Combination of low body mass index and serum albumin level is associated with chronic kidney disease progression: the chronic kidney disease-research of outcomes in treatment and epidemiology (CKD-ROUTE) study.

BACKGROUND

The relationship between protein-energy wasting and chronic kidney disease (CKD) progression is unknown. In the present prospective cohort study, we evaluated the hypothesis that a combination of low body mass index (BMI) and serum albumin level is associated with rapid CKD progression.

METHODS

The study cohort comprised 728 predialysis Japanese patients with CKD (stages 2-5) enrolled from 2010 to 2011. Patients were categorized into four groups according to their serum albumin levels and BMI: group 1, low serum albumin level (<4 g/dL) and low BMI (<23.5 kg/m); group 2, high serum albumin level (≥4 g/dL) and low BMI; group 3, low serum albumin level and high BMI (≥23.5 kg/m); and group 4, high serum albumin level and high BMI. The primary outcome was a 30 % decline in estimated glomerular filtration rate (eGFR) or start of dialysis within 2 years. The secondary outcome was an annual GFR decline (mL/min/1.73 m/year).

RESULTS

Logistic regression analysis adjusted for baseline characteristics (reference, group 4) showed that only group 1 was associated with a significant risk of CKD progression, with adjusted odds ratio of 3.51 [95 % confidence interval (CI) (1.63, 7.56)]. A multivariate linear regression analysis adjusted for baseline characteristics showed a significant difference in annual eGFR decline between groups 1 and 4 [coefficients β (standard error) -2.62 (0.75), p = 0.001].

CONCLUSION

This study suggests that combined effects of low BMI (<23.5 kg/m) and serum albumin level (<4 g/dL) are associated with CKD progression.