Subclinical inflammation/oxidation as revealed by altered gene expression profiles in subjects with impaired glucose tolerance and Type 2 diabetes patients

Although subclinical inflammation and oxidative stress are implicated in the aetiology of diabetes, there are hardly any studies in prediabetes. Therefore, we made an attempt to study the gene expression pattern of certain inflammatory/oxidative genes using lymphocytes from Type 2 diabetic patients, impaired glucose tolerance (IGT), and normal glucose tolerance (NGT) subjects. Compared to NGT group, interleukin-6, tumor necrosis factor-alpha (TNF-alpha), p(22)Phox NADPH oxidase, and thioredoxin interacting protein (TXNIP) mRNA levels were higher and suppressor of cytokine signaling (SOCS-3) mRNA was lower in subjects with IGT and diabetes. The mean (+/- SE) levels of thiobarbituric acid reactive substances and protein carbonyl content were also elevated in glucose intolerant subjects. In multiple linear regression analysis, TXNIP and TNF-alpha showed a significant association with HbA1c even after adjusting for TBARS and PCO (TXNIP: beta A = 1.70, P < 0.01; TNF-alpha: beta = 1.86, P < 0.01). Increased subclinical inflammation/oxidation is seen in Asian Indians with not only Type 2 diabetes but also IGT.