ABSTRACT
Objective:To analyze the differences in whole blood selenium (Se), zinc (Zn), copper (Cu), magnesium (Mg), calcium (Ca), and iron (Fe) levels of rural older adults among areas with different soil selenium levels, and explore the main factors associated with the six nutrient elements status, so as to provide a basis for further evaluating the health risks of people in areas with different soil selenium levels.Methods:Four administrative villages were randomly selected from the Se-deficient (soil Se content < 0.175 mg/kg), Se-sufficient (soil Se content 0.175 - < 0.400 mg/kg), Se-rich (soil Se content 0.400 - < 3.000 mg/kg) and Se-excessive (soil Se content ≥3.000 mg/kg) areas, respectively, in Enshi Tujia and Miao Autonomous Prefecture (Enshi Prefecture) of Hubei Province in 2017 - 2018. And 100 elderly people aged 60 years or older (half male and half female) were randomly selected as the survey subjects in each servey site. The basic information such as general demography and lifestyle was collected through face-to-face questionnaires. Physical examination was performed and fasting venous blood was collected in the morning. The contents of blood Se, Zn, Cu, Mg, Ca, and Fe were determined by inductively coupled plasma mass spectrometry. The main factors associated with the six nutrient elements status were analyzed.Results:A total of 416 subjects were included, including 208 males and 208 females, whose average age was (72.43 ± 5.25) years, and body mass index (BMI) was (22.67 ± 3.49) kg/m 2. There were significant differences of blood Se, Zn, Cu, Mg, Ca and Fe levels between the areas with different Se levels ( Z/F = 288.30, 3.24, 14.81, 29.14, 131.28, 3.37, P < 0.05). Compared with Se-deficient and Se-sufficient areas, blood Se level was higher in Se-rich and Se-excessive areas and blood Zn level was lower in Se-excessive area ( P < 0.05); compared with Se-sufficient area, blood Cu level was lower in Se-deficient, Se-rich and Se-excessive areas, but blood Mg and Ca levels were higher ( P < 0.05), and the blood Fe level was lower in Se-excessive area ( P < 0.05). There were significant differences in the deficiency rates of Se, Zn, Cu, Mg, Ca and Fe among the elderly in different Se level areas (χ 2 = 140.83, 15.39, 31.90, 17.49, 157.60, 30.33, P < 0.01). There were significant differences in blood Zn, Cu, Ca and Fe levels between two gender groups ( P < 0.05); the blood Zn and Fe levels of the smokers were higher than those of the non-smokers, and the blood Cu level was lower than that of the non-smokers ( P < 0.05); the blood Zn and Fe levels of the drinkers were higher than those of the non-drinkers ( P < 0.05). Conclusions:The levels of six nutrient elements in the whole blood of the elderly in areas with different soil Se levels are different. To assess the health risks of the population in areas with different soil Se levels, it is necessary to consider the levels of multiple nutrient elements at the same time.