CST3 and depressive symptom measurement: Of AGELESS Score components, depression was most correlated with exhaustion (r = 0.41, 95% CI: 0.36–0.46, p < 0.001), cystatin C (r = −0.18, 95% CI: −0.25 to −0.12, p < 0.001) and diabetes (r = −0.08, 95% CI: −0.14 to −0.02, p = 0.01) were most correlated with decreased walking speed, FEV1 was most correlated with increased grip strength (r = 0.50, 95% CI: 0.44–0.54, p < 0.001), and educational attainment was most correlated with increased physical activity (r = 0.19, 95% CI: 0.13–0.25, p < 0.001).