Work capacity after iron treatment as a function of hemoglobin and iron deficiency

• Published in: Journal of Nutritional Science and Vitaminology Vol. 27; no. 2; pp. 87 - 96
• Main Authors: Ohira, Y, Edgerton, V.R, Gardner, G.W, Gunawardena, K.A, Senewirathne, B, Ikawa, S
• Format: Journal Article
• Language: English
• Published: Japan Center for Academic Publications Japan 01.01.1981
• Subjects: Anemia, Hypochromic - blood; Anemia, Hypochromic - drug therapy; Anemia, Hypochromic - physiopathology; Blood Transfusion; diet-related diseases; Female; Heart Rate; hemoglobin; Hemoglobins - analysis; human nutrition; Humans; Iron - blood; Iron - therapeutic use; iron deficiency; iron treatment; lactate; Lactates - blood; Lactic Acid; Male; Physical Endurance; Space life sciences; work capacity
• ISSN: 0301-4800; 1881-7742
• DOI: 10.3177/jnsv.27.87

The relative importance of hemoglobin (Hb) and non-Hb iron for physical work capacity was studied in 45 adult male and female subjects, with a range of Hb and serum iron levels. Maximal work capacity, heart rate, venous blood lactate and serum protein were measured before and after 1 week of treatment with Imferon, i.v. Even though some non-Hb related effects on parameters indicative of maximal work capacity were found, the main factor was Hb related. Subjects with low Hb-high serum iron worked longer than ones with low Hb-low iron. When the work performed was similar, the marginal Hb-low iron group had a higher blood lactate concentration than the high Hb-high iron and marginal Hb-high iron groups. The coefficient of correlation between serum iron and post-exercise lactate levels was -0.41 (p<0.05). Even though neither of these groups showed a Hb response within 1 week of iron treatment, the initial low serum iron groups had significantly lower heart rates at a given work load relative to subjects with high iron but with a similar Hb level. This occurred both at rest and during light to heavy exercise. These results suggest that a rather rapid benefit of iron treatment is gained in iron-deficient subjects with severe and moderate anemia which cannot be accounted for by Hb changes. Although the primary factor which affects the physical work capacity of iron-deficient anemic subjects seems to be the Hb level, there also seems to be a significant non-Hb related effect of iron treatment as well.