Relationships between renovascular disease, blood pressure, and renal function in the elderly: a population-based study.

Background: The purpose of this study is to examine the associations between renovascular disease (RVD) and cross-sectional measures of blood pressure and renal function among participants in the Cardiovascular Health Study (CHS).

Methods: The CHS is a prospective cohort study of cardiovascular disease among elderly Americans. As part of an ancillary study, participants in the Forsyth County, NC, cohort of the CHS were invited to undergo renal duplex sonography (RDS) to define the presence or absence of RVD (defined as any focal peak systolic velocity > or = 1.8 milliseconds or the absence of a Doppler shifted signal from an imaged artery). Demographic, risk factor, blood pressure, and serum creatinine data were obtained at the time of RDS and from the annual CHS examination.

Results: Eight hundred thirty-four CHS participants (including 525 women [63%], 309 men [37%], 194 African Americans [23%], and 635 Caucasians [76%]) with a mean age of 77.2 +/- 4.9 years underwent successful RDS. RVD was present in 57 participants (6.8%). When examined according to the presence or absence of RVD, significant univariate differences were observed in the prevalence of clinical hypertension (72% versus 50%; P = 0.001), systolic blood pressure (145 versus 136 mm Hg; P = 0.001), and renal insufficiency (16% versus 8%; P = 0.041). Multivariate analyses showed significant and independent associations for the presence of RVD with increasing systolic blood pressure (P = 0.034), clinical hypertension (odds ratio, 2.68; 95% confidence interval, 1.44 to 4.99; P = 0.002), increasing serum creatinine level, and renal insufficiency (odds ratio, 2.21; 95% confidence interval, 1.02 to 4.79; P = 0.043). A significant interaction was observed between the presence of RVD and increasing systolic blood pressure in association with increasing serum creatinine levels (P = 0.041).

Conclusion: These results suggest important population-based associations between RVD and cross-sectional measures of blood pressure and renal function. Furthermore, the observed relationship between RVD and increasing serum creatinine level was influenced strongly by increasing blood pressure.