Quality of Life in Autosomal Dominant Polycystic Kidney Disease Patients Treated With Tolvaptan

Abstract

Rationale & objective: The impact of tolvaptan on health-related quality-of-life (HRQoL) in patients with autosomal dominant polycystic kidney disease (ADPKD) is unknown. To address this knowledge gap, we studied patient-reported HRQoL in patients enrolled in the Bern ADPKD registry.

Study design: Prospective cohort study.

Settings & participants: Inclusion criteria were age 18 years or older, clinical diagnosis of ADPKD, and informed consent. The main exclusion criterion was need for kidney replacement therapy.

Outcome: HRQoL was assessed using the standardized Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire at start of the study (baseline) and after 1 year (follow-up). The KDQOL-SF has 2 parts: a generic 36-Item Health Survey instrument with 8 subscores and 2 summary scores and a kidney disease-specific instrument to assess health concerns. Higher scores indicate better HRQoL. The influence of tolvaptan treatment on HRQoL and kidney-specific health concerns was analyzed using analysis of covariance, adjusting for HRQoL and health concerns before the start of the study, sex, and age.

Results: In 38 of 121 registry patients, tolvaptan treatment was initiated. Within the first 3 months, treatment had to be discontinued in 6 (16%) patients due to aquaretic side effects (n = 4; 11%) or elevated liver enzyme levels (n = 2; 5%), and a dose reduction was necessary in 8 (21%) patients. We included 98 patients (30 with and 68 without tolvaptan treatment) in the analysis for which baseline and 1-year follow-up data were available. At follow-up, and after adjusting for baseline scores, sex, and age, HRQoL and kidney-specific health concerns were not influenced by tolvaptan treatment, except for patient satisfaction, which was increased.

Limitations: Observational study design, monocentric study at tertiary referral hospital, almost exclusively white study population, grant support by Otsuka Pharmaceuticals.

Conclusions: Our results indicate that tolvaptan does not significantly affect HRQoL in patients with ADPKD who tolerate treatment beyond the first 3 months of therapy.

Keywords: ADPKD; HRQoL; quality of life; tolvaptan.

Graphical abstract

Figure 1

Overview of patients with and without tolvaptan treatment in the Bern autosomal-dominant polycystic kidney disease (ADPKD) registry. Tolvaptan treatment was started in 38 of 121 (31.4%) ADPKD registry patients, therapy was stopped within the first 6 months of treatment in 6 (15.8%) patients due to aquaretic side effects or elevated liver function test (LFT) results. Eight (21.1%) patients did not tolerate the maximal tolvaptan dose (90/30 mg) and a dose reduction to 60/30 or 45/15 mg was necessary. In 68 patients without tolvaptan treatment and 30 patients with tolvaptan treatment, baseline and 1-year follow-up health-related quality of life data were available for analysis.

Figure 2

Change in health-related quality of life (HRQoL) after 1 year of tolvaptan treatment versus no tolvaptan treatment. Abbreviations: PF, physical functioning; RP, role limitations caused by physical health problems; RE, role limitations caused by emotional health problems; SF, social functioning; MH, emotional well-being/mental health; BP, bodily pain; VT, vitality (energy/fatigue); GH, general health perceptions; PCS, physical component summary; MCS, mental component summary. Filled diamonds indicate differences in HRQoL T scores for patients with autosomal-dominant polycystic kidney disease (ADPKD) treated with tolvaptan versus those not treated with tolvaptan (reference) derived from multivariable linear regression involving HRQoL as dependent and tolvaptan status, sex, and age as independent variables. A positive difference indicates better HRQoL in patients with tolvaptan versus those without tolvaptan. Capped spikes indicate 95% confidence intervals.

Figure 3

Change in kidney-specific health concerns after 1 year of tolvaptan treatment versus no tolvaptan treatment. Abbreviations: symptom, symptom/problem; effect, effects of kidney disease; burden, burden of kidney disease; work, work status; cognition, cognitive function; interact, quality of social interaction; sexfunction, sexual function; support; social support; satisfaction, patient satisfaction; health, overall health. Filled diamonds indicate differences in health concern scores for patients with autosomal-dominant polycystic kidney disease (ADPKD) treated with tolvaptan versus those not treated with tolvaptan (reference) derived from multivariable linear regression involving health concerns as dependent and tolvaptan status, sex, and age as independent variables. A positive difference indicates better scores in health concerns of patients with tolvaptan versus those without tolvaptan. Capped spikes indicate 95% confidence intervals.