Human CR model for muscle oxidation

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Hi All,

See another abstract on CR below. It is on a human CR model for skeletal muscle

in

its oxidation in response to weight gain versus weight maintenance.

Clinical Nutrition (2005) 24, 535–710, page 649, Abstract P228, Abstracts

Presented

at the 27th ESPEN Congress

WEIGHT INCREASE IS ASSOCIATED WITH SKELETAL MUSCLE OXIDATIVE DAMAGE

M. P. De la Maza, D. Olivares, S. Hirsch, V. Gattas, G. Barrera, D. Bunout, L.

Leiva, W. Sierralta, M. Fernandez

Rationale: Caloric restriction (CR) prolongs life-span

through reduction of oxidative stress. In

primates, weight maintenance is associated with

prevention of age-related conditions. An equivalent

human model of CR is not yet defined. The aim of

this study was to compare oxidative damage in a

post-mitotic tissue between adults differing in

long-term energy balance.

Methods: During inguinal hernia surgery, a sample

of skeletal muscle was obtained in 17 healthy non-obese

adults, aged 33–47 yr. Subjects were divided

into two groups according to their self-reported

weight change over the last 10 yr: Weight Main-tainers

(WM) reported 4k increase, and Weight

Gainers (WG) reported >5k increment. Muscle

immunohistochemistry for 8-hydroxy-deoxyguano-sine

(8OHdG) and TNF-á, as markers of oxidative

injury, were performed. Anthropometric measures

and blood samples for clinical lab and serum

cytokines were also obtained. Ten elders aged

66–10 yr were studied, as positive controls for

oxidative injury.

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. TNF-á protein in WG was

higher compared with WM (114.0±1.7 versus

70.1±23.3, P=0.025), and was associated with

weight increase. In elders, both markers did not

differ from WG.

Conclusions: Moderate self-reported weight in-crease

and body fat accumulation is associated

with muscle oxidative injury, as in the aging

process. This model could be used as a CR

equivalent, indicating long-term energy balance,

and be useful for the study of the aging process.

Al Pater, PhD; email: old542000@...

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