Association of Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio with Diabetic Kidney Disease among Adult Patients with Type 2 Diabetes Mellitus: A Meta-Analysis of Observational Studies
Objective. This meta-analysis aimed to evaluate the association of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) with the presence of diabetic kidney disease (DKD) among adult patients with Type 2 diabetes mellitus (T2DM).
Methods. A systematic search of articles was performed in various databases. Studies must have fulfilled the following criteria for inclusion: 1) Randomized controlled trial or observational study; 2) Included adults diagnosed with T2DM; 3) Reported data associating NLR or PLR with the presence of DKD; and 4) Controlled for confounders using logistic regression. Data analysis was performed using Review Manager 5.4 software. The estimates were derived using the generic inverse variance method and pooled using the random effects model. Results were presented as odds ratios (OR) and standard errors (SE) with 95% confidence intervals (CI), and graphically shown as forest plots. The I2 value and Chi-square test were used to assess heterogeneity across studies.
Results. Seven studies were included in the review, totaling 1,486 patients. All were cross-sectional studies and had satisfactory methodological quality as evaluated using the Newcastle-Ottawa Quality Assessment Scale. Pooled analysis from six studies showed a statistically significant association between increased NLR and the presence of DKD, defined as either the presence of albuminuria (95% CI, OR 1.68 [1.28, 2.19], p<0.01); or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 (95% CI, OR 1.56 [1.09, 2.23], p=0.01). In both analyses, there was no significant heterogeneity across studies (I2=0%, Chi2=3.54; and I2=28%, Chi2=2.76 respectively). On the other hand, pooled analysis from two studies did not show a statistically significant association between PLR and albuminuria (95% CI, OR 1.75 [0.85, 3.60], p=0.13), although both studies were homogeneous (I2=0%, Chi2=0.57).
Conclusion. We found a statistically significant association between increased NLR and the presence of DKD. However, a similar association was not found with PLR. Larger studies with more robust designs are recommended.