Malathion exposure and insulin resistance among a group of farmers in Al-Sharkia governorate

Objectives: Exposure to certain environmental toxins may be associated with increased risk of developing diabetes mellitus. The aim of the present study was to investigate the relation between chronic exposure to malathion and insulin resistance among farmers. Design and methods: The study included 98 non diabetic farmers who handle agricultural insecticides during their field work. The range of the exposure period for agricultural pesticides was 15-20 years. All farmers were males with mean age 39 +/- 12 years. Another 90 administrative employees at Zagazig University Hospitals, non diabetic males age matched were selected as controls. History taking including family history for diabetes, assessment of blood pressure, height, weight, waist circumference and body mass index was done for all participants. Blood samples were withdrawn for measurement of malathion concentration, fasting blood glucose level and fasting insulin level for calculation of homeostasis model assessment of insulin resistance (HOMA-IR). Results: 24.5\% had positive family history for diabetes. It was observed that there was a significant increase in the mean values of malathion blood concentration among studied farmers compared to corresponding controls. There was a positive correlation between malathion blood concentration, waist circumference and insulin resistance. It was also observed that the increase in the mean values of waist circumference and body mass index was accompanied by a significant increase in the mean values of malathion blood concentration. Conclusion: The current results suggested that chronic exposure of non diabetic farmers to organophosphorus malathion pesticides may induce insulin resistance. This effect tended to strengthen as waist circumference increases. (C) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.