Association of immune-inflammatory markers with chronic kidney disease in older adults with obesity: a large-scale cross-sectional study

Obesity is a major independent risk factor for chronic kidney disease (CKD). Population-level evidence linking immune dysregulation to CKD in obese individuals remains limited. In this cross-sectional study, we analyzed data from community-dwelling adults aged 65-85 years in Shanghai, China. The immune-inflammatory markers were compared between obese and non-obese groups. The associations between routinely measured immune-inflammatory markers (neutrophils, lymphocytes, platelet-to-lymphocyte ratio [PLR]) and CKD prevalence were evaluated using multivariable logistic regression, restricted cubic splines (RCSs). Obese individuals had higher neutrophil, monocyte, and lymphocyte counts and lower PLR than the non-obese group. Among participants with obese, elevated neutrophil and lymphocyte counts were independently associated with greater odds of CKD (adjusted odds ratio [aOR] for highest tertile: 1.42, 95% confidence interval [CI] 1.07-1.90; and 1.53, 95% CI 1.16-2.01, respectively), whereas higher PLR was associated with reduced odds (aOR 0.70, 95% CI 0.53-0.92). Adjusted RCS plots revealed nonlinear associations. Elevated neutrophils and monocytes together with lower PLR emerged as key immunoinflammatory markers that might be associated with obesity-associated CKD. These findings highlight the clinical potential of routine immune-inflammatory biomarkers for early and precise risk stratification of obesity-related CKD.