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Carrasco A, Navren M, Larsson I, Taube F, Björkman F. Systematic Review and Meta-Analysis: Iron Deficiency and Iron Deficiency Anemia Among Military Recruits Undergoing Basic Combat Training. Mil Med 2024:usae437. [PMID: 39301668 DOI: 10.1093/milmed/usae437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 08/12/2024] [Accepted: 09/02/2024] [Indexed: 09/22/2024] Open
Abstract
INTRODUCTION The first period of military service consists of a physically and mentally challenging basic combat training (BCT) program. Factors like demanding physical exercise, limited recovery time, and restricted diet choice and food intake may challenge iron intake and homeostasis in recruits undergoing BCT. Iron-deficient individuals may experience reduced work capacity, fatigue, weakness, frequent infections, and increased injury risk. Limited knowledge is available on the extent of this potential health risk among military recruits. The aim of the present study was to systematically review published studies on the prevalence and change in prevalence of anemia, iron deficiency (ID), and ID anemia (IDA) among recruits undergoing BCT. MATERIALS AND METHODS Electronic searches were conducted in the databases Medline (Ovid), Embase (Embase.com), and Web of Science (Clarivate Analytics) from database inception up until April 16, 2024. Inclusion criteria were observational studies with both cross-sectional and observational longitudinal designs that examined the effects of BCT (intervention) on iron status (outcome) in military recruits (population). Extracted data were the number of participants (n), age, sex, country/population, BCT duration, and relevant measures of prevalence and changes in prevalence of anemia, ID, and IDA (primary outcome) and physical performance, mood state, stress fractures, attrition rate, and nutritional supplements (secondary outcomes). The study quality and risk of bias were assessed using the JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data and The National Institutes of Health Quality Assessment Tool for Before-After (Pre-Post) Studies With No Control Group. Meta-analyses were performed using restricted maximum-likelihood models, and the effect size was calculated as Cohen's h with 95% CI. RESULTS Twenty-two articles were systematically reviewed (n = 111,764 men and 12,650 women), and six of these papers (n = 388 men and 773 women) were included in the meta-analysis. There was a varying prevalence of anemia, ID, and IDA among military recruits at the start of BCT. Results from meta-analyses showed negligible and nonsignificant effects of BCT on the prevalence of anemia, ID, and IDA. The quality of the included cross-sectional studies ranging from fair to good, whereas a large proportion of the included longitudinal studies were classified as poor. No sign of publication bias was found. CONCLUSIONS The prevalence of anemia, ID, and IDA in military recruits seems not to be affected by the completion of BCT shorter than 16 weeks, whereas the effects of longer BCT durations remain unclear. Even though body iron homeostasis seems unaffected, adequate energy and nutritional intake should remain a priority. Future research could focus on dietary interventions to determine the optimal diet among female recruits in specifically exposed populations.
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Affiliation(s)
- Anna Carrasco
- Department of Medicine, Center for Infectious Medicine, Karolinska Institute, Stockholm 171 77, Sweden
| | - Mats Navren
- Defence Health, Command and Control Regiment, Enkoping 749 40, Sweden
| | - Ingrid Larsson
- Department of Medicine, Sahlgrenska University Hospital, Gothenburg 413 41, Sweden
- Institute of Medicine, Sahlgrenska Academy, Gothenburg University, Gothenburg 405 30, Sweden
| | - Fabian Taube
- Research Centre for Disaster Medicine, Institute for Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg 405 30, Sweden
- Joint Centre for Defence Medicine, Swedish Armed Forces, Gothenburg 426 05, Sweden
| | - Frida Björkman
- Department of Physical Activity and Health, The Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
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Angelidi AM, Stefanakis K, Chou SH, Valenzuela-Vallejo L, Dipla K, Boutari C, Ntoskas K, Tokmakidis P, Kokkinos A, Goulis DG, Papadaki HA, Mantzoros CS. Relative Energy Deficiency in Sport (REDs): Endocrine Manifestations, Pathophysiology and Treatments. Endocr Rev 2024; 45:676-708. [PMID: 38488566 DOI: 10.1210/endrev/bnae011] [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: 11/17/2023] [Indexed: 09/18/2024]
Abstract
Research on lean, energy-deficient athletic and military cohorts has broadened the concept of the Female Athlete Triad into the Relative Energy Deficiency in Sport (REDs) syndrome. REDs represents a spectrum of abnormalities induced by low energy availability (LEA), which serves as the underlying cause of all symptoms described within the REDs concept, affecting exercising populations of either biological sex. Both short- and long-term LEA, in conjunction with other moderating factors, may produce a multitude of maladaptive changes that impair various physiological systems and adversely affect health, well-being, and sport performance. Consequently, the comprehensive definition of REDs encompasses a broad spectrum of physiological sequelae and adverse clinical outcomes related to LEA, such as neuroendocrine, bone, immune, and hematological effects, ultimately resulting in compromised health and performance. In this review, we discuss the pathophysiology of REDs and associated disorders. We briefly examine current treatment recommendations for REDs, primarily focusing on nonpharmacological, behavioral, and lifestyle modifications that target its underlying cause-energy deficit. We also discuss treatment approaches aimed at managing symptoms, such as menstrual dysfunction and bone stress injuries, and explore potential novel treatments that target the underlying physiology, emphasizing the roles of leptin and the activin-follistatin-inhibin axis, the roles of which remain to be fully elucidated, in the pathophysiology and management of REDs. In the near future, novel therapies leveraging our emerging understanding of molecules and physiological axes underlying energy availability or lack thereof may restore LEA-related abnormalities, thus preventing and/or treating REDs-related health complications, such as stress fractures, and improving performance.
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Affiliation(s)
- Angeliki M Angelidi
- Department of Medicine, Boston VA Healthcare System, Boston, MA 02115, USA
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Konstantinos Stefanakis
- Department of Medicine, Boston VA Healthcare System, Boston, MA 02115, USA
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- First Propaedeutic Department of Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, Athens 11527, Greece
- Department of Internal Medicine, 251 Air Force General Hospital, Athens 11525, Greece
| | - Sharon H Chou
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital (BWH), Harvard Medical School, Boston, MA 02115, USA
| | - Laura Valenzuela-Vallejo
- Department of Medicine, Boston VA Healthcare System, Boston, MA 02115, USA
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Konstantina Dipla
- Exercise Physiology and Biochemistry Laboratory, Department of Sports Science at Serres, Aristotle University of Thessaloniki, Serres 62100, Greece
| | - Chrysoula Boutari
- Second Propaedeutic Department of Internal Medicine, Hippokration Hospital, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 54642, Greece
| | - Konstantinos Ntoskas
- Department of Internal Medicine, 251 Air Force General Hospital, Athens 11525, Greece
| | - Panagiotis Tokmakidis
- First Propaedeutic Department of Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, Athens 11527, Greece
- Department of Internal Medicine, 251 Air Force General Hospital, Athens 11525, Greece
| | - Alexander Kokkinos
- First Propaedeutic Department of Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, Athens 11527, Greece
| | - Dimitrios G Goulis
- Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Helen A Papadaki
- Department of Hematology, University Hospital of Heraklion, School of Medicine, University of Crete, Heraklion 71500, Greece
| | - Christos S Mantzoros
- Department of Medicine, Boston VA Healthcare System, Boston, MA 02115, USA
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital (BWH), Harvard Medical School, Boston, MA 02115, USA
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Drummer DJ, McNiff JL, Howard EE, Gwin JA, Carrigan CT, Murphy NE, Wilson MA, Michalak J, Ryan BJ, McClung JP, Pasiakos SM, Margolis LM. Exogenous erythropoietin increases hematological status, fat oxidation, and aerobic performance in males following prolonged strenuous training. Physiol Rep 2024; 12:e16038. [PMID: 38757249 PMCID: PMC11099744 DOI: 10.14814/phy2.16038] [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: 03/18/2024] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 05/18/2024] Open
Abstract
This study investigated the effects of EPO on hemoglobin (Hgb) and hematocrit (Hct), time trial (TT) performance, substrate oxidation, and skeletal muscle phenotype throughout 28 days of strenuous exercise. Eight males completed this longitudinal controlled exercise and feeding study using EPO (50 IU/kg body mass) 3×/week for 28 days. Hgb, Hct, and TT performance were assessed PRE and on Days 7, 14, 21, and 27 of EPO. Rested/fasted muscle obtained PRE and POST EPO were analyzed for gene expression, protein signaling, fiber type, and capillarization. Substrate oxidation and glucose turnover were assessed during 90-min of treadmill load carriage (LC; 30% body mass; 55 ± 5% V̇O2peak) exercise using indirect calorimetry, and 6-6-[2H2]-glucose PRE and POST. Hgb and Hct increased, and TT performance improved on Days 21 and 27 compared to PRE (p < 0.05). Energy expenditure, fat oxidation, and metabolic clearance rate during LC increased (p < 0.05) from PRE to POST. Myofiber type, protein markers of mitochondrial biogenesis, and capillarization were unchanged PRE to POST. Transcriptional regulation of mitochondrial activity and fat metabolism increased from PRE to POST (p < 0.05). These data indicate EPO administration during 28 days of strenuous exercise can enhance aerobic performance through improved oxygen carrying capacity, whole-body and skeletal muscle fat metabolism.
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Affiliation(s)
- Devin J. Drummer
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
| | - Julie L. McNiff
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Combat Feeding DivisionU.S. Army Combat Capabilities Development Command (DEVCOM)NatickMassachusettsUSA
| | - Emily E. Howard
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Jess A. Gwin
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Christopher T. Carrigan
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Nancy E. Murphy
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Marques A. Wilson
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Julia Michalak
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
| | - Benjamin J. Ryan
- Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - James P. McClung
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stefan M. Pasiakos
- Office of Dietary Supplements, National Institutes of HealthU.S. Department of Health and Human ServicesBethesdaMarylandUSA
| | - Lee M. Margolis
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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Taube F, Larsson I, Navren M, Ekblom Ö. Changes in haemoglobin and ferritin levels during basic combat training: relevance for attrition and injury frequency. BMJ Mil Health 2024:e002656. [PMID: 38688678 DOI: 10.1136/military-2023-002656] [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: 12/20/2023] [Accepted: 03/30/2024] [Indexed: 05/02/2024]
Abstract
INTRODUCTION The primary aim of the present study was to assess interindividual and intraindividual variations in haemoglobin and ferritin concentrations in Swedish recruits over 5 months of basic combat training (BCT). The secondary aim was to find predictors for missing training (a precursor for attrition) and overuse injuries during BCT. METHODS In a cohort design, a total of 58 female and 104 male recruits provided complete data. We assessed the ferritin concentrations and haemoglobin concentrations at baseline and after 5 months of BCT and physical work capacity at baseline. RESULTS During BCT, haemoglobin concentrations increased significantly in both females and males. Ferritin concentrations decreased significantly in both sexes and the prevalence of iron deficiency (ID) (ie, ferritin levels <30 µg/L) increased significantly in females. The physical work capacity at baseline was related to the risk of missing training in fully adjusted models. In gender-adjusted analyses, baseline ferritin was related to the risk of overuse injury, but neither baseline nor change in iron status was related to injuries or risk of missing training when controlling for confounders. Body mass increased significantly in both genders, but we found no correlation between individual change in body mass and change in haemoglobin or ferritin nor was change in body mass related to the risk of overuse injury or missing training. CONCLUSION In the present study, the prevalence of ID increased over the course of 5 months, while haemoglobin concentrations increased. As baseline physical work capacity was related to missing training, there are reasons to support preparatory physical training before BCT. These findings may inform future preventive interventions aimed at preventing detrimental effects of ID.
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Affiliation(s)
- Fabian Taube
- Research Centre for Disaster Medicine, Institute for Clinical Sciences, Sahlgrenska Academy, Goteborg, Sweden
- Joint Centre for Defence Medicine, Swedish Armed Forces Göta Älvsgatan 426 05, Gothenburg, Sweden
| | - I Larsson
- Unit of Clinical Nutrition, Regional Obesity Centre, Sahlgrenska University Hospital, Blå Stråket 5, 413 4, Gothenburg, Sweden
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - M Navren
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Defence Health, Command and Control Regiment, Enköping, Enköping, Sweden
| | - Ö Ekblom
- Department of Physical Activity and Health, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Neurobiology, Care Sciences and Society, Division of Nursin, Karolinska Institutet, Stockholm, Sweden
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Hatch-McChesney A, Smith TJ. Nutrition, Immune Function, and Infectious Disease in Military Personnel: A Narrative Review. Nutrients 2023; 15:4999. [PMID: 38068857 PMCID: PMC10708187 DOI: 10.3390/nu15234999] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Consuming a diet that meets energy demands and provides essential nutrients promotes a healthy immune system, while both under- and over-nutrition have been associated with immune dysfunction. Military personnel comprise a unique population who frequently endure multi-stressor environments, predisposing them to immune decrements. Additionally, 49% and 22% of active duty U.S. military personnel are classified as overweight and obese, respectively. A literature search on PubMed was conducted to identify studies, reports, review papers, and references within those sources relevant to the topic area. Military personnel experiencing either under- or over-nutrition can suffer from degraded health, readiness, and performance. Insufficient intake of nutrients during military operations increases infection risk and negatively impacts infection recovery. Energy, protein, iron, zinc, and vitamins C and D are nutritional areas of concern that may impact immune competence in a multi-stressor environment. Over-nutrition can promote accretion of excess body fat and obesity, which contributes to a chronic inflammatory state that coincides with immune impairments. Prioritizing efforts to optimize nutrient intake is one approach for reducing disease burden and improving readiness. This review discusses nutritional concerns concomitant to multi-stressor environments that impact immune function, and the relevance of obesity to infectious disease risk in the military population.
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Affiliation(s)
| | - Tracey J. Smith
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Natick, MA 01760, USA;
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Celis AI, Relman DA, Huang KC. The impact of iron and heme availability on the healthy human gut microbiome in vivo and in vitro. Cell Chem Biol 2023; 30:110-126.e3. [PMID: 36603582 PMCID: PMC9913275 DOI: 10.1016/j.chembiol.2022.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 07/12/2022] [Accepted: 12/14/2022] [Indexed: 01/06/2023]
Abstract
Responses of the indigenous human gut commensal microbiota to iron are poorly understood because of an emphasis on in vitro studies of pathogen iron sensitivity. In a study of iron supplementation in healthy humans, we identified gradual microbiota shifts in some participants correlated with bacterial iron internalization. To identify direct effects due to taxon-specific iron sensitivity, we used participant stool samples to derive diverse in vitro communities. Iron supplementation of these communities caused small compositional shifts, mimicking those in vivo, whereas iron deprivation dramatically inhibited growth with irreversible, cumulative reduction in diversity and replacement of dominant species. Sensitivity of individual species to iron deprivation in axenic culture generally predicted iron dependency in a community. Finally, exogenous heme acted as a source of inorganic iron to prevent depletion of some species. Our results highlight the complementarity of in vivo and in vitro studies in understanding how environmental factors affect gut microbiotas.
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Affiliation(s)
- Arianna I Celis
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David A Relman
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Infectious Diseases Section, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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Raz S, Koren A, Levin C. Associations between red blood cell indices and iron status and neurocognitive function in young adults: Evidence from memory and executive function tests and event-related potentials. Ann N Y Acad Sci 2022; 1517:300-313. [PMID: 35976740 PMCID: PMC9804398 DOI: 10.1111/nyas.14877] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cognitive impairment has been associated with anemia and iron deficiency; however, brain electrophysiological studies correlating red blood cell (RBC) indices and iron status to cognition in adulthood are scarce. We aimed to assess neurocognitive function in young adults of the general population and its correlation with RBC indices and iron status. Neurocognitive function was investigated using scalp-recorded event-related potentials (ERPs) within the context of a task-switching paradigm. ERPs and test performance were also compared across groups of "high"/"low" RBC and iron indices. Working memory was examined using the digit span test, in which mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), and ferritin were found to be significant predictors of test performance, with higher MCH/MCV/ferritin being associated with better test scores. In the switching task, MCH, MCV, and ferritin were found to be significant predictors of task performance, with higher MCH/MCV/ferritin levels associated with a lower percentage of errors. Electrophysiological results showed that MCH and MCV were significant predictors of ERPs amplitude, with lower MCH/MCV levels associated with greater amplitude, which may reflect compensatory processes. P1, N1, P2, and P3 were greater for the low MCH/MCV groups. This is the first evidence of association between levels of MCH/MCV and brain function while engaged in an executive function task; possibly reflecting brain iron availability.
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Affiliation(s)
- Sivan Raz
- Department of Behavioral Sciences, The Center for Psychobiological ResearchThe Max Stern Yezreel Valley CollegeJezreel ValleyIsrael,Department of PsychologyTel Hai CollegeTel HaiIsrael
| | - Ariel Koren
- Pediatric Hematology UnitEmek Medical CenterAfulaIsrael,The Ruth and Bruce Rappaport Faculty of Medicine, TechnionIsrael Institute of TechnologyHaifaIsrael
| | - Carina Levin
- Pediatric Hematology UnitEmek Medical CenterAfulaIsrael,The Ruth and Bruce Rappaport Faculty of Medicine, TechnionIsrael Institute of TechnologyHaifaIsrael
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Knapik JJ, Farina EK, Fulgoni VL, Lieberman HR. Clinically diagnosed iron and iodine deficiencies and disorders in the entire population of US military service members from 1997 to 2015. Public Health Nutr 2021; 24:3187-3195. [PMID: 33541462 PMCID: PMC8314918 DOI: 10.1017/s1368980021000495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/24/2020] [Accepted: 02/01/2021] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Iron and/or iodine deficiencies can have multiple serious adverse health outcomes, but examination of incidence rates of these deficiencies has rarely been conducted in any large population. This study examined incidence rates, temporal trends and demographic factors associated with medically diagnosed iron and iodine deficiencies/disorders in US military service members (SM). DESIGN The Defense Medical Epidemiological Database (DMED) was queried for medical visits of active duty SM to obtain specific International Classification of Diseases, Version 9, codes involving clinically diagnosed iron and iodine deficiencies/disorders. SETTING Analysis of existing database (DMED). PARTICIPANTS Entire population of US military SM from 1997 to 2015 (average n per year = 1 382 266, 15 % women). RESULTS Overall incidence rates for iron and iodine were 104 and 36 cases/100 000 person-years, respectively. Over the 19-year period, rates for iron disorders increased steadily (108 % for men, 177 % for women). Rates for iodine disorders also increased steadily for men (91 %), but, for women, there was an initial rise followed by a later decline. Overall, women's rates were 12 and 10 times higher than men's for iron and iodine, respectively. Compared with whites, blacks and those of other races had higher rates of deficiencies of both minerals. Incidence rates for iodine deficiency increased substantially with age. CONCLUSIONS The overall incidence of clinically diagnosed iron and iodine deficiency among SM was low, but increased over the 19 years examined, and certain demographic groups were at significantly greater risk. Given the unexpected increases in incidence of these mineral disorders, increased surveillance may be appropriate.Clinical Trial Registration No. ISRCTN58987177 (http//:www.isrctn.com/ISRCTN58987177).
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Affiliation(s)
- Joseph J Knapik
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA01760, USA
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Emily K Farina
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA01760, USA
| | - Victor L Fulgoni
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA01760, USA
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA01760, USA
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O'Leary TJ, Wardle SL, Greeves JP. Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military. Front Nutr 2020; 7:142. [PMID: 32984399 PMCID: PMC7477333 DOI: 10.3389/fnut.2020.00142] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/15/2022] Open
Abstract
Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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Alexandre L, Manning C, Chan SSM. Prevalence of gastrointestinal malignancy in iron deficiency without anaemia: A systematic review and meta-analysis. Eur J Intern Med 2020; 72:27-33. [PMID: 31932190 DOI: 10.1016/j.ejim.2019.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 12/14/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Iron deficiency anaemia is associated with gastrointestinal (GI) malignancy and is an indication for GI investigations. However, the relevance of iron deficiency without anaemia (IDWA) and the underlying risks of GI malignancy are uncertain. Therefore, the aim of this study was to estimate the prevalence of GI malignancy in patients with IDWA overall and in clinically relevant subgroups. METHODS We searched MEDLINE and EMBASE for studies that reported on the prevalence or risk of GI malignancy in patients with confirmed IDWA. We performed a random effects meta-analysis of proportions and assessed statistical heterogeneity using the I2 statistic. RESULTS A total of 1923 citations were screened and 5 studies (4 retrospective cohorts, 1 prospective cohort) comprising 3329 participants with IDWA were included in the meta-analysis. Overall pooled random-effects estimates for prevalence of GI malignancy in those with IDWA were low (0.38%, 95% CI 0.00%-1.84%, I2 = 87.7%). Older patients (2.58%, 95% CI 0.00%-8.77%); non-screening populations (2.45%, 95% CI 0.16%-6.39%) and men and post-menopausal women (0.90%, 95% CI 0.11%-3.23%) with IDWA were at increased risk of GI malignancy compared to younger patients (0.00%, 95% CI 0.00%-0.21%); screened populations (0.24%, 95% CI 0.00%-1.10%) and pre-menopausal women (0.00%, 95% CI 0.00%-1.05%). CONCLUSION Overall, IDWA is associated with a low risk of GI malignancy. Older patients and non-screening populations are at elevated risk and require GI investigations. Those not in these subgroups have a lower risk of GI malignancy and may wish to be monitored following discussion of the risk and potential benefits of GI investigations.
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Affiliation(s)
- Leo Alexandre
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK; Department of Gastroenterology, Norfolk and Norwich University Hospital, Norwich NR4 7UY, UK
| | - Charelle Manning
- Department of Gastroenterology, Norfolk and Norwich University Hospital, Norwich NR4 7UY, UK
| | - Simon S M Chan
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK; Department of Gastroenterology, Norfolk and Norwich University Hospital, Norwich NR4 7UY, UK.
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11
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Association between mild anemia and physical fitness in a military male cohort: The CHIEF study. Sci Rep 2019; 9:11165. [PMID: 31371766 PMCID: PMC6671998 DOI: 10.1038/s41598-019-47625-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 07/22/2019] [Indexed: 12/15/2022] Open
Abstract
Anemia defined as reduced hemoglobin levels of red blood cells may carry less oxygen to skeletal muscle and impair physical performance. Previous studies have shown that exercise intolerance was related to moderate or severe anemia, however, the relationship to mild anemia was unknown. We investigated the cross-sectional association of mild anemia defined as a hemoglobin level of 10.0-13.9 g/dL with physical fitness in 3,666 military young males in Taiwan in 2014. Aerobic fitness was evaluated by 3000-meter run test, and anaerobic fitness was evaluated by 2-minute sit-ups and 2-minute push-ups, respectively. Multiple logistic regressions for the best 10% and the worst 10% performers were used to determine the relationship. There were 343 mild anemic males in whom 47.8% were microcytic anemia and 3,323 non-anemic males for the analysis. The multiple logistic regression shows that as compared with non-anemic males, mild anemic males were more likely to be the worst 10% performers in the 3000-meter run test (odds ratios (OR) and 95% confidence intervals: 1.47, 1.01-2.14) after adjusting for age, service specialty, body mass index, waist size, mean blood pressure, unhealthy behaviors, lipid profiles, and exercise frequency. On the contrary, mild anemic males had higher possibility to be the best 10% performers in the 2-minute push-ups test (OR: 1.48, 1.08-2.04). However, there was no association between mild anemia and 2-minute sit-ups. Our findings suggest that unspecified mild anemia might be associated with lower cardiorespiratory fitness but not with anaerobic fitness in physically active military males.
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Merkel D, Moran DS. Coping with Iron Deficiency and Iron Deficiency Anemia in Combat Recruits. Acta Haematol 2019; 139:166-167. [PMID: 29597195 DOI: 10.1159/000487387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 02/02/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Drorit Merkel
- Division of Hematology, Chaim Sheba Medical Center, Tel Hashomer affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Burden RJ, Pedlar CR. Understanding Iron Deficiency and Exercise: Looking Beyond Ferritin. Acta Haematol 2018; 139:183-184. [PMID: 29621767 DOI: 10.1159/000487583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 02/09/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Richard J Burden
- St Mary's University, Twickenham, United Kingdom
- English Institute of Sport, Manchester, United Kingdom
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