Gene Polymorphism Associated With Macroangiopathy in Type 2 Diabetes Patients
Condition: Diabetic Angiopathies
MeSH terms: Diabetic Angiopathies
Study type: Observational

Summary: 
      To explore the possible implications of HLA-DRB1*04 alleles in patients with type 2 DM and
      macroangiopathy
    

Detailed description: 
      Previous studies examining the molecular etiology of diabetes mellitus in China and abroad
      have mainly focused on the relationship between HLA and type 1 diabetes mellitus (DM) (1-3).
      Due to the complexity of type 2 DM heredity, few researchers have studied the correlation
      between type 2 DM and HLA. In recent years, it has been suggested that the development of
      coronary heart disease (CHD) in diabetic individuals is not merely a complication of diabetic
      macroangiopathy. CHD and diabetic macroangiopathy share some genetic associations. Previous
      studies have demonstrated that certain HLA*DRB1*04 subtypes are associated with an increased
      risk of cardiovascular disease.

      Experimental methods: For genomic DNA extraction, 3-5ml venous blood samples were collected
      from all patients. Coagulation was prevented using EDTA.

      The procedure for PCR amplification was as follows: denaturing for 100s at 96°C, annealing
      for 60s at 63°C, 1 cycle; denaturing for 10s at 96°C, annealing for 60s at 63°C, 9 cycles;
      denaturing for 10 s at 96°C, annealing for 30 s at 59°C; extending for 30 s at 72°C, 20
      cycles; maintaining at 4°C. Analyzing PCR products stained by Ethidium Bromide on 2.5%
      agarose gel electrophoresis. Bands were observed using an ultraviolet light and a biological
      imaging system.

      Statistical method: The degree of agreement with Hardy-Weinberg equilibrium was determined
      using the χ2 test. A t-test was employed for comparison of CRP levels (M ± s) and a χ2 test
      was performed to compare allelic frequencies. The relative risk rate (RR) was calculated as
      (Number of patients with the gene×Number of people in control group without the gene) divided
      by (Number of people in control group with the gene×Number of the patients without the gene).
      PC was calculated using Fisher's method if χ2 > 3.84.
    

Intervention name(s): Group A; Group B; Group C
Intervention type(s): Other; Other; Other
Intervention description(s): 150 healthy blood donors without a family history of diabetes mellitus were enrolled in the study.; 200 cases of type 2 DM without complications were enrolled in the study.; 120 cases of type 2 DM with macroangiopathy complication were enrolled in the study.. Among the group C subjects, 65 individuals had CHD; 55 patients had cerebrovascular disease (CVD); and 30 subjects had a combination of peripheral vascular diseases (PVD) and CHD.
Other intervention name(s): healthy blood donors; type 2 DM without complications; type 2 DM with macroangiopathy complication
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        150 healthy blood donors without a family history of diabetes mellitus at the Harbin Blood
        Disease Research Center were enrolled in the study, and 320 outpatients and hospitalized
        patients of type 2 diabetes mellitus from the First and Second Affiliated Hospital of
        Harbin Medical University.
      
Biospecimen description: 
      Laboratory analysis Blood samples were collected after over-night fasting, and serum was
      stored at -20°C.