title: Structural equation model for estimating risk factors in type 2 diabetes mellitus in a Middle Eastern setting: evidence from the STEPS Qatar.
abstract: OBJECTIVE
  Understanding type 2 diabetes mellitus is critical for designing effective diabetes prevention policies in Qatar and the Middle East.
  
  
  METHODS
  Using the Qatar 2012 WHO STEPwise approach to surveillance survey, a subsample of 1224 Qatari participants aged 18-64 years was selected. Subjects had their fasting blood glucose levels tested, had not been diagnosed with or treated for diabetes, had a fasting time >12 hours and were not pregnant. We applied a hypothesized structural equation model (SEM) to assess sociodemographic, behavioral, anthropometric and metabolic variables affecting persons with type 2 diabetes mellitus.
  
  
  RESULTS
  There is a direct effect of triglyceride levels (0.336) and body mass index (BMI) (0.164) on diabetes status. We also found that physical activity levels negatively affect BMI (-0.148) and positively affect high-density lipoprotein (HDL) (0.106); sociodemographic background negatively affects diet (-0.522) and BMI (-0.352); HDL positively affects total cholesterol (0.230) and has a negative effect on BMI (-0.108), triglycerides (-0.128) and waist circumference (-0.104). Diet has a positive effect on triglycerides (0.281) while family history of diabetes negatively affects total cholesterol (-0.104). BMI has a positive effect on waist circumference (0.788) and mediates the effects of physical activity over diabetes status (-0.028). BMI also mediates the effects that sociodemographic factors (-0.058) and physical activity (-0.024) have on diabetes status. BMI and HDL (-0.002) together mediate the effect of physical activity on diabetes status and similarly HDL and tryglycerides (-0.005) also mediate the effect of physical activity on diabetes status. Finally diet and tryglycerides mediate the effects that sociodemographic factors have on diabetes status (-0.049).
  
  
  CONCLUSIONS
  This study's main finding is that triglyceride levels and BMI are the main variables directly affecting diabetes status in the Qatari population.
authors.affiliation: LSE Health, London School of Economics and Political Science , London , UK.
authors.forename: Andres
authors.identifier: 0000-0002-2405-9432
authors.initials: A
authors.lastname: Roman-Urrestarazu
authors.affiliation: Qatar Supreme Council of Health , Doha , Qatar.
authors.forename: Faleh Mohamed Hussain
authors.initials: FM
authors.lastname: Ali
authors.affiliation: Qatar Supreme Council of Health , Doha , Qatar.
authors.forename: Husein
authors.initials: H
authors.lastname: Reka
authors.affiliation: LSE Health, London School of Economics and Political Science , London , UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Renwick
authors.affiliation: Institute of Criminology, University of Cambridge , Cambridge , UK.
authors.forename: Gabriela D
authors.initials: GD
authors.lastname: Roman
authors.affiliation: LSE Health, London School of Economics and Political Science , London , UK.
authors.forename: Elias
authors.initials: E
authors.lastname: Mossialos
keywords: Analytic Methods; BMI; Lipids and Diabetes; Triglycerides