Serum selenium and peripheral arterial disease: results from the national health and nutrition examination survey, 2003-2004

Abstract

The authors conducted a cross-sectional study of the association of serum selenium with the prevalence of peripheral arterial disease among 2,062 US men and women 40 years of age or older participating in the National Health and Nutrition Examination Survey, 2003-2004. Serum selenium was measured by using inductively coupled plasma-dynamic reaction cell-mass spectrometry. Peripheral arterial disease was defined as an ankle-brachial blood pressure index <0.90. The age-, sex-, and race-adjusted prevalence of peripheral arterial disease decreased with increasing serum selenium (P for linear trend = 0.02), but there was an indication of an upturn in risk in the highest quartile of serum selenium. The fully adjusted odds ratios for peripheral arterial disease comparing selenium quartiles 2, 3, and 4 with the lowest quartile were 0.75 (95% confidence interval: 0.37, 1.52), 0.58 (95% confidence interval: 0.28, 1.19), and 0.67 (95% confidence interval: 0.34, 1.31), respectively. In spline regression models, peripheral arterial disease prevalence decreased with increasing serum selenium levels up to 150-160 ng/mL, followed by a gradual increase at higher selenium levels. The association between serum selenium levels and the prevalence of peripheral arterial disease was not statistically significant, although a U-shaped relation was suggested.

Figure 1.

Odds ratios for peripheral arterial disease by serum selenium levels, National Health and Nutrition Examination Survey, 2003–2004. Curves represent adjusted odds ratios (solid line) and their 95% confidence intervals (dashed lines) based on restricted quadratic splines for serum selenium levels with knots at the 5th, 50th, and 95th percentiles. The reference value (odds ratio = 1) was set at the 10th percentile of serum selenium distribution (116 ng/mL). Odd ratios were adjusted for age, sex, race-ethnicity, education, family income, postmenopausal status, smoking, serum cotinine, alcohol consumption, body mass index, dietary supplement use, C-reactive protein, total cholesterol, high density lipoprotein cholesterol, cholesterol-lowering medication use, systolic blood pressure, blood-pressure-lowering medication use, diabetes, and glomerular filtration rate. Bars represent the weighted histogram of serum selenium distribution.