Paraoxonase activity in athletes with depleted iron stores and iron-deficient erythropoiesis

Objective: The aim of this study was to evaluate how conditions that precede anaemia (iron store depletion and iron-deficient erythropoiesis) affect human serum paraoxonase PON1 activity.

Design and methods: Based on haemoglobin, transferrin saturation and serum ferritin values 119 athletes were divided into three groups: with iron depletion, with deficient erythropoiesis and controls. The following parameters were measured: paraoxonase activity towards paraoxon (POase) and diazoxon (DZOase), lipid hydroperoxides (LOOH), the pro-oxidant-antioxidant balance (PAB), red blood cells (RBC) and lipid status.

Results: Significant differences were found between athletes with different stages of iron deficiency and controls with respect to PON 1 activity and oxidative stress status parameters (Wilks' Lambda=0.712, F=5.241, p<0.001, η(2)=0.156). There was no significant difference between the PON1 192 Q and R polymorphism distribution in the two groups of athletes with different stages of iron deficiency and controls (χ(2)=1.086; p=0.896). PON1 activity was positively correlated with RBCs, haemoglobin, transferrin saturation (p<0.001) and ferritin (p=0.037) and negatively correlated with LOOH (p=0.044) in all three study groups.

Conclusions: Deficient erythropoiesis in athletes contributes to impaired PON1 activity. In contrast, iron depletion, regardless of increased oxidative stress, does not affect PON1 activity.