#3081 ASSOCIATION OF URINE PROTEIN EXCRETION LEVELS, AS A MEASURE OF DISEASE ACTIVITY, AND QUALITY OF LIFE IN IGA NEPHROPATHY PATIENTS
Authors: Barratt Jonathan , Clayton Sarah , Lowe Mollie , Jackson James , Roughley Adam , Tsong Wan 
Published: June 2023

Abstract

Background and Aims
Little is known about the quality of life (QoL) of patients with IgA nephropathy (IgAN). Understanding the relationship between disease activity (as measured by urine protein excretion [UPE]) and QoL could allow decision-makers to understand how treatments that improve UPE might improve patient QoL.

Methods
The 2021 United States subset of the Adelphi IgAN Disease Specific Programme™ was a point-in-time survey of 43 nephrologists (who completed structured forms for 305 IgAN patients) and 70 patients (who elected to complete patient surveys of the 305). This analysis utilised physician-reported data (patient demographics, disease characteristics, and current 24-hour UPE levels [categories: ≤0.5, &gt;0.5 to ≤1, &gt;1 to ≤2, &gt;2 to ≤3.5, &gt;3.5 grams/day]) and patient-reported data (symptoms, Kidney Disease Quality of Life [KDQOL] scores, and EQ-5D scores). The association between UPE and patient-reported symptoms was evaluated using chi-squared and Fisher's exact tests. The association between UPE and QoL (KDQOL, EQ-5D) was evaluated using generalized linear regression to adjust for age, sex, chronic kidney disease stage, corticosteroid use, and non-steroidal immunosuppressant use.

Results
The analytical dataset included 69 patients with UPE data (reported by 8 physicians) out of the 70 patients who completed the patient survey. Of these 69, data were complete for the symptoms (n=63), KDQOL (n=60), and EQ-5D (n=67). Patients were an average age of 43 years, an average BMI of 26.3, 49% male, 55% White, 23% Asian, 64% never smokers, 78% in full-time occupation, and 74% with commercial health insurance. The most prevalent comorbidities were hypertension (33%), hyperlipidemia (30%), and diabetes (11%). UPE was not associated with any demographic characteristics, regular dialysis, or kidney transplants. Among comorbidities, higher UPE was associated with a higher percentage of hyperlipidaemia (P = .03). Among medications for IgAN, higher UPE was associated with a higher percent use of diuretics (P = .046), sodium-glucose co-transporter 2 inhibitors (P = .002), corticosteroids (P = .0009), non-steroidal immunosuppressants (p&lt;0.0001), and anti-depressants (P = .0009). Higher UPE was associated with a higher percentage of patient-reported aching joints (P = .04), self-awareness of high cholesterol (P = .001), tiredness (P = .005), swollen feet/ankles/legs (p&lt;0.0001), sleep problems (P = .02), feeling sick (P = .0003), and tea-colored urine (P = .03). Higher UPE was associated with worse KDQOL scores (burden [p&lt;0.0001], effects [P = .007], physical health [P = .002], and mental health [p&lt;0.0001]). After adjustment (Table 1), higher UPE continued to be associated with worse KDQOL burden (P = .01) and mental health (P = .03) scores. Unadjusted and adjusted analyses (Table 2) indicated that higher UPE was associated with worse EQ-5D scores.

Conclusion
The results indicate that higher levels of disease activity (UPE) in IgAN are associated with increased symptom burden, worse kidney disease QoL, and worse overall QoL.