Twenty-Four-Hour Urine α 1 -Microglobulin as a Marker of Hypertension-Induced Renal Impairment and Its Response on Different Blood Pressure-Lowering Drugs

The purpose of this study was to assess the role of urine α -microglobulin as a marker of hypertension-induced renal damage compared with estimated glomerular filtration rate, (eGFR), urine albumin, and urine albumin-to-creatinine ratio (ACR). Its response on different blood pressure (BP)-lowering drugs was also studied. Sixty never-treated hypertensive patients (65.0% men, 46.9 years, BP 141.4/94.0 mm Hg) were randomized to an irbesartan (an angiotensin receptor blocker [ARB]) or a diltiazem (a nondihydropyridine calcium channel blocker [CCB])-based regimen. Patients with diabetes or established cardiovascular, renal, or liver disease were excluded. Blood samples and 24-hour urine were analyzed at baseline and 6 months after pharmaceutical BP normalization. Serum creatinine was measured and eGFR was calculated. Urine albumin, creatinine, and α -microglobulin were measured and ACR was calculated. Minor changes (P=not significant [NS]) in eGFR were noted during follow-up in both groups (from 111.0 mL/min/1.73 m to 108.4 mL/min/1.73 m in the ARB group and from 111.3 mL/min/1.73 m to 114.0 mL/min/1.73 m in the CCB group). Twenty-four-hour urine indices were all significantly improved (P