Detection of Heavy Metals and Investigation of Their Association with Risk Factors for Metabolic Disorders in a Pakistani Population
Authors: Feezan Ali , Afzal Samina , Shoaib Syed Muhammad , Akash Muhammad Sajid Hamid , Nadeem Ahmed , Mir Tahir Maqbool 
Published: September 2023

Abstract
Environmental exposure to heavy metals, such as lead (Pb) and nickel (Ni), has been implicated in the development of chronic metabolic diseases, including diabetes mellitus (DM). This cross-sectional study aimed to evaluate the detection of PB and Ni in ground water by ICP-OES and in the urine samples of participants by ICP-MS and found the association between Pb and Ni exposure and the risk factors for DM and metabolic disorders in the participants. A total of 2688 participants were recruited from the district of Sargodha in Punjab, Pakistan. Participants were categorized into Pb-exposed and Ni-exposed groups, and further stratified into diabetic and non-diabetic subgroups. In groundwater, Except for pH, the levels of total dissolved solids, electrical conductivity, hardness, and turbidity exceeded the guidelines set by the World Health Organization (WHO) and the concentrations of Ni and Pb in the groundwater samples exceeded the WHO guidelines in the study area. While in the study participants, the concentrations of Pb and Ni were measured in urine samples, and various biomarkers related to DM, lipid profile, inflammation, oxidative stress, liver function, and kidney function were assessed. The results showed significantly higher levels of Pb and Ni in both diabetic and non-diabetic individuals compared to healthy participants. Pb-exposed diabetic participants had higher Pb levels than Pb-exposed non-diabetics, and similarly, Ni-exposed diabetics had higher Ni levels than Ni-exposed non-diabetics. These findings suggest that Pb and Ni exposure may contribute to the development of DM. The study also revealed that Pb and Ni exposure were associated with disruptions in various biomarkers. Pb-exposed diabetics exhibited elevated levels of glycemic index markers, including fasting blood glucose (FBG) and glycated hemoglobin A1c (HbA1c). Ni-exposed diabetics showed elevated levels of inflammatory markers, such as C-reactive protein (CRP) and interleukin-6 (IL-6). Both Pb and Ni exposure were associated with dyslipidemia, as indicated by elevated total cholesterol and LDL levels. Furthermore, Pb and Ni exposure were found to impair liver and kidney function, as evidenced by elevated levels of AST, ALT, creatinine and blood urea nitrogen. Pb exposure was also associated with higher levels of MDA. The study's findings were supported by correlation analyses, which demonstrated significant associations between urinary Pb and Ni concentrations and various biomarkers related to DM and metabolic disorders. In conclusion, this study provides substantial evidence linking Pb and Ni exposure to the development of DM and metabolic disorders in a Pakistani population. The findings highlight the need for stricter regulations and preventive measures to reduce heavy metal contamination in the environment and safeguard public health. Future longitudinal studies and interventions are warranted to further elucidate the mechanisms underlying the association between heavy metal exposure and metabolic diseases.