SIGNIFICANT ASSOCIATION BETWEEN SIMPLE RENAL CYSTS AND ARTERIAL BLOOD-PRESSURE

Objective To test the hypothesis that there is an association between simple renal cysts and arterial blood pressure (BP). Patients and meth ods The study comprised a review of the case-notes of 115 patients (me an age 67.7 years, range 31-91) in whom renal cyst(s) was an incidenta l ultrasonographic finding, and 115 age- and sex-matched control patie nts. The notes were reviewed without knowledge of the origin or treatm ent. Results The systolic and diastolic BP were significantly higher i n patients with a cyst(s) than in control patients (P = 0.031 and P = 0.0034; mean difference 6.9 mmHg and 5.0 mmHg, respectively). In those aged 30-70 years, the presence of one or more simple renal cysts incr eased the risk of having a diastolic BP greater than or equal to 95 mm Hg from seven in 58 to 17 in 58 patients (P = 0.038). Conclusion The a ssociation between simple renal cysts and higher arterial BP probably arises from underlying renal disease causing both. Occasionally it is possible that renal ischaemia caused by cyst expansion, and therefore increased renin release, generates the elevation in BP. If so, methods to identify such cysts should be developed.