Blood cadmium, mercury, and lead and metabolic syndrome in South Korea: 2005-2010 Korean National Health and Nutrition Examination Survey

Introduction: We present data from the Korean National Health and Nutrition Examination Survey 2005-2010 regarding the association between levels of blood cadmium, mercury, and lead and metabolic syndrome (MS) in a representative sample of the adult South Korean population. MS is defined as a cluster of disorders including central obesity, glucose intolerance, hypertension, low high-density lipoprotein cholesterol, and high triglycerides. Methods: The analysis was restricted to participants ≥20 years of age who completed the health examination survey, including blood lead, cadmium, and mercury measurements. Odds ratios (ORs) for MS were calculated for log₂-transformed blood metal levels and tertiles thereof after covariate adjustment. Results: No significant results were observed in females. In males, adjusted ORs indicated that a doubling of blood cadmium resulted in a 23.0% increase in the risk of MS. Male subjects in the highest tertile of blood cadmium were 36.7% more likely to have MS versus those in the lowest tertile. There were no significant ORs for having MS or its components in any of the models of blood lead and mercury levels after covariate adjustment. Conclusion: The association between blood cadmium level and MS was significant regardless of the type of variable (continuous or categorical) among men with lower blood cadmium levels. Thus, blood cadmium levels were robust risk factors for MS in men. To our knowledge, this is the first report of an association between cadmium exposure and MS.