Circulating Selenium Level Was Positively Related to Visceral Adiposity Index with a Non-linear Trend: a Nationwide Study of the General Population

Selenium plays a role in obesity. However, whether circulating selenium levels are related to the visceral adiposity index (VAI), an indicator of obesity, is still unknown. Based on the National Health and Nutrition Examination Survey (NHANES) 2011–2018, data from 12,777 individuals aged ≥ 20 years were analyzed to clarify this question. In fully adjusted models of multivariate regression analysis, natural logarithm (Ln) selenium was positively related to Ln VAI ( β = 0.41; 95% confidence interval [CI], 0.27, 0.55; P < 0.001). Compared with the lowest quartile of Ln selenium, the highest quartile was also positively associated with Ln VAI ( β = 0.16; 95% CI, 0.11, 0.21; P < 0.001). Moreover, we found that this positive connection was non-linear. When Ln selenium was less than the inflection point, Ln selenium was positively related to Ln VAI ( β = 0.41; 95% CI, 0.31, 0.52; P < 0.001). However, when Ln selenium was greater than or equal to the inflection point, Ln selenium was not significantly related to Ln VAI ( β = −0.15; 95% CI, −0.56, 0.25; P = 0.455). In subgroup analysis, significant interactions were observed with age and sex ( P for interaction < 0.05). Stronger interactions were observed among middle-aged participants ( β = 0.65; 95% CI, 0.31, 0.98; P = 0.002) and males ( β = 0.61; 95% CI, 0.43, 0.79; P < 0.001). Overall, circulating selenium levels were positively related to VAI, with a non-linear trend. Prospective studies and interventional experiments are necessary to verify the possible mechanisms.