Resting Metabolism Research Articles

Cross-sectional association study of hedonic hunger, self-control, cognitive distortion, and well-being with adiposity measures among a sample of urban Malaysian adults

BackgroundWe assessed the association of hedonic hunger, self-control (impulsivity and restraint), cognitive distortion (CD), and well-being with adiposity measures such as waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body mass index (BMI), total body fat (TBF), subcutaneous fat (SF), visceral fat level (VFL), skeletal muscle percentage (SM), and resting metabolism (RM), among a sample of urban Malaysian adults at Sunway University and Sunway College, Selangor, Malaysia.MethodsAmong 186 participants (M/F = 51/135; aged 22.1 ± 5.0), psychometrics were assessed using Power of Food Scale (PFS), Brief Self-Control Scale, CD Questionnaire (CD-Quest), and WHO-5 Well-being Index. Blood pressures, anthropometrics and body compositions were also measured using standard methods and bioimpedance.ResultsMen had significantly higher well-being, but lower overall self-control, impulsivity and Food Available hedonic hunger. Those with moderate/severe CD had higher odds ratio (OR) of having high central adiposity, compared with those with absent/slight CD (OR: 2.52;95% CI: 1.14, 5.61; p = 0.023 for WC and OR: 2.50; 95% CI: 1.19, 5.23; p = 0.015 for WHR). Higher CD and PFS scores were strongly significantly correlated with higher systolic blood pressure (SBP), WC, WHR, WHtR, BMI, TBF, SF, VFL and RM. Lower self-control was weakly correlated with higher WC, while lower impulsivity and restraint were weakly correlated with higher VFL. Those who were overweight, obese, and in high TBF class had significantly higher PFS Aggregate Factor scores. Food Available and Food Present scores, but not Food Tasted, were also significantly higher among overweight participants.ConclusionsHigher hedonic hunger and CD were associated with higher SBP and all adiposity measures. Overweight participants had higher hedonic hunger in the context of ready availability and physical presence of highly palatable foods. Lower self-control was weakly correlated with higher central adiposity; lower impulsivity and restraint were weakly correlated with higher visceral adiposity. These findings have provided some insights into the cognitive factors underlying adiposity.

Hormonal Cycling And Substrate Oxidation At Rest And During Exercise: A Systematic Review And Meta-analysis

Fluctuations of endogenous and exogenous sex hormones across the menstrual cycle (MC) and oral contraceptive (OC) cycle have been suggested to influence rest and exercise substrate metabolism in females. However, there is no clear consensus on the relationship between substrate oxidation and MC or OC phase in females. PURPOSE: This systematic review and meta-analysis aimed to examine the impact of MC and OC cycle phase on substrate oxidation in females at rest and during moderate-intensity continuous exercise. METHODS: Five databases were searched to identify studies including female participants assessed during ≥2 hormonal cycle phases and substrate oxidation determined at rest and/or during moderate-intensity continuous exercise via indirect calorimetry. Data were excluded if substrate metabolism was experimentally manipulated, collected earlier than 5 min into exercise, or if a physiological “steady-state" could not be achieved during exercise. Pairwise meta-analyses examined the effect of MC phase, follicular versus luteal, and OC phase, inactive versus active, on the standardized mean difference (SMD) of each substrate oxidation measurement. Study quality was assessed using a modified Downs and Black checklist, and certainty of the evidence was determined using GRADE criteria. RESULTS: 51 eligible trials were identified for analysis. Analysis of MC phases from 24 studies for resting trials (n = 487) and 23 studies for exercise trials (n = 441) observed that RER was unaffected in the luteal versus follicular phase at rest (SMD = 0.03, 95% CI = -0.16, 0.21, P = 0.78; very low certainty) or during exercise (SMD = -0.01, 95% CI = -0.20, 0.19, P = 0.95; very low certainty). Analysis of OC phase from 7 studies (n = 122) found that RER was lower in the active versus inactive OC phase during exercise (SMD = -0.40, 95% CI = -0.77, -0.03, P = 0.03; low certainty). CONCLUSIONS: We found no effect of MC phase on substrate oxidation at rest or during moderate-intensity continuous exercise. The active OC phase may be associated with greater lipid oxidation during moderate-intensity continuous exercise than the inactive OC phase, indicating a possible effect of exogenous rather than endogenous hormones on substrate oxidation during exercise.

Relationship between obesity-related markers, biochemical metabolic parameters, hormonal profiles and sperm parameters among men attending an infertility clinic.

Obesity causes many health problems as well as has negative effects on fertility. However, little is known about the association between obesity-related markers (hip circumference (HC), waist circumference (WC), waist to hip ratio (WHR), waist to height ratio (WHtR), body fat mass (BFM), skeletal muscle (SM), resting metabolism (RM), visceral fat (VF), and visceral adiposity index (VAI)) and sperm parameters. This cross-sectional study was conducted on 98 men in three groups: normal-weight (Nw; body mass index: BMI < 25 kg/m2 ), overweight (Ow; BMI: 25-29 kg/m2 ), and obese (Ob; BMI: 30-35 kg/m2 ) to investigate this issue. The mean WC, HC, WHtR, BFM, SM, RM, and VF were remarkably higher (p< 0.001) for subjects in the Ob group than in Ow and Nw. In Nw, positive correlations were observed between BFM (r= 0.402) and VAI (r= 0.353) and sperm progressive motility (p< 0.05). In Ob males, there was a positive correlation (r= 0.430) between sperm progressive motility and height and a negative relation (r= -0.447) between sperm progressive motility and WHtR. We found the association between serum testosterone (T) levels, T/estradiol ratios, and semen parameters being dependent on obesity-related markers which confirms the negative effects of obesity on male hormones. In conclusion, WHtR is a valuable parameter in infertility clinics that warrants further studies.

Cardiac rest and stress metabolism in type 2 diabetes (T2D): can the diabetic heart flex under stress?

Abstract Background Efficient matching of energy supply to demand is essential for maintaining normal cardiac function. Altered cardiac metabolism may contribute to the development of cardiac dysfunction by impairing metabolic flexibility in type 2 diabetes (T2D). Purpose We aimed to evaluate the effect of T2D on myocardial substrate preferences in response to acute increases in cardiac workload and the effects on contractile function utilising simultaneous coronary sinus (CS) and aorta blood sampling and cardiac magnetic resonance (CMR) imaging Methods Eligible participants without obstructive coronary artery disease (&amp;gt;50% luminal coronary artery stenosis on coronary angiography) underwent transmyocardial arteriovenous blood sampling. Metabolites in paired coronary sinus and arterial samples were quantified to determine myocardial fuel selection at rest and during a stress protocol with intravenous dobutamine. Free fatty acid (FFA), glucose, 3-hydroxybutyric acid (3HBA) and lactate utilisation at rest and haemodynamic stress was calculated as an extraction fraction % (EF). Participants underwent dobutamine stress multiparametric CMR imaging at 3.0 Tesla (Skyra, Siemens, Germany) on a separate visit within 21 days to quantify cardiac volumes, function and perfusion. Results Two thousand and sixty-one participants were screened and due to stringent inclusion and exclusion criteria for this mechanistic study, three T2D patients and five matching controls were enrolled. Baseline demographics and metabolic and CMR results are documented in Table 1. At peak stress levels there was a significant increase in FFA use from rest to stress in controls only (p=0.002). There were no significant differences in FA or glucose uptake between T2D patients and controls at rest or stress. 3HBA EF was significantly increased in T2D during stress (25.04% vs 5.31%, p=0.007). Mean FFA and 3-HBA changes calculated as extraction fraction at stress and rest are illustrated in Figure 1. Conclusions We demonstrate for the first time in vivo that the diabetic heart switches to ketone bodies during increased workloads as a significant fuel source. At present, it is unknown whether enhanced ketone body metabolism in T2D is beneficial, maladaptive, or a bystander. As the energetic properties of ketones are favourable, increased myocardial ketone oxidation could be an adaptive change designed to compensate for defects in myocardial energy metabolism in diabetes. Further, larger studies are warranted. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation - Clinical Research Training FellowshipWellcome Trust Seed Grant Table 1Figure 1

Association Between Human Adaptation, Resting Metabolism, and Cardiovascular Disease Risk: A Longitudinal Study from India

Modern human being migrated to different parts of the world, arguably out of Africa, and settled in different climatic zones resulting different adaption in the last several thousand years. Apart from differences in morphological appearance the basal metabolic rate (BMR) or resting metabolism (RM) also differ among them worldwide. Those settled in colder climates have relatively higher RM and hence more resistant to obesity related CVD. Whereas, those adapted to relatively hotter and humid climate had relatively low RM hence more susceptible to obesity related CVD risk despite similar lifestyle and calorie intakes. However, the recent and rapid change in lifestyle perhaps mediated through less physical activity and dietary habits showed significant impact on cardiovascular health even among the traditional societies, like the present study among the Toto, India. In the last one decade (2011-2020) it was found that in three visits (2011-12; 2016-17; 2019-200) there was a significant increase in the prevalence of CVD risks, hypertension, dyslipidemia along with subsequent increase in resting metabolism. The present longitudinal study confirms that the South Asians and who adapted to hotter and humid climate have otherwise lower RM, however, rapid change particularly in the last decade, had significantly increased their RM resulting into poor cardiovascular health. It further indicates that the south Asian genome is disadvantageous to this rapid change due to modernization and perhaps one of the reason why they are ethnically more predispose to CVD. Hence RM could be considered clinically a better and non-invasion tool for medication.

Sportive lemurs elevate their metabolic rate during challenging seasons and do not enter regular heterothermy.

Animals experience seasonal changes of environmental and ecological conditions in most habitats. Fluctuations in ambient temperature have a strong influence on thermoregulation, particularly on small endothermic mammals. However, different mammalian species cope differently with these changes. Understanding the physiological responses of organisms to different seasons and analysing the mechanisms that account for intra- and inter-specific differences and the ecological consequences of these variations is important to predict species responses to climatic changes. Consequences of climatic changes will be most pronounced in climatically already challenging habitats, such as the dry regions of western Madagascar. We aimed to identify the seasonal responses and adaptive possibilities in energy budgeting of Lepilemur edwardsi, a small primate of this habitat, by measuring metabolic rate (MR; open-flow respiratory) and skin temperature in the field during different seasons. Resting metabolism was generally low, but our study did not detect any signs of regular heterothermic episodes, despite the fact that these are known in other sympatrically living lemurs with a similar lifestyle. Surprisingly, L. edwardsi responded by elevating its resting MR in the poor-resourced dry season, compared to the better-resourced wet season, presumably to master detoxification of their increasingly toxic diet. As body mass decreased over this time, this strategy is obviously not energetically balanced on the long term. This is cause for concern, as it suggests that L. edwardsi has a very small leeway to adjust to changing conditions as experienced due to climate change, as dry season are expected to become longer and hotter, straining water budgets and food quality even more. Moreover, our findings highlight the importance of studying physiological parameters directly in the field and under differing climatic conditions.

Effects of dietary protein-load and alkaline supplementation on acid-base balance and glucose metabolism in healthy elderly.

Metabolism is controlled by macro- and micronutrients. Protein-rich diets should lead to latent acidosis at tissue level with further negative implications. Food supplements with alkaline salts are available and popular pretending to prevent these changes. Within a randomised double-blind placebo-controlled trial we tested the hypotheses that (1) a 4-week protein-rich diet induces a latent tissue acidosis and (2) an alkaline supplement can compensate this. Acid-base balance and important metabolic parameters were determined before and after 4 weeks of supplementation by peripheral blood samples, indirect calorimetry and muscle microdialysis before and after a protein-rich test meal. Fourty volunteers were randomised 1:1 to either verum or placebo supplements. Protein-rich diet by itself did not significantly affect acid-base balance. Alkaline supplementation increased plasma bicarbonate concentration without changing pH. Postprandial increases in serum glucose and insulin tended to be lower for verum vs. placebo. Resting and postprandial energy metabolism, and carbohydrate and fat oxidation did not differ significantly before and after supplementation in both groups. In muscle, postprandial glucose uptake and aerobic glucose oxidation were significantly higher for verum. In addition, verum significantly increased serum magnesium concentrations. Four weeks of protein-rich diet did not significantly influence acid-base balance. However, alkaline supplementation improved systemic and tissue acid-base parameters and oxidative glucose metabolism.

Regenerative Changes in Resting Energy Balance Demonstrating Metabolic Efficiency and Body Composition Normalization

Resting metabolism plays a critical role in healthy weight management. Metabolic adaptations in response to lifestyle cues induce acclimatization of factors involved in resting state energy homeostasis. PURPOSE: To determine the effects of dietary modification and exercise intensity on resting energy metabolism and body composition in sedentary female cohort. METHODS: Subjects (n=46) with >25% fat mass participated in 10-weeks of 200 kcal·24 h-1 caloric deficit, adherence to whole-foods, plant-based diet, and randomization into three exercise groups. Exercise intensity levels were set by respiratory exchange ratio (RER) ranges determined through submaximal VO2-uptake treadmill test; Low: RER=0.75 (n=16), Moderate: RER=0.85 (n=16), High RER=0.95 (n=14). Resting metabolic rate (RMR) variables—respiratory quotient (RQ), VO2, VCO2, resting energy expenditure (REE), and macronutrient substrate oxidation rates (KCHO, KFAT)—were measured using indirect calorimetry at pre and post treatment stages with whole-body air displacement plethysmography to obtain body composition profiles. One-way ANOVA was performed to evaluate mean changes in resting energy metabolism and body composition. RESULTS: Significant differences in RQ and VCO2 were noted between groups (F 1,46=7.88, p=.001; F 1,46=3.51, p=.039, respectively). Significant differences in KCHO and KFAT substrate oxidation rates were noted between groups likewise (F 1,46=5.74, p=.006; F 1,46=5.05, p=.011, respectively). Changes in total body mass showed significant differences (F 1,46=6.39, p=.004). The most positive improvements in metabolic efficiency variables were appreciated in the low and moderate intensity groups in post hoc analysis. CONCLUSION: The combination of modest caloric adjustment, adherence to plant-based diet, and participating in a low or moderate intensity exercise program confers positive changes in metabolic status and corrective energy homeostasis that promotes effective body composition normalization.

How Age Range Affect Energy Expenditure And Exercise Efficiency Among Older People During Cycling

The reduced cardiorespiratory function and muscle performance in the elderly significantly minify an individual's functional aerobic capacity. Any further decline may make them unable to complete daily activities and then have a negative influence on living independently. PURPOSE: the purpose of this study was to examine the influence of age on changes in energy cost in two significantly different age elderly groups and one young counterpart group. METHODS: The investigation was conducted on 30 healthy women in stationary cycling. Participants were stratified by age into young adults (Y; 20-25 years), older adults (OD; 60-65 years) and the more older adults (OU; 66-70years) with the same sample size. The position on the cycle ergometer was adjusted for each participant. The protocol started with a rest metabolism test using a calibrated K4b2 in which subjects were sitting on the cycle ergometer quietly. Then followed by a familiarization process. During the cycling test, each participant performed eight different 300-second trials. Eight trails were under the combination of 2 power output (60 and 100 Watts, W) and 4 cadences (self-selected, 40, 60 and 90 rotations-per-minute, rpm). Oxygen consumption (ml/min) and energy expenditure (EE, kcal/min) were calculated during the last 3 min of each testing condition. RESULTS: 1. VO2 Outcomes Gross VO2 and net VO2 had a similar pattern. VO2 at 100 W output power was larger than those at 60 W of each age group (p < 0.05). However, for the same level of output power, only VO2 parameters in the Y group (MG = 1916.40 and MN = 1606.96) were significantly higher than those in the OU group (MG = 1577.88 and MN = 1279.05) at 100 W output power (p < 0.05). 2. EE outcomes The age*power interaction effect on gross EE and net EE was significant, which were F(2, 27) = 4.07, p = .029 and F(2, 27) = 3.73, p = .037, respectively. Similarly, The interaction effect of age*cadence was significant with respect to gross EE and net EE, which were F(6, 81) = 2.36, p = .038 and F(6, 81) = 2.66, p = .021, respectively. CONCLUSION: Based on the above findings, the small change of age range would significantly affect the body energy cost during cycling. In view of oxygen consumption and energy cost, the choice of power output and cadence should be mainly considered in older adults, especially for the age ≥ 66yrs individuals.

2022-P: Partial-Body Cryotherapy Acutely Augments Resting Metabolism in Obese Women

Cryotherapy has been shown to reduce pro-inflammatory response, relieve pain and enhance muscles’ post-exercise recovery. Cryostimulation could be also proposed as an alternative strategy to trigger cold-induced thermogenesis in overweight/obese subjects. In this study, 16 obese (BMI: 32±4 kg/m2) women (43.4±4.8 years) underwent Partial-Body Cryotherapy (PBC) (-130°C x 150sec) for 5 days (1/day, h 07:00 AM). Resting energy metabolism (REE) was assessed by indirect calorimetry pre- and post-PBC on day 1 and day 5. Subjects were energy-controlled (physical activity and dietary intake). Before 5th-day PBC, REE was increased by 5.5% versus pre-1st-day PBC values (1755±265 vs. 1664±241 kcal/day; p=0.0005). With a similar design, in a larger sample of 80 subjects (F=61; M=19; 34.4±11.1 years; BMI: 24.4±4.8 kg/m2), REE augmented by 1.89% (p=0.02) after PBC of day 1. In a multivariate analysis, multiple regression output a positive relationship between cryostimulated REE and body weight (Spearman r=0.68; p&amp;lt;0.0001, Figure). Altogether, these preliminary data suggest that cold-induced thermogenesis could be explored as an alternative therapy to combat weight gain and obesity. Longitudinal studies could test chronic effects of cryotherapy, estimating the extent of the metabolic adaptations that could be favorably preserved. Disclosure R. Codella: None. M. De Nardi: None. S. Delbarba: None. C. Facheris: None. L. Luzi: None.

0139 Associations of Actigraphic Sleep Parameters with Maximal Oxygen Consumption and Resting Metabolism in Well-Functioning Older Adults

Abstract Introduction Both poor sleep and poor cardiorespiratory fitness are common in older age and associated with negative health outcomes. Additionally, among older adults, higher resting metabolic rate (RMR) has been associated with increased morbidity and mortality risk. To evaluate whether, and in what ways, sleep may affect these relationships, we investigated the association of actigraphic sleep indices with cardiorespiratory fitness and RMR in older adults. Methods We studied 393 community-dwelling participants in the Baltimore Longitudinal Study of Aging (mean age 73.5±10.3 years, 52% women) who completed 6.7±0.9 nights of wrist actigraphy, RMR testing, and a maximal graded exercise test. Primary predictors included mean actigraphic total sleep time (TST, minutes), sleep efficiency (SE, %), wake after sleep onset (WASO, minutes), and average wake bout length (WBL, minutes). Cardiorespiratory fitness, as measured by maximal oxygen consumption (V O2MAX; ml/kg/min), and RMR (kcal/day) were the primary outcomes. Results After adjustment for age, sex, race, body mass index, comorbidity index, and depressive symptoms, longer WBL was associated with lower V O2MAX (β=-0.12, 95% confidence interval (CI)=-0.20, -0.04), greater WASO was associated with lower V O2MAX (β=-0.09, 95% CI=-0.17, -0.01), and greater SE was associated with higher V O2MAX (β=0.12, 95% CI=0.03, 0.20). In addition, longer TST was associated with lower RMR (β=-0.10, 95% CI=-0.19, -0.01) and longer WBL was linked to higher RMR (β=0.12, 95% CI=0.04, 0.21). Conclusion In well-functioning older adults, indices of greater wakefulness after sleep onset are linked with poorer cardiorespiratory fitness and higher resting metabolism, while longer and more efficient sleep are associated with better fitness and lower resting metabolic rate. Our findings suggest that sleep disturbance may be linked to disrupted energy homeostasis, evidenced by excessive energy expenditure at rest and inefficient energy utilization in response to maximal demands. Prospective analyses are necessary to determine the nature of these associations. Support This study was supported in part by National Institute on Aging (NIA) grants R01AG050507 and T32-AG027668, the NIA Intramural Research Program (IRP), and Research and Development Contract HHSN-260-2004-00012C.

0035 Resting Metabolism and the Metabolic Response to Exercise Follow Circadian Patterns with Day/Night Differences in Substrate Utilization Between Lean and Obese Adults

Abstract Introduction Resting energy expenditure (EE) follows a circadian rhythm in healthy lean participants, with a nadir in the early morning hours. We determined: (1) whether this pattern persists (or how substrate utilization may change), when challenged with exercise, and; (2) whether obesity affects these responses. Methods Fourteen participants (aged 48.5±12.8y; 6-female; 5-obese, BMI 31.9±1.4kg/m2 [avg±SD]) underwent a 5-day inpatient forced desynchrony protocol, comprised of ten 5h 20min ‘days’ in dim-lighting and free of time cues. Resting EE was measured immediately prior to a 15-minute cycle ergometer exercise bout at 50% of estimated heart rate maximum. Substrate utilization was determined from the respiratory quotient (RQ). Circadian phase was calculated using the salivary dim-light melatonin onset (&amp;gt;3pg/mL threshold). EE data were analyzed using a mixed-effect model with group (lean vs. obese) and circadian phase as fixed factors; subject was a random factor. RQ was analyzed using t-tests to determine day/night differences in groups at rest and in response to exercise. Results Resting and exercising EE both displayed endogenous circadian rhythms (p&amp;lt;0.05) with nadirs in the early morning (~5:30am), without any differences between groups (p&amp;gt;0.22). Resting RQ was similar between the day and night in the lean group (p=0.66), but decreased (suggesting lower carbohydrate utilization) at night within the obese group (-2.5±1.6%, p=0.02). The lean group increased RQ in response to exercise both during the day (+8.9±2.8%) and night (+8.0±2.8%) (both p&amp;lt;0.001), but there was no increase in RQ in the obese group during either day or night exercise (p&amp;gt;0.16). Conclusion These data demonstrate that EE during rest and exercise follows a circadian pattern, with limited influence of obesity. Circadian differences in substrate utilization between lean and obese in the resting state and in response to exercise may play a role in expression and maintenance of unwanted weight gain and impaired metabolic health. Support R01HL125893, R01HL140577, KL2TR002370, K01HL146992, F32HL131308, Medical Research Foundation of Oregon, Ford Foundation, and CTSA grant (UL1TR000128)

MON-284 Systematic Screening Reveals Large Number of Undiagnosed and Untreated Cardiovascular Risk Factors in Adults with Prader-Willi Syndrome

Introduction: Prader-Willi syndrome (PWS) is a complex hypothalamic disorder, combining hypotonia, intellectual disability (ID), pituitary hormone deficiencies and hyperphagia. In PWS, up to 3% of patients die every year. In half of the patients, the cause of death is obesity related and / or of cardiovascular (CV) origin.Obesity is caused by hyperphagia combined with a low energy expenditure. Untreated hormone deficiencies like hypogonadism and hypothyroidism can cause low muscle mass and low basal rest metabolism (BRM) leading to this low energy expenditure. Patients with PWS should exercise one hour daily to compensate for their low BRM. However, hormone deficiencies usually cause fatigue, leading to exercise intolerance. Musculoskeletal and / or behavioral problems can also cause reduced physical activity. The subsequent sedentary lifestyle can induce CV risk factors like hypertension, hypercholesterolemia and diabetes mellitus (DM).Another risk factor often present in PWS is sleep apnea, which can be central (CSA), obstructive (OSA) or both. Both CSA and OSA can lead to pulmonary hypertension and a further increase in obesity.The above mentioned health problems often remain unnoticed and untreated, which is partly due to the behavioral phenotype of PWS (patients seldomly report pain and hardly ever complain about physical problems). However, if left untreated, these risk factors can cause CV complications leading to hospital admission or even death. To reveal yet undiagnosed health problems, we performed a systematic health screening among adults with PWS. Methods: We systematically screened 115 adults with PWS (mean age 31.4 ± 12.1 y, mean BMI 31.8 ± 9,5 kg/m2) for the presence of undiagnosed health problems and cardiovascular risk factors. Based on a medical questionnaire, medical file search, extensive interview, thorough physical examination and biochemical measurements we made an overview of the undiagnosed health problems in adults with PWS. If possible, we performed polygraphy to test for sleep apnea. Results: Undiagnosed health problems (hypertension, DM, hypercholesterolemia, sleep apnea, hypothyroidism and hypogonadism) were present in 50% of the patients. 10% had multiple undiagnosed health problems simultaneously. All males and 94% of females had hypogonadism and 15% had hypothyroidism. Hypertension and / or hypercholesterolemia were present in 20% and DM was present in 16%. One third of patients was not on a diet and 22% exercised less than 30 minutes a day. Sleep apnea was present in 17 of 26 patients tested. Conclusion: We detected a striking number of undiagnosed health problems among adults with PWS which, if left untreated, can pose a serious health threat. Systematic screening is needed to detect these problems in an early phase. This will prevent burdensome and expensive complications and might even reduce mortality in this vulnerable patient population.

Chronic Low‐Dose ICV Infusion of Agrp in Mice May Suppress Indices of Resting Metabolism in Brown Adipose Tissue Independent of Effects on Feeding Behavior

Agouti‐related peptide (Agrp) acts within in the central nervous system to stimulate feeding behavior and suppress energy expenditure, which results in body weight gain. Acute and chronic intracerebroventricular (ICV) administration of recombinant Agrp (0.2 to 1.0 nmol/d) induces hyperphagia in rats (Wissig et al. 2003; Tallam et al. 2004), but studies in mice are lacking. Therefore, we tested the effects of this route and range of infusion doses upon food intake, body mass, and adiposity in wildtype male C57BL/6J mice (Jackson Labs, 10–12 wk). Mice were implanted with chronic indwelling ICV cannulae connected to osmotic minipumps (Alzet) to deliver artificial cerebrospinal fluid vehicle (n=6), or 0.1 nmol/d (n=8) or 1.0 nmol/d (n=6) recombinant Agrp(82–132) peptide for 21 days. Unexpectedly, despite the efficacy of these dosing schedules published in rats, these infusion rates had no effect on food intake, body mass, or overall body composition (by NMR) in the present cohort of mice. Interestingly, interscapular “brown” adipose tissue (BAT) was hypertrophied in mice infused with the lower dose of Agrp (aCSF: 0.07±0.01 mg, Agrp 0.1 nmol/d: 0.10±0.01, Agrp 1.0 nmol/d: 0.09±0.01 (mean±sem); p&lt;0.05 by ANOVA), and this difference remained after correction by body mass or tibia length. Although underpowered to detect statistically significant changes with the limited sample size, physiologically relevant trends toward reduction in the mRNA expression of Ucp1 (0.75 (0.92–0.62) fold of aCSF (±1 sem), n=5), Adrb3 (0.65 (0.74–0.57), n=7), and Dio2 (0.49 (0.8–0.42), n=6) were observed in the BAT from mice receiving 1.0 nmol/d Agrp. We conclude that the effects of ICV Agrp on BAT mass (and possible effects on thermogenic gene expression profiles in BAT) are independent of changes in feeding behavior in male C57BL/6J mice. These findings support species‐specific differences in sensitivity to ICV Agrp, and suggest that Agrp influences resting energy expenditure independently from its effects on feeding behavior.Support or Funding InformationHL134850, HL084207

Childhood Leukemia Survivors and Metabolic Response to Exercise: A Pilot Controlled Study.

Background: Leukemia is the most common cancer in pediatrics, with many late effects such as higher risk of dyslipidemia, insulin resistance, obesity, and metabolic syndrome. The objective of this work was to investigate substrate oxidation during submaximal exercise in survivors of childhood acute leukemia. Methods: A total of 20 leukemia survivors and 20 healthy children were matched by sex, age, and Tanner stage. They all took a submaximal incremental exercise test to determine fat and carbohydrate oxidation rates. Results: Cardiorespiratory fitness was significantly lower in leukemia survivors, with lower relative VO2 peaks (p < 0.001), lower heart rate values (p = 0.02), and lower exercise power (p = 0.012), whereas rest metabolism and body mass index did not differ between the two groups. During exercise, upward of heart rate relative to VO2 peak was significantly higher (p < 0.001) in childhood leukemia survivors. We found lower carbohydrate and fat oxidation rates (p = 0.07) in leukemia survivors compared with healthy children, and also a significantly lower relative maximal fat oxidation rate (p = 0.014). Conclusion: Despite impaired physical fitness and metabolic response to exercise, childhood leukemia survivors remained sensitive to physical activity interventions, and could readily adapt to submaximal exercise intensity.

Cardiac Rest and Stress Metabolism in Patients With Type 2 Diabetes

Cardiac Rest and Stress Metabolism in Patients With Type 2 Diabetes

Impact of Time Restricted Feeding on Muscular Strength Within a Healthy Adult Population.

Time restricted feeding (TRF) is a feeding habit that restricts the amount of time during the day in which individuals consume calories. TRF has been shown to produce several health benefits, one of which may be an increase in force production. Muscular strength and nutritional intake have been strongly researched prior to this study. Though little research exists investigating the impacts of TRF on muscular strength in human subjects. PURPOSE: The purpose of this study was to identify the potential impacts of TRF on muscular strength. METHODS: Participants participated in two, four-week periods during which caloric intake, sleep duration, sleep quality, exercise, and medications were all documented. The first period, participants partook in non-TRF eating behavior. The second period participants were exposed to a nine-hour window of TRF. To measure muscular strength, participants were tested using an isokinetic dynamometer. Resting metabolism was also measured. Statistical analyses quantifying within subject effects were performed with a repeated measures ANOVA. Post-hoc analyses were performed to elicit differences between testing periods. RESULTS: Both mean torque flexion at 60 degrees/second (MTF 60) (83.92 Nm ± 29.53Nm vs. 95.63 Nm ± 28.95 Nm) and mean torque flexion at 180 degrees/second (MTF 180) (66.75 Nm ± 25.9 Nm vs. 69.01 Nm ± 21.29 Nm vs. 75.55 Nm ± 23.9 Nm; F = 7.920 Nm) had a significant increase from pre-test to TRF, as well as non-TRF to TRF. Post-hoc testing revealed significant differences between pre-test and TRF MTF 60 increased (p-value=0.001). Similar results were found for MTF 180 as well (p-value=0.037). When observing respiratory quotient (RQ) at rest (0.716±0.077 vs. 0.73 ±0.077 vs. 0.08±0.79; F = 8.352) there was a significant increase from pre-test to TRF (p-value=0.008), as well as non-TRF to TRF (p-value=0.034). Lastly, after analyzing total strength training days from non-TRF to TRF (8.11 days ± 1.18 vs. 5.22 days ± 1.48), a significant decrease was found (p-value=0.003). CONCLUSION: Post TRF, participants showed an increase in muscular strength and resting RQ despite a decrease in strength training. Increased glucose utilization may be linked to short bouts of increased muscular strength activity. Future studies are needed to identify physiological mechanisms behind these findings.

Control of Resting Metabolism by Regulator of G Protein Signaling‐2 (Rgs2) in AgRP Neurons

Resting metabolic rate (RMR) normally accounts for ~70% of total energy expenditure, and obesity is associated with and maintained via suppression of RMR. We recently demonstrated that the angiotensin II (ANG) type 1 receptor (Agtr1a) in cells expressing Agouti‐related peptide (AgRP) within the arcuate nucleus of the hypothalamus (ARC) is required for RMR responses to various stimuli, including leptin, high‐fat diet, and deoxycorticosterone acetate (DOCA)‐salt. Agtr1a activation by ANG results in downstream G‐protein signaling that is negatively modulated by endogenous terminators, such as Regulator of G protein Signaling‐2 (Rgs2). Rgs2 terminates Agtr1a second‐messenger signaling by promoting reassembly of the heterotrimeric G protein. Interestingly, mice with whole‐body disruption of Rgs2 exhibit altered thermoregulation. Rgs2 is known to inhibit Agtr1a signaling in other tissues, and thus we hypothesize that Rgs2 within AgRP neurons modifies RMR control. First, Rgs2 expression in the various subsets of AgRP neurons of the ARC from wildtype C57BL/6J mice was confirmed by in silico reanalysis of a published single‐cell RNAseq dataset (GSE74672), and by RNAscope in situ hybridization. Second, using CRISPR we generated a new mouse model expressing a conditional allele for Rgs2 (Rgs2flox) in which exons 2–4 are flanked by LoxP sites. Third, these animals were iteratively bred with mice expressing Cre‐recombinase via the AgRP locus (Jax 012899) to eliminate Rgs2 from cells expressing AgRP. Preliminary assessments of these Rgs2AgRP‐KO animals under baseline, chow‐fed conditions indicate that the animals are viable and born in expected ratios. Fed standard chow (Teklad 7013), Rgs2AgRP‐KO mice of both sexes exhibit normal body mass, but may consume less food relative to control littermates (at 10 weeks of age, 8.0±1.9 n=8 vs 9.3±1.4 n=19 kcal/hr, p=0.06). Interestingly, Rgs2AgRP‐KO mice may exhibit a shift in body composition, with greater body fat by NMR (10.5±1.2 n=8 vs 7.3±.5 n=22 % total mass, p&lt;0.05). Preliminary tests of RMR indicate that during chow‐fed conditions, RMR is normal in Rgs2AgRP‐KO mice after correction for body mass and sex by generalized linear modeling (0.134±0.006 n=8 vs 0.132±0.005 n=8 kcal/hr, p=0.78). Such findings are expected, as our previous studies of animals lacking Agtr1a in AgRP cells indicate that Agtr1a signaling in these cells is required for RMR responses to various stimuli but not baseline control. Tests of RMR responses of Rgs2AgRP‐KO mice to various stimuli are ongoing, and we anticipate that responses to leptin and ANG will be potentiated. In conclusion, we have demonstrated that Rgs2 is expressed in AgRP cells of the ARC, and we have developed a novel model to study its role in cardiometabolic control.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of Microencapsulated Diindolylmethane on Resting and Exercise Metabolism in Overweight and Obese College Aged Men

Effects of Microencapsulated Diindolylmethane on Resting and Exercise Metabolism in Overweight and Obese College Aged Men

Erratum: Resting and Exercise Energy Metabolism After Liver Transplantation for Nonalcoholic Steatohepatitis: Erratum.

[This corrects the article DOI: 10.1097/TXD.0000000000000701.].