title: Weight increase and overweight are associated with DNA oxidative damage in skeletal muscle.
abstract: OBJECTIVE
  Weight maintenance within normal standards is recommended for prevention of conditions associated with oxidative injury. To compare oxidative damage in a post mitotic tissue, between adults differing in long-term energy balance.
  
  
  METHODS
  During hernia surgery, a sample of skeletal muscle was obtained in 17 non-obese adults. Subjects were divided into two groups according to their self-reported weight change: weight maintainers (WM) reported <4kg increase, and weight gainers (WG) reported >5kg increment. Muscle immunohistochemistry for 8-hydroxy-deoxyguanosine (8OHdG), 4-Hydroxy-2-nonenal (4HNE), and TNF-alpha, as markers of oxidative injury and inflammation, were performed. As known positive controls for oxidative injury, we included 10 elderly subjects (66-101yr). Anthropometric measures and blood samples for clinical laboratory and serum cytokines (TNF-alpha and IL-6) were obtained.
  
  
  RESULTS
  8OHdG was higher in WG compared with WM (149.1+/-16.2 versus 117.8+/-29.5, P=0.03), and was associated with anthropometric indicators of fat accumulation. 4HNE was similar in WG compared with WM (10.9+/-7.6 versus 9.8+/-6.3) but noticeably higher in elderly subjects (21.5+/-15.3, P=0.059). TNF-alpha protein in WG was higher compared with WM (114.0+/-41.7 versus 70.1+/-23.3, P=0.025), and was associated with weight increase.
  
  
  CONCLUSIONS
  Moderate self-reported weight increase, and body fat accumulation, suggesting long-term positive energy balance is associated with muscle DNA oxidative injury and inflammation.
authors: Institute of Nutrition and Food Technology (INTA), University of Chile, Macul 5540, P.O. Box 138-11, Santiago, Chile. mpmaza@inta.cl
authors: María-Pía
authors: MP
authors: de la Maza
authors: Daniela
authors: D
authors: Olivares
authors: Sandra
authors: S
authors: Hirsch
authors: Walter
authors: W
authors: Sierralta
authors: Vivien
authors: V
authors: Gattás
authors: Gladys
authors: G
authors: Barrera
authors: Daniel
authors: D
authors: Bunout
authors: Laura
authors: L
authors: Leiva
authors: Mireya
authors: M
authors: Fernández