UCSF

Background

Few studies have investigated the changes in weight that may occur over time among adults with the progression of chronic kidney disease (CKD). Whether such weight changes are independently associated with death after the onset of end-stage renal disease has also not been rigorously examined.

Study design

Prospective cohort study.

Setting & participants

We studied 3,933 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study, a longitudinal cohort of patients with CKD. We also performed similar analyses among 1,067 participants of the African American Study of Kidney Disease and Hypertension (AASK).

Predictors

Estimated glomerular filtration rate (eGFR) and weight change during CKD.

Outcome

Weight and all-cause mortality after dialysis therapy initiation.

Results

During a median follow-up of 5.7 years in CRIC, weight change was not linear. Weight was stable until cystatin C-based eGFR (eGFR_cys) decreased to <35mL/min/1.73m²; thereafter, weight declined at a mean rate of 1.45 kg (95% CI, 1.19-1.70) for every 10 mL/min/1.73m² decline in eGFR_cys. Among the 770 CRIC participants who began hemodialysis or peritoneal dialysis therapy during follow-up, a >5% annualized weight loss after eGFR decreased to <35mL/min/1.73m² was associated with a 54% higher risk for death after dialysis therapy initiation (95% CI, 1.17-2.03) compared with those with more stable weight (annualized weight changes within 5% of baseline) in adjusted analysis. Similar findings were observed in the AASK.

Limitations

Inclusion of research participants only; inability to distinguish intentional versus unintentional weight loss.

Conclusions

Significant weight loss began relatively early during the course of CKD and was associated with a substantially higher risk for death after dialysis therapy initiation. Further studies are needed to determine whether interventions to optimize weight and nutritional status before the initiation of dialysis therapy will improve outcomes after end-stage renal disease.