Hyperthyroidism, therapy with erythropoietin, malnutrition and systolic function in hemodialysis: echocardiography study

Secondary hyperparathyroidism is a frequent condition of dialysis patients. Endocrine derangements, with disturbance of calcium metabolism are complex, involving bone, heart (left ventricular hypertrophy-dilatation), bone marrow (anemia and erythropoietin resistance), muscle (increase of body fat mass) and insulin resistance. Aim of the study was to assess how these conditions are inter-correlated in the same patients. 45 patients (m 20, f 25; years 61.8±11.6) in maintenance bicarbonate three-weekly hemodialysis since > 3 years were studied. Cardiac function was assessed by echocardiography (EF%: left ventricular ejection fraction), which showed an inverse correlation both with parathormone (iPTH vs EF%: r=-0.64; p<0.001) and with erythropoietin (rHu-EPO vs EF%: r= -0.62 ; p<0.001). This suggests the possibility of a multi-endocrine resistance in dialysis patients with chronic renal failure, secondary to the degree of malnutrition. Lower lean mass is correlated with hyperparathyroidism (iPTH vs fat mass%: r=0.37; p<0.01), with lower left ventricular systolic function (EF% vs fat mass%: r= -0.41; p<0.005) and with rHu-EPO resistance. Moreover, patients with higher iPTH show a hypercatabolic disposition, assessed as protein catabolic rate (PCR/kg vs iPTH r= 0.54; p<0.001). This pattern can be a consequence of chronic renal failure, but bio-compatibility of materials can be involved as well.