Nail Selenium Level and Diabetes in Older People in Rural China / 生物医学与环境科学（英文）

This cross-sectional study aimed to examine the association between selenium levels and diabetes in an older population with life-long natural exposure to selenium in rural China. A total of 1856 subjects aged 65 years or older from four Chinese rural counties with different environmental selenium levels were evaluated. Analysis of covariance models and logistic regression models were used to examine the relationship between nail selenium levels and serum glucose, serum insulin, insulin resistance [using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)], and the risk of diabetes. The mean nail selenium level was 0.461 μg/g and the prevalence rate of diabetes was 8.3% in this population. The mean nail selenium level was significantly higher in the group with diabetes than in the group without diabetes (P<0.0001). The adjusted odds ratios for diabetes were 2.65 (95% CI: 1.48 to 4.73), 2.47 (95% CI: 1.37 to 4.45), and 3.30 (95% CI: 1.85 to 5.88) from the second selenium quartile to the fourth quartile, respectively, compared with the first quartile group. The mean serum glucose and HOMA-IR in the higher selenium quartile groups were significantly higher than those of the lowest quartile group. However, no significant differences in insulin were observed among the four quartile groups. A long-term, higher level of exposure to selenium may be associated with a higher risk of diabetes. Future studies are needed to elucidate the association between selenium and insulin resistance.

Survey of “iodine suitable” region in iodine-deficient areas in Shandong province / 中国地方病学杂志

ObjectiveTo look into the distribution of “iodine suitable” region in iodine-deficient areas in Shandong province and to provide a scientific basis for guiding the redesignate of iodine-deficient areas and launch scientific supply of iodine.Methods One to 3 copies of water source samples were collected in 105 existing iodine-deficient counties by village.Water iodine content was detected by arsenic-cerium catalytic spectrophotometry.The areas with water iodine content below 10 μg/L was defined as iodine-deficient areas and among 10 - 150 μg/L were “iodine suitable areas” and greater than 150 μg/L were high iodine areas.Results The research was carried out in 14 cities,105 counties,and 1337 towns.We collected 65 716 water samples.Sample recovery efficiency reached 99.8％.The median of water iodine was 5.57 μg/L.In the 1337 towns surveyed,there were 82.05％(1097/1337) of the township with water iodine median ＜ 10 μg/L,17.43％(233/1337) between 10 - 150 μg/L,and 0.52％(7/1337) ＞ 150 μg/L.Conclusions In Shandong province,the water “iodine suitable” regions are distributed scattered with considerable proportion.In iodine-deficient areas,there are areas with high water iodine,and iodine-deficient regions should be redrawn.Emphasis should be put on iodine nutritional status of residents in “high iodine and iodine suitable” regions,and iodine supplementation should be carries out scientifically.

Investigation of iodine level in drinking water in iodine deficiency areas in Shandong province / 中国地方病学杂志

Objective To look into the current distribution of iodine deficiency area in Shandong province and to guide the re-defined iodine deficiency area and to supplement iodine scientifically. Methods In 2008, 100 iodine deficiency counties(cities, districts), designated in Shandong province's "to supplement iodized salt to eliminate the hazard of iodine deficiency management regulations", were selected in the study. One to three samples were collected from water source which was used by the majority of local residents in the 100 iodine deficiency places and iodine concentration was tested by As3+-Ce4+ catalyzing spectrophotometry. Results A total of 65 716 water samples were collected. Sample recovery efficiency reached 99.8%(65 572/65 716). The median water iodine was 5.57 μg/L, with 82.05%( 1097/1337 ) of the township(town) met criteria for the classification of iodine deficiency areas(water iodine ＜ 10 μg/L), 17.43%(233/1337) of the township (town) water iodine moderate(water iodine 10 - 150 μg/L), and 0.52%(7/1337)of the township(town) should be defined high iodine areas(water iodine ＞ 150 - 300 μg/L). Conclusions The iodine deficiency areas should be redefined because water iodine concentrations of iodine deficiency areas have changed. We suggest that the smallest place to supply salt with different range of iodine content is set to the township(town).