Mitochondrial complex I impairment in leukocytes from type 2 diabetic patients

Free Radic Biol Med. 2011 May 15;50(10):1215-21. doi: 10.1016/j.freeradbiomed.2011.01.019. Epub 2011 Jan 22.


Diabetes is associated with oxidative stress. This study evaluated the rates of oxidative stress and mitochondrial impairment in type 2 diabetes patients. The study population consisted of 182 diabetic patients and 50 body-composition- and age-matched controls. We assessed anthropometric and metabolic parameters and mitochondrial function by evaluating mitochondrial oxygen (O2) consumption, reactive oxygen species (ROS) production, glutathione (GSH) levels, GSH/GSSG ratio, mitochondrial membrane potential, and mitochondrial complex I activity in polymorphonuclear cells from diabetes type 2 patients. We found an increase in waist circumference and augmented serum levels of triglycerides, proinflammatory cytokines (IL-6 and TNF-α), homocysteine, glycated hemoglobin, ultrasensitive C-reactive protein, glucose, insulin, and homeostasis model assessment of insulin resistance score in diabetic patients versus controls. There was an impairment of mitochondrial function in diabetic patients, evidenced by a decrease in mitochondrial O2 consumption, an increase in ROS production, decreased GSH/GSSG ratio, a drop in GSH levels, and an undermining of the mitochondrial membrane potential. Furthermore, an impairment of mitochondrial complex I was detected. This study supports the hypothesis of an association of type 2 diabetes and the rate of impaired mitochondrial function. We also propose that one of the targets of oxidative stress responsible for diabetes is mitochondrial complex I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / metabolism*
  • Diabetes Mellitus, Type 2 / pathology
  • Electron Transport Complex I / antagonists & inhibitors
  • Electron Transport Complex I / metabolism*
  • Humans
  • Leukocytes / drug effects
  • Leukocytes / metabolism*
  • Leukocytes / pathology
  • Middle Aged
  • Mitochondria / metabolism*
  • Mitochondria / pathology
  • Oxidative Stress
  • Oxygen / metabolism
  • Reactive Oxygen Species / metabolism
  • Rotenone / pharmacology


  • Reactive Oxygen Species
  • Rotenone
  • Electron Transport Complex I
  • Oxygen