Yang Dan, Liu Yang, Chu Yanru, Yang Qing, Jiang Wei, Chen Fuxun, Li Dandan, Qin Ming, Sun Dianjun, Yang Yanmei, Gao Yanhui
Centre for Endemic Disease Control, Chinese Centre for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang, China.
Key Laboratory of Aetiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Harbin, Heilongjiang, China.
BMJ Open. 2016 Nov 10;6(11):e011980. doi: 10.1136/bmjopen-2016-011980.
Brick-tea type fluorosis is a public health concern in the north west area of China. The vitamin D receptor (VDR)-FokI polymorphism is considered to be a regulator of bone metabolism and calcium resorption. However, the association of VDR-FokI polymorphism with the risk of brick-tea type fluorosis has not been reported.
A cross sectional, case control study was conducted in three provinces (Inner Mongolia, Qinghai and Sinkiang) in China. The fluoride content of Brick-tea water and urine was tested using the standards GB 1996-2005 and WS/T89-2006 (China), respectively. Skeletal fluorosis was diagnosed using the standard WS/192-2008 (China). The VDR-FokI polymorphism was detected by the Sequenom MassARRAY system.
Compared with carriers of the CC genotype, participants with the CT/TT genotype had a significantly decreased risk of skeletal fluorosis (OR=0.761 (95% CI 0.580 to 0.997)), after adjustment for risk factors. When investigated among ethnic groups, the protective effect of the CT/TT genotype was limited in the Mongolian participants (OR=0.525 (95% CI 0.278 to 0.991)). Moreover, the interaction of VDR-FokI with risk factors was only found in Mongolian participants: the protective effect of the CT/TT genotype was limited to participants with >7.0 mg/day daily intake of tea fluoride (OR=0.085 (95% CI 0.009 to 0.851), participants with >3.2 mg/L urine fluoride (OR=0.103 (95% CI 0.017 to 0.633)) or participants aged 46-65 years (OR=0.404 (95% CI 0.177 to 0.922).
Our data suggest that the CT/TT genotype of VDR-FokI may be a protective factor for brick-tea type skeletal fluorosis, and this effect is pronounced in Mongolian participants.
砖茶型氟中毒是中国西北地区的一个公共卫生问题。维生素D受体（VDR）-FokI基因多态性被认为是骨代谢和钙重吸收的一个调节因子。然而，VDR-FokI基因多态性与砖茶型氟中毒风险之间的关联尚未见报道。
在中国的三个省份（内蒙古、青海和新疆）开展了一项横断面病例对照研究。分别采用中国国家标准GB 1996 - 2005和WS/T89 - 2006检测砖茶水和尿液中的氟含量。采用中国标准WS/192 - 2008诊断氟骨症。通过Sequenom MassARRAY系统检测VDR-FokI基因多态性。
在对危险因素进行校正后，与CC基因型携带者相比，CT/TT基因型参与者患氟骨症的风险显著降低（OR = 0.761（95%CI 0.580至0.997））。在按民族进行调查时，CT/TT基因型的保护作用在蒙古族参与者中有限（OR = 0.525（95%CI 0.278至0.991））。此外，仅在蒙古族参与者中发现VDR-FokI与危险因素之间存在相互作用：CT/TT基因型的保护作用仅限于每日茶氟摄入量>7.0mg/天的参与者（OR = 0.085（95%CI 0.009至0.851））、尿氟>3.2mg/L的参与者（OR = 0.103（95%CI 0.017至0.633））或年龄在46 - 65岁的参与者（OR = 0.404（95%CI 0.177至0.922））。
我们的数据表明，VDR-FokI的CT/TT基因型可能是砖茶型氟骨症的一个保护因素，且这种作用在蒙古族参与者中更为明显。
