Cross-sectional and longitudinal associations of an inflammatory aging clock with intrinsic capacity and functional ability in older adults with physical and cognitive impairments: the COGFRAIL cohort

Chronic inflammation is considered a hallmark of aging, but its association with indicators of healthy aging such as intrinsic capacity (IC) and functional ability remains unknown. We explored the association of an inflammation-based aging clock (iAge) with IC and functional ability in older adults. We used data from the COGFRAIL cohort, including old adults with prefrailty/frailty and mild cognitive and functional impairment. Biological age acceleration was measured at baseline through the inflammatory clock iAge (BAAiAge) was assessed at baseline. Functional ability on basic (BADL) and instrumental activities of daily living (IADL) as well as IC (a composite score [from 0 to 100] including the locomotion, cognition, psychology, sensory and vitality domains) were determined at baseline and on two follow-up visits. A total of 226 participants (82.5 ± 5.1 years, 64% women) had data at baseline, of whom 180 provided data during a 24.5-month follow-up. During the follow-up, a significant decline was observed in BADL (β=-0.4, 95% confidence interval -0.5 to -0.3, p < 0.001), IADL (β=-1.5; 95%CI=-1.7 to -1.2, p < 0.001) and IC (β=-2.0, 95%CI=-3.7 to -0.3, p = 0.025). Although baseline IC was positively associated with both BADL and IADL in cross-sectional (p = 0.002 and p < 0.001) and longitudinal analyses (p = 0.011 and p = 0.070), no association was found between BAAiAge and any of BADL/IADL, IC or IC domains in cross-sectional or longitudinal analyses. BAAiAge seems not to be associated with IC or functional ability in this cohort of very old adults with mild cognitive and functional impairment. Future research should confirm these findings in other cohorts with varying functional status.