Low serum albumin levels are independently associated with an increased risk of end-stage renal disease (ESRD), according to a new study. The association is independent of chronic kidney disease risk factors, including baseline estimated glomerular filtration rate (eGFR), and urine albumin-to-creatinine ratio (ACR).
In a study of community-dwelling adults, ESRD was 61% and 69% more likely to develop among individuals with serum albumin levels in the first and second quartiles (below 4.0 and 4.0–4.1 g/dL), respectively, compared with those who had levels in the fourth quartile (4.4 g/dL or higher) in a fully adjusted model, Carl P. Walther, MD, of the Baylor College of Medicine in Houston, and colleagues reported online ahead of print in Nephrology Dialysis Transplantation. Each 0.33 g/dL decrease in serum albumin was associated with a 16% increased risk of ESRD.
The researchers adjusted for age, sex, race, baseline eGFR, body mass index, systolic blood pressure, antihypertensive drug use, smoking status, various laboratory measures and comorbidities, and urine ACR.
“To our knowledge, this is the first study to demonstrate an association between serum albumin concentrations and ESRD while accounting for urine ACR in a community-dwelling adult population,” Dr Walther’s team reported.
The association between serum albumin level and incident ESRD was more pronounced in the subgroup of participants with a baseline eGFR of 60 mL/min/1.73 m2 or higher, the investigators reported. In this subgroup, the first and second quartiles of serum albumin were associated with a 7-fold and 4-fold increased risk of ESRD, respectively, compared with the fourth quartile in a fully adjusted model. Each 0.33 g/dL decrease in serum albumin was associated with a 61% increased risk of ESRD.
By comparison, among individuals with an eGFR below 60 mL/min/1.73 m2, the first and second quartiles of serum albumin were associated with an 11% and 39% increased risk of ESRD, respectively, compared with the fourth quartile, and each 0.33 g/dL decrease in serum albumin was associated with a 14% increased risk of ESRD.
The study population consisted of 19,633 individuals who participated in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study, a US prospective, population-based cohort study of black and white adults aged 45 years or older. Dr Walther’s team determined eGFR using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) combined creatinine-cystatin C equation. They identified incident ESRD cases using the US Renal Data System.
Dr Walther and his colleagues acknowledged some study limitations, such as exclusion of individuals of races other than white and black.