[Preclinical diagnosis of renal damage in essential hypertension]

To study renal functional reserve and 24-h beta 2-microglobulinuria (B2-MGU) in patients with different stages of essential hypertension (EH) and to evaluate acceptability of these parameters as early markers of preclinical renal impairment in EH.

We examined 150 patients (mean age 42.1 +/- 3.4 years) with EH without overt clinical manifestations of hypertensive nephropathy. Renal functional reserve (RFR) was determined with the use of acute oral protein loading and was defined as an increase in endogenic creatinine clearance in percent. B2-MGU was evaluated by radioimmunoassay (RIO-BETA-2-MICRO kit). Radioimmunoassay detection of microalbuminuria (MAU) was performed with the use of the standard kit Albumin-RIA.

RFR appeared to be significantly lower in patients with EH compared to the control group, and its level significantly decreased with aggravation of EH. Both B2-MGU and MAU were significantly higher in patients with EH and significantly increased with aggravation of EH.

We suggest that, apart from MAU, RFR abnormalities and excessive B2-MGU should be used as markers of preclinical renal impairment in EH.