Oxidative stress results from either overproduction of free radicals or insufficiency of several anti-oxidant defense systems. It leads to oxidation of main cellular macromolecules and a resultant molecular dysfunction. Thyroid hormones regulate oxidative metabolism and, thus, play a role in free radical production. Studies evaluating oxidative stress in patients with hypothyroidism and hyperthyroidism have been encountered in recent years; however, oxidative status in patients with euthyroid autoimmune thyroiditis (AIT) was not investigated previously. Thirty-five subjects with euthyroid AIT and 35 healthy controls were enrolled in the study. Serum oxidative status was determined by the measurement of total anti-oxidant status (TAS), total oxidant status (TOS), ischemia-modified albumin (IMA), and oxidized-low density lipoprotein (ox-LDL) levels. Serum TAS levels were significantly lower (p<0.001), while serum TOS levels and IMA levels were significantly higher (p<0.001 and p=0.020, respectively) in patients compared to controls. In both groups, ox-LDL levels were similar (p=0.608). Serum TAS levels were negatively correlated with anti-thyroid peroxidase and anti-thyroglobulin (anti-TG) levels (rho=-0.415, p=0.001 and rho=-0.484, p<0.001, respectively). Serum TOS was positively correlated with anti-TG levels (rho=0.547, p<0.001). Further, TAS was positively correlated with free T4 levels (r=0.279, p=0.043). No correlation was observed between thyrotropin, free T3 levels, and TOS and TAS levels. These results suggest that oxidants are increased, and anti-oxidants are decreased in patients with euthyroid AIT, and oxidative/anti-oxidative balance is shifted to the oxidative side. Increased oxidative stress might have a role in thyroid autoimmunity.

Our study indicated that serum IMA, ox-LDL, and TOS may be increased as a result of chronic hypoxia, inflammation, and oxidative stress in patients with severe and very severe stable COPD. Our findings also revealed that IMA is higher in patients with Global Initiative for Chronic Obstructive Lung Disease Stages II, III, and IV, while TOS and ox-LDL are higher in patients with Global Initiative for Chronic Obstructive Lung Disease Stage IV. Measurements of serum IMA, TOS, and ox-LDL levels may be useful markers in the evaluation of stable COPD.

Our findings showed that a significant association is present between circulating miR-370, miR-33, miR-378, miR-27, miR-335, miR-143 and miR-758 values, and childhood obesity. Low levels of miR-335, miR-143 and miR-758, and high levels of miR-27, miR-378, miR-33 and miR-370 may have been responsible for elevated triglycerides and low-density lipoprotein (LDL-C) levels, and low level of high-density lipoprotein (HDL-C) in obese subjects. Therefore, miRNAs may be a good novel biomarker for childhood obesity.

Higher vaspin and lower omentin-1 levels were determined in obese MS children compared to non-MS children and these adipokines were significantly correlated with high CRP values. These data support the view that adipokines in MS children contribute to increased inflammation markers before abnormal glucose metabolism.

Our study indicated that serum suPAR may play an important role in the inflammatory process of COPD, and this increase may be particularly large for patients in Global Initiative for Chronic Obstructive Lung Disease stages III and IV. Serum suPAR and plasma fibrinogen level measurements may be useful for the evaluation of stable COPD.