Riassunto analitico
Introduction and aim of the thesis
The role of micronutrients and trace elements has been an important topic for the last century. Cadmium (Cd) in particular has been implied in many chronic diseases and as such it is of great interest in public health. Indeed, Cd is a heavy metal which easily accumulates in the human body, especially liver and kidney, and exert its toxicity on various organs and systems (e.g., endocrine and cardiovascular systems). Risk is a fundamental concept in medicine and public health, and it is estimated on the basis of various biomarkers; but it is also a necessary step in the elaboration of environmental protection laws and regulations. The estimate of health risks for Cd level so far considered not harmful can lead the way to new and stricter guidelines and regulations.
Materials and methods
In a group of healthy blood donors living in the Reggio Emilia province we estimated Cd daily intake through a semi-quantitative food frequency questionnaire validated for the Central-Northern Italy population. Moreover, we acquired a fasting blood sample and a morning urine sample: the first was used to determinate the levels of hormonal and metabolic parameters (i.e., ALT, glycaemia, total cholesterol and HDL, triglycerides, creatinine, ferritin, total proteins and TSH). For the latter, the following parameters were evaluated: urinary Cd concentration (U-Cd), 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dG), creatinine and cotinine.
Results
In our population, we found a median Cd intake of 6.16 μg/day and a median U-Cd of 0.21 μg/L. Cd intake was positively associated with ALT levels, total cholesterol and TSH, and was negatively associated with HDL levels and ferritin levels. As for U-Cd, we found a positive correlation with ALT levels, total cholesterol, triglycerides and TSH, and a negative association with HDL levels and ferritin levels. Moreover, we found a strong positive correlation between U-Cd and 8-oxo-dG, even after adjustment for creatinine.
Discussion and conclusions
Our population showed overall Cd intake levels below the European estimated mean value of 3.8 μg/kg/week and below the Provisional Tolerable Weekly Intake (PTWI) set by the European Food Safety Authority (EFSA) at 2.5 μg/kg/week. However, a positive correlation between low-level Cd intake and alteration in metabolic parameters was still present. Moreover, it is of particular interest the positive correlation we found between U-Cd and 8-oxo-dG, which was stronger than expected. In conclusion, our study suggests that even low-level Cd exposure, generally considered safe for human, may lead to adverse health effects; as such, re-evaluation of guidelines and regulation could be necessary, along with other public health initiatives.
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