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Boem F, Greslehner GP, Konsman JP, Chiu L. Minding the gut: extending embodied cognition and perception to the gut complex. Front Neurosci 2024; 17:1172783. [PMID: 38260022 PMCID: PMC10800657 DOI: 10.3389/fnins.2023.1172783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 10/30/2023] [Indexed: 01/24/2024] Open
Abstract
Scientific and philosophical accounts of cognition and perception have traditionally focused on the brain and external sense organs. The extended view of embodied cognition suggests including other parts of the body in these processes. However, one organ has often been overlooked: the gut. Frequently conceptualized as merely a tube for digesting food, there is much more to the gut than meets the eye. Having its own enteric nervous system, sometimes referred to as the "second brain," the gut is also an immune organ and has a large surface area interacting with gut microbiota. The gut has been shown to play an important role in many physiological processes, and may arguably do so as well in perception and cognition. We argue that proposals of embodied perception and cognition should take into account the role of the "gut complex," which considers the enteric nervous, endocrine, immune, and microbiota systems as well as gut tissue and mucosal structures. The gut complex is an interface between bodily tissues and the "internalized external environment" of the gut lumen, involved in many aspects of organismic activity beyond food intake. We thus extend current embodiment theories and suggest a more inclusive account of how to "mind the gut" in studying cognitive processes.
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Affiliation(s)
- Federico Boem
- Section Philosophy, University of Twente, Enschede, Netherlands
| | | | - Jan Pieter Konsman
- IMMUNOlogy from CONcepts and ExPeriments to Translation, CNRS UMR, University of Bordeaux, Bordeaux, France
| | - Lynn Chiu
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria
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2
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Freire EBL, d’Alva CB, Madeira MP, Lima GEDCP, Montenegro APDR, Fernandes VO, Montenegro Junior RM. Bone Mineral Density in Congenital Generalized Lipodystrophy: The Role of Bone Marrow Tissue, Adipokines, and Insulin Resistance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18189724. [PMID: 34574647 PMCID: PMC8465110 DOI: 10.3390/ijerph18189724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/05/2021] [Accepted: 07/16/2021] [Indexed: 12/31/2022]
Abstract
Congenital Generalized Lipodystrophy (CGL) is a rare syndrome characterized by the almost total absence of subcutaneous adipose tissue due to the inability of storing lipid in adipocytes. Patients present generalized lack of subcutaneous fat and normal to low weight. They evolve with severe metabolic disorders, non-alcoholic fatty liver disease, early cardiac abnormalities, and infectious complications. Although low body weight is a known risk factor for osteoporosis, it has been reported that type 1 and 2 CGL have a tendency of high bone mineral density (BMD). In this review, we discuss the role of bone marrow tissue, adipokines, and insulin resistance in the setting of the normal to high BMD of CGL patients. Data bases from Pubmed and LILACS were searched, and 113 articles published until 10 April 2021 were obtained. Of these, 76 were excluded for not covering the review topic. A manual search for additional literature was performed using the bibliographies of the studies located. The elucidation of the mechanisms responsible for the increase in BMD in this unique model of insulin resistance may contribute to the understanding of the interrelationships between bone, muscle, and adipose tissue in a pathophysiological and therapeutic perspective.
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Flasbeck V, Bamberg C, Brüne M. Short-Term Fasting and Ingestion of Caloric Drinks Affect Heartbeat-Evoked Potentials and Autonomic Nervous System Activity in Males. Front Neurosci 2021; 15:622428. [PMID: 34267619 PMCID: PMC8276132 DOI: 10.3389/fnins.2021.622428] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 05/20/2021] [Indexed: 11/24/2022] Open
Abstract
Central nervous systems receive and process information from the internal and external environment to maintain homeostasis. This includes interoceptive awareness of the organism’s nutritional state. Whenever food supply is required, feelings of hunger initiate the search for and the consumption of appropriate amounts of nutrients. How this is physiologically regulated in humans has been subjected to research into interoceptive awareness of body states during fasting and food consumption. However, there is no research on the distinct effects of carbohydrate or protein intake on interoception. Therefore, we aimed to investigate the impact of fasting and consumption of standardized carbohydrate and protein shakes on interoception in a repeated-measures cross-over design in a sample of 37 healthy, normal weight males. As a physiological correlate of interoception, we measured heartbeat-evoked potentials (HEPs), which are suggested to reflect the cortical representation of cardiac signals, during eight-minutes resting state EEG-recordings. After a 16-hour fasting period, the HEP amplitudes were lower over right central and parietal electrodes and increased after ingestion of the nutritional shake. Exploratory analyses indicated that the difference between fasting and satiety was more prominent at carbohydrate compared protein testing days. Correlation analyses with heart rate variability (HRV) suggested that high cardiac sympathetic activity is related to lower HEP amplitudes. Furthermore, cardiac sympathetic activity and stress indices decreased from before to after the intervention, whereas HRV increased. Together, this study shows for the first time that fasting and the intake of a nutritional shake affects cardiac measures of autonomic nervous system functioning and the neural correlates of cardiac interoception. These findings could be relevant for diets and psychosomatic disorders, including eating disorders.
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Affiliation(s)
- Vera Flasbeck
- Division of Social Neuropsychiatry and Evolutionary Medicine, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Christoph Bamberg
- Division of Social Neuropsychiatry and Evolutionary Medicine, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Martin Brüne
- Division of Social Neuropsychiatry and Evolutionary Medicine, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr University Bochum, Bochum, Germany
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Allaf M, Elghazaly H, Mohamed OG, Fareen MFK, Zaman S, Salmasi AM, Tsilidis K, Dehghan A. Intermittent fasting for the prevention of cardiovascular disease. Cochrane Database Syst Rev 2021; 1:CD013496. [PMID: 33512717 PMCID: PMC8092432 DOI: 10.1002/14651858.cd013496.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Cardiovascular disease (CVD) is the leading cause of death worldwide. Lifestyle changes are at the forefront of preventing the disease. This includes advice such as increasing physical activity and having a healthy balanced diet to reduce risk factors. Intermittent fasting (IF) is a popular dietary plan involving restricting caloric intake to certain days in the week such as alternate day fasting and periodic fasting, and restricting intake to a number of hours in a given day, otherwise known as time-restricted feeding. IF is being researched for its benefits and many randomised controlled trials have looked at its benefits in preventing CVD. OBJECTIVES To determine the role of IF in preventing and reducing the risk of CVD in people with or without prior documented CVD. SEARCH METHODS We conducted our search on 12 December 2019; we searched CENTRAL, MEDLINE and Embase. We also searched three trials registers and searched the reference lists of included papers. Systematic reviews were also viewed for additional studies. There was no language restriction applied. SELECTION CRITERIA We included randomised controlled trials comparing IF to ad libitum feeding (eating at any time with no specific caloric restriction) or continuous energy restriction (CER). Participants had to be over the age of 18 and included those with and without cardiometabolic risk factors. Intermittent fasting was categorised into alternate-day fasting, modified alternate-day fasting, periodic fasting and time-restricted feeding. DATA COLLECTION AND ANALYSIS Five review authors independently selected studies for inclusion and extraction. Primary outcomes included all-cause mortality, cardiovascular mortality, stroke, myocardial infarction, and heart failure. Secondary outcomes include the absolute change in body weight, and glucose. Furthermore, side effects such as headaches and changes to the quality of life were also noted. For continuous data, pooled mean differences (MD) (with 95% confidence intervals (CIs)) were calculated. We contacted trial authors to obtain missing data. We used GRADE to assess the certainty of the evidence. MAIN RESULTS: Our search yielded 39,165 records after the removal of duplicates. From this, 26 studies met our criteria, and 18 were included in the pooled analysis. The 18 studies included 1125 participants and observed outcomes ranging from four weeks to six months. No studies included data on all-cause mortality, cardiovascular mortality, stroke, myocardial infarction, and heart failure at any point during follow-up. Of quantitatively analysed data, seven studies compared IF with ab libitum feeding, eight studies compared IF with CER, and three studies compared IF with both ad libitum feeding and CER. Outcomes were reported at short term (≤ 3 months) and medium term (> 3 months to 12 months) follow-up. Body weight was reduced with IF compared to ad libitum feeding in the short term (MD -2.88 kg, 95% CI -3.96 to -1.80; 224 participants; 7 studies; low-certainty evidence). We are uncertain of the effect of IF when compared to CER in the short term (MD -0.88 kg, 95% CI -1.76 to 0.00; 719 participants; 10 studies; very low-certainty evidence) and there may be no effect in the medium term (MD -0.56 kg, 95% CI -1.68 to 0.56; 279 participants; 4 studies; low-certainty evidence). We are uncertain about the effect of IF on glucose when compared to ad libitum feeding in the short term (MD -0.03 mmol/L, 95% CI -0.26 to 0.19; 95 participants; 3 studies; very-low-certainty of evidence) and when compared to CER in the short term: MD -0.02 mmol/L, 95% CI -0.16 to 0.12; 582 participants; 9 studies; very low-certainty; medium term: MD 0.01, 95% CI -0.10 to 0.11; 279 participants; 4 studies; low-certainty evidence). The changes in body weight and glucose were not deemed to be clinically significant. Four studies reported data on side effects, with some participants complaining of mild headaches. One study reported on the quality of life using the RAND SF-36 score. There was a modest increase in the physical component summary score. AUTHORS' CONCLUSIONS Intermittent fasting was seen to be superior to ad libitum feeding in reducing weight. However, this was not clinically significant. There was no significant clinical difference between IF and CER in improving cardiometabolic risk factors to reduce the risk of CVD. Further research is needed to understand the safety and risk-benefit analysis of IF in specific patient groups (e.g. patients with diabetes or eating disorders) as well as the effect on longer-term outcomes such as all-cause mortality and myocardial infarction.
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Affiliation(s)
| | | | | | | | - Sadia Zaman
- School of Medicine, Imperial College London, London, UK
| | - Abdul-Majeed Salmasi
- Department of Cardiology, London North West University Healthcare NHS Trust, London, UK
| | - Kostas Tsilidis
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - Abbas Dehghan
- School of Public Health, Imperial College London, London, UK
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Leptin alters energy intake and fat mass but not energy expenditure in lean subjects. Nat Commun 2020; 11:5145. [PMID: 33051459 PMCID: PMC7553922 DOI: 10.1038/s41467-020-18885-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 09/18/2020] [Indexed: 12/21/2022] Open
Abstract
Based on studies in mice, leptin was expected to decrease body weight in obese individuals. However, the majority of the obese are hyperleptinemic and do not respond to leptin treatment, suggesting the presence of leptin tolerance and questioning the role of leptin as regulator of energy balance in humans. We thus performed detailed novel measurements and analyses of samples and data from our clinical trials biobank to investigate leptin effects on mechanisms of weight regulation in lean normo- and mildly hypo-leptinemic individuals without genetic disorders. We demonstrate that short-term leptin administration alters food intake during refeeding after fasting, whereas long-term leptin treatment reduces fat mass and body weight, and transiently alters circulating free fatty acids in lean mildly hypoleptinemic individuals. Leptin levels before treatment initiation and leptin dose do not predict the observed weight loss in lean individuals suggesting a saturable effect of leptin. In contrast to data from animal studies, leptin treatment does not affect energy expenditure, lipid utilization, SNS activity, heart rate, blood pressure or lean body mass. Leptin treatment is effective to reduce body weight in animal models, but patients with obesity and associated hyperleptinemia do not respond well to leptin therapy. Here the authors report a retrospective analysis of four clinical trials in normo- and mildly hypoleptinemic individuals and show that leptin therapy alters food intake in the short term and reduces weight and fat mass in the long term without effects on energy expenditure.
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Brown H, Proulx MJ, Stanton Fraser D. Hunger Bias or Gut Instinct? Responses to Judgments of Harm Depending on Visceral State Versus Intuitive Decision-Making. Front Psychol 2020; 11:2261. [PMID: 33041900 PMCID: PMC7530233 DOI: 10.3389/fpsyg.2020.02261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
Empirical investigation into the emotional and physiological processes that shape moral decision-making is vast and growing. Yet, relatively less attention has been paid to measures of interoception in morality research despite its centrality in both emotional and physiological processes. Hunger and thirst represent two everyday interoceptive states, and hunger, in particular, has been shown to be influential for moral decision-making in numerous studies. It is possible that a tendency to focus on internal sensations interoceptive sensibility (IS), as well as the emotional and physiological states associated with visceral states, could be important in the relationships between hunger, thirst, and moral judgments. This cross-sectional online research (n = 154) explored whether IS, hunger, thirst, and emotional state influenced appropriateness and acceptability judgments of harm. The moral dilemma stimuli used allowed the independent calculation of (1) people's tendency to avoid harmful action at all costs and (2) people's tendency to maximize outcomes that benefit the greater good. The Cognitive Reflection Task (CRT) was implemented to determine whether an ability to override intuitive responses to counterintuitive problems predicted harm-based moral judgments, as found previously. Hunger bias, independent of IS and emotional state, was influential for non-profitable acceptability judgments of harmful actions. Contrary to dual-process perspectives, a novel finding was that more intuitive responses on the CRT predicted a reduced aversion to harmful actions that was indirectly associated with IS. We suggest that IS may indicate people's vulnerability to cognitive miserliness on the CRT task and reduced deliberation of moral dilemma stimuli. The framing of moral dilemmatic questions to encourage allocentric (acceptability questions) versus egocentric perspectives (appropriateness questions) could explain the divergence between hunger bias and intuitive decision-making for predicting these judgments, respectively. The findings are discussed in relation to dual-process accounts of harm-based moral judgments and evidence linking visceral experiences to harm aversion and moral decision-making.
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Affiliation(s)
- Helen Brown
- Crossmodal Cognition Lab, Department of Psychology, University of Bath, Bath, United Kingdom
| | | | - Danaë Stanton Fraser
- Crossmodal Cognition Lab, Department of Psychology, University of Bath, Bath, United Kingdom.,CREATE Lab, University of Bath, Bath, United Kingdom
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7
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Rosenbaum M, Leibel RL. Physiological responses to leptin levels in lipodystrophy: a model for other hypoleptinemias? J Clin Invest 2018; 128:3237-3239. [PMID: 30010621 DOI: 10.1172/jci122042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Brown et al. report that two weeks of exogenous leptin administration to leptin-naive individuals with lipodystrophy resulted in increased energy expenditure and lipolysis, decreased ectopic liver fat, improved hepatic and peripheral insulin sensitivity, and attenuated dyslipidemia. Leptin withdrawal in individuals with lipodystrophy did not produce reciprocal effects on these phenotypes and resulted in significant improvements only in hepatic insulin sensitivity. This asymmetry in responses to leptin initiation and cessation is consistent with the other aspects of leptin biology that are dependent on the metabolic context in which this adipocyte-derived hormone functions.
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8
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Perry RJ, Shulman GI. The Role of Leptin in Maintaining Plasma Glucose During Starvation. POSTDOC JOURNAL : A JOURNAL OF POSTDOCTORAL RESEARCH AND POSTDOCTORAL AFFAIRS 2018; 6:3-19. [PMID: 29682594 PMCID: PMC5909716 DOI: 10.14304/surya.jpr.v6n3.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For 20 years it has been known that concentrations of leptin, a hormone produced by the white adipose tissue (WAT) largely in proportion to body fat, drops precipitously with starvation, particularly in lean humans and animals. The role of leptin to suppress the thyroid and reproductive axes during a prolonged fast has been well defined; however, the impact of leptin on metabolic regulation has been incompletely understood. However emerging evidence suggests that, in starvation, hypoleptinemia increases activity of the hypothalamic-pituitary-adrenal axis, promoting WAT lipolysis, increasing hepatic acetyl-CoA concentrations, and maintaining euglycemia. In addition, leptin may be largely responsible for mediating a shift from a reliance upon glucose metabolism (absorption and glycogenolysis) to fat metabolism (lipolysis increasing gluconeogenesis) which preserves substrates for the brain, heart, and other critical organs. In this way a leptin-mediated glucose-fatty acid cycle appears to maintain glycemia and permit survival in starvation.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine
- Department of Cellular & Molecular Physiology, Yale University School of Medicine
- Howard Hughes Medical Institute
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9
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Abstract
The rising incidence of metabolic diseases worldwide has prompted renewed interest in the study of intermediary metabolism and cellular bioenergetics. The application of modern biochemical methods for quantitating fuel substrate metabolism with advanced mouse genetic approaches has greatly increased understanding of the mechanisms that integrate energy metabolism in the whole organism. Examination of the intermediary metabolism of skeletal cells has been sparked by a series of unanticipated observations in genetically modified mice that suggest the existence of novel endocrine pathways through which bone cells communicate their energy status to other centers of metabolic control. The recognition of this expanded role of the skeleton has in turn led to new lines of inquiry directed at defining the fuel requirements and bioenergetic properties of bone cells. This article provides a comprehensive review of historical and contemporary studies on the metabolic properties of bone cells and the mechanisms that control energy substrate utilization and bioenergetics. Special attention is devoted to identifying gaps in our current understanding of this new area of skeletal biology that will require additional research to better define the physiological significance of skeletal cell bioenergetics in human health and disease.
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Affiliation(s)
- Ryan C Riddle
- Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland; and The Baltimore Veterans Administration Medical Center, Baltimore, Maryland
| | - Thomas L Clemens
- Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland; and The Baltimore Veterans Administration Medical Center, Baltimore, Maryland
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10
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Effect of 48 h Fasting on Autonomic Function, Brain Activity, Cognition, and Mood in Amateur Weight Lifters. BIOMED RESEARCH INTERNATIONAL 2016; 2016:1503956. [PMID: 28025637 PMCID: PMC5153500 DOI: 10.1155/2016/1503956] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 10/10/2016] [Accepted: 11/09/2016] [Indexed: 12/19/2022]
Abstract
Objectives. The acute fasting-induced cardiovascular autonomic response and its effect on cognition and mood remain debatable. Thus, the main purpose of this study was to estimate the effect of a 48 h, zero-calorie diet on autonomic function, brain activity, cognition, and mood in amateur weight lifters. Methods. Nine participants completed a 48 h, zero-calorie diet program. Cardiovascular autonomic function, resting frontal brain activity, cognitive performance, and mood were evaluated before and after fasting. Results. Fasting decreased (p < 0.05) weight, heart rate, and systolic blood pressure, whereas no changes were evident regarding any of the measured heart rate variability indices. Fasting decreased (p < 0.05) the concentration of oxygenated hemoglobin and improved (p < 0.05) mental flexibility and shifting set, whereas no changes were observed in working memory, visuospatial discrimination, and spatial orientation ability. Fasting also increased (p < 0.05) anger, whereas other mood states were not affected by it. Conclusions. 48 h fasting resulted in higher parasympathetic activity and decreased resting frontal brain activity, increased anger, and improved prefrontal-cortex-related cognitive functions, such as mental flexibility and set shifting, in amateur weight lifters. In contrast, hippocampus-related cognitive functions were not affected by it.
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11
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Tanaka H, Tomoto T, Sugawara J. A week of Danjiki (Buddhist fasting ritual) on cardiometabolic health: a case report. J Physiol Sci 2016; 66:431-4. [PMID: 27130193 PMCID: PMC10717696 DOI: 10.1007/s12576-016-0454-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 04/16/2016] [Indexed: 11/24/2022]
Abstract
Danjiki is an ascetic traditional fasting ritual in the Japanese Buddhism training. Here we present a case of a 48-year-old man who underwent a 1-week-long Danjiki fasting ritual in a remote Buddhist temple. The daily ritual consisted of waking up at 3:30 am, hiking strenuously in the steep mountains followed by meditations on the rocks, focused calligraphy of religious drawings and documents, recital of Buddhist prayer chanting, and standing under waterfalls while reciting prayers. He was allowed to drink water ad libitum and a cup of carrot juice a day. After a week of the Danjiki ritual, his body weight decreased by 5 kg. Resting metabolic rate did not change. Fasting blood glucose did not change but plasma triglyceride decreased 35 %. There were no changes in blood pressure. Arterial stiffness increased 15-25 % and endothelium-dependent vasodilation decreased 5 %. These results indicate that the Danjiki ritual produced significant weight loss but unexpectedly reduced vascular functions.
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Affiliation(s)
- Hirofumi Tanaka
- Department of Kinesiology and Health Education, The University of Texas at Austin, 2109 San Jacinto Blvd, D3700, 78712, Austin, TX, USA.
| | - Tsubasa Tomoto
- National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| | - Jun Sugawara
- National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
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12
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Ohara K, Okita Y, Kouda K, Mase T, Miyawaki C, Nakamura H. Cardiovascular response to short-term fasting in menstrual phases in young women: an observational study. BMC WOMENS HEALTH 2015; 15:67. [PMID: 26311347 PMCID: PMC4551691 DOI: 10.1186/s12905-015-0224-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 08/14/2015] [Indexed: 11/24/2022]
Abstract
Background Menstrual cycle-related symptoms are an important health issue for many women, and some may affect cardiac autonomic regulation. In the present study, we evaluated the cardiovascular and physiological stress response to 12-h short-term fasting in the menstrual phases of healthy young women. Methods We performed a randomized crossover study. Subjects were seven female university students (age: 22.3 ± 1.0 years). The experiments comprised four sessions: meal intake in the follicular phase, meal intake in the luteal phase, fasting in the follicular phase, and fasting in the luteal phase. All subjects participated in a total of four experimental sessions during two successive phases (follicular and luteal phase in the same menstrual cycle, or luteal phase and follicular phase in the next menstrual cycle) according to a randomized crossover design. R-R intervals were continuously recorded before and after meals, and power spectral analysis of heart rate variability was performed. Other physiological data were obtained before and 20, 40, 60, and 80 min after meal intake or after the corresponding time point of meal intake (fasting in the follicular or luteal phase). Results Heart rate decreased during fasting in the follicular and luteal phases. High frequency power increased during fasting in the follicular and luteal phases. In addition, salivary cortisol concentrations decreased during fasting in the luteal phase. Conclusions In the present study, short-term fasting resulted in higher parasympathetic activity and lower cortisol levels in the luteal phase in these young women. These results indicate a possibility to produce an anti-stress effect in the luteal phase, which may reduce menstrual symptoms.
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Affiliation(s)
- Kumiko Ohara
- Graduate School of Human Development and Environment, Kobe University, Kobe, Japan. .,Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
| | - Yoshimitsu Okita
- Graduate School of Science and Technology, Shizuoka University, Hamamatsu, Japan.
| | - Katsuyasu Kouda
- Department of Public Health, Kinki University Faculty of Medicine, Osaka-Sayama, Japan.
| | - Tomoki Mase
- Department of Childhood Education, Kyoto Seibo College, Kyoto, Japan.
| | - Chiemi Miyawaki
- Department of Early Childhood Education, Heian Jogakuin (St. Agnes') College, Kyoto, Japan.
| | - Harunobu Nakamura
- Graduate School of Human Development and Environment, Kobe University, Kobe, Japan.
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13
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Upadhyay J, Farr OM, Mantzoros CS. The role of leptin in regulating bone metabolism. Metabolism 2015; 64:105-13. [PMID: 25497343 PMCID: PMC4532332 DOI: 10.1016/j.metabol.2014.10.021] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 10/22/2014] [Accepted: 10/22/2014] [Indexed: 01/17/2023]
Abstract
Leptin was initially best known for its role in energy homeostasis and regulation of energy expenditure. In the past few years we have realized that leptin also plays a major role in neuroendocrine regulation and bone metabolism. Here, we review the literature the indirect and direct pathways through which leptin acts to influence bone metabolism and discuss bone abnormalities related to leptin deficiency in both animal and human studies. The clinical utility of leptin in leptin deficient individuals and its potential to improve metabolic bone disease are also discussed. We are beginning to understand the critical role leptin plays in bone metabolism; future randomized studies are needed to fully assess the potential and risk-benefit of leptin's use in metabolic bone disease particularly in leptin deficient individuals.
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Affiliation(s)
- Jagriti Upadhyay
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215.
| | - Olivia M Farr
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
| | - Christos S Mantzoros
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
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14
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Lack of Day/Night variation in fibroblast growth factor 21 levels in young healthy men. Int J Obes (Lond) 2014; 39:945-8. [PMID: 25540981 DOI: 10.1038/ijo.2014.215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 09/23/2014] [Accepted: 10/01/2014] [Indexed: 01/14/2023]
Abstract
BACKGROUND Fibroblast growth factor (FGF) 21 is an endocrine factor with an emerging role as a metabolic regulator. We previously reported the presence of a significant day/night variation of FGF-21 in energy-replete, healthy female subjects. However the day/night patterns of secretion in male subjects remain to be fully elucidated. To elucidate day/night pattern of FGF-21 levels in male subjects in the energy-replete state, its relationship to FFA and to investigate whether a sexual dimorphism exists in FGF-21 physiology. METHODS Eight healthy lean male subjects were studied for up to 5 days while on an isocaloric diet. Blood samples were obtained for measurement of FGF-21 and free fatty acids (FFA) hourly from 0800 AM on day 4 till 0800AM on day 5. RESULTS FGF-21 did not exhibit any statistically significant day/night variation pattern of circulating FGF-21 levels during the isocaloric fed state in male subjects. FGF-21 levels in male subjects are closely cross-correlated with FFA levels, similar to female subjects. CONCLUSIONS A sexual dimorphism exists in FGF-21 physiology; that as opposed to female subjects, no significant day/night variation exists in FGF-21 rhythm in male subjects in the energy-replete state. Circulating pattern of FGF-21, similar to the female subjects, was highly cross-correlated to the FFA levels in the male subjects, signifying that the sexual dimorphism in FGF-21 physiology may be related to the differing lipid metabolism in both the genders.
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15
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Foo JP, Polyzos SA, Anastasilakis AD, Chou S, Mantzoros CS. The effect of leptin replacement on parathyroid hormone, RANKL-osteoprotegerin axis, and Wnt inhibitors in young women with hypothalamic amenorrhea. J Clin Endocrinol Metab 2014; 99:E2252-8. [PMID: 25148234 PMCID: PMC5393498 DOI: 10.1210/jc.2014-2491] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
CONTEXT Recombinant leptin (metreleptin) treatment restores bone mineral density in women with hypothalamic amenorrhea (HA), a condition characterized by hypoleptinemia, which has adverse impact on bone health. OBJECTIVE The objective of the study was to investigate how metreleptin exerts its positive effect on bone metabolism in humans. DESIGN This was a randomized, double-blinded, placebo-controlled study. SETTING The study was conducted at Beth Israel Deaconess Medical Center (Boston, Massachusetts). PATIENTS AND INTERVENTIONS Women (n = 18) with HA and hypoleptinemia for at least 6 months were randomized to receive either metreleptin or placebo for 36 weeks. Serum samples were obtained at baseline and 12, 24, and 36 weeks of treatment. MAIN OUTCOME MEASURES Circulating levels of leptin, intact PTH (iPTH), receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), sclerostin, dickkopf-1, and fibroblast growth factor-23. RESULTS Metreleptin administration significantly increased leptin levels throughout the treatment period (P = .001). iPTH decreased over the 36 weeks of treatment (P = .01). There was a trend toward a decrease in serum RANKL and increase in serum OPG in the metreleptin-treated group. The RANKL to OPG ratio was significantly decreased within the metreleptin (P = .04) but not the placebo group. Metreleptin had no effect on serum sclerostin, dickkopf-1, and fibroblast growth factor-23. CONCLUSIONS Metreleptin treatment over 36 weeks decreases iPTH and RANKL to OPG ratio levels in hypoleptinemic women with HA.
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Affiliation(s)
- Joo-Pin Foo
- Division of Endocrinology, Diabetes, and Metabolism (J.-P.F., S.A.P., S.C., C.S.M.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215; Department of Endocrinology (A.D.A.), 424 General Military Hospital, 54006 Thessaloniki, Greece; and Section of Endocrinology (C.S.M.), Boston Veterans Affairs Healthcare System, Harvard Medical School, Boston, Massachusetts 02130
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Gouni-Berthold I, Berthold HK, Huh JY, Berman R, Spenrath N, Krone W, Mantzoros CS. Effects of lipid-lowering drugs on irisin in human subjects in vivo and in human skeletal muscle cells ex vivo. PLoS One 2013; 8:e72858. [PMID: 24023786 PMCID: PMC3759413 DOI: 10.1371/journal.pone.0072858] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/15/2013] [Indexed: 01/12/2023] Open
Abstract
Context and Objective The myokine irisin has been proposed to regulate energy homeostasis. Little is known about its association with metabolic parameters and especially with parameters influencing pathways of lipid metabolism. In the context of a clinical trial, an exploratory post hoc analysis has been performed in healthy subjects to determine whether simvastatin and/or ezetimibe influence serum irisin levels. The direct effects of simvastatin on irisin were also examined in primary human skeletal muscle cells (HSKMCs). Design and Participants A randomized, parallel 3-group study was performed in 72 men with mild hypercholesterolemia and without apparent cardiovascular disease. Each group of 24 subjects received a 14-day treatment with either simvastatin 40 mg, ezetimibe 10 mg, or their combination. Results Baseline irisin concentrations were not significantly correlated with age, BMI, estimated GFR, thyroid parameters, glucose, insulin, lipoproteins, non-cholesterol sterols, adipokines, inflammation markers and various molecular markers of cholesterol metabolism. Circulating irisin increased significantly in simvastatin-treated but not in ezetimibe-treated subjects. The changes were independent of changes in LDL-cholesterol and were not correlated with changes in creatine kinase levels. In HSKMCs, simvastatin significantly increased irisin secretion as well as mRNA expression of its parent peptide hormone FNDC5. Simvastatin significantly induced cellular reactive oxygen species levels along with expression of pro- and anti-oxidative genes such as Nox2, and MnSOD and catalase, respectively. Markers of cellular stress such as atrogin-1 mRNA and Bax protein expression were also induced by simvastatin. Decreased cell viability and increased irisin secretion by simvastatin was reversed by antioxidant mito-TEMPO, implying in part that irisin is secreted as a result of increased mitochondrial oxidative stress and subsequent myocyte damage. Conclusions Simvastatin increases irisin concentrations in vivo and in vitro. It remains to be determined whether this increase is a result of muscle damage or a protective mechanism against simvastatin-induced cellular stress. Trial Registration ClinicalTrials.gov NCT00317993 NCT00317993.
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Affiliation(s)
- Ioanna Gouni-Berthold
- University of Cologne, Center for Endocrinology, Diabetes and Preventive Medicine, Cologne, Germany
- * E-mail:
| | - Heiner K. Berthold
- Charité University Medicine Berlin, Evangelical Geriatrics Center Berlin (EGZB) and Virchow Clinic Campus, Lipid Clinic at the Interdisciplinary Metabolism Center, Berlin, Germany
| | - Joo Young Huh
- Section of Endocrinology, Boston VA Healthcare System and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Reena Berman
- Section of Endocrinology, Boston VA Healthcare System and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nadine Spenrath
- University of Cologne, Center for Endocrinology, Diabetes and Preventive Medicine, Cologne, Germany
| | - Wilhelm Krone
- University of Cologne, Center for Endocrinology, Diabetes and Preventive Medicine, Cologne, Germany
| | - Christos S. Mantzoros
- Section of Endocrinology, Boston VA Healthcare System and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
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Moon HS, Dalamaga M, Kim SY, Polyzos SA, Hamnvik OP, Magkos F, Paruthi J, Mantzoros CS. Leptin's role in lipodystrophic and nonlipodystrophic insulin-resistant and diabetic individuals. Endocr Rev 2013; 34:377-412. [PMID: 23475416 PMCID: PMC3660716 DOI: 10.1210/er.2012-1053] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Leptin is an adipocyte-secreted hormone that has been proposed to regulate energy homeostasis as well as metabolic, reproductive, neuroendocrine, and immune functions. In the context of open-label uncontrolled studies, leptin administration has demonstrated insulin-sensitizing effects in patients with congenital lipodystrophy associated with relative leptin deficiency. Leptin administration has also been shown to decrease central fat mass and improve insulin sensitivity and fasting insulin and glucose levels in HIV-infected patients with highly active antiretroviral therapy (HAART)-induced lipodystrophy, insulin resistance, and leptin deficiency. On the contrary, the effects of leptin treatment in leptin-replete or hyperleptinemic obese individuals with glucose intolerance and diabetes mellitus have been minimal or null, presumably due to leptin tolerance or resistance that impairs leptin action. Similarly, experimental evidence suggests a null or a possibly adverse role of leptin treatment in nonlipodystrophic patients with nonalcoholic fatty liver disease. In this review, we present a description of leptin biology and signaling; we summarize leptin's contribution to glucose metabolism in animals and humans in vitro, ex vivo, and in vivo; and we provide insights into the emerging clinical applications and therapeutic uses of leptin in humans with lipodystrophy and/or diabetes.
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Affiliation(s)
- Hyun-Seuk Moon
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Aronis KN, Foo JP, Chamberland JP, Mantzoros CS. Secretion patterns of circulating osteoprotegerin and response to acute and chronic energy deprivation in young healthy adults. J Clin Endocrinol Metab 2012; 97:2765-72. [PMID: 22563105 PMCID: PMC3410259 DOI: 10.1210/jc.2012-1618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Osteoprotegerin (OPGN) is a bone-remodeling marker that is associated with various metabolic and vascular complications. Cross-sectional studies in humans have demonstrated an inverse association between leptin, a marker of energy sufficiency, and OPGN. The physiology of OPGN has not been fully elucidated to date. We thus aim to elucidate 1) whether OPGN levels exhibit any gender dimorphism or day/night secretion pattern; and 2) whether there is any effect of acute and/or chronic energy deprivation on its circulating levels and whether such effects are mediated through leptin. MATERIALS AND METHODS Study A: To evaluate OPGN secretion patterns and OPGN response to acute energy deprivation, we studied 12 healthy subjects under three different conditions for 72 h-in the isocaloric fed state, and during a fasting state with administration of either placebo or metreleptin in replacement doses. Blood samples were obtained every 15 min and pooled hourly during the last 24 h of the study. Study B: To evaluate the effect of chronic energy deprivation on OPGN secretion, we measured its levels in 14 obese subjects before and during weight loss after bariatric surgery. RESULTS OPGN levels exhibited a statistically significant (P < 0.01), albeit clinically limited in magnitude, day/night variation pattern in both genders (R(2) = 14.68%; 10.7-14.8% reduction with lower levels around 1600-1800 h; P < 0.01). Males had lower OPGN levels compared to females (1.81 ± 0.04 vs. 3.65 ± 0.07 pmol/liter; P < 0.001). Three days of fasting with either placebo or metreleptin administration did not change OPGN levels. OPGN levels did not change during bariatric surgery-induced weight loss. CONCLUSIONS OPGN levels are lower in men and exhibit a statistically significant, albeit clinically limited in magnitude, day/night secretion pattern. Neither acute nor chronic energy deprivation leading to significant weight loss has any effects on OPGN levels. Nomenclature Comment: Use of the terms "circadian" and "day/night variation" is meant as follows: Circadian pattern is a functional term that implies a rhythm that has been proven to be regulated by the innate circadian apparatus (anatomical and/or molecular). Conversely, day/night variation pattern is a descriptive term that refers to serum levels that vary during a day, usually in a periodic fashion. It is not known whether this variation is an innate property of the organ that secretes this hormone or whether it is determined by exogenous factors.
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Affiliation(s)
- Konstantinos N Aronis
- Division of Endocrinology, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Abstract
Leptin, a peptide hormone secreted by adipocytes in proportion of the amount of energy stored in fat, plays a central role in regulating human energy homeostasis. In addition, leptin plays a significant permissive role in the physiological regulation of several neuroendocrine axes, including the hypothalamic-pituitary-gonadal, -thyroid, -growth hormone, and -adrenal axes. Decreased levels of leptin, also known as hypoleptinemia, signal to the brain a state of energy deprivation. Hypoleptinemia can be a congenital or acquired condition, and is associated with alterations of the aforementioned axes aimed at promoting survival. More specifically, gonadotropin levels decrease and become less pulsatile under conditions of energy deprivation, and these changes can be at least partially reversed through leptin administration in physiological replacement doses. Similarly, leptin deficiency is associated with thyroid axis abnormalities including abnormal levels of thyrotropin-releasing hormone, and leptin administration may at least partially attenuate this effect. Leptin deficiency results in decreased insulin-like growth factor 1 levels which can be partially ameliorated through leptin administration, and leptin appears to have a much more pronounced effect on the growth of rodents than that of humans. Similarly, adrenal axis function is regulated more tightly by low leptin in rodents than in humans. In addition to congenital leptin deficiency, conditions that may be associated with decreased leptin levels include hypothalamic amenorrhea, anorexia nervosa, and congenital or acquired lipodystrophy syndromes. Accumulating evidence from proof of concept studies suggests that leptin administration, in replacement doses, may ameliorate neuroendocrine abnormalities in individuals who suffer from these conditions.
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Affiliation(s)
- Sami M. Khan
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Ole-Petter R. Hamnvik
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mary Brinkoetter
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
| | - Christos S. Mantzoros
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
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Vamvini MT, Aronis KN, Chamberland JP, Mantzoros CS. Energy deprivation alters in a leptin- and cortisol-independent manner circulating levels of activin A and follistatin but not myostatin in healthy males. J Clin Endocrinol Metab 2011; 96:3416-23. [PMID: 21865351 PMCID: PMC3205881 DOI: 10.1210/jc.2011-1665] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Activin A, myostatin, and follistatin have recently emerged as important regulatory molecules of reproduction and the musculoskeletal system. Little is known, however, about their day/night patterns of secretion and their physiological regulation by energy availability. OBJECTIVE The objective of the study was to explore day/night patterns of secretion and assess whether energy deprivation alters circulating levels of activin A, myostatin, follistatin, and cortisol and to examine whether leptin may mediate this effect. DESIGN, SETTING AND PATIENTS, AND INTERVENTIONS: Seven healthy lean men (aged 23.2 ± 3.7 yr, body mass index 23.6 ± 1.7 kg/m(2)) were studied for 72 h under three different conditions: on their baseline/isocaloric diet and in a complete fasting state with administration of either placebo or metreleptin. The two fasting studies were randomized and double blinded. Blood samples were obtained every 15 min from 0800 h on d 3 until 0800 h on d 4 and pooled hourly. MAIN OUTCOME MEASURES Serum concentrations of activin A, myostatin, follistatin, cortisol, and leptin were measured. RESULTS In contrast to cortisol, we demonstrated no day/night pattern of activin A, myostatin, and follistatin secretion. Activin A concentrations decreased significantly in response to energy deprivation (P < 0.01). Follistatin and cortisol concentrations increased significantly (P < 0.01 and P < 0.01, respectively). Myostatin remained unaffected (P = 0.40). Leptin administration reversed cortisol response (P < 0.01) but failed to alter activin A, follistatin, or myostatin concentrations. CONCLUSIONS Unlike cortisol, there is no day/night variation in the concentrations of activin A, myostatin, and follistatin in healthy young males. Although energy deprivation-induced cortisol changes are leptin mediated, the changes in follistatin and activin A concentrations occur through a leptin-independent pathway.
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Affiliation(s)
- Maria T Vamvini
- Division of Endocrinology, Diabetes, and Metabolism, Harvard Medical School and Harvard School of Public Health, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
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Mantzoros CS, Magkos F, Brinkoetter M, Sienkiewicz E, Dardeno TA, Kim SY, Hamnvik OPR, Koniaris A. Leptin in human physiology and pathophysiology. Am J Physiol Endocrinol Metab 2011; 301:E567-84. [PMID: 21791620 PMCID: PMC3191548 DOI: 10.1152/ajpendo.00315.2011] [Citation(s) in RCA: 378] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Leptin, discovered through positional cloning 15 years ago, is an adipocyte-secreted hormone with pleiotropic effects in the physiology and pathophysiology of energy homeostasis, endocrinology, and metabolism. Studies in vitro and in animal models highlight the potential for leptin to regulate a number of physiological functions. Available evidence from human studies indicates that leptin has a mainly permissive role, with leptin administration being effective in states of leptin deficiency, less effective in states of leptin adequacy, and largely ineffective in states of leptin excess. Results from interventional studies in humans demonstrate that leptin administration in subjects with congenital complete leptin deficiency or subjects with partial leptin deficiency (subjects with lipoatrophy, congenital or related to HIV infection, and women with hypothalamic amenorrhea) reverses the energy homeostasis and neuroendocrine and metabolic abnormalities associated with these conditions. More specifically, in women with hypothalamic amenorrhea, leptin helps restore abnormalities in hypothalamic-pituitary-peripheral axes including the gonadal, thyroid, growth hormone, and to a lesser extent adrenal axes. Furthermore, leptin results in resumption of menses in the majority of these subjects and, in the long term, may increase bone mineral content and density, especially at the lumbar spine. In patients with congenital or HIV-related lipoatrophy, leptin treatment is also associated with improvements in insulin sensitivity and lipid profile, concomitant with reduced visceral and ectopic fat deposition. In contrast, leptin's effects are largely absent in the obese hyperleptinemic state, probably due to leptin resistance or tolerance. Hence, another emerging area of research pertains to the discovery and/or usefulness of leptin sensitizers. Results from ongoing studies are expected to further increase our understanding of the role of leptin and the potential clinical applications of leptin or its analogs in human therapeutics.
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Affiliation(s)
- Christos S Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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Aronis KN, Diakopoulos KN, Fiorenza CG, Chamberland JP, Mantzoros CS. Leptin administered in physiological or pharmacological doses does not regulate circulating angiogenesis factors in humans. Diabetologia 2011; 54:2358-67. [PMID: 21660636 PMCID: PMC3733553 DOI: 10.1007/s00125-011-2201-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 04/26/2011] [Indexed: 12/31/2022]
Abstract
AIM/HYPOTHESIS Leptin has been shown to regulate angiogenesis in animal and in vitro studies by upregulating the production of several pro-angiogenic factors, but its role in regulating angiogenesis has never been studied in humans. METHODS The potential angiogenic effect of two doses of metreleptin (50 and 100 ng/ml) was evaluated in vitro, using a novel three-dimensional angiogenesis assay. Fifteen healthy, normoleptinaemic volunteers were administered both a physiological (0.1 mg/kg) and a pharmacological (0.3 mg/kg) single dose of metreleptin, in vivo, on two different inpatient admissions separated by 1-12 weeks. Serum was collected at 0, 6, 12 and 24 h after metreleptin administration. Twenty lean women, with leptin levels <5 ng/ml, were randomised in a 1:1 fashion to receive either physiological replacement doses of metreleptin (0.04-0.12 mg/kg q.d.) or placebo for 32 weeks. Serum was collected at 0, 8, 20 and 32 weeks after randomisation. Proteomic angiogenesis array analysis was performed to screen for angiogenic factors. Circulating concentrations of angiogenin, angiopoietin-1, platelet derived endothelial factor (PDGF)-AA, matrix metalloproteinase (MMP) 8 and 9, endothelial growth factor (EGF) and vascular EGF (VEGF) were also measured. RESULTS Both metreleptin doses failed to induce angiogenesis in the in vitro model. Although leptin levels increased significantly in response to both short-term and long-term metreleptin administration, circulating concentrations of angiogenesis markers did not change significantly in vivo. CONCLUSIONS/INTERPRETATIONS This is the first study that examines the effect of metreleptin administration in angiogenesis in humans. Metreleptin administration does not regulate circulating angiogenesis related factors in humans. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov NCT00140205 and NCT00130117. FUNDING This study was supported by National Institutes of Health-National Center for Research Resources grant M01-RR-01032 (Harvard Clinical and Translational Science Center) and grant number UL1 RR025758. Funding was also received from the National Institute of Diabetes and Digestive and Kidney Diseases grants 58785, 79929 and 81913, and AG032030.
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Affiliation(s)
- K. N. Aronis
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - K. N. Diakopoulos
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - C. G. Fiorenza
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - J. P. Chamberland
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - C. S. Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA. Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA, USA. Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
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Bouwman FG, de Roos B, Rubio-Aliaga I, Crosley LK, Duthie SJ, Mayer C, Horgan G, Polley AC, Heim C, Coort SLM, Evelo CT, Mulholland F, Johnson IT, Elliott RM, Daniel H, Mariman ECM. 2D-electrophoresis and multiplex immunoassay proteomic analysis of different body fluids and cellular components reveal known and novel markers for extended fasting. BMC Med Genomics 2011; 4:24. [PMID: 21439033 PMCID: PMC3073865 DOI: 10.1186/1755-8794-4-24] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 03/25/2011] [Indexed: 11/20/2022] Open
Abstract
Background Proteomic technologies applied for profiling human biofluids and blood cells are considered to reveal new biomarkers of exposure or provide insights into novel mechanisms of adaptation. Methods Both a non-targeted (classical 2D-electrophoresis combined with mass spectrometry) as well as a targeted proteomic approach (multiplex immunoassay) were applied to investigate how fasting for 36 h, as compared to 12 h, affects the proteome of platelets, peripheral blood mononuclear cells (PBMC), plasma, urine and saliva collected from ten healthy volunteers. Results Between-subject variability was highest in the plasma proteome and lowest in the PBMC proteome. Random Forests analysis performed on the entire dataset revealed that changes in the level of the RhoGDI2 protein in PBMC and plasma ApoA4 levels were the two most obvious biomarkers of an extended fasting. Random Forests (RF) analysis of the multiplex immunoassay data revealed leptin and MMP-3 as biomarkers for extended fasting. However, high between-subject variability may have masked the extended fasting effects in the proteome of the biofluids and blood cells. Conclusions Identification of significantly changed proteins in biofluids and blood cells using a non-targeted approach, together with the outcome of targeted analysis revealed both known and novel markers for a 36 h fasting period, including the cellular proteins RhoGDI2 and CLIC1, and plasma proteins ApoA4, leptin and MMP-3. The PBMC proteome exhibited the lowest between-subject variability and therefore these cells appear to represent the best biosamples for biomarker discovery in human nutrigenomics.
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Affiliation(s)
- Freek G Bouwman
- Department of Human Biology, NUTRIM, Maastricht University, Maastricht, The Netherlands
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Tsioufis C, Kordalis A, Flessas D, Anastasopoulos I, Tsiachris D, Papademetriou V, Stefanadis C. Pathophysiology of resistant hypertension: the role of sympathetic nervous system. Int J Hypertens 2011; 2011:642416. [PMID: 21331155 PMCID: PMC3034926 DOI: 10.4061/2011/642416] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 12/22/2010] [Indexed: 11/20/2022] Open
Abstract
Resistant hypertension (RH) is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS) activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge points towards an impact of several factors on SNS activation, namely, insulin resistance, adipokines, endothelial dysfunction, cyclic intermittent hypoxaemia, aldosterone effects on central nervous system, chemoreceptors, and baroreceptors dysregulation. The further investigation and understanding of the mechanisms leading to SNS activation could reveal novel therapeutic targets and expand our treatment options in the challenging management of RH.
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Affiliation(s)
- Costas Tsioufis
- First Cardiology Clinic, University of Athens, Hippokration Hospital, 3 Kolokotroni Street, P. Penteli, Athens 15236, Greece
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Leptin in human physiology and therapeutics. Front Neuroendocrinol 2010; 31:377-93. [PMID: 20600241 PMCID: PMC2916735 DOI: 10.1016/j.yfrne.2010.06.002] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 12/25/2022]
Abstract
Leptin regulates energy homeostasis and reproductive, neuroendocrine, immune, and metabolic functions. In this review, we describe the role of leptin in human physiology and review evidence from recent "proof of concept" clinical trials using recombinant human leptin in subjects with congenital leptin deficiency, hypoleptinemia associated with energy-deficient states, and hyperleptinemia associated with garden-variety obesity. Since most obese individuals are largely leptin-tolerant or -resistant, therapeutic uses of leptin are currently limited to patients with complete or partial leptin deficiency, including hypothalamic amenorrhea and lipoatrophy. Leptin administration in these energy-deficient states may help restore associated neuroendocrine, metabolic, and immune function and bone metabolism. Leptin treatment is currently available for individuals with congenital leptin deficiency and congenital lipoatrophy. The long-term efficacy and safety of leptin treatment in hypothalamic amenorrhea and acquired lipoatrophy are currently under investigation. Whether combination therapy with leptin and potential leptin sensitizers will prove effective in the treatment of garden-variety obesity and whether leptin may have a role in weight loss maintenance is being greatly anticipated.
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Mantzoros CS, Sweeney L, Williams CJ, Oken E, Kelesidis T, Rifas-Shiman SL, Gillman MW. Maternal diet and cord blood leptin and adiponectin concentrations at birth. Clin Nutr 2010; 29:622-6. [PMID: 20363059 DOI: 10.1016/j.clnu.2010.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 02/04/2010] [Accepted: 03/08/2010] [Indexed: 11/26/2022]
Abstract
BACKGROUND & AIMS The purpose of this study was to determine the effects of total energy intake, macronutrient intake, and maternal adherence to Mediterranean diet or Alternative Healthy Eating Index (AHEI) on cord blood leptin and adiponectin levels, which have been associated with childhood adiposity. METHODS We used multivariable linear regression to assess associations of maternal diet, averaged over 1st and 2nd trimesters, with cord blood adipokines of 780 women from the prospective cohort study Project Viva. RESULTS Mean (SD) energy intake during pregnancy was 2135 (596) kcal. Mean (SD) cord blood levels of leptin and adiponectin were 9.0 (6.6) ng/ml and 28.6 (6.7) μg/ml, respectively. Neither closer adherence to a Mediterranean/AHEI pattern diet nor energy intake was associated with either cord blood leptin or adiponectin. Protein intake was associated with both marginally lower leptin (-0.22 ng/ml [95% CI -0.41, -0.02] for each 1% of energy) and adiponectin (-0.25 μg/ml [95% CI -0.48, -0.02]). CONCLUSIONS Closer adherence to a Mediterranean/AHEI pattern diet during pregnancy was not associated with cord blood leptin or adiponectin. Maternal protein intake was weakly but significantly associated with lower cord blood leptin and adiponectin.
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Affiliation(s)
- Christos S Mantzoros
- Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, ST816, Boston, MA 02215, USA.
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Brydon L. Adiposity, leptin and stress reactivity in humans. Biol Psychol 2010; 86:114-20. [PMID: 20193730 PMCID: PMC3042594 DOI: 10.1016/j.biopsycho.2010.02.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 02/15/2010] [Accepted: 02/22/2010] [Indexed: 12/18/2022]
Abstract
Evidence suggests that individuals who are more obese may be more responsive to stress. Stress activates the sympathetic nervous system (SNS) and the adipose-tissue cytokine leptin stimulates SNS activity in animals. We examined the relationship between adiposity, leptin and physiological responses to acute laboratory stress in 67 women. We predicted that individuals with greater adiposity and/or higher plasma leptin would be more stress-responsive. Adiposity was unrelated to cardiovascular or neuroendocrine stress reactivity. However, women with larger waists had greater stress-induced increases in plasma leptin and interleukin-1 receptor antagonist (IL-1Ra). Similarly, women with higher basal leptin displayed greater stress-induced increases in heart rate and plasma interleukin-6, and larger decreases in heart rate variability and cardiac pre-ejection period. Heightened cardiovascular and inflammatory stress responses are predictive of future cardiovascular risk. Our findings suggest that the cytokines leptin and IL-1Ra may play a role in the association between obesity, stress and cardiovascular health.
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Affiliation(s)
- Lena Brydon
- Psychobiology Group, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, United Kingdom.
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Kelesidis T, Kelesidis I, Chou S, Mantzoros CS. Narrative review: the role of leptin in human physiology: emerging clinical applications. Ann Intern Med 2010; 152:93-100. [PMID: 20083828 PMCID: PMC2829242 DOI: 10.7326/0003-4819-152-2-201001190-00008] [Citation(s) in RCA: 412] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Leptin is a hormone secreted by adipose tissue in direct proportion to amount of body fat. The circulating leptin levels serve as a gauge of energy stores, thereby directing the regulation of energy homeostasis, neuroendocrine function, and metabolism. Persons with congenital deficiency are obese, and treatment with leptin results in dramatic weight loss through decreased food intake and possible increased energy expenditure. However, most obese persons are resistant to the weight-reducing effects of leptin. Recent studies suggest that leptin is physiologically more important as an indicator of energy deficiency, rather than energy excess, and may mediate adaptation by driving increased food intake and directing neuroendocrine function to converse energy, such as inducing hypothalamic hypogonadism to prevent fertilization. Current studies investigate the role of leptin in weight-loss management because persons who have recently lost weight have relative leptin deficiency that may drive them to regain weight. Leptin deficiency is also evident in patients with diet- or exercise-induced hypothalamic amenorrhea and lipoatrophy. Replacement of leptin in physiologic doses restores ovulatory menstruation in women with hypothalamic amenorrhea and improves metabolic dysfunction in patients with lipoatrophy, including lipoatrophy associated with HIV or highly active antiretroviral therapy. The applications of leptin continue to grow and will hopefully soon be used therapeutically.
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Affiliation(s)
- Theodore Kelesidis
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Tentolouris N, Argyrakopoulou G, Katsilambros N. Perturbed autonomic nervous system function in metabolic syndrome. Neuromolecular Med 2008; 10:169-78. [PMID: 18224460 DOI: 10.1007/s12017-008-8022-5] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 12/17/2007] [Indexed: 01/26/2023]
Abstract
The metabolic syndrome is characterized by the clustering of various common metabolic abnormalities in an individual and it is associated with increased risk for the development of type 2 diabetes and cardiovascular diseases. Its prevalence in the general population is approximately 25%. Central fat accumulation and insulin resistance are considered as the common denominators of the abnormalities of the metabolic syndrome. Subjects with metabolic syndrome have autonomic nervous system dysfunction characterized by predominance of the sympathetic nervous system in many organs, i.e. heart, kidneys, vasculature, adipose tissue, and muscles. Sympathetic nervous system activation in metabolic syndrome is detected as increased heart rate and blood pressure, diminished heart rate variability, baroreceptor dysfunction, enhanced lipolysis in visceral fat, increased muscle sympathetic nerve activity, and high urine or plasma catecholamine concentrations as well as turnover rates. The augmented sympathetic activity in individuals with metabolic syndrome worsens prognosis of this high-risk population. The mechanisms linking metabolic syndrome with sympathetic activation are complex and not clearly understood. Whether sympathetic overactivity is involved in the development of the metabolic syndrome or is a consequence of it remains to be elucidated since data from prospective studies are missing. Intervention studies have demonstrated that the autonomic disturbances of the metabolic syndrome may be reversible.
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Affiliation(s)
- Nicholas Tentolouris
- 1st Department of Propaedeutic Medicine, Athens University Medical School, Athens, Greece.
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