the odds of having a USS-measured liver fat per 100 kcal increase in energy intake at age 3 y were 1.79 (95% CI: 1.14, 2.79). Associations between absolute macronutrient intake and liver outcomes were inconsistent and attenuated to the null after adjustment for total energy intake. The majority of associations attenuated to the null after adjustment for fat mass at the time liver outcomes were assessed. Conclusion: Higher childhood and early adolescent energy intake is associated with greater NAFLD risk, and the macronutrients from which energy intake is derived are less important. These associations appear to be mediated, at least in part, by fat mass at the time of outcome assessment

Metabolic Effects of Bariatric Surgery in Mouse Models of Circadian Disruption

Background/Objectives: Mounting evidence supports a link between circadian disruption and metabolic disease. Humans with circadian disruption (for example, night-shift workers) have an increased risk of obesity and cardiometabolic diseases compared with the non-disrupted population. However, it is unclear whether the obesity and obesity-related disorders associated with circadian disruption respond to therapeutic treatments as well as individuals with other types of obesity. Subjects/Methods: Here, we test the effectiveness of the commonly used bariatric surgical procedure, Vertical Sleeve Gastrectomy (VSG), in mouse models of genetic and environmental circadian disruption. Results: VSG led to a reduction in body weight and fat mass in both ClockΔ19 mutant and constant-light mouse models (PP\u3e0.05). Within circadian-disrupted models, VSG also led to improved glucose tolerance and lipid handling (P\u3c0.05). Conclusions: Together these data demonstrate that VSG is an effective treatment for the obesity associated with circadian disruption, and that the potent effects of bariatric surgery are orthogonal to circadian biology. However, as the effects of bariatric surgery are independent of circadian disruption, VSG cannot be considered a cure for circadian disruption. These data have important implications for circadian-disrupted obese patients. Moreover, these results reveal new information about the metabolic pathways governing the effects of bariatric surgery as well as of circadian disruption

An observational study on the dietary intake, nutrition practices, hydration status and energy expenditure in competitive one-day cricket matches : a thesis presented in partial fulfillment of a Masters of Science in Human Nutrition, Massey University, Albany, New Zealand

Background: Cricket is one of the oldest sports in existence, the first international match dates back to 1844. Modern day cricket with increasing elite level representation has resulted in higher physical performance demands on players. Despite this there is little information available regarding the energy cost, dietary intake and hydration status of cricket players during matches. Objective: To investigate pre-match and match dietary intake; hydration status and energy expenditure (EE) of high performing male players within 50-over cricket matches. Methods: High performing male cricket players (>16y) from the Auckland Cricket Association, were invited to participate in an observational study that took place during competitive ‘one-day format’ cricket matches. Pre-match hydration was tested for urine specific gravity (Usg), end of match hydration was determined from percentage body mass (BM) change and sweat loss was estimated from end of match BM less calculated BM (pre-match BM + food and fluid mass – urine output). Dietary intakes were assessed using food records (pre match) and direct observation (during match). Global positioning system units were worn to provide time motion analysis data. EE was calculated from relative metabolic load multiplied by pre-match BM. Statistical analyses using independent t-tests and bivariate correlations were performed to investigate relationships between variables. Results: Match data were collected from 27 cases over six games from 18 participants. Early morning pre-match dehydration (≥Usg 1.020 g.ml-1) was reported in 81.5% of cases. The minimum recommended pre-event fluid intake (5 ml.kg-1) was met by 28% of participants (n=5). A pre-match carbohydrate (CHO) intake of <1 g∙kg-1 was reported for 66.6% of participants, and match CHO intake of < 30 g.h-1 was found for 37% of cases. End of match BM percent losses occurred in 59.2% and the highest loss reported was 2% (n=2). Match fluid intake was positively associated with match sweat loss (P<0.001). The average match EE per hour was 1015 ± 266 kJ∙h-1. There was no relationship between match EE and energy intake. Conclusion: Most players were dehydrated early morning, and almost one third had an inadequate pre-match fluid intake. Match rehydration was insufficient in over two-thirds of the cases and CHO intake was insufficient for two thirds pre-match and for one third during the match. The results from this study indicate that educating this group of cricket players on pre-match and match dietary and fluid requirements and on individual hydration monitoring practices is warranted. Further investigations on the energy cost of cricket matches are warranted to further determine the demands of the game, specifically focusing on positional demands

Does macronutrient consumption affect aerobic capacity?

Background: Fitness in the United States is declining as the prevalence of obesity rises. It is known generally that exercise and diet both play a part in becoming fit, therefore veering away from being obese and/or overweight. Although people are aware they need to eat healthy foods and participate in physical activity, the role that dietary behaviors have on exercise, particularly aerobic capacity, remains unresolved. Purpose: The purpose of this study was to analyze dietary behaviors and to examine associations with maximal aerobic capacity. We hypothesize that those who consume each food group will have a higher volume of oxygen uptake. Methodology: This cross-sectional study consisted of a convenience sample of students, faculty, and staff (at least 18 years and older) that visited the Exercise Science Research Center as part of the larger Exercise is Medicine project. Participants completed a treadmill maximal oxygen uptake test to determine their VO2 max and were administered a 24-hour diet recall. In addition, they completed an online survey on dietary behaviors. Preliminary analyses examined associations between dietary patterns from the online survey and aerobic capacity. Linear regressions were used to test the associations between dietary behaviors (independent variable) and aerobic capacity (dependent variable) and were adjusted for sex and age. Results: There were a total of 47 participants (n=29 women) to date who have participated, with a mean age of 29.2 (SD 12.5, range 19.1 to 66.0). The average aerobic capacity of women was 36.6 ml/kg/min (SD 8.0), ranging from 15.2 to 51.8. The average aerobic capacity of men was 43.4 ml/kg/min (SD 6.8), ranging from 33.1 to 55.1. Aerobic capacity did not differ between those who drank milk daily vs those who did not (β -2.7, p=.350), those who ate fruit daily (β -.06, p=.798), ate whole grains at least 3 times per week (-2.9, p=.257), ate red meat at least 3 days per week (β -0.4, p=.844), or those who never ate dessert (β -7.1, p=.098). Discussion: There were no significant differences in VO2 max scores between those who consumed milk, fruit, whole grains, red meat, and dessert versus those that did not. This is likely because aerobic capacity is altered from performing exercise, rather than eating certain food groups. Although dietary behaviors are not associated with aerobic capacity, the evaluation of macronutrients compared to aerobic capacity will be examined as a part of this study. In the future, studies should include an analysis of both energy consumption and exercise participation to improve health and fitness outcomes

Dietary fat and total energy intake modifies the association of genetic profile risk score on obesity: evidence from 48 170 UK Biobank participants

Background: Obesity is a multifactorial condition influenced by both genetics and lifestyle. The aim of this study was to investigate whether the association between a validated genetic profile risk score for obesity (GPRS-obesity) and body mass index (BMI) or waist circumference (WC) was modified by macronutrient intake in a large general population study. Methods: This study included cross-sectional data from 48 170 white European adults, aged 37–73 years, participating on the UK Biobank. Interactions between GPRS-obesity, and macronutrient intake (including total energy, protein, fat, carbohydrate and dietary fibre intake) and its effects on BMI and WC were investigated. Results: The 93-SNPs genetic profile risk score was associated with a higher BMI (β:0.57 kg.m−2 per standard deviation (s.d.) increase in GPRS, [95%CI:0.53–0.60]; P=1.9 × 10−183) independent of major confounding factors. There was a significant interaction between GPRS and total fat intake (P[interaction]=0.007). Among high fat intake individuals, BMI was higher by 0.60 [0.52, 0.67] kg.m−2 per s.d. increase in GPRS-obesity; the change in BMI with GPRS was lower among low fat intake individuals (β:0.50 [0.44, 0.57] kg.m-2). Significant interactions with similar patterns were observed for saturated fat intake (High β:0.66 [0.59, 0.73] versus Low β:0.49 [0.42, 0.55] kg.m-2, P-interaction=2 × 10-4), and total energy intake (High β:0.58 [0.51, 0.64] versus Low β:0.49 [0.42, 0.56] kg.m−2, P-interaction=0.019), but not for protein intake, carbohydrate intake and fiber intake (P-interaction &gt;0.05). The findings were broadly similar using WC as the outcome. Conclusions: These data suggest that the benefits of reducing the intake of fats and total energy intake, may be more important in individuals with high genetic risk for obesity

Appetite, energy intake and resting metabolic responses to 60 min treadmill running performed in a fasted versus a postprandial state.

This study investigated the effect of fasted and postprandial exercise on appetite, energy intake and resting metabolic responses. Twelve healthy males (mean±SD: age 23±3 years, body mass index 22.9±2.1 kg m(-2), maximum oxygen uptake 57.5±9.7 mL kg(-1) min(-1)) performed three 10 h experimental trials (control, fasted exercise and postprandial exercise) in a Latin Square design. Trials commenced at 8 am after an overnight fast. Sixty min of treadmill running at ∼70% of maximum oxygen uptake was performed at 0-1 h in the fasted exercise trial and 4-5 h in the postprandial exercise trial. A standardised breakfast was provided at 1.5 h and ad libitum buffet meals at 5.5 and 9.5 h. Appetite ratings and resting expired air samples were collected throughout each trial. Postprandial exercise suppressed appetite to a greater extent than fasted exercise. Ad libitum energy intake was not different between trials, resulting in a negative energy balance in exercise trials relative to control after accounting for differences in energy expenditure (control: 9774±2694 kJ; fasted exercise: 6481±2318 kJ; postprandial exercise: 6017±3050 kJ). These findings suggest that 60 min treadmill running induces a negative daily energy balance relative to a sedentary day but is no more effective when performed before or after breakfast