Response of asymmetric dimethylarginine to hemodialysis-associated hypotension in end-stage renal disease patients.

Aims: To define the role of asymmetric dimethylarginine (ADMA) in the control of blood pressure (BP) during hemodialysis (HD).

Methods: L-Arginine, ADMA and symmetric dimethylarginine (SDMA) levels of patients with (n = 18) or without (n = 13) hypotensive episodes during HD sessions were measured before and after HD treatment by liquid chromatography-mass spectrometry. Clinical variables, laboratory parameters and underlying pathologies of end-stage renal disease (ESRD) were comparable in the groups. BP was serially recorded.

Results: In patients with ESRD, plasma dimethylarginines were markedly elevated and decreased significantly by the end of the HD sessions. ADMA levels in patients having hypotensive episodes during HD were significantly higher than in those maintaining their BP (before HD: 0.62 +/- 0.11 micromol/l vs. 0.71 +/- 0.13 micromol/l, p = 0.04; after HD: 0.31 +/- 0.11 micromol/l vs. 0.43 +/- 0.11 micromol/l, p = 0.01). There was a significant inverse relationship of the minimum systolic and diastolic BP during HD to the predialysis ADMA levels (for systolic BP r = -0.50, p < 0.01; for diastolic BP r = -0.59, p < 0.01) and to the postdialysis ADMA levels (for systolic BP r = -0.49, p < 0.01; for diastolic BP r = -0.51, p < 0.005), respectively.

Conclusions: It is suggested that excessive NO generation is involved in the HD-associated hypotension and induces an increase in plasma ADMA levels to prevent further fall in BP.