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Packer M, Anker SD, Butler J, Cleland JG, Kalra PR, Mentz RJ, Ponikowski P, Talha KM. Redefining Iron Deficiency in Patients With Chronic Heart Failure. Circulation 2024; 150:151-161. [PMID: 38733252 PMCID: PMC11224570 DOI: 10.1161/circulationaha.124.068883] [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: 01/24/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024]
Abstract
A serum ferritin level <15 to 20 μg/L historically identified patients who had absent bone marrow iron stores, but serum ferritin levels are distorted by the systemic inflammatory states seen in patients with chronic kidney disease or heart failure. As a result, nearly 25 years ago, the diagnostic ferritin threshold was increased 5- to 20-fold in patients with chronic kidney disease (ie, iron deficiency was identified if the serum ferritin level was <100 μg/L, regardless of transferrin saturation [TSAT], or 100 to 299 μg/L if TSAT was <20%). This guidance was motivated not by the findings of studies of total body or tissue iron depletion, but by a desire to encourage the use of iron supplements to potentiate the response to erythropoiesis-stimulating agents in patients with renal anemia. However, in patients with heart failure, this definition does not reliably identify patients with an absolute or functional iron-deficiency state, and it includes individuals with TSATs (≥20%) and serum ferritin levels in the normal range (20-100 mg/L) who are not iron deficient, have an excellent prognosis, and do not respond favorably to iron therapy. Furthermore, serum ferritin levels may be distorted by the use of both neprilysin and sodium-glucose cotransporter 2 inhibitors, both of which may act to mobilize endogenous iron stores. The most evidence-based and trial-tested definition of iron deficiency is the presence of hypoferremia, as reflected by as a TSAT <20%. These hypoferremic patients are generally iron deficient on bone marrow examination, and after intravenous iron therapy, they exhibit an improvement in exercise tolerance and functional capacity (when meaningfully impaired) and show the most marked reduction (ie, 20%-30%) in the risk of cardiovascular death or total heart failure hospitalizations. Therefore, we propose that the current ferritin-driven definition of iron deficiency in heart failure should be abandoned and that a definition based on hypoferremia (TSAT <20%) should be adopted.
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Affiliation(s)
- Milton Packer
- Baylor University Medical Center (M.P.), Dallas, TX
- Imperial College, London, UK (M.P.)
| | - Stefan D. Anker
- Department of Cardiology, German Heart Center Charité, Institute of Health Center for Regenerative Therapies, German Centre for Cardiovascular Research, partner site Berlin, Charité Universitätsmedizin, Berlin, Germany (S.D.A.)
| | - Javed Butler
- Baylor Scott and White Research Institute (J.B.), Dallas, TX
- Baylor University Medical Center (M.P.), Dallas, TX
- University of Mississippi Medical Center, Jackson (J.B., K.M.T.)
| | - John G.F. Cleland
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Health (J.G.F.C.), University of Glasgow, UK
| | - Paul R. Kalra
- College of Medical, Veterinary & Life Sciences (P.R.K.), University of Glasgow, UK
- Department of Cardiology, Portsmouth Hospitals University NHS Trust, Portsmouth, UK (P.R.K.)
- Faculty of Science and Health, University of Portsmouth, UK (P.R.K.)
| | - Robert J. Mentz
- Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, NC (R.J.M.)
- Duke Clinical Research Institute, Durham, NC (R.J.M.)
| | - Piotr Ponikowski
- Institute of Heart Diseases, Wroclaw Medical University, Poland (P.P.)
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland (P.P.)
| | - Khawaja M. Talha
- University of Mississippi Medical Center, Jackson (J.B., K.M.T.)
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Packer M, Anker SD, Butler J, Cleland JGF, Kalra PR, Mentz RJ, Ponikowski P. Identification of three mechanistic pathways for iron-deficient heart failure. Eur Heart J 2024; 45:2281-2293. [PMID: 38733250 PMCID: PMC11231948 DOI: 10.1093/eurheartj/ehae284] [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: 11/13/2023] [Revised: 02/29/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Current understanding of iron-deficient heart failure is based on blood tests that are thought to reflect systemic iron stores, but the available evidence suggests greater complexity. The entry and egress of circulating iron is controlled by erythroblasts, which (in severe iron deficiency) will sacrifice erythropoiesis to supply iron to other organs, e.g. the heart. Marked hypoferraemia (typically with anaemia) can drive the depletion of cardiomyocyte iron, impairing contractile performance and explaining why a transferrin saturation < ≈15%-16% predicts the ability of intravenous iron to reduce the risk of major heart failure events in long-term trials (Type 1 iron-deficient heart failure). However, heart failure may be accompanied by intracellular iron depletion within skeletal muscle and cardiomyocytes, which is disproportionate to the findings of systemic iron biomarkers. Inflammation- and deconditioning-mediated skeletal muscle dysfunction-a primary cause of dyspnoea and exercise intolerance in patients with heart failure-is accompanied by intracellular skeletal myocyte iron depletion, which can be exacerbated by even mild hypoferraemia, explaining why symptoms and functional capacity improve following intravenous iron, regardless of baseline haemoglobin or changes in haemoglobin (Type 2 iron-deficient heart failure). Additionally, patients with advanced heart failure show myocardial iron depletion due to both diminished entry into and enhanced egress of iron from the myocardium; the changes in iron proteins in the cardiomyocytes of these patients are opposite to those expected from systemic iron deficiency. Nevertheless, iron supplementation can prevent ventricular remodelling and cardiomyopathy produced by experimental injury in the absence of systemic iron deficiency (Type 3 iron-deficient heart failure). These observations, taken collectively, support the possibility of three different mechanistic pathways for the development of iron-deficient heart failure: one that is driven through systemic iron depletion and impaired erythropoiesis and two that are characterized by disproportionate depletion of intracellular iron in skeletal and cardiac muscle. These mechanisms are not mutually exclusive, and all pathways may be operative at the same time or may occur sequentially in the same patients.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 North Hall Street, Dallas, TX 75226, USA
- Imperial College, London, UK
| | - Stefan D Anker
- Department of Cardiology of German Heart Center Charité, Institute of Health Center for Regenerative Therapies, German Centre for Cardiovascular Research, partner site Berlin, Charité Universitätsmedizin, Berlin, Germany
| | - Javed Butler
- Baylor Scott and White Research Institute, Baylor University Medical Center, Dallas, TX, USA
- University of Mississippi Medical Center, Jackson, MS, USA
| | - John G F Cleland
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK
| | - Paul R Kalra
- Department of Cardiology, Portsmouth Hospitals University NHS Trust, Portsmouth, UK
- College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
- Faculty of Science and Health, University of Portsmouth, Portsmouth, UK
| | - Robert J Mentz
- Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- Duke Clinical Research Institute, Durham, NC, USA
| | - Piotr Ponikowski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland
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Yan Y, Zhang W, Wang Y, Yi C, Yu B, Pang X, Li K, Li H, Dai Y. Crosstalk between intestinal flora and human iron metabolism: the role in metabolic syndrome-related comorbidities and its potential clinical application. Microbiol Res 2024; 282:127667. [PMID: 38442456 DOI: 10.1016/j.micres.2024.127667] [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: 11/21/2023] [Revised: 01/31/2024] [Accepted: 02/25/2024] [Indexed: 03/07/2024]
Abstract
The interaction of iron and intestinal flora, both of which play crucial roles in many physiologic processes, is involved in the development of Metabolic syndrome (MetS). MetS is a pathologic condition represented by insulin resistance, obesity, dyslipidemia, and hypertension. MetS-related comorbidities including type 2 diabetes mellitus (T2DM), obesity, metabolism-related fatty liver (MAFLD), hypertension polycystic ovary syndrome (PCOS), and so forth. In this review, we examine the interplay between intestinal flora and human iron metabolism and its underlying mechanism in the pathogenesis of MetS-related comorbidities. The composition and metabolites of intestinal flora regulate the level of human iron by modulating intestinal iron absorption, the factors associated with iron metabolism. On the other hand, the iron level also affects the abundance, composition, and metabolism of intestinal flora. The crosstalk between these factors is of significant importance in human metabolism and exerts varying degrees of influence on the manifestation and progression of MetS-related comorbidities. The findings derived from these studies can enhance our comprehension of the interplay between intestinal flora and iron metabolism, and open up novel potential therapeutic approaches toward MetS-related comorbidities.
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Affiliation(s)
- Yijing Yan
- School of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Wenlan Zhang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yulin Wang
- School of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Chunmei Yi
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Bin Yu
- School of Medical Technology, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Xiaoli Pang
- School of Nursing, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Kunyang Li
- School of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - HuHu Li
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
| | - Yongna Dai
- School of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
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Wang R, Liu Y, Thabane L, Olier I, Li L, Ortega-Martorell S, Lip GYH, Li G. Relationship between trajectories of dietary iron intake and risk of type 2 diabetes mellitus: evidence from a prospective cohort study. Nutr J 2024; 23:15. [PMID: 38302934 PMCID: PMC10835921 DOI: 10.1186/s12937-024-00925-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/30/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND The association between dietary iron intake and the risk of type 2 diabetes mellitus (T2DM) remains inconsistent. In this study, we aimed to investigate the relationship between trajectories of dietary iron intake and risk of T2DM. METHODS This study comprised a total of 61,115 participants without a prior T2DM from the UK Biobank database. We used the group-based trajectory model (GBTM) to identify different dietary iron intake trajectories. Cox proportional hazards models were used to evaluate the relationship between trajectories of dietary iron intake and risk of T2DM. RESULTS During a mean follow-up of 4.8 years, a total of 677 T2DM events were observed. Four trajectory groups of dietary iron intake were characterized by the GBTM: trajectory group 1 (with a mean dietary iron intake of 10.9 mg/day), 2 (12.3 mg/day), 3 (14.1 mg/day) and 4 (17.6 mg/day). Trajectory group 3 was significantly associated with a 38% decreased risk of T2DM when compared with trajectory group 1 (hazard ratio [HR] = 0.62, 95% confidence interval [CI]: 0.49-0.79), while group 4 was significantly related with a 30% risk reduction (HR = 0.70, 95% CI: 0.54-0.91). Significant effect modifications by obesity (p = 0.04) and history of cardiovascular disease (p < 0.01) were found to the relationship between trajectories of dietary iron intake and the risk of T2DM. CONCLUSIONS We found that trajectories of dietary iron intake were significantly associated with the risk of T2DM, where the lowest T2DM risk was observed in trajectory group 3 with a mean iron intake of 14.1 mg/day. These findings may highlight the importance of adequate dietary iron intake to the T2DM prevention from a public health perspective. Further studies to assess the relationship between dietary iron intake and risk of T2DM are needed, as well as intervention studies to mitigate the risks of T2DM associated with dietary iron changes.
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Affiliation(s)
- Ruoting Wang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, China
| | - Yingxin Liu
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, China
| | - Lehana Thabane
- Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St West, Hamilton, ON, L8S 4L8, Canada
| | - Ivan Olier
- Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool John Moores University and Liverpool Heart & Chest Hospital, Liverpool, UK
- School of Computer Science and Mathematics, Liverpool John Moores University, Liverpool, UK
| | - Likang Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, China
| | - Sandra Ortega-Martorell
- Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool John Moores University and Liverpool Heart & Chest Hospital, Liverpool, UK
- School of Computer Science and Mathematics, Liverpool John Moores University, Liverpool, UK
| | - Gregory Y H Lip
- Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool John Moores University and Liverpool Heart & Chest Hospital, Liverpool, UK
- Danish Center for Health Services Research, Aalborg University, Aalborg, Denmark
| | - Guowei Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, China.
- Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St West, Hamilton, ON, L8S 4L8, Canada.
- Father Sean O'Sullivan Research Centre, St Joseph's Healthcare Hamilton, 50 Charlton Ave E, Hamilton, ON, L8N 4A6, Canada.
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Wai KM, Akuzawa R, Umeda Y, Munakata W, Takahashi Y, Nakaji S, Ihara K. Effects of body compositions on the associations between ferritin and diabetes parameters among Japanese community dwellers. J Trace Elem Med Biol 2023; 78:127174. [PMID: 37080017 DOI: 10.1016/j.jtemb.2023.127174] [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: 11/17/2022] [Revised: 03/22/2023] [Accepted: 04/05/2023] [Indexed: 04/22/2023]
Abstract
BACKGROUND Ferritin is associated with an increased prevalence of diabetes mellitus. Moreover, the ferritin levels differ across the body compositions. Although there were studies reporting the association of ferritin and diabetes, the alteration in ferritin-diabetes association by body composition differences is rarely explained. Thus, the aim of this study is to identify the effects of body compositions on the association between ferritin and diabetes parameters among the Japanese population. METHODS This study analyzed the data of a cross-sectional study with 1065 subjects aged over 19 years in the Iwaki area, Japan. Independent variables were ferritin and body compositions, while dependent variables were blood sugar, HbA1c, and diabetes mellitus. Correlations between serum ferritin and blood sugar and HbA1c were analyzed using Spearman's Rank Correlation. Multivariate linear or logistic regressions were used to investigate the effects of body compositions (body fat percentage, muscle mass, or visceral fat level) on the ferritin-diabetes associations by adjusting the confounders. RESULTS There were significant positive correlations between ferritin and blood sugar in both sexes (p < 0.05), while a significant correlation between ferritin and HbA1c was found only in females (p < 0.001). Higher ferritin was significantly associated with an increase in blood sugar in individuals with normal body fat percentage (lowest vs. highest quartile group, coefficient=5.07, 95 % confidence intervals [CI]: 1.48-8.65), normal visceral fat level (lowest vs. highest quartile group, coefficient=4.84, 95 % CI: 1.74-7.94), and very high muscle mass (lowest vs. highest quartile group, coefficient=14.14, 95 % CI: 5.00-23.29). CONCLUSIONS By our study findings, individuals' body composition notably influenced the associations of serum ferritin and diabetes parameters, and the association was attenuated in obese individuals.
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Affiliation(s)
- Kyi Mar Wai
- Department of Social Medicine, Graduate School of Medicine, Hirosaki University, Japan.
| | - Rei Akuzawa
- School of Medicine, Hirosaki University, Japan
| | - Yoko Umeda
- Department of Social Medicine, Graduate School of Medicine, Hirosaki University, Japan
| | - Wataru Munakata
- Department of Hematology, National Cancer Center Hospital, Japan
| | - Yoshiko Takahashi
- Center of Innovation, Research Initiatives Organization, Hirosaki University, Japan
| | - Shigeyuki Nakaji
- Department of Social Medicine, Graduate School of Medicine, Hirosaki University, Japan; Center of Innovation, Research Initiatives Organization, Hirosaki University, Japan
| | - Kazushige Ihara
- Department of Social Medicine, Graduate School of Medicine, Hirosaki University, Japan
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The "Iron Tale"- iron indices and handgrip strength in community-dwelling adults. Aging Clin Exp Res 2022; 34:3025-3032. [PMID: 36149625 DOI: 10.1007/s40520-022-02242-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/24/2022] [Indexed: 11/01/2022]
Abstract
Sarcopenia is a precursor for physical frailty and is associated with adverse outcomes. Low handgrip strength (HGS) is one of the diagnostic criteria for sarcopenia. Multiple factors can influence muscle quality, including muscle composition, architecture, fat infiltration, fibrosis, excessive iron deposition, and neural activation. There is limited evidence on the association of iron and HGS in community-dwelling older adults. We aim to examine the association of HGS with iron indices and inflammation. The Healthy Older People Everyday study is a subset of the Singapore Population Health Studies cohort. Complete cross-sectional data and iron indices were available for 477 participants. Sociodemographics, comorbidities, and final scores of the FRAIL scale, Barthel Index, Lawton Scale, HGS, and timed-up-and-go were collected and analyzed. Laboratory parameters including hemoglobin, hsCRP and iron indices were measured. The mean age of the participants was 70.9 ± 5.0 years, 258(54.1%) were females, and most were of Chinese(85.3%) ethnicity. Amongst the participants, 6.9% were frail, 39.4% were pre-frailt, and 53.7% were robust. Mean HGS was 22.2 ± 7.0 kg. Low HGS was prevalent in 47.8%, the highest amongst Indians. Prevalence of diabetes, chronic kidney disease, and ischaemic heart disease were significantly higher in those with low HGS. In multivariate regression adjusting for age, sex, comorbidities and Hb, ferritin (β = 0.004 95%CI 0.0002-0.007, p = 0.04), transferrin saturation (β = 0.06 95%CI 0.01-0.10, p = 0.02) and hsCRP (β = - 0.15 95%CI - 0.26 to - 0.04, p < 0.01) were significantly associated with HGS. CRP was negatively associated with HGS, whereas ferritin and transferrin saturation were positively associated with HGS. Older people with iron deficiency should be assessed for sarcopenia, and vice versa, as both can occur in multisystemic disorder, and need to be managed concurrently. Prospective longitudinal studies and clinical trials may be required to establish the causal effect of iron deficiency on muscle strength and sarcopenia and the benefits of iron therapy to improve function and quality of life.
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Sakuma Y, Ogino J, Iwai R, Inoue T, Takahashi H, Suzuki Y, Kinoshita D, Takemura K, Takahashi H, Shimura H, Sato Y, Yoshida S, Hashimoto N. Hyperferritinemia Is a Predictor of Onset of Diabetes in Japanese Males Independently of Decreased Renal Function and Fatty Liver: A Fifteen-Year Follow-Up Study. J Clin Med Res 2022; 13:541-548. [PMID: 35059072 PMCID: PMC8734509 DOI: 10.14740/jocmr4635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 11/24/2021] [Indexed: 01/22/2023] Open
Abstract
Background Type 2 diabetes is an important health concern worldwide. The disease etiology may depend on multiple environmental and genetic factors that cause insulin resistance, including dysregulation of iron storage. The goal of this study was to examine the relationship of the serum ferritin concentration with onset of diabetes over a long period. Methods Correlations of serum ferritin and metabolic markers with onset of diabetes mellitus were examined over 15 years in 150 males participating in a health screening program. Results HOMA-β showed a gradual significant decrease in the first 4 years in subjects with ferritin > 190 ng/mL (group H) compared to those with ferritin ≤ 190 ng/mL, but there was no difference in HOMA-R between these groups. A significant number of cases with onset of diabetes was observed over 15 years (hazard ratio (HR): 3.97), and obesity, fasting blood glucose level, hemoglobin A1c (HbA1c), HOMA-R, fasting immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) were all significant in univariate comparison between non-diabetes and diabetes-onset groups. In multivariate analysis, ferritin in group H (HR: 3.25), fatty liver (HR: 3.38), estimated glomerular filtration rate (eGFR) < 70 mL/min/1.73 m2 (HR: 3.48) and high-density lipoprotein (HDL) < 40 mg/dL (HR: 2.61) were significant predictive factors for onset of type 2 diabetes mellitus. Conclusions These results suggest that the serum ferritin level is an important index for priority intervention in preventive medicine for reduction of onset of diabetes.
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Affiliation(s)
- Yukie Sakuma
- Clinical Research Support Center, Asahi General Hospital, Chiba, Japan
| | - Jun Ogino
- Department of Diabetes and Metabolic Diseases, Asahi General Hospital, Chiba, Japan
| | - Rie Iwai
- Department of Clinical Laboratory, Asahi General Hospital, Chiba, Japan
| | - Takashi Inoue
- Clinical Research Support Center, Asahi General Hospital, Chiba, Japan
| | - Haruo Takahashi
- Clinical Research Support Center, Asahi General Hospital, Chiba, Japan
| | - Yoshifumi Suzuki
- Department of Diabetes and Metabolic Diseases, Asahi General Hospital, Chiba, Japan
| | - Daisuke Kinoshita
- Department of Diabetes and Metabolic Diseases, Asahi General Hospital, Chiba, Japan
| | - Koji Takemura
- Department of Diabetes and Metabolic Diseases, Asahi General Hospital, Chiba, Japan
| | - Hidenori Takahashi
- Preventive Medicine Research Center, Asahi General Hospital, Chiba, Japan
| | - Haruhisa Shimura
- Preventive Medicine Research Center, Asahi General Hospital, Chiba, Japan.,Department of Internal Medicine, Asahi General Hospital, Chiba, Japan
| | - Yasunori Sato
- Department of Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan
| | - Shouji Yoshida
- Department of Internal Medicine, Asahi General Hospital, Chiba, Japan
| | - Naotake Hashimoto
- Preventive Medicine Research Center, Asahi General Hospital, Chiba, Japan
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Ryan BJ, Foug KL, Gioscia-Ryan RA, Varshney P, Ludzki AC, Ahn C, Schleh MW, Gillen JB, Chenevert TL, Horowitz JF. Exercise training decreases whole-body and tissue iron storage in adults with obesity. Exp Physiol 2021; 106:820-827. [PMID: 33559926 DOI: 10.1113/ep089272] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 01/29/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does exercise training modify tissue iron storage in adults with obesity? What is the main finding and its importance? Twelve weeks of moderate-intensity exercise or high-intensity interval training lowered whole-body iron stores, decreased the abundance of the key iron storage protein in skeletal muscle (ferritin) and tended to lower hepatic iron content. These findings show that exercise training can reduce tissue iron storage in adults with obesity and might have important implications for obese individuals with dysregulated iron homeostasis. ABSTRACT The regulation of iron storage is crucial to human health, because both excess and deficient iron storage have adverse consequences. Recent studies suggest altered iron storage in adults with obesity, with increased iron accumulation in their liver and skeletal muscle. Exercise training increases iron use for processes such as red blood cell production and can lower whole-body iron stores in humans. However, the effects of exercise training on liver and muscle iron stores in adults with obesity have not been assessed. The aim of this study was to determine the effects of 12 weeks of exercise training on whole-body iron stores, liver iron content and the abundance of ferritin (the key iron storage protein) in skeletal muscle in adults with obesity. Twenty-two inactive adults (11 women and 11 men; age, 31 ± 6 years; body mass index, 33 ± 3 kg/m2 ) completed 12 weeks (four sessions/week) of either moderate-intensity continuous training (MICT; 45 min at 70% of maximal heart rate; n = 11) or high-intensity interval training (HIIT; 10 × 1 min at 90% of maximal heart rate, interspersed with 1 min active recovery; n = 11). Whole-body iron stores were lower after training, as indicated by decreased plasma concentrations of ferritin (P = 3 × 10-5 ) and hepcidin (P = 0.02), without any change in C-reactive protein. Hepatic R2*, an index of liver iron content, was 6% lower after training (P = 0.06). Training reduced the skeletal muscle abundance of ferritin by 10% (P = 0.03), suggesting lower muscle iron storage. Interestingly, these adaptations were similar in MICT and HIIT groups. Our findings indicate that exercise training decreased iron storage in adults with obesity, which might have important implications for obese individuals with dysregulated iron homeostasis.
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Affiliation(s)
- Benjamin J Ryan
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine L Foug
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Rachel A Gioscia-Ryan
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Pallavi Varshney
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alison C Ludzki
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Cheehoon Ahn
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael W Schleh
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jenna B Gillen
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA.,Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Thomas L Chenevert
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jeffrey F Horowitz
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
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