RESUMEN
Objective:To investigate the relationship between low vitamin D levels and the risk of Graves' disease.Methods:Computer was used to search PubMed, EMbase, China National Knowledge Infrastructure (CNKI), Wanfang Database (Wanfang Data) and China Biomedical Database (CBM). Relevant Chinese and English literatures were collected, including literatures of vitamin D, Graves' disease and autoimmune thyroid disease from the earliest publication time of the literature in the database to September 2019. Statistical software Stata 12.0 was used for Meta-analysis of the data. Heterogeneity test was conducted on the literature that met the inclusion criteria. According to the results, a random-effect model fixed-effect model was selected for comprehensive quantitative analysis. Standardized mean difference ( SMD) and 95% confidence interval ( CI) were calculated, and Egger's test was used to evaluate publication bias and sensitivity analysis. Results:A total of 29 literatures were included in the study, covering 2 281 patients with Graves' disease and 4 200 control population. Meta-analysis results showed: after the data were combined using a random-effects model, vitamin D levels in patients with Graves' disease were significantly lower than that in the control population ( SMD = - 0.90, 95% CI: - 1.14, - 0.66, P < 0.01﹚; heterogeneity analysis and Meta-regression analysis showed that the four factors of national development degree, geographical location, indicator measurement method and whether Graves' disease was primary were not the main source of heterogeneity. However, in developing countries or Asian, the vitamin D levels of patients with Graves' disease were significantly lower than that of the control population ( P < 0.01). In developed countries or Europe, the difference was not statistically significant ( P > 0.05). Sensitivity analysis and publication bias analysis showed that the results of this study had certain stability and reliability. Conclusion:Low vitamin D levels may increase the risk of Graves' disease.
RESUMEN
Objective To investigate the association of single nucleotide polymorphisms in the rs2268458 locus of thyroid-stimulating hormone receptor (TSHR) gene with Graves disease (GD) and Hashimoto's thyroiditis (HT).Methods Part of the cases diagnosed through the epidemiological investigation project about thyroid diseases of Cangzhou City in 2016 was selected as the case group.The case group was subdivided into GD group and HT group according to the diagnosis.At the same time,healthy people with similar gender and age to the case group were selected as the control group.All subjects were from the Han nationality and were not related to each other.The genotypes and alleles of the TSHR gene rs2268458 (C/T) of all subjects were detected by restriction endonuclease (RFLP).And based on genotyping analysis of patient risk (odds ratio,OR) and 95％ confidence interval (95％CI).Results There were 87 cases in GD group [aged (43.17 ± 12.56) years old],including 64 females and 23 males.There were 31 cases in HT group [aged (44.41 ± 16.51) years old],including 26 females and 5 males.In the control group,there were 147 cases [age (40.26 ± 9.31) years old],including 80 females and 67 males.HardyWeinberg equilibrium test was performed on each group.The results showed that P ＞ 0.05,suggesting that the study samples were representative of the population.The results of genetic analysis showed that in females,the C allele frequency of GD patients was significantly higher than that of the control group [x2 =4.632,36.7％ (47/128) vs 25.0％ (40/160),P ＜ 0.05,OR =1.741,95％CI =1.048-2.891].The frequency distribution of each genotype (CC,CT,TT) at TSHR rs2268458 (T/C) was statistically different (x2 =6.104,P ＜ 0.05),and the frequency of TC ± CC combined genotype was significantly higher in GD patients than in controls (x2 =6.092,P ＜ 0.05,OR =2.333,95％ CI =1.184-4.598),however,there was no statistical difference between the HT group and the control group in genotype (CC,CT,TT) frequency distribution and alleles (P ＞ 0.05).In males,there was no statistically significant difference in genotype (CC,CT,TT) frequency distribution and allele between groups (P ＞ 0.05).Conclusion Among women in Cangzhou,the single nucleotide polymorphism of rs2268458 in TSHR gene is associated with the susceptibility to GD,but not to HT,and C genotype increases the risk of GD by dominant inheritance.