Hematological inflammatory indices and Long-Term risk of depressive symptoms: a korean cohort study

This study was to evaluate the associations between the systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and depressive symptoms in the general population.

We analysed data from 96,838 participants in a large-scale Korean cohort study. Depressive symptoms were assessed using the Centre for Epidemiologic Studies Depression Scale (CES-D), and Cox proportional hazard models were used to estimate unadjusted and multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident depressive symptoms across quartiles of hematological inflammatory indices.

During a median follow-up of 6.5 years, 17.3% (n = 16,793) of the participants developed incidental depressive symptoms. Higher quartiles of SII, SIRI, and MLR were significantly associated with slight increase in the risk of depressive symptoms with a dose-response pattern. Sex-stratified analyses revealed that the SII was a stronger predictor of depressive symptoms in men, whereas the SIRI and MLR showed stronger associations in women.

Hematological inflammatory indices including SII, SIRI, and MLR appeared to have a potential in predicting depressive symptoms.