Introduction: The uncoupling proteins belong to the family of anion transporting proteins which uncouple the ATP production from the mitochondrial respiration, cause proton leakage through the inner mitochondrial membrane, and release energy as heat. Although uncoupling protein function has not been well established, specific polymorphisms in these proteins have been associated with type 2 diabetes mellitus, obesity and insulin resistance.
Objective: The association was assessed between the polymorphisms in uncoupling protein genes 1, 2 and 3 genes and type 2 diabetes mellitus.
Materials and methods: In a northwestern Colombian population, 545 diabetes cases and 449 controls were investigated for presence of 14 polymorphisms in uncoupling protein genes (3826A/G, ID 45, 2723T/A, 1957G/A, 866G/A, and 55C/T) by PCR and PCR-RFLP. Single associations were evaluated by chi-square test, and bayesian logistic regression analysis was done including as covariates the individual admixture estimates obtained by 54 informative markers for European, African and Amerind ancestry.
Results: Association between type 2 diabetes mellitus and the polymorphisms 3826A (OR=0.78; 95% CI = 0.63-0.97; p = 0.02) and 55 C (OR = 1.41; 95% CI = 1.04-1.92; p = 0.03) and the haplotype D45, 866G, 1957G, 2723T, and 55C (OR = 1.26; 95% CI = 1.02-1.56; p = 0.03) were found. These associations remained after adjustment using individual genetic admixture estimates.
Conclusion: Some alleles of uncoupling protein genes 1, 2 and 3, and their haplotypes confer risk to type 2 diabetes in a northwestern Colombian population.