Correlation between mitochondrial DNA copy number and coal-burning-borne endemic fluorosis / 中华地方病学杂志

ABSTRACT

Objective:To investigate the association between relative mitochondrial DNA copy number (mtDNA-CN) and coal-burning-borne endemic fluorosis (abbreviated as coal-burning-borne fluorosis).Methods:From June 2018 to March 2019, using cross-sectional study, 482 patients with coal-burning-borne fluorosis were selected as the case group in Bijie City, a typical coal-burning-borne fluorosis area of Guizhou Province; meanwhile, 212 healthy individuals from Changshun County, a non-coal-burning-borne fluorosis area in Guizhou Province, were selected as the control group. Questionnaire survey and physical examination were used to collect general condition such as basic information and living habits of the two groups, peripheral venous blood samples were collected, and real-time fluorescence quantitative PCR was used to detect the relative mtDNA-CN in peripheral blood. The correlation between relative mtDNA-CN and coal-burning-borne fluorosis was analyzed by binary and unordered multi-class logistic regression.Results:There were significant differences in the body mass index (BMI), and the distribution of gender rario, marital status and education level between the control group and the case group ( t = 7.91, χ 2 = 5.11, 13.33, 34.32, P < 0.05). The relative mtDNA-CN in the control group was higher than that in the case group [median (quartile): 202 (138, 292) vs 131 (96, 217), Z = - 7.80, P < 0.001]. The results of binary logistic regression analysis [odds ratio (95% confidence interval)] showed that educational level [primary school: 0.572 (0.377 - 0.868), junior high school and above: 0.292 (0.174 - 0.493)], relative mtDNA-CN [131 - < 217: 0.265 (0.144 - 0.488), ≥217: 0.183 (0.100 - 0.335)] and BMI [1.222 (1.142 - 1.307)] were the influencing factors for the risk of coal-burning-borne fluorosis( P < 0.05). In subgroups with different BMI and educational levels, the relative mtDNA-CN was significantly negatively correlated with the risk of coal-burning-borne fluorosis( Ptrend < 0.05), and there was no interaction between mtDNA-CN and BMI and educational levels ( Pinteraction > 0.05). The results of unordered multi-class logistic regression analysis showed that the relative mtDNA-CN were significantly negatively correlated with the risk of dental fluorosis and skeletal fluorosis ( Ptrend < 0.05). Conclusion:The higher the relative mtDNA-CN, the lower the risk of coal-burning-borne fluorosis, suggesting that mtDNA-CN may be a potential biomarker of coal-burning fluorosis.