Kidney function and symptom development over time in elderly patients with advanced chronic kidney disease: results of the EQUAL cohort study

Abstract

Background Initiation of renal replacement therapy often results from a combination of kidney function deterioration and symptoms related to chronic kidney disease (CKD) progression. We investigated the association between kidney function decline and symptom development in patients with advanced CKD. Methods In the European Quality study on treatment in advanced CKD (EQUAL study), a European prospective cohort study, patients with advanced CKD aged ≥65 years and a kidney function that dropped <20 mL/min/1.73 m2 were followed for 1 year. Linear mixed-effects models were used to assess the association between kidney function decline and symptom development. The sum score for symptom number ranged from 0 to 33 and for overall symptom severity from 0 to 165, using the Dialysis Symptom Index. Results At least one kidney function estimate with symptom number or overall symptom severity was available for 1109 and 1019 patients, respectively. The mean (95% confidence interval) annual kidney function decline was 1.70 (1.32; 2.08) mL/min/1.73 m2. The mean overall increase in symptom number and severity was 0.73 (0.28; 1.19) and 2.93 (1.34; 4.52) per year, respectively. A cross-sectional association between the level of kidney function and symptoms was lacking. Furthermore, kidney function at cohort entry was not associated with symptom development. However, each mL/min/1.73 m2 of annual kidney function decline was associated with an extra annual increase of 0.23 (0.07; 0.39) in the number of symptoms and 0.87 (0.35; 1.40) in overall symptom severity. Conclusions A faster kidney function decline was associated with a steeper increase in both symptom number and severity. Considering the modest association, our results seem to suggest that repeated thorough assessment of symptom development during outpatient clinic visits, in addition to the monitoring of kidney function decline, is important for clinical decision-making.

Patient-Reported Measures and Lifestyle Are Associated With Deterioration in Nutritional Status in CKD Stage 4-5: The EQUAL Cohort Study

“…43,44 Several studies report that the symptom burden in CKD is high. 1,45 In other publications from the EQUAL cohort, we have observed that the number and burden of symptoms increase progressively as renal function deteriorate. 45 Moreover, a higher symptom burden has also been associated to a lower quality of life.…”

“…1,45 In other publications from the EQUAL cohort, we have observed that the number and burden of symptoms increase progressively as renal function deteriorate. 45 Moreover, a higher symptom burden has also been associated to a lower quality of life. 2 In our present study, we found that both constipation and decreased appetite were risk factors for decline in nutritional status.…”

Prevalence and Severity of Lower Gastrointestinal Symptoms amongst Non-Dialysis Chronic Kidney Disease Patients: A Systematic Review and Meta-Analysis

“…Interestingly, Dawson et al found an association between taste disturbances and constipation prevalence [ 37 ], while the EQUAL study showed that constipation was an independent predictor of a decline in nutritional status [ 23 ]. Finally, Murtagh et al showed that the prevalence of constipation within a month before death was 1.87 times higher than in the whole baseline CKD group [ 62 , 63 ]; nonetheless, the increase in the prevalence of constipation in CKD patients was evidenced also over the 1-year follow-up period in the EQUAL study [ 52 ].…”

Health-Related Quality-of-Life Trajectories over Time in Older Men and Women with Advanced Chronic Kidney Disease

“…We previously demonstrated a faster kidney decline in men compared with women in the EQUAL population 12 , and others have demonstrated that lower levels of eGFR correlate well with lower HRQOL 39 . In addition, a faster decline in kidney function is associated with a steeper increase in symptom burden 41 , which in turn negatively affects HRQOL.…”