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Racial/ethnic disparities in basal muscle protein metabolism
Author(s) -
Fujita Satoshi,
Rasmussen Blake B,
SheffieldMoore Melinda,
Volpi Elena
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a837-b
Subject(s) - medicine , phenylalanine , endocrinology , basal (medicine) , muscle protein , metabolism , cohort , protein metabolism , amino acid , muscle mass , biology , skeletal muscle , biochemistry , insulin
Variability in body composition and muscle mass may be partially explained by race/ethnicity. The purpose of the current, ongoing study was to determine if race/ethnicity influences basal muscle protein metabolism. Using stable isotope methodologies, we measured muscle protein and amino acid metabolism in a multiethnic cohort of 49 healthy adult men (28±1 yrs) after an overnight fast. Preliminary results indicate that arterial and venous phenylalanine concentrations were significantly higher in Asians (ASI: 69±4 μmol/L) than Caucasians (C: 59±2, P<0.05), and muscle free phenylalanine concentrations were significantly higher in African Americans (AA: 126±15) than C: (95±6) and Hispanic (H: 85±5) (P<0.05). No differences in muscle protein synthesis were found between groups. Muscle breakdown (Ra, nmol/min/100 ml leg) was significantly higher (ASI 69±4, C: 57±5, P<0.05) and net balance (NB, nmol/min/100 ml leg) was significantly lower in ASI than C (ASI: −33±5, C: −16±2, P<0.05). NB significantly correlated with body weight and height (P<0.01) suggesting that body size may influence muscle protein turnover. In conclusion, key parameters of muscle protein and amino acid metabolism are influenced by ethnicity; however, these differences may simply reflect differences in body size. Support: NIH R01 AG18311, P30 AG17231