Neutrophil-lymphocyte ratio as a predictor of slow gait speed in older adults: The Rugao Longitudinal Aging Study.

BACKGROUND:Few studies have investigated the association of the neutrophil-to-lymphocyte ratio (NLR) with gait speed, but whether the NLR is predictive of slow gait speed in older adults remains unknown. The aim of this study is to examine the association of NLR levels with risk of slow gait speed development in older adults. METHODS:Overall, 1753 participants (53.11% male, aged 60-92 years, with a mean age of 77.01 ± 4.27 years) from the second wave of the Rugao Longitudinal Aging Study were included. The second wave was recognized as the baseline in this study. Gait speed was measured using a 5-m walk test at baseline and at the 3.5-year follow-up. A slow gait speed was considered a walking speed less than 0.8 m/s. The NLR was calculated based on absolute blood neutrophil and lymphocyte counts. Logistic regression models were used to investigate the association between NLR levels and slow gait speed. RESULTS:In the cross-sectional analysis, 394 individuals were identified as having slow gait speed. We found that increased NLR levels were associated with a higher risk of slow gait speed in older adults with and without comorbidities (P-value <0.05). During the 3.5-year follow-up period, 440 individuals had developed new-onset slowness. After confounding factors were controlled, increased NLR levels were significantly and independently associated with an increased risk of slow gait speed among older adults with (odds ratio [OR] 3.82, 95% confidence interval [CI] 1.87-7.89) and without (OR 3.29, 95% CI: 1.54-7.10) comorbidities. CONCLUSION:The NLR is an inexpensive and easily obtainable inflammatory biomarker that robustly and independently predicts slow gait speed risk in older adults.