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Nagami GT, Kraut JA. The Role of the Endocrine System in the Regulation of Acid-Base Balance by the Kidney and the Progression of Chronic Kidney Disease. Int J Mol Sci 2024; 25:2420. [PMID: 38397097 PMCID: PMC10889389 DOI: 10.3390/ijms25042420] [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: 11/28/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
Systemic acid-base status is primarily determined by the interplay of net acid production (NEAP) arising from metabolism of ingested food stuffs, buffering of NEAP in tissues, generation of bicarbonate by the kidney, and capture of any bicarbonate filtered by the kidney. In chronic kidney disease (CKD), acid retention may occur when dietary acid production is not balanced by bicarbonate generation by the diseased kidney. Hormones including aldosterone, angiotensin II, endothelin, PTH, glucocorticoids, insulin, thyroid hormone, and growth hormone can affect acid-base balance in different ways. The levels of some hormones such as aldosterone, angiotensin II and endothelin are increased with acid accumulation and contribute to an adaptive increase in renal acid excretion and bicarbonate generation. However, the persistent elevated levels of these hormones can damage the kidney and accelerate progression of CKD. Measures to slow the progression of CKD have included administration of medications which inhibit the production or action of deleterious hormones. However, since metabolic acidosis accompanying CKD stimulates the secretion of several of these hormones, treatment of CKD should also include administration of base to correct the metabolic acidosis.
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Affiliation(s)
- Glenn T. Nagami
- Nephrology Section, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA;
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Jeffrey A. Kraut
- Nephrology Section, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA;
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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Kohzuki M. Renal Rehabilitation: Present and Future Perspectives. J Clin Med 2024; 13:552. [PMID: 38256684 PMCID: PMC10816861 DOI: 10.3390/jcm13020552] [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: 11/28/2023] [Revised: 12/28/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Chronic kidney disease (CKD) is a global health problem. In patients with CKD, exercise endurance is decreased, especially as renal dysfunction advances. This is due to the combined effects of protein-energy wasting, uremic acidosis, and inflammatory cachexia, which lead to sarcopenia and are aggravated by a sedentary lifestyle, resulting in a progressive downward spiral of deconditioning. Renal rehabilitation (RR) is a coordinated, multifaceted intervention designed to optimize a patient's physical, psychological, and social functioning, as well as to stabilize, slow, or even reverse the progression of renal deterioration, improving exercise tolerance and preventing the onset and worsening of heart failure, thereby reducing morbidity and mortality. This review focused on the history and benefits of RR in patients with CKD. Based on current evidence, RR is an effective, feasible, and safe secondary prevention strategy in CKD. RR is a promising model for a new field of rehabilitation. Therefore, efforts to increase RR implementation rates are urgently needed.
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Affiliation(s)
- Masahiro Kohzuki
- President and Chairman, Department of Health Sciences, Yamagata Prefectural University of Health Sciences, Yamagata 990-2212, Japan; ; Tel./Fax: +81-23-686-6601
- Professor Emeritus, Department of Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
- Chairman of the Board of Directors, International Society of Renal Rehabilitation, Sendai 980-8575, Japan
- Former Chairman of the Board of Directors, Japanese Society of Renal Rehabilitation; Tokyo 150-0043, Japan
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3
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Perez-Dominguez B, Suso-Marti L, Dominguez-Navarro F, Perpiña-Martinez S, Calatayud J, Casaña J. Effects of resistance training on patients with End-Stage Renal Disease: an umbrella review with meta-analysis of the pooled findings. J Nephrol 2023; 36:1805-1839. [PMID: 37318646 PMCID: PMC10543800 DOI: 10.1007/s40620-023-01635-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2023] [Indexed: 06/16/2023]
Abstract
OBJECTIVES This umbrella review aimed to review the effects of resistance training on patients with end-stage renal disease and assess the methodological quality of the available literature. METHODS An umbrella review and meta-meta-analysis was performed. A systematic search was conducted until May 2022. Article selection, quality assessment, and risk of bias assessment were performed by two independent reviewers. The meta-meta-analyses were performed with a random-effects model and the summary statistics were presented in the form of a forest plot with a weighted compilation of all standardized mean differences and corresponding 95% confidence interval. Twenty-four reviews were eventually included. The protocol was registered in the international registry PROSPERO (CRD42022321702). RESULTS Resistance training showed positive effects on functional capacity (g = 0.614), aerobic capacity (g = 0.587), health-related quality of life (g = 0.429), and peak force (g = 0.621). Fifteen of the included studies (63%) presented low risk of bias, and the remaining studies (37%) showed unclear risk of bias. CONCLUSION Resistance training in patients undergoing hemodialysis is an intervention that shows positive results regarding physical and functional outcomes. The quality level of the literature is inconclusive, but the included studies present low risk of bias.
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Affiliation(s)
- Borja Perez-Dominguez
- Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010, Valencia, Spain
| | - Luis Suso-Marti
- Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010, Valencia, Spain
| | - Fernando Dominguez-Navarro
- Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010, Valencia, Spain
| | - Sara Perpiña-Martinez
- Department of Nursing and Physiotherapy, Pontifical University of Salamanca, Salamanca, Spain
| | - Joaquin Calatayud
- Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010, Valencia, Spain.
| | - Jose Casaña
- Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010, Valencia, Spain
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Stange K, Schumacher T, Miersch C, Whelan R, Klünemann M, Röntgen M. Methionine Sources Differently Affect Production of Reactive Oxygen Species, Mitochondrial Bioenergetics, and Growth of Murine and Quail Myoblasts In Vitro. Curr Issues Mol Biol 2023; 45:2661-2680. [PMID: 37185698 PMCID: PMC10136669 DOI: 10.3390/cimb45040174] [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] [Received: 02/07/2023] [Revised: 03/14/2023] [Accepted: 03/21/2023] [Indexed: 05/17/2023] Open
Abstract
An optimal supply of L-methionine (L-Met) improves muscle growth, whereas over-supplementation exerts adverse effects. To understand the underlying mechanisms, this study aims at exploring effects on the growth, viability, ROS production, and mitochondrial bioenergetics of C2C12 (mouse) and QM7 (quail) myoblasts additionally supplemented (100 or 1000 µM) with L-Met, DL-methionine (DL-Met), or DL-2-hydroxy-4-(methylthio)butanoic acid (DL-HMTBA). In both cell lines, all the supplements stimulated cell growth. However, in contrast to DL-Met, 1000 µM of L-Met (C2C12 cells only) or DL-HMTBA started to retard growth. This negative effect was stronger with DL-HMTBA and was accompanied by significantly elevated levels of extracellular H2O2, an indicator for OS, in both cell types. In addition, oversupplementation with DL-HMTBA (1000 µM) induced adaptive responses in mitochondrial bioenergetics, including reductions in basal (C2C12 and QM7) and ATP-synthase-linked (C2C12) oxygen consumption, maximal respiration rate, and reserve capacity (QM7). Only QM7 cells switched to nonmitochondrial aerobic glycolysis to reduce ROS production. In conclusion, we found a general negative effect of methionine oversupplementation on cell proliferation. However, only DL-HMTBA-induced growth retardation was associated with OS and adaptive, species-specific alterations in mitochondrial functionality. OS could be better compensated by quail cells, highlighting the role of species differences in the ability to cope with methionine oversupplementation.
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Affiliation(s)
- Katja Stange
- Institute of Muscle Biology and Growth, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Toni Schumacher
- Institute of Muscle Biology and Growth, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Claudia Miersch
- Institute of Muscle Biology and Growth, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
- Nutritional Physiology and Dietetics, International University of Applied Sciences (IU), Juri-Gagarin-Ring 152, 99084 Erfurt, Germany
| | - Rose Whelan
- Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457 Hanau, Germany
| | - Martina Klünemann
- Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457 Hanau, Germany
| | - Monika Röntgen
- Institute of Muscle Biology and Growth, Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
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Mansordehghan M, Daneshzad E, Basirat V, Gargari BP, Rouzitalab T. The association between dietary acid load and body composition in physical education students aged 18-25 years. JOURNAL OF HEALTH, POPULATION, AND NUTRITION 2022; 41:58. [PMID: 36529754 PMCID: PMC9761980 DOI: 10.1186/s41043-022-00340-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
AIM To find the association between dietary acid load (DAL) and body composition in physical education students. METHODS This study was carried out on 207 students of both genders aged 18-25 years. DAL was calculated based on potential renal acid load (PRAL) and net endogenous acid production (NEAP) methods. Anthropometric indices were measured. Bioelectric impedance was used to assess body composition and other related items. RESULTS The mean score of NEAP and PRAL was 80.18 ± 31.30 and 33.94 ± 22.11, respectively. The mean weight and fat mass of subjects were 64.05 ± 9.72 kg and 20.28 ± 0.67 kg, respectively. Participants in the highest tertile of PRAL had a higher weight (64.56 ± 1.14 kg) in comparison with participants in the lowest tertile (61.65 ± 1.19 kg) (P = 0.027). After adjusting for confounders, a significant positive association was found between NEAP score and hip circumference (β = 0.206, P = 0.039), body mass index (β = 0.214, P = 0.031), fat mass (β = 0.218, P = 0.001) and body adiposity index (β = 0.182, P = 0.037). Furthermore, a statistically significant negative association was observed between total body water and NEAP score (β = - 0.217, P = 0.001) and the percentage of fat-free mass and NEAP (β = - 0.229, P = 0.001). CONCLUSION Individuals with a higher DAL score may have a higher weight, fat mass and hip circumference and a lower fat-free mass. In addition, there might be an association between DAL and obesity.
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Affiliation(s)
- Maryam Mansordehghan
- Department of Nutritional Sciences, School of Nutritional Sciences and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Elnaz Daneshzad
- Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Vahid Basirat
- Department of Gastroenterology, School of Medicine, Isfahan University of Medical Sciences and Health Services, Isfahan, Iran
| | - Bahram Pourghassem Gargari
- Department of Biochemistry and Diet Therapy, Nutrition Research Center, School of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Tohid Rouzitalab
- Department of Biochemistry and Diet Therapy, Nutrition Research Center, School of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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Methionine Supplementation during Pregnancy of Goats Improves Kids' Birth Weight, Body Mass Index, and Postnatal Growth Pattern. BIOLOGY 2022; 11:biology11071065. [PMID: 36101442 PMCID: PMC9312974 DOI: 10.3390/biology11071065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/01/2022] [Accepted: 07/13/2022] [Indexed: 11/21/2022]
Abstract
The last third of gestation is a period of high energy and protein demand for the dam to support fetal growth and the following onset of lactation. Methionine is an essential amino acid that contributes to protein formation, fetal development, and milk synthesis; thus, is likely to have positive effects on the weight and size of the newborn and, afterward, milk yield and milk composition, which may improve growth patterns of the progeny. To test these hypotheses, we used 60 pregnant multiparous Alpine goats with similar live weights and gestational ages (~Day 100 of pregnancy; Mean ± SD; 1410 ± 14 days old and 50.4 ± 6.6 kg) and were separated into two groups: control and supplemented with the delivery. Treatments were T-MET (n = 30; received 1% herbal methionine Optimethione® dry matter based on from Day 100 of the pregnancy to delivery) or T-CTL (n = 30; served as the control and did not receive methionine). The methionine powder provided individual supplementation and was adjusted every week as the live weight and dry matter intake changed. At birth, the weight, body mass index (BMI), birth type, and sex of the kids were determined. Subsequently, the progeny was weighed weekly up to weaning. Two weeks after parturition, the milk composition was recorded weekly, and the milk yield was recorded monthly. The maternal live weight at the start (Mean ± SEM; T-CTL: 50.5 ± 1.1 vs. T-MET: 50.3 ± 1.3 kg) and end (T-CTL: 54.2 ± 1.3 vs. T-MET: 52.8 ± 1.4 kg) of the experiment did not differ statistically among treatments (p > 0.05); however, daily live weight changes tended to differ between groups (T-CTL: 73 ± 10 vs. T-MET: 51 ± 7 g day−1; p = 0.06). The birth weight (T-CTL: 3.1 ± 0.1 vs. T-MET: 3.5 ± 0.1 kg; p < 0.001), daily live weight change (T-CTL: 121 ± 6 vs. T-MET: 141 ± 6 g day−1; p < 0.01), and weaning weight (T-CTL: 8.3 ± 0.2 vs. T-MET: 9.3 ± 0.3 kg; p < 0.01) differed between treatments. The BMI at birth (T-CTL: 0.28 ± 0.01 vs. T-MET: 0.3 ± 0.01 units kg m−2; p < 0.01) and at weaning (T-CTL: 0.85 ± 0.1 kg vs. T-MET: 1.00 ± 0.06 units kg m−2; p < 0.05) differed between treatments. Milk components (protein, fat, lactose, and solids non-fat) and milk yield were similar between treatments (p > 0.05). It is concluded that the inclusion of methionine in the maternal goat diet during the last third of gestation increases the birth and growth variables of the progeny but without significant influence on the milk yield and composition.
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Han Z, Ma K, Tao H, Liu H, Zhang J, Sai X, Li Y, Chi M, Nian Q, Song L, Liu C. A Deep Insight Into Regulatory T Cell Metabolism in Renal Disease: Facts and Perspectives. Front Immunol 2022; 13:826732. [PMID: 35251009 PMCID: PMC8892604 DOI: 10.3389/fimmu.2022.826732] [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: 12/01/2021] [Accepted: 01/24/2022] [Indexed: 11/29/2022] Open
Abstract
Kidney disease encompasses a complex set of diseases that can aggravate or start systemic pathophysiological processes through their complex metabolic mechanisms and effects on body homoeostasis. The prevalence of kidney disease has increased dramatically over the last two decades. CD4+CD25+ regulatory T (Treg) cells that express the transcription factor forkhead box protein 3 (Foxp3) are critical for maintaining immune homeostasis and preventing autoimmune disease and tissue damage caused by excessive or unnecessary immune activation, including autoimmune kidney diseases. Recent studies have highlighted the critical role of metabolic reprogramming in controlling the plasticity, stability, and function of Treg cells. They are also likely to play a vital role in limiting kidney transplant rejection and potentially promoting transplant tolerance. Metabolic pathways, such as mitochondrial function, glycolysis, lipid synthesis, glutaminolysis, and mammalian target of rapamycin (mTOR) activation, are involved in the development of renal diseases by modulating the function and proliferation of Treg cells. Targeting metabolic pathways to alter Treg cells can offer a promising method for renal disease therapy. In this review, we provide a new perspective on the role of Treg cell metabolism in renal diseases by presenting the renal microenvironment、relevant metabolites of Treg cell metabolism, and the role of Treg cell metabolism in various kidney diseases.
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Affiliation(s)
- Zhongyu Han
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.,Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Kuai Ma
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hongxia Tao
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hongli Liu
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jiong Zhang
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Xiyalatu Sai
- Affiliated Hospital of Inner Mongolia University for the Nationalities, Tongliao, China
| | - Yunlong Li
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mingxuan Chi
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Qing Nian
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.,Department of Blood Transfusion Sicuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Linjiang Song
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Chi Liu
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
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Rampersad C, Darcel J, Harasemiw O, Brar RS, Komenda P, Rigatto C, Prasad B, Bohm C, Tangri N. Change in Physical Activity and Function in Patients with Baseline Advanced Nondialysis CKD. Clin J Am Soc Nephrol 2021; 16:1805-1812. [PMID: 34697092 PMCID: PMC8729498 DOI: 10.2215/cjn.07050521] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 10/14/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Although progressive decline in physical activity and function are common in individuals with worsening CKD, little is known about the effect of dialysis initiation on physical activity. We assessed for any association of progression to dialysis in people with advanced CKD with temporal rates of change in physical activity and function. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Canadian Frailty Observation and Interventions Trial (CanFIT) participants with an eGFR of <30 ml/min per 1.73 m2 were included. Outcomes included change in physical activity level, measured using the Physical Activity Scale for the Elderly, and physical function, measured using the chair stand, 4-m gait speed, and grip strength tests. Generalized linear regression models were conducted to determine whether dialysis initiation was associated with greater decline in physical activity or function. RESULTS Of 386 individuals, 162 progressed to dialysis. Both assessments were completed by 98% of individuals for the Physical Activity Scale for the Elderly, 86% for the chair stand test, 84% for the gait speed test, and 91% for the grip strength test. Median (interquartile range) interassessment follow-up was 427 (357-578) days for the "stable advanced CKD" group and 606 (428-1000) days for the "progressed to dialysis" group. Self-reported physical activity and gait speed significantly declined in both groups. Mean (SD) chair stand time increased from 20.8 (17.1) to 24.0 (21.0) seconds among patients with stable advanced CKD, and from 18.5 (15.4) to 27.4 (22.2) seconds among those who progressed to dialysis (adjusted difference in change, 5.2 seconds; 95% confidence interval, 0.8 to 9.7 seconds; P=0.02). CONCLUSIONS Patients with advanced CKD experience progressive declines in physical activity and function. Transition to dialysis is associated with accelerated decline in physical function, as measured by the chair stand test.
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Affiliation(s)
- Christie Rampersad
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Joseph Darcel
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Oksana Harasemiw
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
| | - Ranveer S. Brar
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
| | - Paul Komenda
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
| | - Claudio Rigatto
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
| | - Bhanu Prasad
- Regina Qu’Appelle Health Region, Regina General Hospital, Regina, Saskatchewan, Canada
| | - Clara Bohm
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
| | - Navdeep Tangri
- Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada,Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Manitoba, Canada
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Saitsu A, Iwazu Y, Matsushita H, Hayashi H, Mizuhashi Y, Kotani K. Low urine pH associated with sarcopenia in the elderly: A multi-center observational study. Medicine (Baltimore) 2021; 100:e26114. [PMID: 34032755 PMCID: PMC8154474 DOI: 10.1097/md.0000000000026114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/10/2021] [Indexed: 01/04/2023] Open
Abstract
The pathophysiology of sarcopenia is complex and must be further explored. While metabolic acidosis may be a risk factor for sarcopenia, it remains unclear whether acidic urine is related to sarcopenia. The purpose of the present study was to investigate the association between sarcopenia and urine pH in the elderly.An elderly population (n = 123 [male = 46]; mean age = 81.7 years) was classified into 2 groups based on the sarcopenia status according to their strength, requirement of assistance in walking, their ability to rise from a chair their ability to climb stairs, and their history of falls. Urinalysis was measured using dipstick tests.The sarcopenia group (n = 32) was significantly older, had less exercise habit and showed a lower urine pH (mean pH = 5.5) in comparison to the nonsarcopenia group (mean pH = 6.2, P < .01). A multivariate analysis that was adjusted for age, male sex, body mass index, uro-renal variables and exercise habit revealed that urine pH (odds ratio, 0.43; 95% confidence interval, 0.22-0.85, P = .02), age and less exercise habit were independently and significantly associated with sarcopenia.The findings of the present study suggest a potential association between metabolic acidosis and the pathophysiology of sarcopenia in the elderly. As urine pH is a simple biomarker that can be obtained using dipstick tests, it is therefore expected to be helpful for detecting sarcopenia in the clinical setting.
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Affiliation(s)
- Akihiro Saitsu
- Division of Community and Family Medicine, Center for Community Medicine
| | - Yoshitaka Iwazu
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Shimotsuke-City, Tochigi
| | - Haruka Matsushita
- Department of Internal Medicine, Kamiamakusa General Hospital, Ryugatake-Town, Kamiamakusa-City
| | - Hirotaka Hayashi
- Department of Internal Medicine, Kamiamakusa General Hospital, Ryugatake-Town, Kamiamakusa-City
| | - Yumiko Mizuhashi
- Department of Internal Medicine, Oguni Municipal Hospital, Oguni-Town, Aso-Country, Kumamoto, Japan
| | - Kazuhiko Kotani
- Division of Community and Family Medicine, Center for Community Medicine
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Lee YJ, Lee M, Wi YM, Cho S, Kim SR. Potassium intake, skeletal muscle mass, and effect modification by sex: data from the 2008-2011 KNHANES. Nutr J 2020; 19:93. [PMID: 32861249 PMCID: PMC7456505 DOI: 10.1186/s12937-020-00614-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023] Open
Abstract
Background A loss of muscle mass may be influenced by multiple factors. Insulin sensitivity and metabolic acidosis are associated with muscle wasting and may be improved with potassium intake. This study evaluated the association between dietary potassium intake and skeletal muscle mass. Methods We performed a cross-sectional study with data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008–2011). Participant’s daily food intake was assessed using a 24-h recall method. Appendicular skeletal muscle mass (ASM) was calculated as the sum of muscle mass in both arms and legs, measured using dual energy X-ray absorptiometry. The skeletal muscle index (SMI) was calculated as ASM divided by height2 (kg/m2). Low muscle mass was defined as a SMI < 7.0 kg/m2 for men and < 5.4 kg/m2 for women. Results Data from 16,558 participants (age ≥ 19 years) were analyzed. Participants were categorized into quintiles according to their potassium intake. Sex-specific differences were found in the association between potassium intake and muscle mass (PInteraction < 0.001). In men, higher potassium intake was associated with lower odds for low muscle mass; the fully adjusted odds ratios (95% confidence intervals) were 0.78 (0.60–1.03), 0.71 (0.54–0.93), 0.68 (0.51–0.90), and 0.71 (0.51–0.98) for the top four quintiles (referenced against the lowest quintile), respectively. However, this association was attenuated in women after adjusting for total energy intake. Higher potassium intakes were also associated with a greater SMI. Conclusions Higher dietary potassium intake decreased the odds of low muscle mass in men but not in women.
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Affiliation(s)
- Yu-Ji Lee
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158, Paryong-ro, Masanhoewon-gu, 51353, Changwon, Republic of Korea.
| | - Mirae Lee
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158, Paryong-ro, Masanhoewon-gu, 51353, Changwon, Republic of Korea
| | - Yu Mi Wi
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158, Paryong-ro, Masanhoewon-gu, 51353, Changwon, Republic of Korea
| | - Seong Cho
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158, Paryong-ro, Masanhoewon-gu, 51353, Changwon, Republic of Korea
| | - Sung Rok Kim
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158, Paryong-ro, Masanhoewon-gu, 51353, Changwon, Republic of Korea
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Baranauskas M, Jablonskienė V, Abaravičius JA, Samsonienė L, Stukas R. Dietary Acid-Base Balance in High-Performance Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5332. [PMID: 32722186 PMCID: PMC7432059 DOI: 10.3390/ijerph17155332] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 01/06/2023]
Abstract
Physical exercise leads to metabolic changes that affect the acid-base balance in skeletal muscles and other tissues. Nutrition is one of the factors that may influence the acid-base balance in the body. Keeping alkaline circumstances in the body is important not only for health and athletic performance in training but also during competition in many sport events. This is especially significant for athletes who practice in sport at the highest level of competition. The aim of the study was to determine the dietary acid-base balance in competitive Lithuanian high-performance athletes, and to evaluate the effect of actual diets of athletes on NEAP (net endogenous acid production), muscle mass and body mineral content during a four-year Olympic cycle. The research participants were 18.1 ± 3.3-year-old Lithuanian high performance athletes (n = 323). The actual diet was investigated using the 24 h recall dietary survey method. The measurements of body composition were performed using BIA (bioelectrical impedance analysis). The potential renal acid load of the diets of athletes (dietary PRAL) and NEAP were calculated. In 10.2% of athletes, NEAP exceeds 100 mEq · day-1 and is on average 126.1 ± 32.7 mEq · day-1. Higher NEAP in athletes is associated with lower muscle mass (β -1.2% of body weight, p < 0.001) but has no effect on the amount of minerals in the body (β 0.01% of body weight, p = 0.073). Overall, 25-30% of Lithuanian high-performance athletes use high-protein diets (2.0-4.8 g · kg-1 · day-1) leading to a dietary acid-base imbalance as well as an excessive production of endogenous acids in the body. Athletes are recommended to consume higher amounts of potassium and magnesium. An increase in calcium intake up to 1500 mg per day is recommended. In exceptional cases, periodised nutrition for athletes may involve diets complemented with bicarbonate and/or beta-alanine supplements.
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Affiliation(s)
- Marius Baranauskas
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine of the Faculty of Medicine, Institute of Biomedical Sciences, Vilnius University, 01513 Vilnius, Lithuania; (V.J.); (J.A.A.)
| | - Valerija Jablonskienė
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine of the Faculty of Medicine, Institute of Biomedical Sciences, Vilnius University, 01513 Vilnius, Lithuania; (V.J.); (J.A.A.)
| | - Jonas Algis Abaravičius
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine of the Faculty of Medicine, Institute of Biomedical Sciences, Vilnius University, 01513 Vilnius, Lithuania; (V.J.); (J.A.A.)
| | - Laimutė Samsonienė
- Department of Rehabilitation, Physical and Sports Medicine, Institute of Health Sciences of the Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania;
| | - Rimantas Stukas
- Department of Public Health, Institute of Health Sciences of the Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania;
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12
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Laflamme DP. Understanding the Nutritional Needs of Healthy Cats and Those with Diet-Sensitive Conditions. Vet Clin North Am Small Anim Pract 2020; 50:905-924. [PMID: 32646606 DOI: 10.1016/j.cvsm.2020.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Diets for cats must provide complete nutrition and meet the needs of the individual patient. There is no single diet that is perfect for all cats, and veterinarians must consider the needs of the cat as well as the preferences of the owners when making dietary recommendations. This article focuses on the interface between animal factors and nutritional needs in cats and is divided into 3 sections. Section 1 addresses the dietary needs of healthy cats, including differences among life stages. Section 2 addresses common myths regarding feline nutrition. Section 3 addresses common nutrient-sensitive conditions in cats, including sarcopenia of aging.
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Affiliation(s)
- Dottie P Laflamme
- Veterinary Communications, 473 Grandma's Place, Floyd, VA 24091, USA.
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13
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Kim JK, Kim SG, Oh JE, Lee YK, Noh JW, Kim HJ, Song YR. Impact of sarcopenia on long-term mortality and cardiovascular events in patients undergoing hemodialysis. Korean J Intern Med 2019; 34:599-607. [PMID: 29161801 PMCID: PMC6506738 DOI: 10.3904/kjim.2017.083] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/11/2017] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIMS A high body mass index (BMI) is known to correlate with better survival in patients on hemodialysis (HD). However, the impacts of body composition and sarcopenia on survival have not been well studied in this population. METHODS One hundred and forty-two prevalent HD patients were recruited and followed prospectively for up to 4.5 years. Low muscle mass (measured using a portable, whole-body, bioimpedance spectroscopic device) was defined as a lean tissue index (LTI) two standard deviations (SD) or more below the normal gender-specific mean for young people. Low muscle strength was a handgrip strength (HGS) of less than 30 kg in males and less than 20 kg in females. Sarcopenia was considered present when both LTI and HGS were reduced. RESULTS The mean age was 59.8 ± 13.1 years; 57.0% were male and 47.2% had diabetes. Forty-seven patients (33.1%) had sarcopenia. During follow-up, 28 patients (19.7%) died, and low LTI (adjusted hazard ratio [HR], 2.77; 95% confidence interval [CI], 1.10 to 6.97) and low HGS (HR 5.65; 95% CI, 1.99 to 16.04) were independently associated with mortality. Sarcopenia was a significant predictor for death (HR, 6.99; 95% CI, 1.84 to 26.58; p = 0.004) and cardiovascular events (HR, 4.33; 95% CI, 1.51 to 12.43; p = 0.006). CONCLUSION Sarcopenia was strongly associated with long-term mortality and cardiovascular events in HD patients. Assessment of muscle strength and muscle mass may provide additional prognostic information to survival in patients with end-stage renal disease.
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Affiliation(s)
- Jwa-Kyung Kim
- Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Sung Gyun Kim
- Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Ji-Eun Oh
- Department of Internal Medicine, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea
| | - Young-Ki Lee
- Department of Internal Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
| | - Jung-Woo Noh
- Department of Internal Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
| | - Hyung Jik Kim
- Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Young Rim Song
- Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
- Correspondence to Young Rim Song, M.D. Department of Internal Medicine, Hallym University Sacred Heart Hospital, 22 Gwanpyeong-ro 170 beon-gil, Dongan-gu, Anyang 14068, Korea Tel: +82-31-380-3720 Fax: +82-31-386-2269 E-mail:
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14
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Osuna-Padilla IA, Leal-Escobar G, Garza-García CA, Rodríguez-Castellanos FE. Dietary Acid Load: mechanisms and evidence of its health repercussions. Nefrologia 2019; 39:343-354. [PMID: 30737117 DOI: 10.1016/j.nefro.2018.10.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/20/2018] [Accepted: 10/03/2018] [Indexed: 12/26/2022] Open
Abstract
Diet composition has long been known to influence acid-base balance by providing acid or base precursors. In general, foods rich in protein, such as meat, cheese, eggs, and others, increase the production of acid in the body, whereas fruit and vegetables increase alkalis. The capacity of acid or base production of any food is called potential renal acid load (PRAL). Diets high in PRAL induce a low-grade metabolic acidosis state, which is associated with the development of metabolic alterations such as insulin resistance, diabetes, hypertension, chronic kidney disease, bone disorders, low muscle mass and other complications. The aim of this paper is to review the available evidence which evaluates the association of the PRAL of the diet with the incidence of chronic diseases and metabolic disorders, as well as related mechanisms involved in their development.
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Affiliation(s)
- I A Osuna-Padilla
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, CDMX, México
| | - G Leal-Escobar
- Departamento de Nefrología, Instituto Nacional de Cardiología Ignacio Chávez, CDMX, México.
| | - C A Garza-García
- Hospital Universitario Dr. José Eleuterio González, Nuevo León, México
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Resistance training downregulates macrophages infiltration in the kidney of 5/6 nephrectomized rats. Life Sci 2018; 213:190-197. [PMID: 30352243 DOI: 10.1016/j.lfs.2018.10.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/14/2018] [Accepted: 10/19/2018] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Chronic kidney disease (CKD) is considered a significant world health problem with elevated mortality rates. Patients with CKD are restricted to mild physical activity, present chronic inflammatory state and loss of muscle strength. Currently, the influence of resistance exercise (RE) on the progression of renal disease has not being fully elucidated. PURPOSE To evaluate the effects of RE on the progression of CKD in a remnant kidney model (5/6Nx) in rats. METHODS Eight-week-old Wistar rats were submitted to 5/6 nephrectomy and were divided into four groups: Sham sedentary (Sham SD); Sham RE (Sham RE); 5/6Nx SD and 5/6Nx RE. The animals were trained for 8 weeks in a vertical climbing ladder for 3 days per week, on non-consecutive days. RESULTS As expected, 5/6Nx SD group presented a markedly loss of renal function, increased plasma inflammatory cytokines and increased oxidative stress with a reduced activity of nitric oxide. The higher macrophage infiltration and fibrosis confirmed these conditions. RE attenuated systolic blood pressure and renal function decrease and also improved serum lipid parameters in 5/6 Nx animals. It was evident the increase of muscle strength and mass in the trained groups while the sedentary group showed reduced muscle weight and strength compared to Sham SD. CONCLUSIONS RE implemented following 5/6Nx retard the progression of chronic kidney injury while simultaneously allowed the maintenance of skeletal muscle strength.
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Margolis LM, Ceglia L, Rivas DA, Dawson-Hughes B, Fielding RA. Pilot Study Examining the Influence of Potassium Bicarbonate Supplementation on Nitrogen Balance and Whole-Body Ammonia and Urea Turnover Following Short-Term Energy Restriction in Older Men. Nutrients 2018; 10:nu10050624. [PMID: 29772642 PMCID: PMC5986503 DOI: 10.3390/nu10050624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/10/2018] [Accepted: 05/11/2018] [Indexed: 01/07/2023] Open
Abstract
With aging there is a chronic low-grade metabolic-acidosis that may exacerbate negative protein balance during weight loss. The objective of this randomized pilot study was to assess the impact of 90 mmol∙day−1 potassium bicarbonate (KHCO3) versus a placebo (PLA) on 24-h urinary net acid excretion (NAE), nitrogen balance (NBAL), and whole-body ammonia and urea turnover following short-term diet-induced weight loss. Sixteen (KHCO3; n = 8, PLA; n = 8) older (64 ± 4 years) overweight (BMI: 28.5 ± 2.1 kg∙day−1) men completed a 35-day controlled feeding study, with a 7-day weight-maintenance phase followed by a 28-day 30% energy-restriction phase. KHCO3 or PLA supplementation began during energy restriction. NAE, NBAL, and whole-body ammonia and urea turnover (15N-glycine) were measured at the end of the weight-maintenance and energy-restriction phases. Following energy restriction, NAE was −9.8 ± 27.8 mmol∙day−1 in KHCO3 and 43.9 ± 27.8 mmol∙day−1 in PLA (p < 0.05). No significant group or time differences were observed in NBAL or ammonia and urea turnover. Ammonia synthesis and breakdown tended (p = 0.09) to be higher in KHCO3 vs. PLA following energy restriction, and NAE was inversely associated (r = −0.522; p < 0.05) with urea synthesis in all subjects. This pilot study suggests some benefit may exist with KHCO3 supplementation following energy restriction as lower NAE indicated higher urea synthesis.
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Affiliation(s)
- Lee M Margolis
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
| | - Lisa Ceglia
- Bone Metabolism Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
- Division of Endocrinology, Diabetes, and Metabolism, Tufts Medical Center, Boston, MA 02111, USA.
| | - Donato A Rivas
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
| | - Bess Dawson-Hughes
- Bone Metabolism Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
| | - Roger A Fielding
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
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17
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Biolo G, Di Girolamo FG, Heer M, Sturma M, Mazzucco S, Agostini F, Situlin R, Vinci P, Giordano M, Buehlmeier J, Frings-Meuthen P, Mearelli F, Fiotti N. Alkalinization with potassium bicarbonate improves glutathione status and protein kinetics in young volunteers during 21-day bed rest. Clin Nutr 2018; 38:652-659. [PMID: 29739680 DOI: 10.1016/j.clnu.2018.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 12/22/2017] [Accepted: 04/06/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND & AIMS Physical inactivity is associated with lean body mass wasting, oxidative stress and pro-inflammatory changes of cell membrane lipids. Alkalinization may potentially counteract these alterations. We evaluated the effects of potassium bicarbonate supplementation on protein kinetics, glutathione status and pro- and anti-inflammatory polyunsaturated fatty acids (PUFA) in erythrocyte membranes in humans, during experimental bed rest. METHODS Healthy, young, male volunteers were investigated at the end of two 21-day bed rest periods, one with, and the other without, daily potassium bicarbonate supplementation (90 mmol × d-1), according to a cross-over design. Oxidative stress in erythrocytes was evaluated by determining the ratio between reduced (GSH) and oxidized glutathione (GSSG). Glutathione turnover and phenylalanine kinetics, a marker of whole body protein metabolism, were determined by stable isotope infusions. Erythrocyte membranes PUFA composition was analyzed by gas-chromatography. RESULTS At the end of the two study periods, urinary pH was 10 ± 3% greater in subjects receiving potassium bicarbonate supplementation (7.23 ± 0.15 vs. 6.68 ± 0.11, p < 0.001). Alkalinization increased total glutathione concentrations by 5 ± 2% (p < 0.05) and decreased its rate of clearance by 38 ± 13% (p < 0.05), without significantly changing GSH-to-GSSG ratio. After alkalinization, net protein balance in the postabsorptive state improved significantly by 17 ± 5% (p < 0.05) as well as the sum of n-3 PUFA and the n-3-to-n-6 PUFA ratio in erythrocyte membranes (p < 0.05). CONCLUSIONS Alkalinization during long-term inactivity is associated with improved glutathione status, anti-inflammatory lipid pattern in cell membranes and reduction in protein catabolism at whole body level. This study suggests that, in clinical conditions characterized by inactivity, oxidative stress and inflammation, alkalinization could be a useful adjuvant therapeutic strategy.
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Affiliation(s)
- Gianni Biolo
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy.
| | | | - Martina Heer
- Department of Nutrition and Food Science, Nutrition Physiology, University of Bonn, Bonn, Germany
| | - Mariella Sturma
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Sara Mazzucco
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Francesco Agostini
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Roberta Situlin
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Pierandrea Vinci
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Mauro Giordano
- Department of Medical, Surgical, Neurological, Metabolic and Geriatrics Sciences, Second University of Naples, Naples, Italy
| | - Judith Buehlmeier
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Köln, Germany
| | | | - Filippo Mearelli
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Nicola Fiotti
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
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Tammaro G, Zacchia M, Zona E, Zacchia E, Capasso G. Acute and chronic effects of metabolic acidosis on renal function and structure. J Nephrol 2018; 31:551-559. [DOI: 10.1007/s40620-018-0493-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/11/2018] [Indexed: 11/24/2022]
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Svart MV, Rittig N, Kampmann U, Voss TS, Møller N, Jessen N. Metabolic effects of insulin in a human model of ketoacidosis combining exposure to lipopolysaccharide and insulin deficiency: a randomised, controlled, crossover study in individuals with type 1 diabetes. Diabetologia 2017; 60:1197-1206. [PMID: 28389705 DOI: 10.1007/s00125-017-4271-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/15/2017] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Diabetic ketoacidosis (DKA) is often caused by concomitant systemic inflammation and lack of insulin. Here we used an experimental human model to test whether and how metabolic responses to insulin are impaired in the early phases of DKA with a specific focus on skeletal muscle metabolism. METHODS Nine individuals with type 1 diabetes from a previously published cohort were investigated twice at Aarhus University Hospital using a 120 min infusion of insulin (3.0/1.5 mU kg-1 min-1) after an overnight fast under: (1) euglycaemic conditions (CTR) or (2) hyperglycaemic ketotic conditions (KET) induced by an i.v. bolus of lipopolysaccharide and 85% reduction in insulin dosage. The primary outcome was insulin resistance in skeletal muscle. Participants were randomly assigned to one of the two arms at the time of screening using www.randomizer.org . The study was not blinded. RESULTS All nine volunteers completed the 2 days and are included in the analysis. Circulating concentrations of glucose and 3-hydroxybutyrate increased during KET (mean ± SEM 17.7 ± 0.6 mmol/l and 1.6 ± 0.2 mmol/l, respectively), then decreased after insulin treatment (6.6 ± 0.7 mmol/l and 0.1 ± 0.07 mmol/l, respectively). Prior to insulin infusion (KET vs CTR) isotopically determined endogenous glucose production rates were 17 ± 1.7 μmol kg-1 min-1 vs 8 ± 1.3 μmol kg-1 min-1 (p = 0.003), whole body phenylalanine fluxes were 2.9 ± 0.5 μmol kg-1 min-1 vs 3.1 ± 0.4 μmol kg-1 min-1 (p = 0.77) and urea excretion rates were 16.9 ± 2.4 g/day vs 7.3 ± 1.7 g/day (p = 0.01). Insulin failed to stimulate forearm glucose uptake and glucose oxidation in KET compared with CTR (p < 0.05). Glycogen synthase phosphorylation was impaired in skeletal muscle. CONCLUSIONS/INTERPRETATION In KET, hyperglycaemia is primarily driven by increased endogenous glucose production. Insulin stimulation during early phases of DKA is associated with reduced glucose disposal in skeletal muscle, impaired glycogen synthase function and lower glucose oxidation. This underscores the presence of muscle insulin resistance in the pathogenesis of DKA. Trial registration www.clinicaltrials.gov (ID number: NCT02157155). Funding This work was funded by the Danish Council for Strategic Research (grant no. 0603-00479B).
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Affiliation(s)
- Mads V Svart
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Nikolaj Rittig
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Kampmann
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Thomas S Voss
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Møller
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Jessen
- Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark.
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK-8000, Aarhus C, Denmark.
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Margolis LM, Rivas DA, Pasiakos SM, McClung JP, Ceglia L, Fielding RA. Upregulation of circulating myomiR following short-term energy restriction is inversely associated with whole body protein synthesis. Am J Physiol Regul Integr Comp Physiol 2017; 313:R298-R304. [PMID: 28659285 DOI: 10.1152/ajpregu.00054.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 06/22/2017] [Accepted: 06/26/2017] [Indexed: 01/05/2023]
Abstract
The objective of the present investigation was to determine whether energy restriction (ER) influences expression of skeletal muscle-specific microRNA (miRNA) in circulation (c-myomiR) and whether changes in c-myomiR are associated with rates of whole body protein synthesis. Sixteen older (64 ± 2 yr) overweight (28.5 ± 1.2 kg/m2) men enrolled in this 35-day controlled feeding trial. A 7-day weight maintenance (WM) period was followed by 28 days of 30% ER. Whole body protein turnover was determined from [15N]glycine enrichments in 24-h urine collections, and c-myomiR (miR-1-3p, miR-133a-3p, miR-133b, and miR-206) expression was assessed from serum samples by RT-quantitative PCR upon completion of the WM and ER periods. Participants lost 4.4 ± 0.3 kg body mass during ER (P < 0.05). After 28 days of ER, miR-133a and miR-133b expression was upregulated (P < 0.05) compared with WM. When all four c-myomiR were grouped as c-myomiR score (sum of the median fold change of all myomiR), overall expression of c-myomiR was higher (P < 0.05) at ER than WM. Backward linear regression analysis of whole body protein synthesis and breakdown and carbohydrate, fat, and protein oxidation determined protein synthesis to be the strongest predictor of c-myomiR score. An inverse association (P < 0.05) was observed with ER c-myomiR score and whole body protein synthesis (r = -0.729, r2 = -0.530). Findings from the present investigation provide evidence that upregulation of c-myomiR expression profiles in response to short-term ER is associated with lower rates of whole body protein synthesis.
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Affiliation(s)
- Lee M Margolis
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| | - Donato A Rivas
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| | - Stefan M Pasiakos
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - James P McClung
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Lisa Ceglia
- Bone Metabolism Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts; and.,Division of Endocrinology, Diabetes, and Metabolism, Tufts Medical Center, Boston, Massachusetts
| | - Roger A Fielding
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, United States Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts;
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Kataya Y, Murakami K, Kobayashi S, Suga H, Sasaki S. Higher dietary acid load is associated with a higher prevalence of frailty, particularly slowness/weakness and low physical activity, in elderly Japanese women. Eur J Nutr 2017; 57:1639-1650. [DOI: 10.1007/s00394-017-1449-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/04/2017] [Indexed: 12/26/2022]
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Metabolic alterations by indoxyl sulfate in skeletal muscle induce uremic sarcopenia in chronic kidney disease. Sci Rep 2016; 6:36618. [PMID: 27830716 PMCID: PMC5103201 DOI: 10.1038/srep36618] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/12/2016] [Indexed: 11/25/2022] Open
Abstract
Sarcopenia is associated with increased morbidity and mortality in chronic kidney disease (CKD). Pathogenic mechanism of skeletal muscle loss in CKD, which is defined as uremic sarcopenia, remains unclear. We found that causative pathological mechanism of uremic sarcopenia is metabolic alterations by uremic toxin indoxyl sulfate. Imaging mass spectrometry revealed indoxyl sulfate accumulated in muscle tissue of a mouse model of CKD. Comprehensive metabolomics revealed that indoxyl sulfate induces metabolic alterations such as upregulation of glycolysis, including pentose phosphate pathway acceleration as antioxidative stress response, via nuclear factor (erythroid-2-related factor)-2. The altered metabolic flow to excess antioxidative response resulted in downregulation of TCA cycle and its effected mitochondrial dysfunction and ATP shortage in muscle cells. In clinical research, a significant inverse association between plasma indoxyl sulfate and skeletal muscle mass in CKD patients was observed. Our results indicate that indoxyl sulfate is a pathogenic factor for sarcopenia in CKD.
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Mastrototaro L, Sponder G, Saremi B, Aschenbach JR. Gastrointestinal methionine shuttle: Priority handling of precious goods. IUBMB Life 2016; 68:924-934. [DOI: 10.1002/iub.1571] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/22/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Lucia Mastrototaro
- Institute of Veterinary Physiology, Department of Veterinary Medicine, Free University of Berlin; Berlin Germany
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Department of Veterinary Medicine, Free University of Berlin; Berlin Germany
| | - Behnam Saremi
- Evonik Nutrition & Care GmbH; Animal Nutrition-Animal Nutrition Services; Hanau Germany
| | - Jörg R. Aschenbach
- Institute of Veterinary Physiology, Department of Veterinary Medicine, Free University of Berlin; Berlin Germany
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Chan R, Leung J, Woo J. A Prospective Cohort Study to Examine the Association Between Dietary Patterns and Sarcopenia in Chinese Community-Dwelling Older People in Hong Kong. J Am Med Dir Assoc 2016; 17:336-42. [PMID: 26774365 DOI: 10.1016/j.jamda.2015.12.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Dietary pattern analysis has recently emerged as an alternative approach to investigate the association between diet and sarcopenia. This study examined the association of dietary patterns with sarcopenia in Chinese community-dwelling older people. METHODS Chinese men and women aged 65 years or older participating in a cohort study examining the risk factors for osteoporosis completed a validated food frequency questionnaire at baseline between 2001 and 2003. Adherence to a priori dietary patterns, namely the Diet Quality Index-International (DQI-I) and the Mediterranean Diet Score (MDS) was assessed. Factor analysis identified 3 a posterior dietary patterns: "vegetables-fruits," "snacks-drinks-milk products," and "meat-fish." Sarcopenia was defined using the Asian Working Group for Sarcopenia algorithm. Multiple logistic regression was used for cross-sectional analysis (n = 3957) to assess the associations between dietary patterns and prevalent sarcopenia, and for longitudinal analysis (n = 2948) on their associations with 4-year incident sarcopenia with adjustment for sociodemographic and lifestyle factors. RESULTS There were 290 (7.3%) (185 men, 105 women) sarcopenic cases at baseline and 264 (9.0%) (160 men, 104 women) incident sarcopenic cases at the 4-year follow-up. At baseline, men in the highest quartile of DQI-I had reduced odds of sarcopenia (Adjusted OR 0.50, 95% CI 0.31-0.81, Ptrend = .004) compared with men in the lowest quartile. Men in the highest quartile of "vegetables-fruits" pattern score (Adjusted OR 0.60, 95% CI 0.36-0.99, Ptrend = .034) showed lower likelihood of sarcopenia compared with men in the lowest quartile. Higher quartile of "snacks-drinks-milk products" pattern score was associated with lower odds of sarcopenia in men (Adjusted OR 0.41, 95% CI 0.24-0.70, Ptrend < .001). There was no association between dietary patterns and prevalent sarcopenia in women. None of the dietary patterns was associated with incident sarcopenia at 4-year in both sexes. CONCLUSIONS Higher DQI-I, higher "vegetables-fruits" dietary pattern score, and higher "snacks-drinks-milk products" dietary pattern score were associated with lower odds of prevalent sarcopenia in Chinese older men.
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Affiliation(s)
- Ruth Chan
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
| | - Jason Leung
- Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Jean Woo
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
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Tapia-Rojas C, Lindsay CB, Montecinos-Oliva C, Arrazola MS, Retamales RM, Bunout D, Hirsch S, Inestrosa NC. Is L-methionine a trigger factor for Alzheimer's-like neurodegeneration?: Changes in Aβ oligomers, tau phosphorylation, synaptic proteins, Wnt signaling and behavioral impairment in wild-type mice. Mol Neurodegener 2015; 10:62. [PMID: 26590557 PMCID: PMC4654847 DOI: 10.1186/s13024-015-0057-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND L-methionine, the principal sulfur-containing amino acid in proteins, plays critical roles in cell physiology as an antioxidant and in the breakdown of fats and heavy metals. Previous studies suggesting the use of L-methionine as a treatment for depression and other diseases indicate that it might also improve memory and propose a role in brain function. However, some evidence indicates that an excess of methionine can be harmful and can increase the risk of developing Type-2 diabetes, heart diseases, certain types of cancer, brain alterations such as schizophrenia, and memory impairment. RESULTS Here, we report the effects of an L-methionine-enriched diet in wild-type mice and emphasize changes in brain structure and function. The animals in our study presented 1) higher levels of phosphorylated tau protein, 2) increased levels of amyloid-β (Aβ)-peptides, including the formation of Aβ oligomers, 3) increased levels of inflammatory response,4) increased oxidative stress, 5) decreased level of synaptic proteins, and 6) memory impairment and loss. We also observed dysfunction of the Wnt signaling pathway. CONCLUSION Taken together, the results of our study indicate that an L-methionine-enriched diet causes neurotoxic effects in vivo and might contribute to the appearance of Alzheimer's-like neurodegeneration.
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Affiliation(s)
- Cheril Tapia-Rojas
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carolina B Lindsay
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carla Montecinos-Oliva
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Macarena S Arrazola
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rocio M Retamales
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniel Bunout
- Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile
| | - Sandra Hirsch
- Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile
| | - Nibaldo C Inestrosa
- Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas, P. Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile. .,Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia. .,Centro UC Síndrome de Down, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile. .,CARE Biomedical Center, Pontificia Universidad Católica de Chile, Av. Alameda 340, Santiago, Chile.
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Cheema BS, Chan D, Fahey P, Atlantis E. Effect of progressive resistance training on measures of skeletal muscle hypertrophy, muscular strength and health-related quality of life in patients with chronic kidney disease: a systematic review and meta-analysis. Sports Med 2015; 44:1125-38. [PMID: 24696049 DOI: 10.1007/s40279-014-0176-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND OBJECTIVE Skeletal muscle wasting resulting in reduced muscular strength and health-related quality of life (HR-QOL) is common in chronic kidney disease (CKD) and may be reversed with progressive resistance training (PRT). Therefore, we systematically assessed the effect of PRT on measures of skeletal muscle hypertrophy, muscular strength and HR-QOL in this cohort to inform clinical practice and guidelines. DESIGN We performed a systematic review and meta-analysis. INCLUSION CRITERIA We included randomised controlled trials (RCTs) that investigated the independent effect of PRT (>6 weeks) on measures of skeletal muscle hypertrophy [muscle mass or cross-sectional area (CSA)], muscular strength and/or HR-QOL in adults with CKD. DATA EXTRACTION AND ANALYSIS The standardised mean difference (SMD) from each study was pooled to produce an overall estimate of effect and associated 95% confidence interval (95% CI) between treatment and control groups on primary outcomes. RESULTS Seven RCTs in 271 patients with Stage 3-5 CKD yielded seven studies on muscular strength (N = 249), six studies on total body muscle mass (N = 200) and six studies on HR-QOL (N = 223). PRT significantly improved standardised muscular strength [SMD 1.15 (95% CI 0.80-1.49)] and HR-QOL [SMD 0.83 (95% CI 0.51-1.16)], but not total body muscle mass [SMD 0.29 (95% CI -0.27 to 0.86)] in our primary analysis. However, secondary analysis of six studies showed that PRT induced significant muscle hypertrophy of the lower extremities (leg mass, or mid-thigh or quadriceps CSA) [SMD 0.43 (95% CI 0.11-0.76)], a pertinent analysis given that most studies implemented lower-body PRT only. CONCLUSIONS Robust evidence from RCTs indicates that PRT can induce skeletal muscle hypertrophy and increase muscular strength and HR-QOL outcomes in men and women with CKD. Therefore, clinical practice guidelines should be updated to inform clinicians on the benefits of PRT in this cohort.
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Affiliation(s)
- Birinder S Cheema
- School of Science and Health, University of Western Sydney, Campbelltown Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia,
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Chan R, Leung J, Woo J. Association Between Estimated Net Endogenous Acid Production and Subsequent Decline in Muscle Mass Over Four Years in Ambulatory Older Chinese People in Hong Kong: A Prospective Cohort Study. ACTA ACUST UNITED AC 2014; 70:905-11. [DOI: 10.1093/gerona/glu215] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 10/23/2014] [Indexed: 01/03/2023]
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Mori A, Nishino T, Obata Y, Nakazawa M, Hirose M, Yamashita H, Uramatsu T, Shinzato K, Kohno S. The Effect of Active Vitamin D Administration on Muscle Mass in Hemodialysis Patients. Clin Drug Investig 2013; 33:837-46. [DOI: 10.1007/s40261-013-0132-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Abstract
Muscle wasting is a serious complication of various clinical conditions that significantly worsens the prognosis of the illnesses. Clinically relevant models of muscle wasting are essential for understanding its pathogenesis and for selective preclinical testing of potential therapeutic agents. The data presented here indicate that muscle wasting has been well characterized in rat models of sepsis (endotoxaemia, and caecal ligation and puncture), in rat models of chronic renal failure (partial nephrectomy), in animal models of intensive care unit patients (corticosteroid treatment combined with peripheral denervation or with administration of neuromuscular blocking drugs) and in murine and rat models of cancer (tumour cell transplantation). There is a need to explore genetically engineered mouse models of cancer. The degree of protein degradation in skeletal muscle is not well characterized in animal models of liver cirrhosis, chronic heart failure and chronic obstructive pulmonary disease. The major difficulties with all models are standardization and high variation in disease progression and a lack of reflection of clinical reality in some of the models. The translation of the information obtained by using these models to clinical practice may be problematic.
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Affiliation(s)
- Milan Holecek
- Department of Physiology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic.
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Jablonski KL, Chonchol M. Frequent Hemodialysis: A Way to Improve Physical Function?: Figure 1. Clin J Am Soc Nephrol 2012; 7:707-10. [DOI: 10.2215/cjn.02880312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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The alkaline diet: is there evidence that an alkaline pH diet benefits health? JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2011; 2012:727630. [PMID: 22013455 PMCID: PMC3195546 DOI: 10.1155/2012/727630] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Accepted: 08/08/2011] [Indexed: 12/04/2022]
Abstract
This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.
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Mak RH, Ikizler AT, Kovesdy CP, Raj DS, Stenvinkel P, Kalantar-Zadeh K. Wasting in chronic kidney disease. J Cachexia Sarcopenia Muscle 2011; 2:9-25. [PMID: 21475675 PMCID: PMC3063874 DOI: 10.1007/s13539-011-0019-5] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 01/25/2011] [Indexed: 11/17/2022] Open
Abstract
Wasting/cachexia is prevalent among patients with chronic kidney disease (CKD). It is to be distinguished from malnutrition, which is defined as the consequence of insufficient food intake or an improper diet. Malnutrition is characterized by hunger, which is an adaptive response, whereas anorexia is prevalent in patients with wasting/cachexia. Energy expenditure decreases as a protective mechanism in malnutrition whereas it remains inappropriately high in cachexia/wasting. In malnutrition, fat mass is preferentially lost and lean body mass and muscle mass is preserved. In cachexia/wasting, muscle is wasted and fat is relatively underutilized. Restoring adequate food intake or altering the composition of the diet reverses malnutrition. Nutrition supplementation does not totally reverse cachexia/wasting. The diagnostic criteria of cachexia/protein-energy wasting in CKD are considered. The association of wasting surrogates, such as serum albumin and prealbumin, with mortality is strong making them robust outcome predictors. At the patient level, longevity has consistently been observed in patients with CKD who have more muscle and/or fat, who report better appetite and who eat more. Although inadequate nutritional intake may contribute to wasting or cachexia, recent evidence indicates that other factors, including systemic inflammation, perturbations of appetite-controlling hormones from reduced renal clearance, aberrant neuropeptide signaling, insulin and insulin-like growth factor resistance, and metabolic acidosis, may be important in the pathogenesis of CKD-associated wasting. A number of novel therapeutic approaches, such as ghrelin agonists and melanocortin receptor antagonists are currently at the experimental level and await confirmation by randomized controlled clinical trials in patients with CKD-associated cachexia/wasting syndrome.
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Affiliation(s)
- Robert H. Mak
- Division of Pediatric Nephrology, University of California San Diego, 9500 Gilman Drive. MC 0634, La Jolla, CA 92093-0634 USA
- Rady Children’s Hospital of San Diego, San Diego, CA 92093-0634 USA
| | - Alp T. Ikizler
- Division of Nephrology, Vanderbilt University Med. Center, Nashville, TN USA
| | - Csaba P. Kovesdy
- Division of Nephrology, University of Virginia, Charlottesville, VA USA
- Division of Nephrology, Salem Veterans Affairs Medical Center, Salem, VA USA
| | - Dominic S. Raj
- Division of Renal Diseases and Hypertension, The George Washington University, Washington, DC USA
| | - Peter Stenvinkel
- Division of Renal Medicine, Karolinska University Hospital at Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Kamyar Kalantar-Zadeh
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA USA
- Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA USA
- David Geffen School of Medicine at UCLA, Los Angeles, CA USA
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Gorostiaga EM, Asiáin X, Izquierdo M, Postigo A, Aguado R, Alonso JM, Ibáñez J. Vertical jump performance and blood ammonia and lactate levels during typical training sessions in elite 400-m runners. J Strength Cond Res 2010; 24:1138-49. [PMID: 20300013 DOI: 10.1519/jsc.0b013e3181cf769f] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study described the effects of 6 typical high-intensity intermittent running training sessions of varying distances (60-300 m) and intensities (80-105% of the individual best 400-m record time) on blood ammonia and lactate concentration changes and on vertical jumping height, in twelve 400-m elite male runners. At the end of the training sessions, similar patterns of extremely high blood lactate (14-23 mmol.L) and ammonia levels (50-100 mumol.L) were observed. Vertical jumping performance was maintained during the initial exercise bouts up to a break zone of further increase in the number of exercise bouts, which was associated, especially in subjects with the highest initial vertical jump, with a pronounced decrease (6-28%) in vertical jumping performance, as well as with blood lactate concentrations exceeding 8-12 mmol.L, and blood ammonia levels increasing abruptly from rest values. This break zone may be related to signs of energetic deficiency of the muscle contractile machinery associated with the ability to regenerate adenosine triphosphate at high rates. It is suggested that replacing some of these extremely demanding training sessions with other intermittent training sessions that preserve muscle generating capacity should allow elite athletes to practice more frequently at competitive intensity with lower fatigue.
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Affiliation(s)
- Esteban M Gorostiaga
- Research, Studies and Sport Medicine Center, Government of Navarra, Pamplona, Spain.
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Xue Y, Liao SF, Son KW, Greenwood SL, McBride BW, Boling JA, Matthews JC. Metabolic acidosis in sheep alters expression of renal and skeletal muscle amino acid enzymes and transporters1. J Anim Sci 2010; 88:707-17. [DOI: 10.2527/jas.2009-2101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Edwards MJ, Wallis IR, Foley WJ. Acid loads induced by the detoxification of plant secondary metabolites do not limit feeding by common brushtail possums (Trichosurus vulpecula). J Comp Physiol B 2009; 180:247-57. [DOI: 10.1007/s00360-009-0404-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 07/30/2009] [Accepted: 08/16/2009] [Indexed: 11/28/2022]
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Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fukuda DH, Beck TW, Cramer JT, Stout JR. Effects of beta-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. J Int Soc Sports Nutr 2009; 6:5. [PMID: 19210788 PMCID: PMC2649036 DOI: 10.1186/1550-2783-6-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 02/11/2009] [Indexed: 11/21/2022] Open
Abstract
Background Intermittent bouts of high-intensity exercise result in diminished stores of energy substrates, followed by an accumulation of metabolites, promoting chronic physiological adaptations. In addition, β-alanine has been accepted has an effective physiological hydrogen ion (H+) buffer. Concurrent high-intensity interval training (HIIT) and β-alanine supplementation may result in greater adaptations than HIIT alone. The purpose of the current study was to evaluate the effects of combining β-alanine supplementation with high-intensity interval training (HIIT) on endurance performance and aerobic metabolism in recreationally active college-aged men. Methods Forty-six men (Age: 22.2 ± 2.7 yrs; Ht: 178.1 ± 7.4 cm; Wt: 78.7 ± 11.9; VO2peak: 3.3 ± 0.59 l·min-1) were assessed for peak O2 utilization (VO2peak), time to fatigue (VO2TTE), ventilatory threshold (VT), and total work done at 110% of pre-training VO2peak (TWD). In a double-blind fashion, all subjects were randomly assigned into one either a placebo (PL – 16.5 g dextrose powder per packet; n = 18) or β-alanine (BA – 1.5 g β-alanine plus 15 g dextrose powder per packet; n = 18) group. All subjects supplemented four times per day (total of 6 g/day) for the first 21-days, followed by two times per day (3 g/day) for the subsequent 21 days, and engaged in a total of six weeks of HIIT training consisting of 5–6 bouts of a 2:1 minute cycling work to rest ratio. Results Significant improvements in VO2peak, VO2TTE, and TWD after three weeks of training were displayed (p < 0.05). Increases in VO2peak, VO2TTE, TWD and lean body mass were only significant for the BA group after the second three weeks of training. Conclusion The use of HIIT to induce significant aerobic improvements is effective and efficient. Chronic BA supplementation may further enhance HIIT, improving endurance performance and lean body mass.
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Affiliation(s)
- Abbie E Smith
- Metabolic and Body Composition Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA.
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Bishop D, Edge J, Thomas C, Mercier J. Effects of high-intensity training on muscle lactate transporters and postexercise recovery of muscle lactate and hydrogen ions in women. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1991-8. [PMID: 18832090 DOI: 10.1152/ajpregu.00863.2007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to investigate the effects of high-intensity interval training (3 days/wk for 5 wk), provoking large changes in muscle lactate and pH, on changes in intracellular buffer capacity (betam(in vitro)), monocarboxylate transporters (MCTs), and the decrease in muscle lactate and hydrogen ions (H+) after exercise in women. Before and after training, biopsies of the vastus lateralis were obtained at rest and immediately after and 60 s after 45 s of exercise at 190% of maximal O2 uptake. Muscle samples were analyzed for ATP, phosphocreatine (PCr), lactate, and H+; MCT1 and MCT4 relative abundance and betam(in vitro) were also determined in resting muscle only. Training provoked a large decrease in postexercise muscle pH (pH 6.81). After training, there was a significant decrease in betam(in vitro) (-11%) and no significant change in relative abundance of MCT1 (96 +/- 12%) or MCT4 (120 +/- 21%). During the 60-s recovery after exercise, training was associated with no change in the decrease in muscle lactate, a significantly smaller decrease in muscle H+, and increased PCr resynthesis. These results suggest that increases in betam(in vitro) and MCT relative abundance are not linked to the degree of muscle lactate and H+ accumulation during training. Furthermore, training that is very intense may actually lead to decreases in betam(in vitro). The smaller postexercise decrease in muscle H+ after training is a further novel finding and suggests that training that results in a decrease in H+ accumulation and an increase in PCr resynthesis can actually reduce the decrease in muscle H+ during the recovery from supramaximal exercise.
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Affiliation(s)
- David Bishop
- School of Human Movement and Exercise Science, The University of Western Australia, Crawley, Western Australia, Australia.
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Fujita S, Dreyer HC, Drummond MJ, Glynn EL, Volpi E, Rasmussen BB. Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis. J Appl Physiol (1985) 2008; 106:1730-9. [PMID: 18535123 DOI: 10.1152/japplphysiol.90395.2008] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ingestion of an essential amino acid-carbohydrate (EAA + CHO) solution following resistance exercise enhances muscle protein synthesis during postexercise recovery. It is unclear whether EAA + CHO ingestion before resistance exercise can improve direct measures of postexercise muscle protein synthesis (fractional synthetic rate; FSR). We hypothesized that EAA + CHO ingestion before a bout of resistance exercise would prevent the exercise-induced decrease in muscle FSR and would result in an enhanced rate of muscle FSR during postexercise recovery. We studied 22 young healthy subjects before, during, and for 2 h following a bout of high-intensity leg resistance exercise. The fasting control group (n = 11) did not ingest nutrients, and the EAA + CHO group (n = 11) ingested a solution of EAA + CHO 1 h before beginning the exercise bout. Stable isotopic methods were used in combination with muscle biopsies to determine FSR. Immunoblotting procedures were utilized to assess cell signaling proteins associated with the regulation of FSR. We found that muscle FSR increased in the EAA + CHO group immediately following EAA + CHO ingestion (P < 0.05), returned to basal values during exercise, and remained unchanged at 1 h postexercise. Muscle FSR decreased in the fasting group during exercise and increased at 1 h postexercise (P < 0.05). However, the 2 h postexercise FSR increased by approximately 50% in both groups with no differences between groups (P > 0.05). Eukaryotic elongation factor 2 phosphorylation was reduced in both groups at 2 h postexercise (EAA + CHO: 39 +/- 7%; fasting: 47 +/- 9%; P < 0.05). We conclude that EAA + CHO ingestion before resistance exercise does not enhance postexercise FSR compared with exercise without nutrients.
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Affiliation(s)
- Satoshi Fujita
- Univ. of Texas Medical Branch, Dept. of Physical Therapy, Div. of Rehabilitation Sciences, Sealy Center on Aging, 301 Univ. Blvd., Galveston, TX 77555-1144, USA
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Abstract
PURPOSE OF REVIEW This review will provide an update on advances in the understanding of the pathophysiology and novel therapeutic approach to cachexia in chronic kidney disease. RECENT FINDINGS Recent studies examine the metabolic effects of nutritional supplementation and show short-term salutary effects. Studies on peripheral hormones involved in energy homeostasis and their hypothalamic signaling in the pathophysiology of uremic cachexia have led to potential novel therapeutic strategies. SUMMARY Most of the information on therapeutic strategy for cachexia of chronic kidney disease is currently at the experimental level and awaits confirmation by clinical trials. The few available clinical studies are preliminary and have the limitation of not having a randomized placebo-controlled group. Further long-term well designed studies to assess the clinical applicability as well as side-effects are needed before these therapeutic strategies can be recommended for treatment of cachexia in chronic kidney disease.
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Abstract
This report reviews decade two of the lifetime diet restriction study of the dog. Labrador retrievers (n 48) were paired at age 6 weeks by sex and weight within each of seven litters, and assigned randomly within the pair to control-feeding (CF) or 25 % diet restriction (DR). Feeding began at age 8 weeks. The same diet was fed to all dogs; only the quantity differed. Major lifetime observations included 1.8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis. Long-term DR did not negatively affect skeletal maturation, structure or metabolism. Among all dogs, high static fat mass and declining lean body mass predicted death, most strongly at 1 year prior. Fat mass above 25 % was associated with increasing insulin resistance, which independently predicted lifespan and chronic diseases. Metabolizable energy requirement/lean body mass most accurately explained energy metabolism due to diet restriction; diet-restricted dogs required 17 % less energy to maintain each lean kilogram. Metabonomics-based urine metabolite trajectories reflected DR-related differences, suggesting that signals from gut microbiota may be involved in the DR longevity and health responses. Independent of feeding group, increased hazard of earlier death was associated with lower lymphoproliferative responses to phytohaemagglutinin, concanavalin A, and pokeweed mitogen; lower total lymphocytes, T-cells, CD4 and CD8 cells; lower CD8 percentages and higher B-cell percentages. When diet group was taken into account, PWM responses and cell counts and percentages remained predictive of earlier death.
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Ambühl PM. Posttransplant metabolic acidosis: a neglected factor in renal transplantation? Curr Opin Nephrol Hypertens 2007; 16:379-87. [PMID: 17565282 DOI: 10.1097/mnh.0b013e3281bd8860] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE OF REVIEW The occurrence and pathogenesis of metabolic acidosis after renal transplantation is reviewed. Posttransplant acidosis is shown to be a key mechanism for major metabolic complications in mineral and muscle metabolism, and for anemia, discussed in the context of both acidosis and renal transplantation. RECENT FINDINGS Continuous improvement in kidney transplant survival has shifted attention to long-term outcomes, specifically to disorders linked to cardiovascular disease, physical capacity and quality of life. Metabolic acidosis is gaining growing acceptance as a clinical entity and has occasionally come into focus in the context of renal transplantation. The possible link to metabolic disturbances resulting in impairment of musculoskeletal disorders and physical limitations, however, has not been considered specifically. SUMMARY Available evidence suggests a high prevalence of (compensated) metabolic acidosis after renal transplantation, presenting as low serum bicarbonate and impaired renal acid excretion. This condition is associated with relevant disorders in mineral metabolism and muscle function. Current knowledge about the effects of acidosis on renal electrolyte handling, mineral metabolism and protein synthesis suggests that acid/base derangements contribute to the muscle and bone pathology, as well as anemia, encountered after kidney transplantation. Consequently, posttransplant acidosis may be a relevant factor in the causal pathway of impaired physical capacity observed in this patient group.
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Affiliation(s)
- Patrice M Ambühl
- Department of Nephrology, University Hospital, Zurich, Switzerland.
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Cheema B, Abas H, Smith B, O'Sullivan A, Chan M, Patwardhan A, Kelly J, Gillin A, Pang G, Lloyd B, Singh MF. Progressive Exercise for Anabolism in Kidney Disease (PEAK): A Randomized, Controlled Trial of Resistance Training during Hemodialysis. J Am Soc Nephrol 2007; 18:1594-601. [PMID: 17409306 DOI: 10.1681/asn.2006121329] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Skeletal muscle wasting is common and insidious in patients who receive maintenance hemodialysis treatment for the management of ESRD. The objective of this study was to determine whether 12 wk of high-intensity, progressive resistance training (PRT) administered during routine hemodialysis treatment could improve skeletal muscle quantity and quality versus usual care. Forty-nine patients (62.6 +/- 14.2 yr; 0.3 to 16.7 yr on dialysis) were recruited from the outpatient hemodialysis unit of the St. George Public Hospital (Sydney, Australia). Patients were randomized to PRT + usual care (n = 24) or usual care control only (n = 25). The PRT group performed two sets of 10 exercises at a high intensity (15 to 17/20 on the Borg Scale) using free weights, three times per week for 12 wk during routine hemodialysis treatment. Primary outcomes included thigh muscle quantity (cross-sectional area [CSA]) and quality (intramuscular lipid content via attenuation) evaluated by computed tomography scan. Secondary outcomes included muscle strength, exercise capacity, body circumference measures, proinflammatory cytokine C-reactive protein, and quality of life. There was no statistically significant difference in muscle CSA change between groups. However, there were statistically significant improvements in muscle attenuation, muscle strength, mid-thigh and mid-arm circumference, body weight, and C-reactive protein in the PRT group relative to the nonexercising control group. These findings suggest that patients with ESRD can improve skeletal muscle quality and derive other health-related adaptations solely by engaging in a 12-wk high-intensity PRT regimen during routine hemodialysis treatment sessions. Longer training durations or more sensitive analysis techniques may be required to document alterations in muscle CSA.
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Affiliation(s)
- Bobby Cheema
- School of Exercise and Sport Science and Faculty of Medicine, University of Sydney, Australia.
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Abstract
Underlying the pathogenesis of chronic disease is the state of oxidative stress. Oxidative stress is an imbalance in oxidant and antioxidant levels. If an overproduction of oxidants overwhelms the antioxidant defenses, oxidative damage of cells, tissues, and organs ensues. In some cases, oxidative stress is assigned a causal role in disease pathogenesis, whereas in others the link is less certain. Along with underlying oxidative stress, chronic disease is often accompanied by muscle wasting. It has been hypothesized that catabolic programs leading to muscle wasting are mediated by oxidative stress. In cases where disease is localized to the muscle, this concept is easy to appreciate. Transmission of oxidative stress from diseased remote organs to skeletal muscle is thought to be mediated by humoral factors such as inflammatory cytokines. This review examines the relationship between oxidative stress, chronic disease, and muscle wasting, and the mechanisms by which oxidative stress acts as a catabolic signal.
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Affiliation(s)
- Jennifer S Moylan
- Department of Physiology, University of Kentucky, 800 Rose Street, Room MS-509, Lexington, Kentucky 40536-0298, USA
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Shoja MM, Tubbs RS, Ansarin K. The role of myoendothelial gap junctions in the formation of arterial aneurysms: the hypothesis of "connexin 43:40 stoichiometry". Med Hypotheses 2007; 69:575-9. [PMID: 17374558 DOI: 10.1016/j.mehy.2007.01.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 01/17/2007] [Indexed: 10/24/2022]
Abstract
Heterocellular myoendothelial gap junctions (MEGJs) are essential in coordinating and regulating vasomotion. Little is known about their potential role in disease states. We discuss how alteration in the Cx 43:40 expression ratio at the level of MEGJs may begin a chain of reactions in the arterial wall resulting in an aneurysm formation. In this model, we assumed that aneurysm is a chronic arterial disease associated with medial degeneration and intimal hyperplasia. It also was assumed that MEGJs are composed of Cx43 and Cx40 in different stoichiometry and that the characteristic of a given junction is in the favor of its most abundantly expressed constituent. The hypothesis of Cx 43:40 stoichiometry indicates that impaired MEGJs may play a role in the pathogenesis of arterial aneurysms. Cx43 upregulation and Cx40 downregulation (increased Cx 43:40 stoichiometry) may induce a cascade of inflammatory, electrical, metabolic and proliferative derangements in the arterial wall, which finally lead to the matrix degradation, intimal hyperplasia, endothelial-medial dissociation and loss of endothelium-dependent hyperpolarizing currents, irregular vasomotion, impaired growth factor activation, and arterial sympathetic deprivation. The final consequence of these alterations is aneurysm formation.
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Affiliation(s)
- Mohammadali M Shoja
- Tuberculosis and Lung Diseases Research Center, Tabriz Medical University, Tabriz, Iran.
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Dreyer HC, Fujita S, Cadenas JG, Chinkes DL, Volpi E, Rasmussen BB. Resistance exercise increases AMPK activity and reduces 4E-BP1 phosphorylation and protein synthesis in human skeletal muscle. J Physiol 2006; 576:613-24. [PMID: 16873412 PMCID: PMC1890364 DOI: 10.1113/jphysiol.2006.113175] [Citation(s) in RCA: 374] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Resistance exercise is a potent stimulator of muscle protein synthesis and muscle cell growth, with the increase in protein synthesis being detected within 2-3 h post-exercise and remaining elevated for up to 48 h. However, during exercise, muscle protein synthesis is inhibited. An increase in AMP-activated protein kinase (AMPK) activity has recently been shown to decrease mammalian target of rapamycin (mTOR) signalling to key regulators of translation initiation. We hypothesized that the cellular mechanism for the inhibition of muscle protein synthesis during an acute bout of resistance exercise in humans would be associated with an activation of AMPK and an inhibition of downstream components of the mTOR pathway (4E-BP1 and S6K1). We studied 11 subjects (seven men, four women) before, during, and for 2 h following a bout of resistance exercise. Muscle biopsy specimens were collected at each time point from the vastus lateralis. We utilized immunoprecipitation and immunoblotting methods to measure muscle AMPKalpha2 activity, and mTOR-associated upstream and downstream signalling proteins, and stable isotope techniques to measure muscle fractional protein synthetic rate (FSR). AMPKalpha2 activity (pmol min(-1) (mg protein)(-1)) at baseline was 1.7 +/- 0.3, increased immediately post-exercise (3.0 +/- 0.6), and remained elevated at 1 h post-exercise (P < 0.05). Muscle FSR decreased during exercise and was significantly increased at 1 and 2 h post-exercise (P < 0.05). Phosphorylation of 4E-BP1 at Thr37/46 was significantly reduced immediately post-exercise (P < 0.05). We conclude that AMPK activation and a reduced phosphorylation of 4E-BP1 may contribute to the inhibition of muscle protein synthesis during resistance exercise. However, by 1-2 h post-exercise, muscle protein synthesis increased in association with an activation of protein kinase B, mTOR, S6K1 and eEF2.
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Affiliation(s)
- Hans C Dreyer
- University of Texas Medical Branch, Department of Physical Therapy, Division of Rehabilitation Sciences, 301 University Blvd, Galveston, TX 77555-1144, USA
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Abstract
The literature has been searched to identify evidence relating to the possible toxicity of the amino acid methionine in human subjects. Nutritional and metabolic studies have employed amounts of methionine, including the d and dl isomers, both below and above the requirement and have not reported adverse effects in adults and children. Although methionine is known to exacerbate psychopathological symptoms in schizophrenic patients, there is no evidence of similar effects in healthy subjects. The role of methionine as a precursor of homocysteine is the most notable cause for concern. A "loading dose" of methionine (0.1 g/kg) has been given, and the resultant acute increase in plasma homocysteine has been used as an index of the susceptibility to cardiovascular disease. Although this procedure results in vascular dysfunction, this is acute and unlikely to result in permanent damage. However, a 10-fold larger dose, given mistakenly, resulted in death. Longer-term studies in adults have indicated no adverse consequences of moderate fluctuations in dietary methionine intake, but intakes higher than 5 times normal resulted in elevated homocysteine levels. These effects of methionine on homocysteine and vascular function are moderated by supplements of vitamins B-6, B-12, C, and folic acid. In infants, methionine intakes of 2-5 times normal resulted in impaired growth and extremely high plasma methionine levels, but no adverse long-term consequences were observed.
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Affiliation(s)
- Peter J Garlick
- Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
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Edge J, Bishop D, Goodman C. Effects of chronic NaHCO3 ingestion during interval training on changes to muscle buffer capacity, metabolism, and short-term endurance performance. J Appl Physiol (1985) 2006; 101:918-25. [PMID: 16627675 DOI: 10.1152/japplphysiol.01534.2005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study determined the effects of altering the H(+) concentration during interval training, by ingesting NaHCO(3) (Alk-T) or a placebo (Pla-T), on changes in muscle buffer capacity (beta m), endurance performance, and muscle metabolites. Pre- and posttraining peak O(2) uptake (V(O2 peak)), lactate threshold (LT), and time to fatigue at 100% pretraining V(O2 peak) intensity were assessed in 16 recreationally active women. Subjects were matched on the LT, were randomly placed into the Alk-T (n = 8) or Pla-T (n = 8) groups, and performed 8 wk (3 days/wk) of six to twelve 2-min cycle intervals at 140-170% of their LT, ingesting NaHCO(3) or a placebo before each training session (work matched between groups). Both groups had improvements in beta m (19 vs. 9%; P < 0.05) and V(O2 peak) (22 vs. 17%; P < 0.05) after the training period, with no differences between groups. There was a significant correlation between pretraining beta m and percent change in beta m (r = -0.70, P < 0.05). There were greater improvements in both the LT (26 vs. 15%; P = 0.05) and time to fatigue (164 vs. 123%; P = 0.05) after Alk-T, compared with Pla-T. There were no changes to pre- or postexercise ATP, phosphocreatine, creatine, and intracellular lactate concentrations, or pH(i) after training. Our findings suggest that training intensity, rather than the accumulation of H(+) during training, may be more important to improvements in beta m. The group ingesting NaHCO(3) before each training session had larger improvements in the LT and endurance performance, possibly because of a reduced metabolic acidosis during training and a greater improvement in muscle oxidative capacity.
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Affiliation(s)
- Johann Edge
- School of Human Movement and Exercise Science, The University of Western Australia, Perth, Australia
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McIntyre CW, Selby NM, Sigrist M, Pearce LE, Mercer TH, Naish PF. Patients receiving maintenance dialysis have more severe functionally significant skeletal muscle wasting than patients with dialysis-independent chronic kidney disease. Nephrol Dial Transplant 2006; 21:2210-6. [PMID: 16504974 DOI: 10.1093/ndt/gfl064] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Chronic renal replacement therapy patients exhibit reduction in skeletal muscle function as a result of a combination of metabolic effects and muscle fibre size reduction. The aim of this study was to compare muscle mass with function in patients with chronic kidney disease (CKD) at stages 4 and 5 on haemodialysis (HD) and peritoneal dialysis (PD), and investigate the associations of muscle wasting in a cross-sectional cohort. METHODS We studied 134 patients (60 HD, 28 PD and 46 CKD 4). The three groups were well matched for age, sex, diabetes and dialysis vintage. Cross-sectional area (CSA) of muscle and fat was measured from a standardized multi-slice CT scan of a 6 cm long section of thigh. CSA of soft tissue was taken from appropriate fat and muscle densities. Functional assessment was by the sit-to-stand 60 test, assessing both the number of sit-to-stands possible under controlled conditions in 60 s (STS 60), and the time taken to perform five sit-to-stand movements (STS 5). Data were collected on a wide range of potential determinants of muscle CSA. RESULTS There were no significant differences in haemoglobin between males or females or between any of the groups studied. Serum phosphate and calcium-phosphate product were higher in HD patients as compared to CKD4 patients, but there were no differences in these variables when comparing PD patients with either CKD4 or HD patients. Muscle CSA correlated well with objective functional assessments in males (STS 60 R = 0.52, P<0.0001) and females (R = 0.41, P = 0.004), and STS performance was reduced in dialysed patients as compared with CKD 4. Univariate analysis demonstrated that muscle CSA was associated with serum albumin concentration (R = 0.49, P<0.0001), age (R = -0.35, P = 0.005) and C-reactive protein (R = -0.34, P = 0.004). Creatinine clearance, dialysis adequacy, dialysis vintage and time-averaged serum bicarbonate, calcium and phosphate concentrations were not correlated with muscle CSA. CONCLUSION In conclusion, patients with dialysis-treated CKD 5 exhibited more functionally significant muscle wasting than patients with CKD 4. This may be amenable to modification with targeted exercise or amelioration of factors associated with observed differences in muscle mass.
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Affiliation(s)
- Christopher W McIntyre
- Department of Renal Medicine, Derby City General Hospital, Uttoxeter Rd, Derby, DE22 3NE, UK.
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