Saf Health Work.  2011 Dec;2(4):365-374.

The Effects of Long-Term, Low-Level Exposure to Monocyclic Aromatic Hydrocarbons on Worker's Insulin Resistance

• Won YL
• Ko Y
• Heo KH
• Ko KS
• Lee MY
• Kim KW

Abstract

OBJECTIVES
This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance.
METHODS
The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared.
RESULTS
There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-alpha, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs exposure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530).
CONCLUSION
This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.

Keyword

Aromatic hydrocarbons; Insulin resistance; Cytokines; Oxidative stress

MeSH Terms

Cholesterol
Cytokines
Fasting
Glucose
Glyoxylates
Homeostasis
Humans
Hydrocarbons, Aromatic
Insulin
Insulin Resistance
Linear Models
Logistic Models
Male
Mandelic Acids
Occupations
Oxidative Stress
Solvents
Styrene
Toluene
Tumor Necrosis Factor-alpha
Xylenes
Cholesterol
Cytokines
Glucose
Glyoxylates
Hydrocarbons, Aromatic
Insulin
Mandelic Acids
Solvents
Styrene
Toluene
Tumor Necrosis Factor-alpha
Xylenes