title: Analysis of risk factors and their interactions in type 2 diabetes mellitus: A cross-sectional survey in Guilin, China.
abstract: OBJECTIVE
  Type 2 diabetes is a metabolic disease characterized by insulin resistance, and is associated with the effects of genetic and environmental factors. The present study aimed to not only analyze the influence of a single factor for type 2 diabetes, but also to investigate the interaction effects between risk factors.
  
  
  METHODS
  A total of 6,660 individuals selected by the method of cluster random sampling accepted a cross-sectional survey (questionnaire investigation, physical measurement, laboratory examination and liver ultrasound examination). The classification tree was used to analyze the risk factors and their interactions in type 2 diabetes. The clinical and metabolic characteristics were compared between type 2 diabetes patients and controls, and the non-conditional logistic regression model was used to quantitatively analyze the interactions.
  
  
  RESULTS
  A total of 338 participants were classified as type 2 diabetes (217 men and 121 women), the classification tree model showed three variables with close associations with type 2 diabetes: age, triglycerides (TG) and non-alcoholic fatty liver disease (NAFLD). Type 2 diabetes patients had higher age and incidences of high TG, NAFLD, hypertension, high body mass index, high uric acid, high total cholesterol, high low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol. The multivariate logistic regression analysis showed that the following factors had interactions in type2 diabetes: high TG × advanced age (odds ratio 2.499, 95% confidence interval 1.868-3.344, P = 0.000), NAFLD × advanced age (odds ratio 1.250, 95% confidence interval 1.048-1.491, P = 0.013) and NAFLD × high TG (odds ratio 1.349, 95% confidence interval 1.144-1.590, P = 0.000).
  
  
  CONCLUSIONS
  The present study showed that type 2 diabetes resulted from the interactions of many factors; the interactions among age, TG and NAFLD are important risk factors for type 2 diabetes.
authors.affiliation: Department of Endocrinology, The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
authors.forename: Disha
authors.initials: D
authors.lastname: Zou
authors.affiliation: Department of Endocrinology, The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Ye
authors.affiliation: The Nursing Group of Loudi Health School, Loudi, Hunan, China.
authors.forename: Nina
authors.initials: N
authors.lastname: Zou
authors.affiliation: Department of Endocrinology, The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
mesh_terms: D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors
keywords: Interaction; Risk factor; Type 2 diabetes