Researchers measured serum alpha-Klotho in 86 adults undergoing coronary CT angiography (CCTA) and found that lower Klotho levels correlated strongly with higher Agatston calcium scores and worse CAD-RADS stenosis grades. These associations remained significant after adjusting for age. Klotho also inversely correlated with the Atherogenic Index of Plasma (AIP) independent of age, while links to TyG and METS-IR metabolic indices were attenuated after adjustment. In ordinal logistic regression, Klotho independently predicted CAD-RADS severity. ROC analysis showed moderate ability to detect any coronary atherosclerosis (AUC = 0.754), with an exploratory cutoff of ≤823 pg/mL yielding ~72% sensitivity and 75% specificity. The findings suggest alpha-Klotho is a promising circulating biomarker of coronary atherosclerotic burden warranting validation in larger cohorts.