[Blood selenium in healthy persons and individuals with malignant diseases]

Preliminary researches taken part in Yugoslavia showed the risky low concentration of selenium in soil, food items and in serum of the examined population [10]. This research was carried out to discover the some factors which could influence the relationship of serum selenium concentration and the appearance of malignant diseases.

The investigation was carried out in two Belgrade communities, one rural (Barajevo), and the other central (Stari Grad), in two groups: cancer patients (57 + 17) and healthy controls (41 + 13). These groups were similar in median age and gender. Samples of human serum were obtained by venepunction, and after wet digestion selenium concentration was determined by hydride generated AAS (Perkin-Elmer 5000). Anamnestic data concerning family history of malignancy and comorbidity, especially chronic noncommunicable diseases, were collected by questionnaire. All the participants were asked about their health related habits like: cigarette smoking and alcohol consumption. Dietary habits were assessed by food frequency method. Body mass index (BMI) was calculated as the parameter of nutritional status.

The mean serum selenium level in cancer patients and healthy control (Table 1) were not significantly different. But, both cancer patients and healthy controls from Barajevo have significantly lower values comparing to those living in Stari Grad. Table 2 shows the relationship between serum selenium level and various environmental factors. The factors identified as the most important are: living in community Barajevo, age, history of chronic disease and some dietary factors. The univariate analysis (Table 3) revealed that factors like cigarette smoking, alcohol consumption, family history of malignancy and comorbid states were not important predictive factors for patient malignant disease. The multivariate analysis revealed that consumption of sugar, fat and fruit were of the highest predictive value in assessing cancer relative risk.

The results of selenium serum level in investigated population are in agreement with those published by Maksimovic [10]. They are among the lowest concentrations in Europe, especially in participants living in Barajevo. Thought the number of investigators found generally lower serum selenium levels in cancer patients, the finding is not entirely consistent [14, 15], and so are the results obtained here. Consumption frequency calculated for 44 food items which may be most important source of dietary selenium intake (like: meat, fish, diary products and cereals), didn't show important relationship with serum selenium levels. People living in Barajevo consume food grown in their own soils (proofed deficient with selenium), and this might the reason for the striking differences in serum selenium levels between people living in Barajevo and Stari Grad.

The results obtained in this investigation indicated that serum selenium level is low both groups cancer patients and healthy controls too. Food items identified as sources of selenium in diet are not connected with this low selenium level.