Association between Neutrophil-to-Lymphocyte Ratio and Physical Function in Older Adults: A Community-Based Cross-Sectional Study in Japan

Inflammatory responses contribute to physical decline in older adults. Clinical studies have shown that the neutrophil-to-lymphocyte ratio (NLR), a marker of inflammation, is associated with physical decline. However, its association with physical function in community-dwelling older people is still unclear. Hence, we used cross-sectional data to investigate the relationship between NLR and physical function in community-dwelling older adults. Specifically, we analyzed data corresponding to 818 individuals (336 men and 482 women) aged ≥ 75 years, all of whom participated in comprehensive health examinations, including face-to-face interviews, biochemical analyses, and physical function tests. Using these data, we performed multivariable logistic regression analysis to assess the relationship between NLR and physical function, adjusting for sex, age, education, alcohol consumption, smoking, instrumental activity of daily living, body mass index, chronic disease, physical activity, serum albumin level, and depressive mood. The results showed that a higher NLR was associated with a lower grip strength, lower knee extension strength, and slower walking speed. Importantly, the relationship between NLR and physical function was maintained after adjusting for the confounding factors. Thus, we showed a significant association between NLR and physical function, supporting the use of NLR as a marker of physical function in community-dwelling older adults.