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Feng L, Li B, Yong SS, Wu X, Tian Z. Exercise and nutrition benefit skeletal muscle: From influence factor and intervention strategy to molecular mechanism. SPORTS MEDICINE AND HEALTH SCIENCE 2024; 6:302-314. [PMID: 39309454 PMCID: PMC11411340 DOI: 10.1016/j.smhs.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/24/2024] [Accepted: 02/18/2024] [Indexed: 09/25/2024] Open
Abstract
Sarcopenia is a progressive systemic skeletal muscle disease induced by various physiological and pathological factors, including aging, malnutrition, denervation, and cardiovascular diseases, manifesting as the decline of skeletal muscle mass and function. Both exercise and nutrition produce beneficial effects on skeletal muscle growth and are viewed as feasible strategies to prevent sarcopenia. Mechanisms involve regulating blood flow, oxidative stress, inflammation, apoptosis, protein synthesis and degradation, and satellite cell activation through exerkines and gut microbiomes. In this review, we summarized and discussed the latest progress and future development of the above mechanisms for providing a theoretical basis and ideas for the prevention and treatment of sarcopenia.
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Affiliation(s)
- Lili Feng
- College of Education, Physical Education Department, Zhejiang University, Hangzhou, 310058, China
| | - Bowen Li
- College of Education, Physical Education Department, Zhejiang University, Hangzhou, 310058, China
| | - Su Sean Yong
- College of Education, Physical Education Department, Zhejiang University, Hangzhou, 310058, China
| | - Xiaonan Wu
- The Information and Communication College, National University of Defense Technology, Xi'an, 710106, China
| | - Zhenjun Tian
- Institute of Sports Biology, College of Physical Education, Shaanxi Normal University, Xi'an, 710119, China
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2
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Granic A, Sayer AA, Cooper R, Robinson SM. Nutrition in the prevention and treatment of skeletal muscle ageing and sarcopenia: a single nutrient, a whole food and a whole diet approach. Proc Nutr Soc 2024:1-16. [PMID: 39417264 PMCID: PMC7616828 DOI: 10.1017/s0029665124007432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects - both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.
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Affiliation(s)
- Antoneta Granic
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, UK
| | - Avan A Sayer
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, UK
| | - Rachel Cooper
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, UK
| | - Sian M Robinson
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, UK
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Salazar P, Poínhos R, Correia F. Chrononutrition, eating behaviour, and metabolic health among obese patients elected for bariatric surgery. Chronobiol Int 2024; 41:1217-1225. [PMID: 39163148 DOI: 10.1080/07420528.2024.2393873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 06/04/2024] [Accepted: 08/13/2024] [Indexed: 08/22/2024]
Abstract
There is evidence of the impact of chrononutrition on weight loss and metabolic control. However, the precise chrononutrition behaviours that promote these benefits are not fully described, and there are doubts if chrononutrition may be related to other eating behaviour features. The main aim was to evaluate the associations between chrononutrition and eating behaviour, and their relationships with anthropometric and biochemical parameters among obese patients elected for bariatric surgery. Eighty participants (76.3% females, mean age = 45 years, mean BMI = 41.6 kg/m2) attending bariatric surgery consultations at Centro Hospitalar Universitário de São João (Porto, Portugal) were assessed regarding chrononutrition (Chrononutrition Profile - Questionnaire) and eating behaviour (Three-Factor Eating Questionnaire - R21 and General Eating Self-Efficacy Scale). Height, weight, waist circumference, and biochemical values (total, HDL and LDL cholesterol, triglycerides and glycated haemoglobin) were collected. Eating window midpoint was positively correlated with uncontrolled eating and negatively with eating self-efficacy. Sleep duration and midpoint on free days negatively correlated with eating self-efficacy, mainly due to later waking times, supporting that predominantly later energy consumption may negatively impact eating behaviour.
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Affiliation(s)
- Pedro Salazar
- Faculdade de Ciências da Nutrição e Alimentação da Universidade do Porto, Porto, Portugal
| | - Rui Poínhos
- Faculdade de Ciências da Nutrição e Alimentação da Universidade do Porto, Porto, Portugal
| | - Flora Correia
- Faculdade de Ciências da Nutrição e Alimentação da Universidade do Porto, Porto, Portugal
- Unidade Local de Saúde de São João, E.P.E., Porto, Portugal
- Centro de Responsabilidade Integrado da Obesidade (CRIO), Porto, Portugal
- Unidade de Nefrologia e Infecciologia INEB/i3S [Nephrology & Infectious Diseases R&D], Porto, Portugal
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Li X, He J, Sun Q. Sleep Duration and Sarcopenia: An Updated Systematic Review and Meta-Analysis. J Am Med Dir Assoc 2023; 24:1193-1206.e5. [PMID: 37295459 DOI: 10.1016/j.jamda.2023.04.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 06/12/2023]
Abstract
OBJECTIVES In adults, short and long sleep duration has been associated with sarcopenia risk. Studies have shown that various factors, including biological and psychological factors, could be the underlying cause of the association between aberrant sleep duration and sarcopenia risk. In this study, we have qualitatively and quantitatively summarized previously published studies on sleep duration to assess the relationship between sleep duration and sarcopenia risk in adults. This would aid in enhancing our understanding of recent advancements in this field and the association between sleep duration and sarcopenia risk. DESIGN Systematic review and meta-analysis. SETTING AND PARTICIPANTS In this review, we included studies evaluating the association between the duration of sleep and sarcopenia in adults in observational studies. METHODS Five electronic databases (PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Web of Science) were searched to April 20, 2023, to identify studies related to sarcopenia and sleep duration. Next, we calculated the odds ratios (ORs) for sarcopenia prevalence based on the adjusted data from individual studies. Statistical analyses were performed using Stata 11.0. RESULTS Sarcopenia prevalence was high (18%) in adults with long sleep duration. Our results showed a significant association between short duration of sleep and high sarcopenia prevalence in older adults (OR 1.2, 95% CI 1.02-1.41, I2 = 56.6%). Furthermore, a significant association was observed between all participants with long-duration sleep and high sarcopenia prevalence (OR 1.53, 95% CI 1.34-1.75, I2 = 56.8%). We also observed significant heterogeneity in the adjusted ORs. CONCLUSIONS AND IMPLICATIONS There was a correlation between sarcopenia and short or long sleep duration, especially in older adults. In adults with a long duration of sleep, sarcopenia prevalence was relatively high.
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Affiliation(s)
- Xiaoyan Li
- School of Nursing, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jie He
- Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Qiuhua Sun
- School of Nursing, Zhejiang Chinese Medical University, Hangzhou, China.
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Calvani R, Picca A, Coelho-Júnior HJ, Tosato M, Marzetti E, Landi F. "Diet for the prevention and management of sarcopenia". Metabolism 2023:155637. [PMID: 37352971 DOI: 10.1016/j.metabol.2023.155637] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/05/2023] [Accepted: 06/15/2023] [Indexed: 06/25/2023]
Abstract
Sarcopenia is a geriatric condition characterized by a progressive loss of skeletal muscle mass and strength, with an increased risk of adverse health outcomes (e.g., falls, disability, institutionalization, reduced quality of life, mortality). Pharmacological remedies are currently unavailable for preventing the development of sarcopenia, halting its progression, or impeding its negative health outcomes. The most effective strategies to contrast sarcopenia rely on the adoption of healthier lifestyle behaviors, including adherence to high-quality diets and regular physical activity. In this review, the role of nutrition in the prevention and management of sarcopenia is summarized. Special attention is given to current "blockbuster" dietary regimes and agents used to counteract age-related muscle wasting, together with their putative mechanisms of action. Issues related to the design and implementation of effective nutritional strategies are discussed, with a focus on unanswered questions on the most appropriate timing of nutritional interventions to preserve muscle health and function into old age. A brief description is also provided on new technologies that can facilitate the development and implementation of personalized nutrition plans to contrast sarcopenia.
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Affiliation(s)
- Riccardo Calvani
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy.
| | - Anna Picca
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy; Department of Medicine and Surgery, LUM University, 70100 Casamassima, Italy.
| | - Hélio José Coelho-Júnior
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Matteo Tosato
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy.
| | - Emanuele Marzetti
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy.
| | - Francesco Landi
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy.
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Juliana N, Azmi L, Effendy NM, Mohd Fahmi Teng NI, Abu IF, Abu Bakar NN, Azmani S, Yazit NAA, Kadiman S, Das S. Effect of Circadian Rhythm Disturbance on the Human Musculoskeletal System and the Importance of Nutritional Strategies. Nutrients 2023; 15:nu15030734. [PMID: 36771440 PMCID: PMC9920183 DOI: 10.3390/nu15030734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/26/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
The circadian system in the human body responds to daily environmental changes to optimise behaviour according to the biological clock and also influences various physiological processes. The suprachiasmatic nuclei are located in the anterior hypothalamus of the brain, and they synchronise to the 24 h light/dark cycle. Human physiological functions are highly dependent on the regulation of the internal circadian clock. Skeletal muscles comprise the largest collection of peripheral clocks in the human body. Both central and peripheral clocks regulate the interaction between the musculoskeletal system and energy metabolism. The skeletal muscle circadian clock plays a vital role in lipid and glucose metabolism. The pathogenesis of osteoporosis is related to an alteration in the circadian rhythm. In the present review, we discuss the disturbance of the circadian rhythm and its resultant effect on the musculoskeletal system. We also discuss the nutritional strategies that are potentially effective in maintaining the system's homeostasis. Active collaborations between nutritionists and physiologists in the field of chronobiological and chrononutrition will further clarify these interactions. This review may be necessary for successful interventions in reducing morbidity and mortality resulting from musculoskeletal disturbances.
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Affiliation(s)
- Norsham Juliana
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
- Correspondence: ; Tel.: +60-13-331-1706
| | - Liyana Azmi
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Nadia Mohd Effendy
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | | | - Izuddin Fahmy Abu
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kajang 43000, Malaysia
| | - Nur Nabilah Abu Bakar
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Sahar Azmani
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Noor Anisah Abu Yazit
- Faculty Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Suhaini Kadiman
- Anaesthesia and Intensive Care Unit, National Heart Institute, Kuala Lumpur 50400, Malaysia
| | - Srijit Das
- Department of Human & Clinical Anatomy, College of Medicine & Health Sciences, Sultan Qaboos University, Al-Khoud, Muscat 123, Oman
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Yong YN, Henry CJ, Haldar S. Is There a Utility of Chrono-Specific Diets in Improving Cardiometabolic Health? Mol Nutr Food Res 2022; 66:e2200043. [PMID: 35856629 DOI: 10.1002/mnfr.202200043] [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: 01/17/2022] [Revised: 05/31/2022] [Indexed: 11/10/2022]
Abstract
Modern lifestyle is generally associated with the consumption of three main meals per day, one of which is typically in the evening or at night. It is also well established that consumption of meals in the later part of the day, notably in the evenings, is associated with circadian desynchrony, which in turn increases the risk of non-communicable diseases, particularly cardiometabolic diseases. While it is not feasible to avoid food consumption during the evenings altogether, there is an opportunity to provide chrono-specific, diet-based solutions to mitigate some of these risks. To date, there has been substantial progress in the understanding of chrononutrition, with evidence derived mainly from in vitro and in vivo animal studies. Some of these approaches include the manipulation of the quality and quantity of certain nutrients to be consumed at specific times of the day, as well as incorporating certain dietary components (macronutrients, micronutrients, or non-nutrient bioactives, including polyphenols) with the ability to modulate circadian rhythmicity. However, robust human studies are generally lacking. In this review, the study has consolidated and critically appraised the current evidence base, with an aim to translate these findings to improve cardiometabolic health and provides recommendations to move this field forward.
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Affiliation(s)
- Yi Ning Yong
- Clinical Nutrition Research Centre, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, 117599, Singapore
| | - Christiani Jeyakumar Henry
- Clinical Nutrition Research Centre, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, 117599, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117599, Singapore
| | - Sumanto Haldar
- Clinical Nutrition Research Centre, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, 117599, Singapore
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Shinto T, Makino S, Tahara Y, Nitta L, Kuwahara M, Tada A, Abe N, Michie M, Shibata S. Relationship Between Protein Intake in Each Traditional Meal and Physical Activity: Cross-sectional Study. JMIR Public Health Surveill 2022; 8:e35898. [PMID: 35819831 PMCID: PMC9328787 DOI: 10.2196/35898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/23/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022] Open
Abstract
Background Protein intake plays an important role in the synthesis and maintenance of skeletal muscles for the prevention of health risks. It is also widely known that physical activity influences muscle function. However, no large-scale studies have examined the relationship between daily dietary habits, especially the timing of protein intake, and daily physical activity. Objective The purpose of this cross-sectional study was to investigate how protein intake and composition (involving the 3 major nutrients protein, fat, and carbohydrate) in the 3 traditional meals (breakfast, lunch, and dinner) are associated with physical activity. Methods Using daily dietary data accumulated in the smartphone food log app “Asken” and a web-based cross-sectional survey involving Asken users (N=8458), we analyzed nutrient intake and composition, as well as daily activity levels. As very few individuals skipped breakfast (1102/19,319 responses, 5.7%), we analyzed data for 3 meals per day. Results Spearman rank correlation analysis revealed that breakfast and lunch protein intakes had higher positive correlations with daily physical activity among the 3 major macronutrients (P<.001). These findings were confirmed by multivariate logistic regression analysis with confounding factors. Moreover, participants with higher protein intake and composition at breakfast or lunch tended to exhibit significantly greater physical activity than those with higher protein intake at dinner (P<.001). Conclusions Among the 3 macronutrients, protein intake during breakfast and lunch was closely associated with daily physical activity.
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Affiliation(s)
- Takae Shinto
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
| | - Saneyuki Makino
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
| | - Yu Tahara
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
| | - Lie Nitta
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
| | - Mai Kuwahara
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
| | | | | | | | - Shigenobu Shibata
- Department of Bioscience and Engineering, Waseda University, Tokyo, Japan
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Healy KL, Morris AR, Liu AC. Circadian Synchrony: Sleep, Nutrition, and Physical Activity. FRONTIERS IN NETWORK PHYSIOLOGY 2021; 1:732243. [PMID: 35156088 PMCID: PMC8830366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/20/2021] [Indexed: 11/11/2022]
Abstract
The circadian clock in mammals regulates the sleep/wake cycle and many associated behavioral and physiological processes. The cellular clock mechanism involves a transcriptional negative feedback loop that gives rise to circadian rhythms in gene expression with an approximately 24-h periodicity. To maintain system robustness, clocks throughout the body must be synchronized and their functions coordinated. In mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is entrained to the light/dark cycle through photic signal transduction and subsequent induction of core clock gene expression. The SCN in turn relays the time-of-day information to clocks in peripheral tissues. While the SCN is highly responsive to photic cues, peripheral clocks are more sensitive to non-photic resetting cues such as nutrients, body temperature, and neuroendocrine hormones. For example, feeding/fasting and physical activity can entrain peripheral clocks through signaling pathways and subsequent regulation of core clock genes and proteins. As such, timing of food intake and physical activity matters. In an ideal world, the sleep/wake and feeding/fasting cycles are synchronized to the light/dark cycle. However, asynchronous environmental cues, such as those experienced by shift workers and frequent travelers, often lead to misalignment between the master and peripheral clocks. Emerging evidence suggests that the resulting circadian disruption is associated with various diseases and chronic conditions that cause further circadian desynchrony and accelerate disease progression. In this review, we discuss how sleep, nutrition, and physical activity synchronize circadian clocks and how chronomedicine may offer novel strategies for disease intervention.
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Affiliation(s)
| | | | - Andrew C. Liu
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
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Healy KL, Morris AR, Liu AC. Circadian Synchrony: Sleep, Nutrition, and Physical Activity. FRONTIERS IN NETWORK PHYSIOLOGY 2021; 1:732243. [PMID: 35156088 PMCID: PMC8830366 DOI: 10.3389/fnetp.2021.732243] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/20/2021] [Indexed: 08/01/2023]
Abstract
The circadian clock in mammals regulates the sleep/wake cycle and many associated behavioral and physiological processes. The cellular clock mechanism involves a transcriptional negative feedback loop that gives rise to circadian rhythms in gene expression with an approximately 24-h periodicity. To maintain system robustness, clocks throughout the body must be synchronized and their functions coordinated. In mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is entrained to the light/dark cycle through photic signal transduction and subsequent induction of core clock gene expression. The SCN in turn relays the time-of-day information to clocks in peripheral tissues. While the SCN is highly responsive to photic cues, peripheral clocks are more sensitive to non-photic resetting cues such as nutrients, body temperature, and neuroendocrine hormones. For example, feeding/fasting and physical activity can entrain peripheral clocks through signaling pathways and subsequent regulation of core clock genes and proteins. As such, timing of food intake and physical activity matters. In an ideal world, the sleep/wake and feeding/fasting cycles are synchronized to the light/dark cycle. However, asynchronous environmental cues, such as those experienced by shift workers and frequent travelers, often lead to misalignment between the master and peripheral clocks. Emerging evidence suggests that the resulting circadian disruption is associated with various diseases and chronic conditions that cause further circadian desynchrony and accelerate disease progression. In this review, we discuss how sleep, nutrition, and physical activity synchronize circadian clocks and how chronomedicine may offer novel strategies for disease intervention.
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