Cross-sectional association between relative fat mass and abdominal aortic calcification among US adults: The NHANES 2013 to 2014.

Abdominal aortic calcification (AAC) serves as a reliable predictor of future cardiovascular incidents. This study investigated the association between relative fat mass (RFM) and AAC in US adults. A total of 3079 adults aged ≥40 years from the National Health and Nutrition Examination Survey 2013 to 2014 were included in the cross-sectional study. AAC was evaluated using a semi-quantitative scoring system known as AAC-24, with an AAC score >6 considered severe AAC (SAAC). Logistic regression analyses and restricted cubic splines were applied. Subgroup analyses were also conducted. After adjusting for confounding factors, a clear link was established between RFM and AAC score (β = -0.048, 95% CI: -0.078 to -0.017, P < .01) and between RFM and SAAC (OR = 0.96, 95% CI: 0.92 to 1.00, P < .05). Further restricted cubic spline analysis indicated a negative correlation between RFM and both AAC score and SAAC. In this cross-sectional study, an inverse association was observed between RFM and both AAC score and severe AAC, with a threshold of approximately 48 to 50. Below this threshold, lower RFM was associated with a sharply higher probability of calcification; above it, higher RFM corresponded to a gradually lower probability. Due to the cross-sectional design, causality cannot be inferred. Further prospective cohort studies are needed to validate these findings.