Impact of Oxidative Stress in Premature Aging and Iron Overload in Hemodialysis Patients

Abstract EN

Background.

Increased oxidative stress is a well described feature of patients in hemodialysis.

Their need for multiple blood transfusions and supplemental iron causes a significant iron overload that has recently been associated with increased oxidation of polyunsaturated lipids and accelerated aging due to DNA damage caused by telomere shortening.

Methods.

A total of 70 patients were evaluated concomitantly, 35 volunteers with ferritin levels below 500 ng/mL (Group A) and 35 volunteers with ferritin levels higher than 500 ng/mL (Group B).

A sample of venous blood was taken to extract DNA from leukocytes and to measure relative telomere length by real-time PCR.

Results.

Patients in Group B had significantly higher plasma TBARS (p=0.008), carbonyls (p=0.0004), and urea (p=0.02) compared with those in Group A.

Telomeres were significantly shorter in Group B, 0.66 (SD, 0.051), compared with 0.75 (SD, 0.155) in Group A (p=0.0017).

We observed a statistically significant association between relative telomere length and ferritin levels (r=-0.37, p=0.001).

Relative telomere length was inversely related to time on hemodialysis (r=-0.27, p=0.02).

Conclusions.

Our findings demonstrate that iron overload was associated with increased levels of oxidative stress and shorter relative telomere length.