Clinical Relevance of Serum Selenium Levels and Abdominal Aortic Calcification

Selenium (Se) is an essential micronutrient with antioxidative properties, but previous studies have shown that extremely high circulating Se concentrations are associated with a higher prevalence of cardiovascular diseases (CVDs). To date, it remains unknown whether this association has connections with arterial calcification. A total of 982 participants with both serum Se concentration and abdominal aortic calcification (AAC) score data were enrolled from the 2013-2014 National Health and Nutrition Examination Survey (NHANES), a cross-sectional study of a noninstitutionalized population in the USA. Serum Se levels were determined by inductively coupled plasma-dynamic reaction cell-mass spectrometry. AAC was obtained from dual-energy X-ray absorptiometry and quantified by the Kauppila score system. Severe AAC was defined as Kauppila score ≥ 5. Among all participants, the mean serum Se level was 132.89 μg/L. The average AAC score was 1.51, and 11.7% had severe AAC. Compared with those in the lowest quartile of Se (< 121.1 μg/L), the highest quartile subgroup (> 143.1 μg/L) was associated with a higher mean AAC score (β-coefficient 0.88; 95% CI 0.28, 1.47; p = 0.004) and greater odds of having severe AAC (odds ratio 2.19; 95% CI 1.10, 4.36; p = 0.026) after adjusting for demographic, biochemical, and clinical characteristics. The concentrations of other circulating trace elements showed no statistically significant association with the AAC score. High serum Se levels were independently associated with an increased mean AAC score and aggravated AAC severity among noninstitutionalized US adults. Serum Se might adversely affect the cardiovascular system when the serum Se concentration exceeds 143 μg/L.