[Estimation of urinary excretion rate of guanidinoacetic acid in essential hypertension].

78 patients with essential hypertension (17 with borderline hypertension and 61 with hypertension) and 13 normal controls were examined to evaluate the relation between the urinary excretion rate of guanidinoacetic acid/creatinine (U-GAA/Cr), beta 2-microglobulin/creatinine (U-BMG/Cr), radio-sensitive microalbumin excretion rate/creatinine (U-AER/Cr), N-acetyl-D-glucosaminidase/creatinine (U-NAG/Cr) and renal function. There was no significant difference among these groups in creatinine clearance (Ccr), serum creatinine (Cr) or in U-BMG/Cr, U-NAG/Cr and U-AER/Cr. In hypertensive patients U-GAA/Cr was 49.2 +/- 16.7 mg/gCr, which was much lower than in controls (78.1 +/- 13.4) (p less than 0.001). The Ccr has a significant relation with U-GAA/Cr (r = 0.29, p less than 0.01) but not with U-AER/Cr, U-BMG/Cr nor U-NAG/Cr. In 44 patients, all of the above factors were investigated for 24 weeks during 4 kinds of anti-hypertensive treatment (10 with an angiotensin-converting enzyme inhibitor: A group, 11 with a beta-adrenergic blocker: B group, 12 with a Ca entry blocker: C group and 12 with diuretics: D group). In A and C group, U-GAA/Cr was elevated during therapeutic course. However, in B and D group it declined during treatment. These findings suggested that urinary excretion of GAA may be a more sensitive marker than AER, BMG or NAG in hypertension and angiotensin-converting enzyme inhibitor and Ca entry blocker can be useful in the treatment of patients with essential hypertension with renal damage.