DIETARY ACID LOAD, KIDNEY FUNCTION AND RISK OF CHRONIC KIDNEY DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS OF OBSERVATIONAL STUDIES

Background and Aim: Study findings examining the association between dietary acid load (DAL), kidney function and risk of chronic kidney disease (CKD) are inconsistent and there has been no meta-analysis on the relationship between DAL, kidney function and risk of chronic kidney disease (CKD), hence we investigated this association in this paper.Methods: PubMed, ISI web of science and Scopus were searched up to January 2018 to identify all relevant articles. Effect sizes of eligible studies were pooled in random- effect model using the DerSimonian-Laird method. The I2 index was used to assess the amount of heterogeneity. Results: Meta-analysis of 9 observational studies showed that DAL had a positive significant association with risk of CKD (1.31; 95%CI: 1.06, 1.62; P= 0.011). Furthermore, increased DAL can decrease urine pH (-0.47; 95%CI: -0.85, -0.08; P= 0.017) significantly. Subgroup analysis could not identify the source of heterogeneity about the risk of CKD. However, it showed a method of measurement was the source of heterogeneity about urine pH (24h urine pH -0.62; 95%CI: -0.70, -0.54; P< 0.0001; Fasting urine pH -0.08; 95%CI: -0.18, 0.02; P= 0.111). Conclusion: Our study showed that DAL can increase the risk of CKD and have an inverse association with urine pH.

Keywords:

Dietary acid load , chronic kidney disease , Urine pH , Meta-analysis