The effects of occupational aluminum exposure on blood pressure and blood glucose in workers - A longitudinal study in northern China

Background: Trace element and metal exposure is closely related to the occurrence of chronic diseases, particularly affecting blood pressure and blood glucose. Current studies suggest that heavy metal exposure is a risk factor for hypertension and diabetes. Aluminum can enter the human body through daily life and occupational exposure from food, environment, drugs, and other sources, affecting the cardiovascular, endocrine, and other systems. Therefore, it is significant to observe the effect of aluminum on blood pressure and blood glucose in workers with high concentration. Objective: In this study, electrolytic workers naturally exposed to high concentrations of aluminum were selected. The aim of the 5-year cohort study was to investigate the effects of continuous occupational aluminum exposure on blood pressure and blood glucose in workers and to assess the risk of potential cardiovascular and metabolic diseases due to heavy metal exposure. Methods: In 2014, 183 participants from an electrolysis workshop at an aluminum plant in Shanxi were enrolled. Inductively coupled plasma mass spectrometry (ICP-MS) was performed to determine the plasma aluminum (PAl) concentration of the workers and measured their blood pressure and glucose levels. At the 2019 follow-up, all parameters were measured again in the same workers. The relationship of the P-Al concentration with blood pressure and glucose levels was assessed using generalized linear regression, and risks of developing hypertension and hyperglycemia (diabetes or pre-diabetes) due to Al exposure were assessed using binary logistic regression. Dose-response relationships between average annual rates of change in P-Al and average annual rates of change in blood pressure and blood glucose were analyzed using RCS. The relative risk (RR) and attributable risk (AR) were also calculated. Results: Generalized linear regression showed that the average annual rate of change in P-Al concentration was positively correlated with the annual rates of change in SBP, DBP, and blood glucose levels, with each e-fold increase in P-Al concentration increasing the annual rates of change in SBP and DBP by 3.55 % (P < 0.01) and 3.43 % (P = 0.03), respectively. Binary logistic regression showed that as the average annual rate of change in PAl concentration (categorical variable) increased, the risk of developing hypertension increased (P-trend < 0.05). The RCS results showed that the relationship between the average annual rate of change in P-Al and the average annual rate of change in SBP was a showed a dose-response relationship (P for overall association<0.05). RR and AR increased with increasing P-Al concentration in both hypertensive and diabetic patients. Conclusion: Persistent occupational aluminum exposure is associated with elevated blood pressure levels in workers and increases the risk of developing hypertensive disorders.