A Retrospective Analysis of the Association of Neutrophil–Lymphocyte Ratio (NLR) with Anemia in the Saudi Population

Background: The link between inflammation and anemia is well established but fluctuations in the emerging inflammatory index, neutrophil–lymphocyte ratio (NLR), in anemic subjects remain ambiguous. The purpose of this study is to address the prevailing knowledge gaps regarding the association of NLR with anemia in the Saudi population. Methods: Laboratory results of NLR, C-reactive protein (CRP), and hemoglobin for 14,261 subjects were obtained from Al Borg Diagnostics and retrospectively analyzed. Means, risk measures, and the diagnostic performance of NLR for anemia were examined in age- and gender-wise comparisons. Results: NLR was significantly elevated in anemic individuals and those with high NLR had a significantly lower Hb concentration. Moreover, elevated NLR was more prevalent in anemic subjects (PR: 1.87, 95% CI: 1.46–2.40, p < 0.0001) and carried a greater risk for the condition (OR: 1.91, 95% CI: 1.47–2.48, p < 0.0001) as did CRP. These observations demonstrated distinct age- and gender-specific patterns. However, both parameters were of no value in the diagnosis of anemia as seen from receiver operating characteristic curves. Conclusions: Altogether, these findings indicate that elevated NLR is associated with anemia, which suggests its usefulness for monitoring rather than diagnosing anemia associated with inflammation in Saudi subjects. Further examination of this association in longitudinal studies is needed.