title: Short repeats in the heme oxygenase 1 gene promoter is associated with increased levels of inflammation, ferritin and higher risk of type-2 diabetes mellitus.
abstract: OBJECTIVE
  We evaluated the relationship between the HO1 genotype, ferritin levels and the risk of type-2 diabetes and inflammation.
  
  
  METHODS
  Eight hundred thirty-five individuals were evaluated and classified according to their nutritional status and the presence of type-2 diabetes: 153 overweight (OW); 62 obese (OB); 55 type-2 diabetes mellitus (DM); 202 OWDM; 239 OBDM and 124 controls (C). We studied biochemical (glycemia, insulin, lipid profile, liver enzyme, creatinine, hsCRP), hematological (hemoglobin, free erythrocyte protoporphyrin, transferrin receptor and serum Fe and ferritin) and oxidative stress (SOD, GHS and TBARS) parameters. We determined heme oxygenase activity and the (GT)n polymorphism in its gene promoter.
  
  
  RESULTS
  Individuals with diabetes, independent of nutritional status, showed high levels of ferritin and HO activity compared to control subjects. Allelic frequency was not different between the groups (Chi(2), NS) however, genotypes were different (Chi(2), P<0.001). The SS (short-short) genotype was higher in all DM individuals compared to controls and MM was higher in controls. SM (short-medium) genotype was an independent risk factor for DM in logistic regression analysis. We observed high risk for type-2 diabetes mellitus in the presence of SM genotype and high levels of ferritin (OR adjusted: 2.7; 1.9-3.6; p<0.001; compared to control group). It was also significantly related to inflammation.
  
  
  CONCLUSIONS
  The SM genotype in HO1 gene promoter and ferritin levels were associated with higher risk for type-2 diabetes and for having a higher marker of inflammation, which is the main risk factor for the development of chronic diseases.
authors.affiliation: Micronutrient Laboratory, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Macul, Santiago, Chile.
authors.forename: Mónica
authors.initials: M
authors.lastname: Andrews
authors.affiliation: Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Faculty of Health Science, University of Talca, Talca, Chile.
authors.forename: Elba
authors.initials: E
authors.lastname: Leiva
authors.affiliation: Micronutrient Laboratory, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Macul, Santiago, Chile. Electronic address: marredon@inta.uchile.cl.
authors.forename: Miguel
authors.initials: M
authors.lastname: Arredondo-Olguín
mesh_terms: D000328:Adult; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005260:Female; D005293:Ferritins / Q000378:metabolism*; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006801:Humans; D007249:Inflammation / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012307:Risk Factors
chemical_list: D005293:Ferritins; D051547:Heme Oxygenase-1
keywords: Ferritin; Heme oxygenase; Inflammation; Iron; Polymorphism; Type-2 diabetes mellitus