Page kidney: etiology, renal function outcomes and risk for future hypertension.

The initial description of Page kidney, a form of renin-mediated hypertension, included athletes with renal subcapsular hematoma after flank trauma. Subsequently, nontraumatic etiologies were identified. In this study, the authors compare traumatic and nontraumatic causes of Page kidney. All cases with hypertension attributable to renal hematoma at our institution from 1960 to 2010 were reviewed. Twenty-six patients (9 trauma, 17 nontrauma), with a mean age of 36.7 years, were included. Trauma patients were younger (P<.001), had lower systolic blood pressures (P=.011), and higher baseline estimated glomerular filtration rate (eGFR), (P=.027) at presentation. No differences in presenting features, imaging, urinalysis, or pathology are noted. Nontrauma cases required more antihypertensive medications (P=.001) and had higher nephrectomy rates. eGFR improved in all, but more in, trauma cases (P=.05). Through the analysis of 26 cases of Page kidney, two distinct groups were identified. Trauma patients tended to be younger, male, have less renal impairment and lower systolic blood pressure. Nontrauma patients required more antihypertensive medications and had a higher nephrectomy rate. New-onset hypertension occurred independent of etiology, calling for close surveillance of blood pressures.