Long-term decline of renal function in patients with resistant and non-resistant arterial hypertension

Abstract

Abstract Background The negative effect of arterial hypertension on renal function is well known. Until present, the detrimental effect of resistant arterial hypertension (RAH) on kidneys was not clearly defined. Purpose To assess the deterioration of renal function in patients with RAH in comparison to patients with non-resistant arterial hypertension (AH) during a long term follow-up. Methods We retrospectively reviewed records of 307 patients followed between May 2007 and January 2019 in an Hypertension Excellence Centre of a tertiary hospital. In all patients we assessed basic demographic characteristics, co-morbidities, laboratory findings, secondary causes of AH, medication, blood pressure including ambulatory blood pressure monitoring, studies and invasive procedures (CT, MRI, coronarography). We statistically evaluated differences in both groups and compared the decline of renal function. Results 160 patients had resistant and 147 patients non-resistant hypertension. Patients were followed for a mean of 6 years. Patients with RAH were older (58.1±10.8 years vs. 51±13 years), more frequently diabetics (39.3% vs. 8.7%), had more frequent exposure to diagnostic studies and invasive procedures (86,5% vs. 64%). Age at baseline visit and diabetes mellitus were established as statistically significant independent risk factors. Linear mixed effect model adjusted to age and diabetes demonstrated that patients with RAH have increased decline of renal function than patients with AH: patients with AH had mean increase of creatinine +0.24 μmol/l per year, while patients with RAH + 2.12 μmol/l per year (P=0.005). Similarly the decrease of eGFR in patients with AH was −0.66 compared to −1.5 mL/s/1.73 m2 per year in patients with RAH (P=0.005). Figures 1 and 2 show the difference in mean slope of creatinine and eGFR in patients with resistant and non-resistant hypertension (based on linear mixed effect models)). Conclusion Patients with resistant hypertension had faster decline of renal function in comparison to patients with non-resistant hypertension independently on age and diabetes. Further studies are needed to determine the key factors affecting renal function decline in both subgroups. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): University Hospital Olomouc, Palacky University Olomouc, Faculty of Medicine, Czech Republic