Comparative analysis of blood parameters of the erythrocyte lineage between patients with chronic periodontitis and healthy patients: Results obtained from a meta-analysis.

Objective Quantitatively evaluate blood parameters of the erythrocyte lineage in patients with chronic periodontitis and healthy controls by means of a meta-analysis. Material and methods A review of literature was performed in the scientific databases for studies published before September 2016. The abstracts were evaluated and the extraction of data performed by two examiners. The parameters assessed were: hemoglobin levels, number of circulating red blood cells, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in patients with chronic periodontitis and healthy controls. The calculations were obtained through the statistical software Review Manager version 5.3, with calculation of Mean Difference, heterogeneity (I²) and funnel plot with P < 0.05. Results Nine case/control studies composed the results with 342 patients with chronic periodontitis and 359 healthy controls. There was a significant decrease in hemoglobin levels (MD = -1.60, 95% CI: -2.72, -0.48, P = 0.005) and number of circulating red blood cells (MD = -0.51, 95% CI: -0.78, -0.24, P = 0.0002), hematocrit (MD = -4.41, IC 95%: -7.13, -1.68, P = 0.002), mean corpuscular hemoglobin (MD = -0.80; IC 95%: -1.38, -0,22, P = 0.007) and mean corpuscular hemoglobin concentration (MD = -0.93, IC 95%: -1.63, -0.23, P = 0.009) in patients with chronic periodontitis when compared to healthy controls. No publication bias was found through the funnel plot asymmetry. Conclusion There is an associated of the reduction of hematological parameters (such as levels of hemoglobin and circulating red blood cells, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration) to patients with chronic periodontitis.