MO051EFFECT OF TOLVAPTAN ON THE SUPPRESSION OF TOTAL KIDNEY VOLUME INCREASE IN PATIENTS WITH MODERATE-TO-SEVERE RENAL DYSFUNCTION IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Abstract

Abstract Background and Aims Tolvaptan (TV) slows down the increase in total kidney volume (TKV) in patients with autosomal dominant polycystic kidney disease (ADPKD). The efficacy of TV in patients with moderate-to-severe renal dysfunction (RD) in ADPKD remains unknown. Method This was a single-centre retrospective study involving 27 patients with ADPKD who took TV and visited our hospital in the past six years. The participants were divided into two groups: the normal-to-mild RD (estimated glomerular filtration rate (eGFR) ≥ 45mL/min/1.73m2) group and the moderate-to-severe RD (eGFR < 45mL/min/1.73m2) group. Treatment effects were evaluated using ΔTKV, which was calculated as post-/pre-treatment annual TKV change. Continuous variables are presented using the median [interquartile range]. Results The moderate-to-severe RD group comprised 11 patients. Baseline characteristics of the normal-to-mild vs. moderate-to-severe RD group were as follows: eGFR, 56 [50–69] vs. 29 [24–38] mL/min/1.73m2; age, 48 [39–55] vs. 49 [43–58] years; male gender, 57% vs. 36%; body mass index (BMI) , 26 [23–28] vs. 24 [22–27] kg/m2; TKV 1700 [1084–2574] vs. 1827 [1331–2424] mL; family history of ADPKD, 100% vs. 82%; history of cerebral aneurysm, 19% vs. 36%; hypertension, 81% vs. 82%; hyperuricemia, 13% vs. 27%; dyslipidaemia, 19% vs. 18%; diabetes, 6.1% vs. 9.1% and systolic blood pressure (sBP) on admission 138 [129–144] vs. 131 [128-137] mmHg. No significant differences were noted in all these parameters, except for renal function. The starting dose of TV was 60 mg/day in all cases (0.9 [0.7–1.0] vs. 0.9 [0.8–1.1] mg/kg; P = 0.35). Urine volume (7.5 [5.7–9.6] vs. 4.0 [3.3–4.7] L/day; P = 0.006) and urinary sodium excretion (163 [126–226] vs. 89 [81–120] mEq/day; P = 0.003) were higher in the normal-to-mild RD group. Between the groups, there were no differences in urine protein (0.12 [0.0–0.3] vs. 0.16 [0.08–0.29] g/day; P = 0.31) and ΔeGFR (98% [88–123] vs. 106% [102–112]; P = 0.45), which was calculated as post-/pre-treatment annual eGFR change. Although both groups experienced the therapeutic effects of TV, the efficacy was poorer in the moderate-to-severe RD group (ΔTKV, 82% [76–85] vs. 96% [86–97]; P = 0.001). Conclusion The efficacy of TV patients with moderate-to-severe RD in ADPKD might be modest.