Human exposure to polyhalogenated hydrocarbons and incidence of selected malignancies -central European experience.

This paper describes results of two ecological studies design to analyze the incidence of selected malignancies in two populations exposed to polychlorinated hydrocarbons, mostly PCBs and TCDDs/Fs by comparing data available in the National Cancer Registry of the Slovak Republic and National Oncological Registry of the Czech Republic databases for the Slovak Republic (approximately 5M inhabitants) and the Czech Republic (10,3 M inhabitants) to the data relevant for the population of Michalovce District, the Slovak Republic (approximately 112,000 inhabitants) and Uherske Hradiste, the Czech Republic (146,000 inhabitants). Those districts are recognized as PCB-contaminated areas due to production and industrial use of PCBs. Data were analyzed for the 10-year period 1987-1996. The age adjusted world standard ratio (WSR) incidence of thyroid, pancreatic, breast, ovarian, bladder, and brain tumors in females and thyroid, pancreatic, breast, bladder, brain, prostate and testicular tumors in males were compared. Neither PCBs nor TCDDs/Fs appear to contribute to the observed significantly lower incidence of breast and prostate cancer in the Michalovce District and lower bladder cancer incidence in Uherske Hradiste District. However, anti-estrogenic and anti-androgenic properties have been described for hydroxylated and methylsulfonyl PCB metabolites. These properties could contribute to a mechanism through which these metabolites might modulate the development of breast, prostate and bladder cancer. The results of our analysis points to substantial potential problems of risk assessment for cancer incidence in populations exposed to xenobiotics, or more generally, as it relates to a wide spectrum of confoundings of cancer risk factors.

Associations Between Homeostasis Model Assessment (HOMA) and Routinely Examined Parameters in Individuals With Metabolic Syndrome.

The aim of the study was to investigate whether routine clinical parameters, including visceral adiposity index (VAI) and atherogenic index of plasma (AIP), could become widely applicable predictors of insulin resistance (IR), evaluated using homeostasis model assessment (HOMA-IR, HOMA-ß), with regard to presence of metabolic syndrome (MS). The study comprised 188 individuals identified to meet the MS criteria during regular health examinations and an equal number of age, sex-matched controls without MS. The strongest correlations were noted between HOMA-IR and waist circumference (WC) in the MS group (r=0.57) as well as between HOMA-IR and alanine aminotransferase (ALT, r=0.57) or aspartate aminotransferase (r=0.56) in the controls, with a statistical significance of p<0.001. In a multivariate linear regression model, the predictors of HOMA-IR were WC (linear coefficient ß=0.1, p<0.001), ALT (ß=2.28, p<0.001) and systolic blood pressure (ß=0.04, p<0.001). HOMA-ß was determined by WC (ß=1.97, p=0.032) and ALT (ß=99.49, p=0.004) and inversely associated with age (ß=-1.31, p=0.004). Neither VAI nor AIP were significant predictors. The presence of MS was significantly associated with both HOMA-IR and HOMA-ß. These results indicate that WC and ALT appear to be reliable predictors of IR. Comprehensive assessment of these parameters may serve for estimating the level of IR.