A large amount of data has been accumulated in Chinese medical area. Problems as how to use big data to carry out randomized controlled trials have also been increasingly noteworthy. Through learning the successful experiences in conducting randomized controlled trials on big data from abroad, this article introduces the knowledge regarding sources of data, identification of research subjects and outcomes, interventions, methods of randomization and the implementation of informed consent, etc., all related to big data, hoping to shed light on studies of this kind, for the years to come in China.

OBJECTIVETo assess the association of S447X mutation and Hind III polymorphism in the lipoprotein lipase gene with dyslipidemia of the metabolic syndrome in patients with essential hypertension.

METHODSA total of 983 patients were randomly selected from those with hypertension (diagnosed in the Community-based Comprehensive Studies on Prevention and Control of Hypertension Project in China) and those not treated with anti-hypertensive medications for at least in 2 weeks immediately before blood collection. Among them were 389 subjects with dyslipidemia and 594 subjects without dyslipidemia. The definition of dyslipidemia in patients with hypertension was used only when triglyceride or HDL-cholesterol was at abnormal level. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine Ser447stop mutation and Hind III polymorphism in LPL gene.

RESULTSLinkage disequilibrium between the two sites was observed, with three major haplotypes identified: H+S, H-S, and H-X. The LPL gene S447X mutation and H-X haplotype were significantly associated with dyslipidemia (OR=0.547, 95%CI: 0.348-0.859 for S447X mutation; OR=0.537, 95%CI: 0.328-0.880 for H-X haplotype) in male, both by themselves and after adjustment for age, body mass index, smoking, alcohol intake, systolic blood pressure, diastolic blood pressure, education and serum glucose. The LPL H- carriers and H-S haplotype were significantly associated with dyslipidemia (OR=0.575, 95%CI: 0.358-0.923) in female after multivariate adjustment. Moreover, compared with the H+S haplotype, the H-X haplotypes were associated with significantly lower TG and Log (TG/HDL-C) levels in both men and women, and with higher HDL-C levels in women; whereas no significant difference was observed between the H-S and H+S haplotype. Compared with the H-S haplotype, the H-X haplotypes had significant effect on the HDL-C levels in women.

CONCLUSIONThe LPL H-X haplotype was one of the protective factors of dyslipidemia of metabolic syndrome in hypertensive patients. It is significantly associated with low triglyceride, log triglyceride-to-HDL-cholesterol ratio and high HDL-cholesterol levels. S447X mutation does not explain all the effect associated with the Hind III polymorphism, although the effect on serum lipids associated with the H-X haplotype appeared to be mainly mediated by the S447X mutation. It is possible that some functional mutations in the LPL gene besides the S447X mutation are in linkage disequilibrium with the Hind III polymorphism.

Aged ; Cholesterol, HDL ; blood ; Dyslipidemias ; blood ; complications ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Haplotypes ; Humans ; Hypertension ; complications ; Linkage Disequilibrium ; Lipoprotein Lipase ; genetics ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length ; Triglycerides ; blood

Objective:To assess the diagnostic value of whole-lesion intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in differentiating benign and malignant thyroid nodules based on turbo spin echo (TSE) sequence.Methods:Totally 57 patients with thyroid nodules diagnosed by pathology were prospectively collected at the Affiliated Lianyungang Hospital of Xuzhou Medical University from March 2019 to December 2019. A total of 62 nodules were included for analysis, including 27 benign nodules and 35 malignant nodules. All patients underwent routine MRI scan and IVIM-DWI based on TSE sequence before surgery. The regions of interest were drawn along the edge of the lesion on multiple consecutive slices to cover the entire nodule, and the apparent diffusion coefficient (ADC), diffusivity (D), pseudo-diffusivity (D *) and quantitation of perfusion fraction (f) values were measured, and the mean value of the multilayer measurement was recorded for further analysis. The differences of the parameters between benign and malignant thyroid nodules were analyzed using independent samples ttest (normal distribution) and Mann-Whitney U test (non-normal distribution). The diagnostic efficacy of parameters with statistical significance was evaluated using the receiver operating characteristics (ROC) curve. Results:The ADC, D and D *values in the malignant nodules were lower than those in benign nodules, the differences were statistically significant ( t=3.821, P=0.001; t=2.034, P=0.046).There were no statistical differences of D * and f values ( t=-1.170, P=0.247; Z=-0.559, P=0.577).The optimal cut-off values of ADC and D were 1.90×10 -3mm 2/s and 1.10×10 -3mm 2/s, with both sensitivity of 81.5%, specificity of 73.5% and 61.8%, respectively. The area under ROC curve of ADC and D were 0.782 and 0.688, and the statistical difference was found ( Z=2.098, P=0.040). Conclusion:The whole-lesion IVIM parameters (ADC and D) based on the TSE sequence provide imaging features for preoperative differentiation of benign and malignant nodules of the thyroid gland.