Background and purpose: cardiovascular diseases (CVDs) remain the leading cause of global morbidity and mortality. Inflammation plays a central role in CVD pathogenesis, and the neutrophil-to-lymphocyte ratio (NLR) has been proposed as a simple, inexpensive inflammatory marker with potential prognostic value. However, evidence regarding its association with prevalent CVD in population-based Iranian cohorts is limited and inconsistent. This study aimed to evaluate the association between NLR and prevalent cardiovascular diseases in participants of the Tabari Cohort Study, and to determine whether NLR provides independent predictive value beyond established cardiovascular risk factors.
Methods: This case-control study was conducted using enrollment-phase data from the Tabari Cohort (2014–2016), including 10,255 adults aged 35–70 years in northern Iran. A total of 2,652 participants were analyzed, comprising 884 CVD cases and 1,768 age- and sex-matched controls (2:1 ratio). Data on demographics, socioeconomic status, lifestyle, comorbidities, and laboratory indices were collected using standardized protocols. NLR was calculated from complete blood counts. Multivariable logistic regression models were used to assess associations between NLR and CVD after adjustment for confounders. Significance was set at p < 0.05.
Results: Participants with CVD had a higher prevalence of obesity, diabetes, hypertension, and dyslipidemia compared with controls (all p < 0.001). Although mean NLR was slightly higher in the CVD group, the difference was not statistically significant. Across predefined NLR cut-offs (1.77, 2.15, and 4.57), no significant association was observed between NLR and CVD in univariate or multivariable models (all p > 0.05). Traditional risk factors remained strongly associated with CVD.
Conclusion: NLR was not independently associated with prevalent cardiovascular disease in this population-based cohort. These findings suggest limited value of NLR as a standalone screening marker for CVD, while traditional cardiometabolic risk factors remain more reliable for risk assessment and prevention strategies.