Health-related quality of life in patients with autosomal dominant polycystic kidney disease and CKD stages 1-4: a cross-sectional study.

BACKGROUND: In people with early autosomal dominant polycystic kidney disease (ADPKD), average total kidney volume (TKV) is 3 times normal and increases by an average of 5% per year despite a seemingly normal glomerular filtration rate (GFR). We hypothesized that increased TKV would be a source of morbidity and diminished quality of life that would be worse in patients with more advanced disease.

STUDY DESIGN: Cross-sectional.

SETTING & PARTICIPANTS: 1,043 patients with ADPKD, hypertension, and a baseline estimated GFR (eGFR)> 20mL/min/1.73m(2).

PREDICTORS: (1) eGFR, (2) height-adjusted TKV (htTKV) in patients with eGFR> 60mL/min/1.73m(2).

OUTCOMES: 36-Item Short Form Health Survey (SF-36) and the Wisconsin Brief Pain Survey.

MEASUREMENTS: Questionnaires were self-administered. GFR was estimated from serum creatinine using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. htTKV was measured by magnetic resonance imaging.

RESULTS: Back pain was reported by 50% of patients, and 20% experienced it "often, usually, or always." In patients with early disease (eGFR> 60mL/min/1.73m(2)), there was no association between pain and htTKV, except in patients with large kidneys (htTKV> 1,000mL/m). Comparing across eGFR levels and including patients with eGFRs< 60mL/min/1.73m(2), patients with eGFRs of 20-44mL/min/1.73m(2) were significantly more likely to report that pain impacted on their daily lives and had lower SF-36 scores than patients with eGFRs of 45-60 and ≥60mL/min/1.73m(2). Symptoms relating to abdominal fullness were reported by 20% of patients and were related significantly to lower eGFRs in women, but not men.

LIMITATIONS: TKV and liver volume were not measured in patients with eGFR < 60mL/min/1.73m(2). The number of patients with eGFRs< 30mL/min/1.73m(2) is small. Causal inferences are limited by cross-sectional design.

CONCLUSIONS: Pain is a common early symptom in the course of ADPKD, although it is not related to kidney size in early disease (eGFR> 60mL/min/1.73m(2)), except in individuals with large kidneys (htTKV> 1,000 mL/m). Symptoms relating to abdominal fullness and pain are greater in patients with more advanced (eGFR, 20-45mL/min/1.73m(2)) disease and may be due to organ enlargement, especially in women. More research about the role of TKV in quality of life and outcomes of patients with ADPKD is warranted.