A national cross-sectional analysis of dietary copper intake and abdominal aortic calcification in the US adults: NHANES 2013-2014

Abstract

Background and aims: Copper is an essential dietary element with a crucial role in physiological regulation. However, the relationship between dietary copper intake and abdominal aortic calcification (AAC) remains uncertain.

Methods and results: This study encompassed a cohort of 2535 adults aged over 40 years, derived from the National Health and Nutrition Examination Survey 2013-2014. Dietary copper intake from both food sources and supplements was assessed through two 24-h dietary recall interviews. AAC was measured by dual-energy X-ray absorptiometry and classified into 3 groups using the Kauppila score system. Multivariable logistic regression models were constructed to evaluate the association between dietary copper intake and AAC. Among the participants, a total of 771 individuals (30.4%) were diagnosed with AAC, of which 239 (9.4%) exhibited severe AAC. Higher dietary copper intake was significantly associated with a lower incidence of severe AAC. Specifically, for each 1 mg/day increase in dietary copper intake, the incidence of severe AAC decreased by 38% (odds ratios [OR] 0.62, 95% confidence intervals [CI] 0.39-0.98) after adjustment for relevant covariates. Moreover, individuals in the third tertile of copper intake had a 37% lower incidence of AAC compared to those in the first tertile [OR 0.63, 95% CI (0.43-0.95)]. However, no significant associations were found between supplemental copper intake or serum copper levels and AAC.

Conclusions: This study demonstrates that lower dietary copper intake, rather than serum copper levels or supplement copper intake, is significantly associated with a higher prevalence of AAC in adults ≥40 years old in the United States.

Keywords: Abdominal aortic calcification; Cardiovascular disease; Copper; Mineral metabolism; NHANES; Nutrition.