Abstract 12021: Ambulatory Blood Pressure Correlates With Chronic Renal Tubulointerstitial Injury in Patients With IgA Nephropathy

Introduction: Hypertension is a major prognostic factor in IgA nephropathy (IgAN), the most common form of primary glomerulonephritis and a major cause of ESRD worldwide. However, there are few studies that assessed the ambulatory blood pressure (ABP) in IgAN patients, which could detect the abnormality in circadian BP and predict long-term renal or cardiovascular outcomes. Hypothesis: Renal histopathological changes established by chronic exposure to injuries may have effects on the abnormal regulation of circadian BP in IgAN patients. Methods: This cross-sectional study included biopsy-proven IgAN patients, in whom both renal biopsy and ABP monitoring were performed during the same hospitalization. The histopathological findings were assessed and analyzed in relation to ABP. Results: A total of 111 IgAN patients were included. The score for interstitial fibrosis and tubular atrophy (IF/TA) was significantly associated with the both values of daytime and nighttime ABP. In contrast, the score for global and segmental glomerulosclerosis, arterial, and arteriole lesions did not show significant associations with these ABP values. These results were almost similar in the subgroup analyses of patients without apparent renal function decline (eGFR>30mL/min/1.73m2) or those without antihypertensive medications. In the multiple linear regression analyses, the severity of IF/TA was associated with the both values of daytime and nighttime ABP, independent of age, gender, renal function, severity of proteinuria, and use of antihypertensive medications. On the other hand, the severity of glomerular lesions was not associated with these ABP values after adjustment (Table). The night to day ratio of mean ABP did not display significant trends according to any renal histopathological lesions. Conclusions: These results suggest that IF/TA is the most relevant renal histopathological finding associated with abnormal regulation of circadian BP in IgAN patients.