Serum albumin and kidney function decline in HIV-infected women

Background: Serum albumin concentrations are a strong predictor of mortality and cardiovascular disease in human immunodeficiency virus (HIV)-infected individuals. We studied the longitudinal associations between serum albumin levels and kidney function decline in a population of HIV-infected women.

Study design: Retrospective cohort analysis.

Setting & participants: Study participants were recruited from the Women's Interagency HIV Study (WIHS), a large observational study designed to understand risk factors for the progression of HIV infection in women living in urban communities. 908 participants had baseline assessment of kidney function and 2 follow-up measurements over an average of 8 years.

Predictor: The primary predictor was serum albumin concentration.

Outcomes: We examined annual change in kidney function. Secondary outcomes included rapid kidney function decline and incident reduced estimated glomerular filtration rate (eGFR).

Measurements: Kidney function decline was determined by cystatin C-based (eGFR(cys)) and creatinine-based eGFR (eGFR(cr)) at baseline and follow-up. Each model was adjusted for kidney disease and HIV-related risk factors using linear and relative risk regression.

Results: After multivariate adjustment, each 0.5-g/dL decrement in baseline serum albumin concentration was associated with a 0.56-mL/min faster annual decline in eGFR(cys) (P < 0.001), which was attenuated only slightly to 0.55 mL/min/1.73 m(2) after adjustment for albuminuria. Results were similar whether using eGFR(cys) or eGFR(cr). In adjusted analyses, each 0.5-g/dL lower baseline serum albumin level was associated with a 1.71-fold greater risk of rapid kidney function decline (P < 0.001) and a 1.72-fold greater risk of incident reduced eGFR (P < 0.001).

Limitations: The cohort is composed of only female participants from urban communities within the United States.

Conclusions: Lower serum albumin levels were associated strongly with kidney function decline and incident reduced eGFRs in HIV-infected women independent of HIV disease status, body mass index, and albuminuria.