Effect of changing grain and selenium supplementation on control of children's Kaschin-Beck disease in Qinghai province

Objective To observe the effect of changing grain and selenium supplementation for 1-year on control of children's Kaschin-Beck disease in Qinghai province. Methods Epidemiology, clinical and right-hand X-ray examination were carried out on children aged 7 - 12 years in 2008. Patients were diagnosed and divided into 3 groups by village, control group from Xinjianping village in Guide county, changing grain group from Xiemalang village in Guide county and supplying salt with selenium and iodine group from Shanglujuan and Xialujuan villages in Xinghai county. One year before and after the treatment, right-hand X-ray photograph (including carpal bones)was taken and child hair samples were collected, selenium was detected by 2,3-diaminonaphthalene fluorescence spectrophotometry. Results After 1 year prevention and control, the detectable rate of X-ray in control group was raised from 4.88%(2/41) to 12.20%(5/41) , the detection rate in changing grain group was declined from 17.54%(10/57) to 5.26%(3/57), and from 13.51%(10/74) to 5.41%(4/74) in supplying salt with selenium and iodine group. In changing grain group, there were 10 patients, 7 cases were cured, 2 patients stable, 1 case progressed,no new case;in supplying salt with selenium and iodine group of 10 patients, 7 were cured, 3 patients stable, 1 new diagnosed case;in control group, 2 patients stable, 2 new diagnosed metaphysis cases, 1 new diagnosed metaphyseal case. Compared with control group, the difference was statistically significant between changing grain group and supplying salt with selenium and iodine group(x2 = 5.49,4.14, all P ＜ 0.05). After 1 year control and prevention,hair selenium contents in control group and changing grain group were increased from (107.15 ± 42.30), (125.30 ±40.30)μg/kg to (108.32 ± 35.67), (135.38 ± 65.24)μg/kg, the difference was statistically insignificant(t = 0.01,0.68, all P ＞ 0.05), and selenium contents in supplying salt with selenium and iodine group were obviously increased from (95.62 ± 43.42)μg/kg to (197.64 ± 97.08)μg/kg (t = 5.41, P ＜ 0.05). Conclusion Changing grain and supplying selenium can prevent and control children's Kaschin-Beck disease. Key words: Kaschin-Beck disease; Selenium; X-rays