Coronary artery calcium as a marker of healthy and unhealthy aging in adults aged 75 and older: The Atherosclerosis Risk in Communities (ARIC) study

Background and aims: Coronary artery calcium (CAC) is validated for risk prediction among middle-aged adults, but there is limited research exploring implications of CAC among older adults. We used data from the Atherosclerosis Risk in Communities (ARIC) study to evaluate the association of CAC with domains of healthy and unhealthy aging in adults aged ≥75 years. Methods: We included 2,290 participants aged ≥75 years free of known coronary heart disease who underwent CAC scoring at study visit 7. We examined the cross-sectional association of CAC = 0, 1–999 (reference), and ≥1000 with seven domains of aging: cognitive function, hearing, ankle-brachial index (ABI), pulse-wave velocity (PWV), forced vital capacity (FVC), physical functioning, and grip strength. Results: The mean age was 80.5 ± 4.3 years, 38.6% male, and 77.7% White. 10.3% had CAC = 0 and 19.2% had CAC≥1000. Individuals with CAC = 0 had the lowest while those with CAC≥1000 had the highest proportion with dementia (2% vs 8%), hearing impairment (46% vs 67%), low ABI (3% vs 18%), high PWV (27% vs 41%), reduced FVC (34% vs 42%), impaired grip strength (66% vs 74%), and mean composite abnormal aging score (2.6 vs 3.7). Participants with CAC = 0 were less likely to have abnormal ABI (aOR:0.15, 95%CI:0.07–0.34), high PWV (aOR:0.57, 95%CI:0.41–0.80), and reduced FVC (aOR:0.69, 95%CI:0.50–0.96). Conversely, participants with CAC≥1000 were more likely to have low ABI (aOR:1.74, 95%CI:1.27–2.39), high PWV (aOR:1.52, 95%CI:1.15–2.00), impaired physical functioning (aOR:1.35, 95%CI:1.05–1.73), and impaired grip strength (aOR:1.46, 95%CI:1.08–1.99). Conclusions: Our findings highlight CAC as a simple measure broadly associated with biological aging, with clinical and research implications for estimating the physical and physiological aging trajectory of older individuals.