Quality -of-life scores ( Piper Fatigue Scale MD 0.73 , 95 % CI 0.29 to 1.18 ; I2 = 0 % ; studies = 3 ) and peak oxygen consumption ( MD 2.77 mL/kg/min , 95 % CI -0.89 to 6.43 ; I2 = 36 % ; 2 studies , 32 participants ) were associated with very low- quality evidence , and we remain uncertain about the role of intravenous iron for these metrics .
Current evidence is insufficient to show benefit of intravenous iron preparations for the treatment of non-anaemic iron deficiency across a variety of patient population s , beyond stating that it may result in a small , clinical ly insignificant increase in haemoglobin concentration .
BACKGROUND Iron deficiency is one of the most common nutritional deficiencies , and has a number of physiological manifestations .
Early , or non-anaemic iron deficiency can result in fatigue and diminished exercise capacity .
Oral iron preparations have a high incidence of intolerable side effects , and are ineffective in certain forms of iron deficiency .
Consequently , intravenous iron preparations are increasingly used in the treatment of non-anaemic iron deficiency .
The newer , more stable iron preparations in particular purport to have a lower incidence of side effects , and are now used across a range of different patient population s. OBJECTIVES To assess the effects of intravenous iron therapy in the treatment of adults with non-anaemic iron deficiency .
Effect of Iron Isomaltoside on Skeletal Muscle Energetics in Patients With Chronic Heart Failure and Iron Deficiency.
BACKGROUND Iron repletion augments exercise capacity in chronic heart failure ( HF ) , but there is a lack of mechanistic data explaining how iron could augment exercise performance despite minimal changes in hemoglobin ( Hb ) . Besides Hb , iron is an obligate component of mitochondrial enzymes that generate cellular energy in the form of adenosine triphosphate and phosphocreatine ( PCr ) . Dynamic phosphorus magnetic resonance spectroscopy is a noninvasive tool that quantifies in vivo muscle energetics by measuring the kinetics of PCr recovery after exertion . We tested the hypothesis that intravenous iron repletion in chronic HF enhances skeletal muscle energetics as reflected by shorter PCr recovery half-times ( PCr t1/2 ) on phosphorus magnetic resonance spectroscopy . METHODS We enrolled 40 patients ( 50 % anemic ) with chronic HF , New York Heart Association class ≥II , left ventricular ejection fraction ≤45 % , and iron deficiency ( ferritin<100 μg/L or 100 - 300 μg/L with transferrin saturation < 20 % ) . Subjects underwent stratified ( anemic versus nonanemic ) r and omization ( 1:1 ) to a single , double-blinded , total dose infusion of iron isomaltoside or saline placebo with end points reassessed early at 2 weeks posttreatment to minimize confounding from exercise adaptation . The primary end point was PCr t1/2 at 2 weeks . Secondary end points included ADP recovery half-time ( ADP t1/2 ; energetic marker ) , iron status , symptoms , Hb , exercise capacity , and safety . RESULTS In the total population , treatment groups were similar at baseline . At 2 weeks , iron isomaltoside  improved PCr t1/2 ( adjusted difference , -6.8 s ; 95 % CI , 11.5 to -2.1 ; P=0.006 ) , ADP t1/2 ( -5.3 s ; 95 % CI , -9.7 to -0.9 ; P=0.02 ) , ferritin ( 304 ng/mL ; 95 % CI , 217 - 391 ; P<0.0001 ) , transferrin saturation ( 6.8 % ; 95 % CI , 2.7 - 10.8 ; P=0.002 ) , New York Heart Association class ( -0.23 ; 95 % CI , -0.46 to -0.01 ; P=0.04 ) , resting respiratory rate ( -0.7 breaths/min ; 95 % CI , -1.2 to -0.2 ; P=0.009 ) , and postexercise Borg dyspnea score ( -2.0 ; 95 % CI , -3.7 to -0.3 ; P=0.04 ) , but not Hb ( 2.4 g/L ; 95 % CI , -3.5 to 8.4 ; P=0.41 ) . Adverse events were similar between groups . In subgroup analyses , iron isomaltoside improved PCr t1/2 in anemic ( -8.4 s ; 95 % CI , -16.7 to -0.2 ; P=0.04 ) and nonanemic ( -5.2 s ; 95 % CI , -10.6 to 0.2 ; P=0.06 ) cohorts . CONCLUSIONS In patients with chronic HF and iron deficiency , a total repletion dose of iron isomaltoside given at a single sitting is well tolerated and associated with faster skeletal muscle PCr t1/2 at 2 weeks , implying better mitochondrial function . Augmented skeletal muscle energetics might therefore be an important mechanism via which iron repletion confers benefits in chronic HF despite minimal Hb changes . CLINICAL TRIAL REGISTRATION URL : https://www . clinical trialsregister.eu/ctr- search /trial/2012 - 005592 - 13/GB . Unique identifier : EudraCT 2012 - 005592 - 13
Quality -of-life scores ( Piper Fatigue Scale MD 0.73 , 95 % CI 0.29 to 1.18 ; I2 = 0 % ; studies = 3 ) and peak oxygen consumption ( MD 2.77 mL/kg/min , 95 % CI -0.89 to 6.43 ; I2 = 36 % ; 2 studies , 32 participants ) were associated with very low- quality evidence , and we remain uncertain about the role of intravenous iron for these metrics .
Current evidence is insufficient to show benefit of intravenous iron preparations for the treatment of non-anaemic iron deficiency across a variety of patient population s , beyond stating that it may result in a small , clinical ly insignificant increase in haemoglobin concentration .
BACKGROUND Iron deficiency is one of the most common nutritional deficiencies , and has a number of physiological manifestations .
Early , or non-anaemic iron deficiency can result in fatigue and diminished exercise capacity .
Oral iron preparations have a high incidence of intolerable side effects , and are ineffective in certain forms of iron deficiency .
Consequently , intravenous iron preparations are increasingly used in the treatment of non-anaemic iron deficiency .
The newer , more stable iron preparations in particular purport to have a lower incidence of side effects , and are now used across a range of different patient population s. OBJECTIVES To assess the effects of intravenous iron therapy in the treatment of adults with non-anaemic iron deficiency .