CONTEXT: Aging is associated with insulin resistance and unfavorable changes in body composition including increased fat accumulation, particularly in visceral and ectopic depots. Recent studies suggest that skeletal muscle mitochondrial activity may underlie some age-associated metabolic abnormalities. OBJECTIVE: Our objective was to measure mitochondrial capacity and coupling of the vastus lateralis muscle in elderly and young adults using novel in vivo approaches and relate mitochondrial activity to metabolic characteristics. DESIGN: This was a cross-sectional study. PARTICIPANTS AND INTERVENTION: Fourteen sedentary young (seven males and seven females, 20-34 yr of age) and 15 sedentary elderly (seven males and eight females, 70-84 yr of age) nonobese subjects selected for similar body weight underwent measures of body composition by magnetic resonance imaging and dual-energy x-ray absorptiometry, oral glucose tolerance, and in vivo mitochondrial activity by (31)P magnetic resonance and optical spectroscopy. Muscle biopsy was carried out in the same muscle to measure mitochondrial content, antioxidant activity, fiber type, and markers of mitochondrial biogenesis. RESULTS: Elderly volunteers had reduced mitochondrial capacity (P = 0.05) and a trend for decreased coupling efficiency (P = 0.08) despite similar mitochondrial content and fiber type distribution. This was accompanied by greater whole-body oxidative stress (P = 0.007), less skeletal muscle mass (P < 0.001), more adipose tissue in all depots (P ≤ 0.002) except intramyocellular (P = 0.72), and lower glucose tolerance (P = 0.07). CONCLUSIONS: Elderly adults show evidence of altered mitochondrial activity along with increased adiposity, oxidative stress, and reduced glucose tolerance, independent of obesity. We propose that mild uncoupling may be induced secondary to age-associated oxidative stress as a mechanism to dissipate the proton-motive force and protect against further reactive oxygen species production and damage.
CONTEXT: Aging is associated with insulin resistance and unfavorable changes in body composition including increased fat accumulation, particularly in visceral and ectopic depots. Recent studies suggest that skeletal muscle mitochondrial activity may underlie some age-associated metabolic abnormalities. OBJECTIVE: Our objective was to measure mitochondrial capacity and coupling of the vastus lateralis muscle in elderly and young adults using novel in vivo approaches and relate mitochondrial activity to metabolic characteristics. DESIGN: This was a cross-sectional study. PARTICIPANTS AND INTERVENTION: Fourteen sedentary young (seven males and seven females, 20-34 yr of age) and 15 sedentary elderly (seven males and eight females, 70-84 yr of age) nonobese subjects selected for similar body weight underwent measures of body composition by magnetic resonance imaging and dual-energy x-ray absorptiometry, oral glucose tolerance, and in vivo mitochondrial activity by (31)P magnetic resonance and optical spectroscopy. Muscle biopsy was carried out in the same muscle to measure mitochondrial content, antioxidant activity, fiber type, and markers of mitochondrial biogenesis. RESULTS: Elderly volunteers had reduced mitochondrial capacity (P = 0.05) and a trend for decreased coupling efficiency (P = 0.08) despite similar mitochondrial content and fiber type distribution. This was accompanied by greater whole-body oxidative stress (P = 0.007), less skeletal muscle mass (P < 0.001), more adipose tissue in all depots (P ≤ 0.002) except intramyocellular (P = 0.72), and lower glucose tolerance (P = 0.07). CONCLUSIONS: Elderly adults show evidence of altered mitochondrial activity along with increased adiposity, oxidative stress, and reduced glucose tolerance, independent of obesity. We propose that mild uncoupling may be induced secondary to age-associated oxidative stress as a mechanism to dissipate the proton-motive force and protect against further reactive oxygen species production and damage.
Authors: Dympna Gallagher; Patrick Kuznia; Stanley Heshka; Jeanine Albu; Steven B Heymsfield; Bret Goodpaster; Marjolein Visser; Tamara B Harris Journal: Am J Clin Nutr Date: 2005-04 Impact factor: 7.045
Authors: M Krssak; K Falk Petersen; A Dresner; L DiPietro; S M Vogel; D L Rothman; M Roden; G I Shulman Journal: Diabetologia Date: 1999-01 Impact factor: 10.122
Authors: Iva Miljkovic; Allison L Kuipers; Jane A Cauley; Tanushree Prasad; Christine G Lee; Kristine E Ensrud; Peggy M Cawthon; Andrew R Hoffman; Thuy-Tien Dam; Christopher L Gordon; Joseph M Zmuda Journal: J Gerontol A Biol Sci Med Sci Date: 2015-04-02 Impact factor: 6.053
Authors: Jeffrey D Covington; Robert C Noland; R Caitlin Hebert; Blaine S Masinter; Steven R Smith; Arild C Rustan; Eric Ravussin; Sudip Bajpeyi Journal: J Clin Endocrinol Metab Date: 2015-07-14 Impact factor: 5.958
Authors: Gwenael Layec; Joel D Trinity; Corey R Hart; James Hopker; Louis Passfield; Paul M Coen; Kevin E Conley; Gary R Hunter; Gordon Fisher; Richard A Ferguson; Kazushige Sasaki; Davide Malatesta; Nicola A Maffiuletti; Fabio Borrani; Alberto E Minetti; Charles L Rice; Brian H Dalton; Chris J McNeil; Geoff A Power; Todd M Manini Journal: J Appl Physiol (1985) Date: 2013-04
Authors: Steven K Malin; Jacob M Haus; Thomas P J Solomon; Alecia Blaszczak; Sangeeta R Kashyap; John P Kirwan Journal: Am J Physiol Endocrinol Metab Date: 2013-09-24 Impact factor: 4.310
Authors: Ryan O Walters; Esperanza Arias; Antonio Diaz; Emmanuel S Burgos; Fangxia Guan; Simoni Tiano; Kai Mao; Cara L Green; Yungping Qiu; Hardik Shah; Donghai Wang; Adam D Hudgins; Tahmineh Tabrizian; Valeria Tosti; David Shechter; Luigi Fontana; Irwin J Kurland; Nir Barzilai; Ana Maria Cuervo; Daniel E L Promislow; Derek M Huffman Journal: Cell Rep Date: 2018-10-16 Impact factor: 9.423