The Relation of Erythropoietin Towards Hemoglobin and Hematocrit in Varying Degrees of Renal Insufficiency

Introduction: Hypoxia is a basic stimulant in production of erythropoietin (EPO). The primary function of erythrocytes is the transport of oxygen to tissues. Erythropoietin stimulates erythropoiesis which leads to increased production of erythrocytes- their total mass. This increases the capacity of the blood to carry oxygen, reduces the hypoxic stimulus and provides a negative feedback of stopping EPO production. The aim of this study was to establish a quantitative relationship between the concentration of erythropoietin, hemoglobin and hematocrit in different values of renal insufficiency. Material and methods: The survey was conducted on 562 subjects divided into two groups: with and without renal insufficiency. EPO, hemoglobin, hematocrit, serum creatinine and additional parameters iron, vitamin B12, and folic acid were determined by using immunochemical and spectrophotometric methods and glomerular filtration rate (GFR) was calculated as well. Results: EPO values (median) grow to the first degree of renal insufficiency, as compared to EPO values of healthy subjects, this increase is statistically significant, p=0.002. With further deterioration of renal function the values of EPO between all pathological groups are decreasing, and this decrease is statistically significant between first and second degree of renal insufficiency (RI) p<0.001. In the group of healthy subjects EPO is correlated rho = -0.532, p <0.0005 with hematocrit. The correlations are negative and strong and can be predicted by regression line (EP0 = 41.375- Hct * .649; EPO = 61.41–Hb * 0.355). In the group of subjects with the first degree of renal insufficiency EPO is in correlation with hematocrit rho=-0.574, p<0, 0005. It is also correlated with hemoglobin rho=-0.580, p< 0.0005. The correlation is negative (EP0= 42.168- Hct * 0.678). In the group of subjects with the third degree of renal insufficiency EPO is in correlation with hemoglobin rho=0.257, p=0.028. The correlation is medium strong and positive. In the group of subjects with third and fourth degree of renal insufficiency EPO is not in correlation with hemoglobin and hematocrit p>0.05. Conclusion: Renal dysfunction, depending on the level of RI effects differently on the biosynthesis of EPO in a diseased kidney, and consequently it also has a different effect on biosynthesis of HB in bone marrow and its content in the blood.