Effects of Chronic Exposure to Low Doses of Trichloroethylene on Steroid Hormone and Insulin Levels in Normal Men

Abstract

The aim ofdis studywas to exmine the senum leves ofinsulin and some adrena steroid hormones in men c expbosd toXlow doe of tricooety e (TCE). A tiotal of 85 workers participated in tis study Each worker had urine collected and analyze for trichioroacetic adds (UTCA) on the same day that a blood sample was taken for analyses of serum rone, hormOnebinding globulin (SHBG), androstenedione, cortisol, d rone, and insulin. lle mean concentraion of e UTCA was 22.4 pmg a creanTnine (rnge 0.8-136.4 (1) indicated that exposure to TCE in excess of national norms can cause ill effects induding speech and hearing impairments, effects of stroke, liver problems, anemia and other blood disorders, diabetes, kidney disease, urinary tract disorders, and skin rashes. However, relatively few studies have evaluated the long-term effects of exposure to TCE at levels below the threshold limit value (TLV) (2-6).In two early publications, we showed that long-term exposure to TCE at levels below the TLV was not associated with any significant changes in levels of reproductive hormone or spermatogenesis and semen quality (7,8). In this paper, we present the effects of long-term exposure to TCE on insulin and adrenal hormones and discuss their associations with sex hormone-binding globulin (SHBG) and testsosterone (T) levels. Materials and MethodsDetails of recruitment and profiles of subjects involved in the study, as well as the experimental design, were reported earlier (8). The study population consisted of 85 male workers of Chinese descent who worked in an electronic fictory where TCE was used as a degreaser to dean small metal parts. Informed consent was obtained from each subject.In all 85 subjects ranging from 22 to 39 years of age, there were no factors in their medical histories that would influence the endocrine functions, e.g., no history of diabetes mellitus, long-term medication, or testicular injury. No abnormalities were detected clinically. All subjects had normal liver function tests (serum glutamic oxalacetic transaminase, serum glutamic pyruvic transaminase, gamma glutamyl transpeptidase, and alkaline phosphatase).Blood colection and hormonal assay. A single venous blood sample was collected between 7:30 and 8:00 A.M. from each subject throughout the study to reduce the diurnal variation of the hormonal levels.Sera were separated and stored at -700C until assayed.Serum concentrations of testosterone, androstenedione (A4), cortisol, aldosterone, insulin, and SHBG were measured by established immunoassays. Testosterone and cortisol were measured using the World Health Organization (WHO) matched reagents and methods (9). The intra-and interassay coefficients of variation of the assays were less than 10% over the effective concentration ranges.Serum levels of SHBG and aldosterone were measured using radioimmunoassay kits purchased from DPC Inc. (Los Angeles, CA). The intra-and interassay coefficients of variation were less than 15%. Serum insulin levels were measured using kits from CIS Bio International (Yvette, Cedex,...

Effects of occupational solvent exposure on reproductive hormone concentrations and fecundability in men

“…White spirit contains appreciable levels of aromatic solvents [Lewander et al, 2002]; therefore, it is possible that the effects of white spirit on FSH secretion were due to the toluene component. In contrast to the finding in the present study of increased FSH with increasing exposure to chlorinated solvents as a category, increasing years of exposure to the chlorinated solvent trichloroethylene were significantly associated with decreasing serum FSH and testosterone concentrations in two studies of one occupational cohort [Chia et al, 1997;Goh et al, 1998]. …”

“…Exposure to aromatic solvents, glycol ethers, styrene, and 2-bromopropane has been associated with reduced semen quality [Welch et al, 1988;Ratcliffe et al, 1989;Kim et al, 1996;Kolstad et al, 1999;Tielemans et al, 1999;De Celis et al, 2000]. Altered plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and/or testosterone have been reported in men occupationally exposed to toluene [Mørck et al, 1988;Svensson et al, 1992a,b], 2-bromopropane [Kim et al, 1996], and trichloroethylene [Chia et al, 1997;Goh et al, 1998]. …”

Mechanism Involved in Trichloroethylene-Induced Liver Cancer: Importance to Environmental Cleanup

“…Recent reports have associated increased serum insulin concentrations with occupational exposures to trichloroethylene (Goh et al 1998). Increased amounts of insulin could also account for the large accumulations of glycogen in the liver of mice treated with DCA.…”