Low systolic blood pressure values, renal resistive index measurement and glomerular filtration rate in a non-dialysis dependent chronic kidney disease population

Abstract

Objective: A longitudinal prospective case control study was organized to explore the relationships between glomerular filtration rate (GFR), renal resistive index (RRI) and blood pressure values in a non-dialysis dependent adult population affected by chronic kidney disease and exposed to low systolic blood pressure (SBP) values. Material and methods: The study sample (54 patients: 31 males and 23 females with an average age of 61.7 ± 19.2 years) was randomly selected from a population of adult non-dialysis dependent patients that scored a SBP 100 mmHg. Results: In the group with chronic renal disease, the comparison between the data recorded with SBP < 100 mmHg (t0) and those detected with SBP ≥ 100 mmHg (t1) showed a statistically significant decrease of serum creatinine as well as an increase of GFR (mean serum creatinine t0 – serum creatinine t1: 0.194 ± 0.35, p < 0.01; mean GFR t0 – GFR t1: -4.615 ± 8.8, p < 0.013). There was also a statistically significant reduction of the RRI (mean right kidney RRI t0 – mean right kidney RRI t1: + 0.082 ± 0.03, p < 0; mean left kidney RRI t0 – mean left kidney RRI t1: 0.076 ± 0.03, p < 0). Conclusion: We concluded that, in CKD, when aorta is stiffed, a decrease of SBP can limit the renal perfusion that, in this condition, is mostly dependent by stroke volume, causing an increase of RRI and a decrease of GFR that we suppose as reversible with the restoration of SBP.

Keywords

• longitudinal prospective case control study
• chronic kidney disease
• renal Doppler ultrasonography
• renal resistive index
• low systolic blood pressure