Weight increase and overweight are associated with DNA oxidative damage in skeletal muscle.
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.
de la Maza
María-Pía
MP
Institute of Nutrition and Food Technology (INTA), University of Chile, Macul 5540, P.O. Box 138-11, Santiago, Chile. mpmaza@inta.cl
Olivares
Daniela
D
Hirsch
Sandra
S
Sierralta
Walter
W
Gattás
Vivien
V
Barrera
Gladys
G
Bunout
Daniel
D
Leiva
Laura
L
Fernández
Mireya
M