Simple renal cysts and arterial hypertension: does their evacuation decrease the blood pressure?

OBJECTIVE To evaluate the relationships between simple renal cysts and arterial hypertension and whether their evacuation decreases the blood pressure (BP). METHODS In a cross-sectional design, we analyzed 184 study participants with cysts and compared hypertensive and nonhypertensive among them. Outcomes were the number, the size and the location of a cyst. In a cross-over design, we first evaluated the change in absolute value of SBP, DBP and mean BP in 62 hypertensive patients who underwent percutaneous evacuation of a cyst and then the decrease of BP as a categorical variable that comprised all study participants. RESULTS There were 55% giant renal cysts among hypertensive and 24% among nonhypertensive patients (P = 0.0001). The prevalence rates of multiple and peripheral cysts in hypertensive and nonhypertensive patients were similar to those of single and perihilar cysts, respectively. Significant differences in SBP, DBP and mean BP were found between pretreatment readings and 3 days, 1 month, 3 months and 6 months after cyst evacuation (P < 0001). The differences were significant in all hypertensive patients (P < 0.001). There were less hypertensive patients 3 days after treatment than before treatment (P < 0.0001). CONCLUSION An apparent association between the size of a simple renal cyst and hypertension was found, and aspiration of cysts resulted in a reduction of BP. Location and number of cysts were not related to BP.