The adipose tissue to serum dichlorodiphenyldichloroethane (DDE) ratio: Some methodological considerations

Dichlorodiphenyldichloroethane (DDE) adipose tissue level has been regarded as a preferred indicator of accumulated human exposure to DDT; however blo od sera are more feasible to obtain and analyze than adipose tissue samples . Inconsistent and scarce information exists in relation to the adipose tis sue/serum DDE ratio. As a part of a hospital-based case-control study perfo rmed in Mexico City from 1994 to 1996, 198 paired serum and adipose tissue samples were obtained from 72 women with histologically confirmed breast ca ncer and 126 women with benign breast disease. Both adipose tissue and seru m DDE levels were determined by gas-liquid chromatography and reported as p pb lipid weight (ng/g) as well as wet basis (ng/ml). Results showed that th e adipose tissue/serum DDE ratio (ADSE) varies according to the type of inf ormation (lipid vs wet basis, arithmetic vs geometric means) used for its e stimation. ADSE gets a value near 1 (1.1) only when the geometric DDE level s in lipid basis are used for its estimation. The correlation between DDE s erum and adipose tissue levels was found (r = 0.364, P < 0.001), The ADSE d id not vary by disease status, nor was it altered by parity, history of bre ast-feeding, and other reproductive characteristics. We endorse the use of venipuncture instead of biopsy as a way to estimate DDT body burden levels in further research, (C) 1999 Academic Press.