P0155CHARACTERISTICS OF HYPERTENSIVE NEPHROSCLEROSIS DIAGNOSED BY RENAL BIOPSY BASED ON 40-YEAR EXPERIENCE
Authors: Kim Hea Eun , CHIN HO JUN 
Published: June 2020

Abstract

Background and Aims
Hypertensive nephrosclerosis (HT-N) is known as the second common cause of end stage renal disease (ESRD) in Korea as well as in other countries. However, the HT-N is assumed by clinical findings which are not well correlated to the pathologic findings. Therefore, we report the clinical characteristics of HT-N diagnosed by renal biopsy and compare the prognosis between patients with HT-N and hypertensive patients with focal segmental nephrosclerosis (FSGS) without pathologic HT-N.

Method
We enrolled 21,617 patients having native kidney biopsy for diagnosis of nephritis between 1979 and 2018, retrospectively. Among them, we selected 267 adult hypertensive patients with only HT-N and 984 hypertensive patients with FSGS without HT-N or other diagnoses (FSGS-HT). The estimated glomerular filtration rate (GFR) was calculated by original MDRD equation. The final outcomes were incidences of end stage renal disease (ESRD) and death. We matched blood pressures and GFR between two groups and analyzed the difference of outcomes within the matched cohort (mHT-N and mFSGS-HTN), also.

Results
The age of patients with HT-N was 49.5 ± 15.3 years at renal biopsy. There were 175 (65.5 %) men. Systolic blood pressure (SBP) was 139.1 ± 24.0 mmHg and diastolic blood pressure (DBP) was 83.7 ± 15.6 mmHg at renal biopsy. Levels of serum creatinine, GFR, and urine protein to creatinine ratio were 3.17 ± 3.05 mg/dl, 40.7 ± 32.5 ml/min/1.73 m2, and 2.277 ± 2.803 g/g cr, respectively. During follow-up period of 64.1 months (median), there were 52 (22.7%) patients progressed to ESRD and 8 (3.1%) patients were dead. Age, SBP, and hemoglobin were risk factors to mortality by Cox’s hazard proportional model adjusted with related factors to mortality. With increase of 10 mmHg in the level of SBP at renal biopsy, hazard ratio(HR) of mortality was increase by 1.645 folds (95% CI: 1.192-2.270, P=0.002). Presence of diabetes mellitus, serum albumin, and GFR were risk factors to incident ESRD. Compared to patients with FSGS-HT, patients with HT-N showed higher levels of SBP, DBP, and serum creatinine and lower levels of GFR, serum albumin, hemoglobin, and UPCR (all p-values &lt;0.05), however, the risk of incident ESRD and mortality was not different. Therefore, we matched BP and GFR between groups and selected 235 patients in each group. The matched groups were not different in the values of age, SBP, DBP, and GFR. The risk of mortality was not different between groups (p-value =0.502), however, HR of incident ESRD was 1.558-fold higher (95% CI: 1.004-2.419, P=0.048) in mFSGS-HT compared to mHT-N by Cox’s hazard proportional model adjusted by factors related to ESRD.

Conclusion
Hypertensive nephrosclerosis was diagnosed in more advanced stage of CKD compared to hypertensive FSGS. Considering levels of GFR and SBP as risk factors to hard outcomes, we should consider early pathologic diagnosis for proteinuric and/or azotemic hypertensive patients and control blood pressures and renal dysfunction in more aggressive manners.