OBJECTIVES: To assess the prognostic role of the inflammatory cytokine, interleukin 6 (IL-6), and insulin-like growth factor-1 (IGF-1) in predicting 2-year changes in fat-free mass (FFM) while controlling for potential confounders. DESIGN: Population-based cohort, the Framingham Heart Study, examined in 1992-93 and 1994-95. SETTING: General community. PARTICIPANTS: Two hundred thirty-two men and 326 women aged 72 to 92. MEASUREMENTS: IGF-1 was measured using radio-immunoassay and cellular IL-6 production using non-cross-reacting radioimmunoassays. FFM was estimated using population-specific equations for predicting FFM from bioelectrical impedance analysis developed separately for men and women. RESULTS: Higher IGF-1 predicted smaller loss of FFM in men than lower IGF-1 did (P=.002), after adjusting for age, baseline FFM, fat mass, and 2-year weight changes, whereas cellular IL-6 was a significant predictor of sarcopenia in women (P=.02). Weight change was a strong determinant of change in FFM in both sexes (P<.0001). CONCLUSION: Predictors of sarcopenia include body composition characteristics that are common to men and women and sex-specific metabolic predictors. Sarcopenia appears to reflect a withdrawal of anabolic stimuli, such as growth hormone, in men but an increase in catabolic stimuli, such as cellular IL-6, in women.
OBJECTIVES: To assess the prognostic role of the inflammatory cytokine, interleukin 6 (IL-6), and insulin-like growth factor-1 (IGF-1) in predicting 2-year changes in fat-free mass (FFM) while controlling for potential confounders. DESIGN: Population-based cohort, the Framingham Heart Study, examined in 1992-93 and 1994-95. SETTING: General community. PARTICIPANTS: Two hundred thirty-two men and 326 women aged 72 to 92. MEASUREMENTS: IGF-1 was measured using radio-immunoassay and cellular IL-6 production using non-cross-reacting radioimmunoassays. FFM was estimated using population-specific equations for predicting FFM from bioelectrical impedance analysis developed separately for men and women. RESULTS: Higher IGF-1 predicted smaller loss of FFM in men than lower IGF-1 did (P=.002), after adjusting for age, baseline FFM, fat mass, and 2-year weight changes, whereas cellular IL-6 was a significant predictor of sarcopenia in women (P=.02). Weight change was a strong determinant of change in FFM in both sexes (P<.0001). CONCLUSION: Predictors of sarcopenia include body composition characteristics that are common to men and women and sex-specific metabolic predictors. Sarcopenia appears to reflect a withdrawal of anabolic stimuli, such as growth hormone, in men but an increase in catabolic stimuli, such as cellular IL-6, in women.
Authors: Richard D Semba; Ravi Varadhan; Benedetta Bartali; Luigi Ferrucci; Michelle O Ricks; Caroline Blaum; Linda P Fried Journal: Age Ageing Date: 2006-11-17 Impact factor: 10.668
Authors: Laura A Schaap; Saskia M F Pluijm; Dorly J H Deeg; Tamara B Harris; Stephen B Kritchevsky; Anne B Newman; Lisa H Colbert; Marco Pahor; Susan M Rubin; Frances A Tylavsky; Marjolein Visser Journal: J Gerontol A Biol Sci Med Sci Date: 2009-07-21 Impact factor: 6.053