Association of polymorphisms at -174 in IL-6, and -308 and -238 in TNF-α, in the development of tuberculosis and type 2 diabetes mellitus in the Mexican population.

Polymorphisms at -176 in IL-6, and -238 and -308 in TNF-α have been described as risk factors for developing tuberculosis (TB) and type 2 diabetes mellitus (T2DM). However, it is not known how these changes influence the development of TB-T2DM comorbidity. The objective of this work was therefore to analyze the impact of these polymorphisms in the Mexican population. This is a cross-sectional study of cases and controls in which polymorphisms at -174 in IL-6, -238 and -308 in TNF-α were identified in healthy subjects, those with TB, T2DM and carriers of the comorbidity, each group consisted of 30 individuals. Descriptions of the population, frequency of genotypes and risk association were calculated, and a reduction of multifactorial dimensionality between groups (MDR) was determined. Genotype 174 G/G-of IL-6 was observed in 78% of individuals, while -308 G/G and -238 G/G of TNF-α occurred in 90% and 91% of individuals, respectively. The -174 G/G IL-6 in individuals with T2DM increased five-fold (p = .02) the risk of developing the comorbidity. The MDR analysis showed that the association of -174 G/G IL-6 and -308 G/G TNF-α in healthy individuals increased the risk of developing the comorbidity up to six-fold (p = .019), while in individuals with T2DM, this risk augmented 14-fold (p = .0002). The -174 G/G IL-6 genotype increases the risk of developing comorbidity in the T2DM population and this risk is raised when associated with -308 G/G TNF-α. These findings have implications for understanding the epidemiological dynamics of the TB-T2DM comorbidity, promoting prevention strategies and inhibiting the development of this co-morbidity.