1
|
Kikyo N. Circadian Regulation of Bone Remodeling. Int J Mol Sci 2024; 25:4717. [PMID: 38731934 PMCID: PMC11083221 DOI: 10.3390/ijms25094717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/20/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Adult bones are continuously remodeled by the balance between bone resorption by osteoclasts and subsequent bone formation by osteoblasts. Many studies have provided molecular evidence that bone remodeling is under the control of circadian rhythms. Circadian fluctuations have been reported in the serum and urine levels of bone turnover markers, such as digested collagen fragments and bone alkaline phosphatase. Additionally, the expressions of over a quarter of all transcripts in bones show circadian rhythmicity, including the genes encoding master transcription factors for osteoblastogenesis and osteoclastogenesis, osteogenic cytokines, and signaling pathway proteins. Serum levels of calcium, phosphate, parathyroid hormone, and calcitonin also display circadian rhythmicity. Finally, osteoblast- and osteoclast-specific knockout mice targeting the core circadian regulator gene Bmal1 show disrupted bone remodeling, although the results have not always been consistent. Despite these studies, however, establishing a direct link between circadian rhythms and bone remodeling in vivo remains a major challenge. It is nearly impossible to repeatedly collect bone materials from human subjects while following circadian changes. In addition, the differences in circadian gene regulation between diurnal humans and nocturnal mice, the main model organism, remain unclear. Filling the knowledge gap in the circadian regulation of bone remodeling could reveal novel regulatory mechanisms underlying many bone disorders including osteoporosis, genetic diseases, and fracture healing. This is also an important question for the basic understanding of how cell differentiation progresses under the influence of cyclically fluctuating environments.
Collapse
Affiliation(s)
- Nobuaki Kikyo
- Stem Cell Institute, Minneapolis, MN 55455, USA
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
2
|
Rassow K, Obst A, Nauck M, Völzke H, Stubbe B, Fietze I, Penzel T, Ewert R, Hannemann A. Sleep characteristics and parameters of bone turnover and strength in the adult population: results from the Study of Health in Pomerania-TREND. J Sleep Res 2024; 33:e14019. [PMID: 37646341 DOI: 10.1111/jsr.14019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 09/01/2023]
Abstract
Poor sleep quality or sleep deprivation may be related to decreased bone mineral density. We aimed to assess whether associations of sleep characteristics and bone turnover or strength are present in adults from the general population and whether these are independent of common risk factors such as sex, age, and obesity. A total of 1037 participants from the Study of Health in Pomerania-TREND underwent laboratory-based polysomnography and quantitative ultrasound measurements at the heel. Of these participants, 804 completed standardised questionnaires to assess daytime sleepiness, insomnia, and sleep quality. Serum concentrations of two bone turnover markers, intact amino-terminal propeptide of type 1 procollagen (P1NP) and carboxy-terminal telopeptide of type 1 collagen (CTX) were measured. Cross-sectional associations of polysomnography variables (total sleep time, sleep efficiency, time spent wake after sleep onset, oxygen desaturation index, apnea-hypopnea index, and obstructive sleep apnea [OSA]), as well as sleep questionnaire scores with the bone turnover markers and the ultrasound-based stiffness index were assessed in linear regression models. In adjusted models, higher insomnia scores and lower sleep quality scores were related to a higher bone turnover in women but not in men. However, associations between polysomnography variables or questionnaire scores and the stiffness index were absent. Our study provides limited evidence for relationships between sleep characteristics and bone turnover and strength independent of common risk factors for OSA and osteoporosis. Nevertheless, women reporting poor sleep or insomnia in combination with risk factors for osteoporosis might benefit from an evaluation of bone health.
Collapse
Affiliation(s)
- Kathrin Rassow
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Anne Obst
- Department of Internal Medicine B, Cardiology, Pneumology, Weaning, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Matthias Nauck
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, University Medicine Greifswald, Greifswald, Germany
| | - Henry Völzke
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, University Medicine Greifswald, Greifswald, Germany
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Beate Stubbe
- Department of Internal Medicine B, Cardiology, Pneumology, Weaning, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Ingo Fietze
- Interdisciplinary Center of Sleep Medicine, CC 12, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Penzel
- Interdisciplinary Center of Sleep Medicine, CC 12, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Ralf Ewert
- Department of Internal Medicine B, Cardiology, Pneumology, Weaning, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Anke Hannemann
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, University Medicine Greifswald, Greifswald, Germany
| |
Collapse
|
3
|
Fu J, Fan Z, He L, Liu Q, Liu H, Li Y, Guan H. Circadian clock disruption in autoimmune thyroiditis. Eur Thyroid J 2023; 12:e230035. [PMID: 37548297 PMCID: PMC10503217 DOI: 10.1530/etj-23-0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 08/07/2023] [Indexed: 08/08/2023] Open
Abstract
Objective A vicious cycle between circadian disruption and escalating immune responses has been described in diverse inflammatory disease. The current study aimed to explore the role of circadian clock disruption in autoimmune thyroiditis (AIT). Methods Thirty AIT patients and 30 controls were enrolled and biopsied for thyroid tissues. Alterations of core clock genes expression in AIT thyroid tissues, and its association with serum and tissue inflammatory biomarkers were assessed. For animal studies, C57BL/6J mice administered with porcine thyroglobulin or PBS (as control) combined with adjuvants were sacrificed at four time points to investigate the circadian characteristic of experimental autoimmune thyroiditis (EAT). Light shift (LS) conditions were used to explore the influence of external circadian disturbance on EAT. Results The expression of clock genes BMAL1 and PER2 was significantly reduced in thyroid tissues from AIT patients and was negatively correlated to levels of thyroid peroxidase antibodies. In mouse models, diurnal fluctuations of proinflammatory cytokines were demonstrated, and further exposing mice to LS led to overproduction of TNF-α, IFN-γ, and anti-thyroglobulin antibodies. Circadian analysis revealed significant oscillations of Bmal1, Clock, Per2, Cry1, Ror, and Rev-erb, which was broadly disturbed in EAT, LS, and EAT + LS groups. Conclusions This study demonstrates that expression pattern of clock genes was disrupted in AIT thyroid, and chronic circadian disruption may aggravate the inflammatory responses in AIT. Whether maintaining a regular circadian rhythm can alleviate autoimmune thyroid diseases warrants further research.
Collapse
Affiliation(s)
- Jinrong Fu
- Department of Endocrinology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Zihao Fan
- Department of Geriatrics, Guangdong Provincial Geriatrics Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Liang He
- Department of Thyroid Surgery, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Qian Liu
- Department of Endocrinology and Metabolism, Jilin Cancer Hospital, Changchun, Jilin, China
| | - He Liu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Yushu Li
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Haixia Guan
- Department of Endocrinology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| |
Collapse
|
4
|
Yan J, Wang J, Chen J, Shi H, Liao X, Pan C, Liu Y, Yang X, Ren Z, Yang X. Adjusting phosphate feeding regimen according to daily rhythm increases eggshell quality via enhancing medullary bone remodeling in laying hens. J Anim Sci Biotechnol 2023; 14:17. [PMID: 36894995 PMCID: PMC9999492 DOI: 10.1186/s40104-023-00829-0] [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: 08/11/2022] [Accepted: 01/03/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Body phosphorus metabolism exhibits a circadian rhythm over the 24-h daily cycle. The egg laying behavior makes laying hens a very special model for investigating phosphorus circadian rhythms. There is lack of information about the impact of adjusting phosphate feeding regimen according to daily rhythm on the phosphorus homeostasis and bone remodeling of laying hens. METHODS AND RESULTS Two experiments were conducted. In Exp. 1, Hy-Line Brown laying hens (n = 45) were sampled according the oviposition cycle (at 0, 6, 12, and 18 h post-oviposition, and at the next oviposition, respectively; n = 9 at each time point). Diurnal rhythms of body calcium/phosphorus ingestions and excretions, serum calcium/phosphorus levels, oviduct uterus calcium transporter expressions, and medullary bone (MB) remodeling were illustrated. In Exp. 2, two diets with different phosphorus levels (0.32% and 0.14% non-phytate phosphorus (NPP), respectively) were alternately presented to the laying hens. Briefly, four phosphorus feeding regimens in total (each included 6 replicates of 5 hens): (1) fed 0.32% NPP at both 09:00 and 17:00; (2) fed 0.32% NPP at 09:00 and 0.14% NPP at 17:00; (3) fed 0.14% NPP at 09:00 and 0.32% NPP at 17:00; (4) fed 0.14% NPP at both 09:00 and 17:00. As a result, the regimen fed 0.14% NPP at 09:00 and 0.32% NPP at 17:00, which was designed to strengthen intrinsic phosphate circadian rhythms according to the findings in Exp. 1, enhanced (P < 0.05) MB remodeling (indicated by histological images, serum markers and bone mineralization gene expressions), elevated (P < 0.05) oviduct uterus calcium transportation (indicated by transient receptor potential vanilloid 6 protein expression), and subsequently increased (P < 0.05) eggshell thickness, eggshell strength, egg specific gravity and eggshell index in laying hens. CONCLUSIONS These results underscore the importance of manipulating the sequence of daily phosphorus ingestion, instead of simply controlling dietary phosphate concentrations, in modifying the bone remodeling process. Body phosphorus rhythms will need to be maintained during the daily eggshell calcification cycle.
Collapse
Affiliation(s)
- Jiakun Yan
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jiajie Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jie Chen
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hao Shi
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xujie Liao
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Chong Pan
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yanli Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xin Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhouzheng Ren
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Xiaojun Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| |
Collapse
|
5
|
Diemar SS, Dahl SS, West AS, Simonsen SA, Iversen HK, Jørgensen NR. A Systematic Review of the Circadian Rhythm of Bone Markers in Blood. Calcif Tissue Int 2023; 112:126-147. [PMID: 35305134 DOI: 10.1007/s00223-022-00965-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/23/2022] [Indexed: 01/25/2023]
Abstract
There exists a marked circadian variation for several bone markers (BM), which is influenced by endogenous as well as exogenous factors including hormones, physical activity, and fasting. Consequently, was the aim of this review to provide an overview of the knowledge of the circadian variation of BM and which factors influence this rhythmicity. A systematic search of PubMed was performed for studies evaluating the circadian variation of BM and which factors influence this rhythmicity. The studies were screened for eligibility by a set of predetermined criteria including a list of relevant BM and a minimum study duration of 24 h with at least 3 blood samples of which two should be at least 6 h apart. In total were 29 papers included. There exists a marked circadian variation for most BM including Carboxy-terminal Cross-Linked Telopeptide of Type I Collagen (CTX) and osteocalcin (OC) with nighttime or early morning peak. Pro-collagen Type I N-terminal Propeptide (PINP) and PTH also showed circadian rhythm but with less amplitude. The inter-osteoblast-osteoclast regulatory markers such as OPG, RANKL, FGF23, and sclerostin showed no circadian rhythm. The markers were differently affected by exogenous factors like fasting, which greatly reduced the circadian variation of CTX but did not affect PINP or OC. The marked circadian variation and the factors which influence the rhythmicity, e.g., fasting are of great consequence when measuring BM. To reduce variation and heighten validity should circadian variation and fasting be kept in mind when measuring BM.
Collapse
Affiliation(s)
- Sarah Seberg Diemar
- Department of Clinical Biochemistry, Rigshospitalet Glostrup, Valdemar Hansens vej 1-23, 2600, Glostrup, Denmark
| | - Stig Søgaard Dahl
- Department of Surgical Gastroenterology, Rigshospitalet Blegdamsvej, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Anders Sode West
- Clinical Stroke Research Unit, Department of Neurology, Rigshospitalet Glostrup, Valdemar Hansens vej 1-23, 2600, Glostrup, Denmark
| | - Sofie Amalie Simonsen
- Clinical Stroke Research Unit, Department of Neurology, Rigshospitalet Glostrup, Valdemar Hansens vej 1-23, 2600, Glostrup, Denmark
| | - Helle Klingenberg Iversen
- Clinical Stroke Research Unit, Department of Neurology, Rigshospitalet Glostrup, Valdemar Hansens vej 1-23, 2600, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Niklas Rye Jørgensen
- Department of Clinical Biochemistry, Rigshospitalet Glostrup, Valdemar Hansens vej 1-23, 2600, Glostrup, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
- Department of Clinical Biochemistry, Rigshospitalet Glostrup, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.
| |
Collapse
|
6
|
Schini M, Vilaca T, Gossiel F, Salam S, Eastell R. Bone Turnover Markers: Basic Biology to Clinical Applications. Endocr Rev 2022; 44:417-473. [PMID: 36510335 PMCID: PMC10166271 DOI: 10.1210/endrev/bnac031] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 11/26/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022]
Abstract
Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.
Collapse
Affiliation(s)
- Marian Schini
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK.,Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Tatiane Vilaca
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - Fatma Gossiel
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - Syazrah Salam
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK.,Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Richard Eastell
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| |
Collapse
|
7
|
Cherian KE, Kapoor N, Paul TV. Disrupted Sleep Architecture Is Associated With Incident Bone Loss in Indian Postmenopausal Women: A Prospective Study. J Bone Miner Res 2022; 37:1956-1962. [PMID: 35880668 DOI: 10.1002/jbmr.4662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/06/2022] [Accepted: 07/21/2022] [Indexed: 11/06/2022]
Abstract
Inadequate sleep has been shown to be detrimental to several body systems, including the bone. We proposed to study the impact of insomnia on bone health in Indian postmenopausal women. In a 2-year prospective study, ambulant community-dwelling postmenopausal women aged >50 years were recruited through simple random sampling. Sleep duration was recorded based on self-reported sleep duration and sleep quality using the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Anthropometry, bone biochemistry including bone turnover markers (C-terminal telopeptide of type 1 collagen [CTX], N-terminal telopeptide of type 1 pro-collagen [P1NP]), bone mineral density (BMD), and trabecular bone score (TBS) were assessed at baseline and at the end of 2 years. Among 190 postmenopausal women with mean (SD) age of 58.2 (6.9) years, 65/190 (34.2%) had insomnia (WHIIRS ≥ 9) and 20/190 (10.5%) developed osteoporosis at any site on follow-up. The percentage decline over 2 years in BMD in women with insomnia was significantly (p < 0.001) higher at femoral neck (2.9 [1.6] versus 1.2 [1.2]%) and lumbar spine (4.5 [2.0] versus 1.6 [1.1]%). The decrement in TBS was also significantly higher (p < 0.001) in women with suboptimal sleep (1.5 [2.1] versus 0.5 [1.0] %) when compared with those with adequate sleep. The increment in CTX (46.4 [32.2] versus 18.9 [26.4]) and decrement in P1NP (35.4 [9.1] versus 16.7 [18.9]), respectively, were also greater (p < 0.001) in women with insomnia compared with those without. On multivariate analysis, insomnia was the sole factor that was predictive (adjusted odds ratio [OR] = 9.3; 95% confidence interval [CI] 2.9-29.6; p < 0.001) of incident osteoporosis. In conclusion, poor sleep quality was associated with incident osteoporosis in Indian postmenopausal women. Optimal sleep may help to retard ongoing bone loss that results from sleep deprivation and requires further research. © 2022 American Society for Bone and Mineral Research (ASBMR).
Collapse
Affiliation(s)
- Kripa Elizabeth Cherian
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College and Hospital, Vellore, India
| | - Nitin Kapoor
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College and Hospital, Vellore, India
| | - Thomas Vizhalil Paul
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College and Hospital, Vellore, India
| |
Collapse
|
8
|
Xu X, Zhou X, Liu W, Ma Q, Deng X, Fang R. Evaluation of the correlation between frailty and sleep quality among elderly patients with osteoporosis: a cross-sectional study. BMC Geriatr 2022; 22:599. [PMID: 35854210 PMCID: PMC9295528 DOI: 10.1186/s12877-022-03285-z] [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: 12/06/2021] [Accepted: 07/11/2022] [Indexed: 02/08/2023] Open
Abstract
Background The incidence of osteoporosis increases with age. Frailty is a distinct characteristic seen in older osteoporosis patients. Poor sleep quality is common in elderly individuals. However, there are few studies on the correlation between frailty and sleep quality in elderly patients with osteoporosis in China. Methods This cross-sectional study was conducted from December 8, 2020, to April 30, 2021. A total of 247 patients who met the inclusion and exclusion criteria were recruited in outpatient departments at West China Hospital. A self-designed demographic data questionnaire, the Pittsburgh Sleep Quality Index (PSQI), and the Frailty Phenotype scale were used to evaluate the sleep quality and frailty of the participants. Multivariate logistic regression was performed to evaluate the factors affecting frailty and sleep quality in osteoporosis patients. Results A total of 231 valid questionnaires were statistically analysed. The mean frailty score was 3.2 ± 1.6 and a total of 152 (65.8%) were frailty. The mean PSQI score was 11.9 ± 4.5 and a total of 183 (79.2%) patients had poor sleep quality (PSQI > 7). Multiple logistic regression showed that female, pain, polypharmacy, activities of daily living status (ADLs), and sleep quality were independent influencing factors for frailty, while comorbidity, ADLs and frailty status were independent influencing factors for sleep quality. Conclusion We found that frailty and sleep quality were prevalent and that frailty was positively correlated with the PSQI score in elderly patients with osteoporosis in China. The higher the frailty score is, the worse the sleep quality. It means the frailer old patients were, the worse their sleep quality, and poor sleep quality may increase the risk of frailty in elderly patients with osteoporosis. To manage elderly patients with osteoporosis effectively, medical staff should pay attention to frailty, sleep quality and its influencing factors.
Collapse
Affiliation(s)
- Xiaoru Xu
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoping Zhou
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Wenjing Liu
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Qing Ma
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xuexue Deng
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China.
| | - Ronghua Fang
- West China School of Nursing/Department of International Medical Center, West China Hospital, Sichuan University, Chengdu, China.
| |
Collapse
|
9
|
Swanson CM, Shanbhag P, Tussey EJ, Rynders CA, Wright KP, Kohrt WM. Bone Turnover Markers After Six Nights of Insufficient Sleep and Subsequent Recovery Sleep in Healthy Men. Calcif Tissue Int 2022; 110:712-722. [PMID: 35133471 PMCID: PMC9117441 DOI: 10.1007/s00223-022-00950-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/22/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE The goal of this study was to determine the bone turnover marker (BTM) response to insufficient and subsequent recovery sleep, independent of changes in posture, body weight, and physical activity. METHODS Healthy men (N = 12) who habitually slept 7-9 h/night were admitted to an inpatient sleep laboratory for a baseline 8 h/night sleep opportunity followed by six nights of insufficient sleep (5 h/night). Diet, physical activity, and posture were controlled. Serum markers of bone formation (osteocalcin, PINP) and resorption (β-CTX) were obtained over 24 h at baseline and on the last night of sleep restriction, and on fasted samples obtained daily while inpatient and five times after discharge over 3 weeks. Maximum likelihood estimates in a repeated measures model were used to assess the effect of insufficient and subsequent recovery sleep on BTM levels. RESULTS There was no statistically or clinically significant change in PINP (p = 0.53), osteocalcin (p = 0.66), or β-CTX (p = 0.10) in response to six nights of insufficient sleep. There were no significant changes in BTMs from the inpatient stay through 3 weeks of recovery sleep (all p [Formula: see text] 0.63). On average, body weight was stable during the inpatient stay (Δweight = - 0.55 ± 0.91 kg, p = 0.06). CONCLUSION No significant changes in serum BTMs were observed after six nights of insufficient or subsequent recovery sleep in young healthy men. Changes in weight and physical activity may be required to observe significant BTM change in response to sleep and circadian disruptions. Clinical Trials Registration Registered at ClinicalTrials.gov (NCT03733483) on November 7, 2018.
Collapse
Affiliation(s)
- Christine M Swanson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, 12801 E. 17th Ave, Mail Stop 8106, Aurora, CO, 80045, USA.
| | - Prajakta Shanbhag
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| | - Emma J Tussey
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| | - Corey A Rynders
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| | - Kenneth P Wright
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, 12801 E. 17th Ave, Mail Stop 8106, Aurora, CO, 80045, USA
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Wendy M Kohrt
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW Review recent literature investigating the relationship between bone health and sleep/circadian disruptions (e.g., abnormal sleep duration, night shift work). RECENT FINDINGS Short and long sleep are associated with low bone mineral density (BMD). Recent data from observational studies identified an increased risk of fracture in women with short sleep. Studies suggest that age, sex, weight change, and concurrent circadian misalignment may modify the effects of sleep restriction on bone metabolism. Interventional studies demonstrate alterations in bone metabolism and structure in response to circadian disruption that could underlie the increased fracture risk seen with night shift work. The effects of sleep and circadian disruption during adolescence may have lifelong skeletal consequences if they adversely impact bone modeling. Data suggest that short sleep and night shift work negatively impact bone metabolism and health. Rigorous studies of prevalent sleep and circadian disruptions are needed to determine mechanisms and develop prevention strategies to optimize lifelong skeletal health.
Collapse
Affiliation(s)
- Christine Swanson
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, 12801 E. 17th Ave., Mail Stop 8106, Aurora, CO, 80045, USA.
| |
Collapse
|
11
|
Duan X, Pan Q, Guo L. Chronic Sleep Deprivation Impaired Bone Formation in Growing Rats and Down-Regulated PI3K/AKT Signaling in Bone Tissues. Nat Sci Sleep 2022; 14:697-710. [PMID: 35444481 PMCID: PMC9015811 DOI: 10.2147/nss.s351850] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/06/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND This study aimed to assess the effects of chronic sleep deprivation (CSD) on bone metabolism in growing rats and the likely underlying mechanism. METHODS Twenty 5-week-old male Wistar rats and randomly divided into the CSD and normal control (NC) groups after one-week acclimatization. After a 6-week intervention of sleep deprivation, the distal femurs of both groups were harvested for micro-computed tomography scans and histological analysis. Meanwhile, the femur tissues were measured the mRNA and protein expression via RNA sequencing and immunohistochemical analysis. Serum bone turnover markers were evaluated at 0, 2, 4, and 6 weeks. RESULTS CSD impaired the bone growth, showing an imbalance of bone turnover status, dysphasia in the metaphysis growth plate, and deterioration of bone microarchitecture. Further, CSD suppressed bone formation, showing that the expression of osteogenesis-related proteins (col1α1 and osteocalcin) and mRNA (igf1, bglap, runx2, col1α1, pth1r) are down-regulated. Differentially expressed genes were detected, and functional enrichment analyses revealed that the PI3K/AKT pathway was significantly down-regulated in the CSD group. CONCLUSION These results suggest that CSD can significantly impaire bone health, and it may exert these effects in part by suppressing bone formation and osteoblast differentiation, and inactivating the PI3K/AKT signaling pathway.
Collapse
Affiliation(s)
- Xiaoye Duan
- Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.,Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Qi Pan
- Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Lixin Guo
- Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.,Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| |
Collapse
|
12
|
Spatial-Temporal Patterns and Inflammatory Factors of Bone Matrix Remodeling. Stem Cells Int 2021; 2021:4307961. [PMID: 34777503 PMCID: PMC8580647 DOI: 10.1155/2021/4307961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/05/2021] [Accepted: 10/07/2021] [Indexed: 11/18/2022] Open
Abstract
The bone extracellular matrix (ECM) contains organic and mineral constituents. The establishment and degradation processes of ECM connect with spatial and temporal patterns, especially circadian rhythms in ECM. These patterns are responsible for the physical and biological characteristics of bone. The disturbances of the patterns disrupt bone matrix remodeling and cause diverse bone diseases, such as osteogenesis imperfecta (OI) and bone fracture. In addition, the main regulatory factors and inflammatory factors also follow circadian rhythms. Studies show that the circadian oscillations of these factors in bone ECM potentially influence the interactions between immune responses and bone formation. More importantly, mesenchymal stem cells (MSCs) within the specific microenvironments provide the regenerative potential for tissue remodeling. In this review, we summarize the advanced ECM spatial characteristics and the periodic patterns of bone ECM. Importantly, we focus on the intrinsic connections between the immunoinflammatory system and bone formation according to circadian rhythms of regulatory factors in bone ECM. And our research group emphasizes the multipotency of MSCs with their microenvironments. The advanced understandings of bone ECM formation patterns and MSCs contribute to providing optimal prevention and treatment strategies.
Collapse
|
13
|
Beetz G, Herrero Babiloni A, Jodoin M, Charlebois-Plante C, Lavigne GJ, De Beaumont L, Rouleau DM. Relevance of Sleep Disturbances to Orthopaedic Surgery: A Current Concepts Narrative and Practical Review. J Bone Joint Surg Am 2021; 103:2045-2056. [PMID: 34478407 DOI: 10.2106/jbjs.21.00176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
➤ Sleep disturbances can increase the risk of falls and motor vehicle accidents and may reduce bone density. ➤ Poor sleep can lead to worse outcomes after fracture, such as chronic pain and delayed recovery. ➤ Orthopaedic surgeons can play an important role in the screening of sleep disorders among their patients.
Collapse
Affiliation(s)
- Gabrielle Beetz
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Alberto Herrero Babiloni
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Marianne Jodoin
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Department of Psychology, University of Montreal, Montreal, Quebec, Canada
| | | | - Gilles J Lavigne
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada.,Faculty of Dental Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Louis De Beaumont
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Department of Surgery, University of Montreal, Montreal, Quebec, Canada
| | - Dominique M Rouleau
- Montreal Sacré-Coeur Hospital, Montreal, Quebec, Canada.,Department of Surgery, University of Montreal, Montreal, Quebec, Canada
| |
Collapse
|
14
|
Depner CM, Rice JD, Tussey EJ, Eckel RH, Bergman BC, Higgins JA, Melanson EL, Kohrt WM, Wright KP, Swanson CM. Bone turnover marker responses to sleep restriction and weekend recovery sleep. Bone 2021; 152:116096. [PMID: 34216838 PMCID: PMC8316414 DOI: 10.1016/j.bone.2021.116096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/28/2021] [Accepted: 06/25/2021] [Indexed: 01/29/2023]
Abstract
BACKGROUND Prior data demonstrated three weeks of sleep restriction and concurrent circadian disruption uncoupled bone turnover markers (BTMs), indicating decreased bone formation and no change or increased bone resorption. The effect of insufficient sleep with or without ad libitum weekend recovery sleep on BTMs is unknown. METHODS BTMs were measured in stored serum from 20 healthy adults randomized to one of three study groups consisting of a control group (N = 3 men; 9 h/night) or one of two nocturnal sleep restriction groups in an inpatient laboratory environment. One Sleep Restriction group ("SR"; N = 9; 4 women) had 5 h sleep opportunity per night for nine nights. The other sleep restriction group had an opportunity for ad libitum Weekend Recovery sleep ("WR"; N = 8; 4 women) after four nights of 5 h sleep opportunity per night. Food intake was energy balanced at baseline and ad libitum thereafter. Fasted morning BTM levels and hourly 24 h melatonin levels were obtained on study days 3 (baseline), 5 (after 1 night of sleep restriction for WR and SR), and 11 (after a sleep restricted workweek with weekend recovery sleep in WR or 7 nights of sleep restriction in SR). Linear mixed-effects modeling was used to examine the effect of study duration (e.g., change over time), study condition, age, and sex on BTMs. Pearson correlations were used to determine associations between changes in BTMs and changes in weight and morning circadian misalignment (i.e., duration of high melatonin levels after wake time). RESULTS There was no significant difference between the three study groups in change over time (p ≥ 0.4 for interaction between assigned group and time for all BTMs), adjusted for age and sex. There was no significant change in N-terminal propeptide of procollagen type I (P1NP), osteocalcin, or C-telopeptide of type I collagen (CTX) from baseline to day 11 (all p ≥ 0.3). In women <25 years old, there was a non-significant decline in P1NP from day 3 to day 5 (= -15.74 ± 7.80 ng/mL; p = 0.06). Change in weight and morning circadian misalignment from baseline to day 11 were correlated with statistically non-significant changes in BTMs (all p ≤ 0.05). CONCLUSION In this small secondary analysis, we showed that nine nights of prescribed sleep restriction with or without weekend recovery sleep and ad libitum food intake did not alter BTMs. It is possible that age, sex, weight change and morning circadian misalignment modify the effects of sleep restriction on bone metabolism.
Collapse
Affiliation(s)
- Christopher M Depner
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA; Department of Health and Kinesiology, University of Utah, Salt Lake City, UT, USA
| | - John D Rice
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Aurora, CO, USA
| | - Emma J Tussey
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Robert H Eckel
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Bryan C Bergman
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Janine A Higgins
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Edward L Melanson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| | - Wendy M Kohrt
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado VA Geriatric, Research, Education, and Clinical Center (GRECC), Aurora, CO, USA
| | - Kenneth P Wright
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA; Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Christine M Swanson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
15
|
Winter EM, Kooijman S, Appelman-Dijkstra NM, Meijer OC, Rensen PC, Schilperoort M. Chronobiology and Chronotherapy of Osteoporosis. JBMR Plus 2021; 5:e10504. [PMID: 34693186 PMCID: PMC8520066 DOI: 10.1002/jbm4.10504] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/31/2021] [Accepted: 04/10/2021] [Indexed: 12/31/2022] Open
Abstract
Physiological circadian (ie, 24-hour) rhythms are critical for bone health. Animal studies have shown that genes involved in the intrinsic molecular clock demonstrate potent circadian expression patterns in bone and that genetic disruption of these clock genes results in a disturbed bone structure and quality. More importantly, circulating markers of bone remodeling show diurnal variation in mice as well as humans, and circadian disruption by, eg, working night shifts is associated with the bone remodeling disorder osteoporosis. In this review, we provide an overview of the current literature on rhythmic bone remodeling and its underlying mechanisms and identify critical knowledge gaps. In addition, we discuss novel (chrono)therapeutic strategies to reduce osteoporosis by utilizing our knowledge on circadian regulation of bone. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Elizabeth M Winter
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands.,Department of Medicine, Center for Bone Quality Leiden University Medical Center Leiden The Netherlands
| | - Sander Kooijman
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands
| | - Natasha M Appelman-Dijkstra
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands.,Department of Medicine, Center for Bone Quality Leiden University Medical Center Leiden The Netherlands
| | - Onno C Meijer
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands
| | - Patrick Cn Rensen
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands
| | - Maaike Schilperoort
- Department of Medicine, Division of Endocrinology Leiden University Medical Center Leiden The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine Leiden The Netherlands
| |
Collapse
|
16
|
Abstract
PURPOSE OF REVIEW This review briefly summarizes the growing body of literature addressing the skeletal consequences of sleep and circadian disruption. RECENT FINDINGS The most recent data in the field suggest that the diurnal variation in bone turnover markers are because of endogenous circadian rhythmicity linked to clock genes in all bone cells; in a small human intervention study, cumulative sleep restriction with concurrent circadian disruption negatively alter bone turnover markers in a way that could explain the lower BMD and increased fracture risk identified in some prior night shift work studies; abnormal sleep duration and obstructive sleep apnea are associated with low BMD and increased fracture risk in some but not all studies. SUMMARY Normal physiology and some animal and human intervention studies suggest that sleep and circadian disruptions, such as night shift work, abnormal sleep durations and obstructive sleep apnea are detrimental to skeletal health. However, additional research in this area is needed to determine which sleep/circadian disturbances are most detrimental to skeletal health, the reversibility of such impairments, and underlying mechanisms.
Collapse
Affiliation(s)
- Christine M Swanson
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
17
|
Hughes JM, O'Leary TJ, Koltun KJ, Greeves JP. Promoting adaptive bone formation to prevent stress fractures in military personnel. Eur J Sport Sci 2021; 22:4-15. [PMID: 34269162 DOI: 10.1080/17461391.2021.1949637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Mechanical loading leads to adaptive bone formation - the formation of new bone on existing skeletal surfaces - which increases bone strength and fatigue resistance. The same mechanical loading can also cause microdamage to bone and development of a stress fracture through targeted remodelling. Stress fractures are common in military recruits and cause significant morbidity, lost training time, and discharge from military service. This narrative review proposes strategies to promote adaptive bone formation as a novel approach to mitigate the risk of stress fracture injuries during arduous military training. Exercise that is unaccustomed, dynamic, high-impact, multidirectional, intermittent, and includes extended rest periods to restore bone mechanosensitivity, is most osteogenic. New bone formation can take up to one year to mineralize, and so new exercise training programmes should be initiated well in advance of military activities with high risk of stress fracture. Bone mechanosensitivity is highest in adolescence, before puberty, and so increasing physical activity in youth is likely to protect skeletal health in later life, including for those in the military. Recent data show that adaptive bone formation takes place during initial military training. Adaptive bone formation can also be supported with adequate sleep, vitamin D, calcium, and energy availability. Further evidence on how strategies to promote adaptive bone formation affect stress fracture risk are required. Adaptive bone formation can be optimized with a range of training and nutritional strategies to help create a resilient skeleton, which may protect against stress fracture throughout military service.
Collapse
Affiliation(s)
- Julie M Hughes
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, UK.,Division of Surgery and Interventional Science, University College London, London, UK
| | - Kristen J Koltun
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PN, USA
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, UK.,Division of Surgery and Interventional Science, University College London, London, UK.,Norwich Medical School, University of East Anglia, Norwich, UK
| |
Collapse
|