Serum zinc levels and multiple health outcomes: Implications for zinc-based biomaterials

Background: Zinc-based biomaterials, including biodegradable metal, nanoparticles, and coatings used in medical implants release zinc ions that may increase the whole-body and serum zinc concentrations. The impact of serum zinc concentrations on major health outcomes can provide insights for device design and clinical transformation of zinc-based biomaterials. Methods: This nationally representative cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (NHANES, 2011-2014) including 3607 participants. Using unadjusted and multivariate-adjusted logistic regression analyses, two-piecewise linear regression model with a smoothing function and threshold level analysis, we evaluated the associations between elevated serum zinc levels and major health outcomes. Results: Elevated serum zinc levels were significantly associated with an increase in total spine and total femur bone mineral density (BMD). Every 10 μg/dL increase was associated with a 1.12-fold increase in diabetes mellitus (DM) and 1.23-fold and 1.29-fold increase in cardiovascular diseases (CVD) and coronary heart disease (CHD), in participants with serum zinc levels ≥ 100 μg/dL. It had no significant linear or nonlinear associations with risk of fractures, congestive heart failure, heart attack, thyroid disease, arthritis, osteoarthritis, rheumatoid arthritis, dyslipidemia and cancer. Conclusion: Serum zinc levels are significantly associated with increased BMD in the total spine and total femur, and risk of DM, and CVD/CHD among participants with serum zinc levels ≥100 μg/dL.