The association between serum copper and obesity and all-cause mortality: the NHANES 2011-2016

Excessive serum copper has multiple effects on human health, while the association between copper and obesity remains unclear. The objective of this study is to examine the associations of serum copper concentrations with obesity and adiposity measures, including body fat composition and distribution among adults in the USA. This analysis utilized data from the National Health and Nutrition Examination Survey (NHANES) (2011-2016). A total of 7285 adults aged 18 years or older who had serum copper measures were included in this cross-sectional study. Multi-linear regression and logistic regression were used to estimate the independent risky effect of copper on fat deposition and all-cause mortality. Moreover, these associations were analyzed in stratification analysis by gender, age, and physical activity (PA). Generally, we found that participants who were females, non-Hispanic Black, or with inactive PA tended to have a higher serum level of copper. In addition, we observed positive associations between serum copper and adiposity measurements. Furthermore, a serum copper level higher than 133.9 μg/dL was a risk factor for all-cause mortality, which doubled the odds ratio of all-cause mortality compared to the normal serum copper level. Serum copper was positively associated with fat deposition of whole body and regional parts, and all-cause mortality. Furthermore, the effects of copper on fat distribution were also significant and could be modified by age, gender, and PA.