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

Abstract

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.

Keywords: Autosomal dominant polycystic kidney disease (ADPKD); activities of daily life; chronic kidney disease (CKD); extrarenal symptoms; patient-reported outcomes; quality of life (QoL); renal disease.

Figure 1. ADPKD patients’ reports of frequency of abdominal symptoms

1A There were no statistically significant differences in the frequency at which abdominal fullness interfered with usual activities across eGFR strata in men or women. 1B Women with eGFR 20–44 mL/min/1.73 m² were more likely than women with GFR 45–60 or >60 mL/min/1.73 m² to report that they ate less due to abdominal fullness (p=0.05). No differences by eGFR were seen in men. *Significant p-value <0.05 when comparing across eGFR groups 1C There were no statistically significant differences in the frequency at which patients reported that their appetite was poor due to abdominal fullness across eGFR strata in men or women. 1D Women with eGFR 20–44 mL/min/1.73 m² were more likely than women with eGFR 45–60 or >60 mL/min/ 1.73 m² to report that their abdomen had gotten bigger over the past year (p=0.01). No differences by eGFR were seen in men. *Significant p-value <0.05 when comparing across eGFR groups

Figure 2. SF-36 Scores in ADPKD Patients Compared with Age-Matched Healthy Controls

SF-36 scores in ADPKD patients with eGFR>60 mL/min/1.73 m2 were the same as or higher than their age-matched general population for all but GH. The same pattern was found for SF-36 scores among ADPKD patients with eGFR 45–60 and 20–44 mL/min/1.73 m² as compared with the age-matched general population. Abbreviations: PF physical functioning; RP role physical; BP bodily pain; GH general health; VT vitality; SF social functioning; RE role emotional; MH mental health ¹ significant difference between general population (age 35–44 y) and ADPKD GFR >60 mL/min/1.73 m² population ² significant difference between general population (age 45–54 y) and ADPKD eGFR 45–60 mL/min/1.73 m² population ³significant difference between general population (age 45–54 y) and ADPKD eGFR 20–44 mL/min/1.73 m² population ^ General population scores are based on respondents of the 1989 and 1990 General Social Survey (GSS), conducted by the National Opinion Research Center [14]