Circulating adrenomedullin in erythropoietin-induced hypertension

Levels of adrenomedullin (AM) have been shown to be elevated in hypertensio n and chronic renal failure, suggesting that AM plays a role in the pathoge nesis of these diseases. The objective of the present study was to investig ate whether circulating AM is involved in erythropoietin (Epo)-induced hype rtension in patients with renal anemia due to progressive renal disease. Fo llowing treatment with 6,000 IU of Epo once a week, the hematocrit (Ht) ros e significantly from 25.9+/-4.0 to 33.4+/-3.3% (n=54, p<0.001) with an over all rate of increase in Ht of 0.43+/-0.04%/week. In response to treatment w ith Epo, a rise in mean blood pressure of >10 mmHg (Epo-induced hypertensio n) was found in 22% (12/54 cases) of the patients enrolled. There was no di fference in the rate of Ht increase between patients with and without Epo-i nduced hypertension. There was a significant positive correlation between m ature AM and serum creatinine (Cr) concentration before treatment with Epo. However, no correlation was found between the plasma concentration of tota l AM and serum Cr concentration. Long-term treatment with Epo did not influ ence plasma concentration of either mature AM or total AM in patients devel oping hypertension during the study period. These results suggest that circ ulating AM may play a role in the progression of renal disease. However, th e present study does not support the notion that circulating AM is associat ed with the pathogenesis of Epo-induced hypertension, It is too early yet t o claim that there is no AM-mediated mechanism in Epo-induced hypertension.