TY - JOUR
T1 - Differences in muscle energy metabolism and metabolic flexibility between sarcopenic and nonsarcopenic older adults
AU - Shoemaker, Marni E.
AU - Pereira, Suzette L.
AU - Mustad, Vikkie A.
AU - Gillen, Zachary M.
AU - McKay, Brianna D.
AU - Lopez-Pedrosa, Jose M.
AU - Rueda, Ricardo
AU - Cramer, Joel T.
N1 - Funding Information:
This work was sponsored by Abbott Nutrition, who contributed to study design, reviewed this manuscript, and made minor edits to the final draft. Abbott Nutrition had no part in data collection, data analysis or interpretations of the findings. The authors would like to thank all participants, Nicholas Bohannon, Sydney Gibson, Gaye Homer, Kimberly Thompson, Sophie Alvarez and staff of the Proteomics & Metabolomics Facility at the Center for Biotechnology/University of Nebraska-Lincoln, Dr Heather Eberspacher, Janette Drohman and Savannnah Pines Retirement Community, the UNL Osher Lifelong Learning Institute (OLLI), Aging Partners, and NEP Nebraska Extension for their help. This study was supported in part by the University of Nebraska Agriculture Research Division with funds provided by the Hatch Act (Agency: US Department of Agriculture, National Institute of Food and Agriculture). The authors acknowledge that they comply with the ethical guidelines for authorship and publishing of the Journal of Cachexia, Sarcopenia and Muscle.38
Funding Information:
This work was sponsored by Abbott Nutrition, who contributed to study design, reviewed this manuscript, and made minor edits to the final draft. Abbott Nutrition had no part in data collection, data analysis or interpretations of the findings.
Funding Information:
The authors would like to thank all participants, Nicholas Bohannon, Sydney Gibson, Gaye Homer, Kimberly Thompson, Sophie Alvarez and staff of the Proteomics & Metabolomics Facility at the Center for Biotechnology/University of Nebraska‐Lincoln, Dr Heather Eberspacher, Janette Drohman and Savannnah Pines Retirement Community, the UNL Osher Lifelong Learning Institute (OLLI), Aging Partners, and NEP Nebraska Extension for their help. This study was supported in part by the University of Nebraska Agriculture Research Division with funds provided by the Hatch Act (Agency: US Department of Agriculture, National Institute of Food and Agriculture). The authors acknowledge that they comply with the ethical guidelines for authorship and publishing of the . Journal of Cachexia, Sarcopenia and Muscle 38
Publisher Copyright:
© 2022 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.
PY - 2022/4
Y1 - 2022/4
N2 - Background: Metabolic flexibility is the ability of skeletal muscle to adapt fuel utilization to the demand for fuel sources [carbohydrates (CHO) and fats (FAT)]. The purpose of this study was to explore muscle energy metabolism and metabolic flexibility under various conditions in sarcopenic (S) versus nonsarcopenic (NS) older adults. Methods: Twenty-two older adults aged 65 years or older were categorized as NS [n = 11; mean ± standard deviation (SD); age = 73.5 ± 6.0 years (males, n = 5; females, n = 6)] or S [n = 11; 81.2 ± 10.5 years (males, n = 6; females, n = 5) based on handgrip strength, body composition and physical performance. Indirect calorimetry was recorded before and after consumption of a high-CHO meal and during aerobic and anaerobic exercise. Respiratory quotient (RQ), CHO and FAT oxidation were assessed. Venous blood samples were collected for glucose and insulin concentrations. Results: At rest, compared with NS, S exhibited a 5–8% higher RQ at 0 (0.72 vs. 0.76) and 120 (0.77 vs. 0.82), 150 (0.76 vs. 0.80), and 180 min (0.74 vs. 0.80) (P = 0.002–0.025); 59–195% higher CHO oxidation at 0, 120, and 180 min (0.0004–0.002 vs. 0.001–0.002 g·min−1·kg-1) (P = 0.010–0.047); and 20–31% lower FAT oxidation at 0, 15, and 90–180 min (0.0009–0.0022 vs. 0.0011–0.002 g·min−1·kg−1) (P = 0.004–0.038). Glucose levels were significantly elevated in S versus NS at 0, 60 and 75 min (144.64–202.78 vs. 107.70–134.20 mg·dL−1) but not insulin. During aerobic exercise, RQ was 5% greater (0.90 vs. 0.86) (P = 0.039), and FAT oxidation was 35% lower at 6–8 min (0.003 vs. 0.005 g·min−1·kg−1) (P = 0.033) in S versus NS. During anaerobic exercise, CHO oxidation was 31% greater in NS versus S at 60–80% time to exhaustion (0.011 vs. 0.007 g·min−1·kg−1) (P = 0.015). Per cent contribution to energy expenditure was greater in S for CHO but lower for FAT at 0 (CHO: 22% vs. 10%; FAT: 78% vs. 91%) and 120–180 min (CHO: 35–42% vs. 17–25%; FAT: 58–65% vs. 75%–84%) (P = 0.003–0.046) at rest and 6–8 min during aerobic exercise (CHO: 70% vs. 57%; FAT: 30% vs. 45%) (P = 0.046). Conclusions: The data show differences in skeletal muscle energy metabolism and substrate utilization between S and NS at rest, transitioning from fasted to fed state, and during exercise. Compared with NS, S displayed a diminished ability to adapt fuel utilization in response to feeding and exercise, reflecting metabolic inflexibility. Impaired metabolic flexibility could be a mechanism underlying the losses of strength and physical function accompanying sarcopenia.
AB - Background: Metabolic flexibility is the ability of skeletal muscle to adapt fuel utilization to the demand for fuel sources [carbohydrates (CHO) and fats (FAT)]. The purpose of this study was to explore muscle energy metabolism and metabolic flexibility under various conditions in sarcopenic (S) versus nonsarcopenic (NS) older adults. Methods: Twenty-two older adults aged 65 years or older were categorized as NS [n = 11; mean ± standard deviation (SD); age = 73.5 ± 6.0 years (males, n = 5; females, n = 6)] or S [n = 11; 81.2 ± 10.5 years (males, n = 6; females, n = 5) based on handgrip strength, body composition and physical performance. Indirect calorimetry was recorded before and after consumption of a high-CHO meal and during aerobic and anaerobic exercise. Respiratory quotient (RQ), CHO and FAT oxidation were assessed. Venous blood samples were collected for glucose and insulin concentrations. Results: At rest, compared with NS, S exhibited a 5–8% higher RQ at 0 (0.72 vs. 0.76) and 120 (0.77 vs. 0.82), 150 (0.76 vs. 0.80), and 180 min (0.74 vs. 0.80) (P = 0.002–0.025); 59–195% higher CHO oxidation at 0, 120, and 180 min (0.0004–0.002 vs. 0.001–0.002 g·min−1·kg-1) (P = 0.010–0.047); and 20–31% lower FAT oxidation at 0, 15, and 90–180 min (0.0009–0.0022 vs. 0.0011–0.002 g·min−1·kg−1) (P = 0.004–0.038). Glucose levels were significantly elevated in S versus NS at 0, 60 and 75 min (144.64–202.78 vs. 107.70–134.20 mg·dL−1) but not insulin. During aerobic exercise, RQ was 5% greater (0.90 vs. 0.86) (P = 0.039), and FAT oxidation was 35% lower at 6–8 min (0.003 vs. 0.005 g·min−1·kg−1) (P = 0.033) in S versus NS. During anaerobic exercise, CHO oxidation was 31% greater in NS versus S at 60–80% time to exhaustion (0.011 vs. 0.007 g·min−1·kg−1) (P = 0.015). Per cent contribution to energy expenditure was greater in S for CHO but lower for FAT at 0 (CHO: 22% vs. 10%; FAT: 78% vs. 91%) and 120–180 min (CHO: 35–42% vs. 17–25%; FAT: 58–65% vs. 75%–84%) (P = 0.003–0.046) at rest and 6–8 min during aerobic exercise (CHO: 70% vs. 57%; FAT: 30% vs. 45%) (P = 0.046). Conclusions: The data show differences in skeletal muscle energy metabolism and substrate utilization between S and NS at rest, transitioning from fasted to fed state, and during exercise. Compared with NS, S displayed a diminished ability to adapt fuel utilization in response to feeding and exercise, reflecting metabolic inflexibility. Impaired metabolic flexibility could be a mechanism underlying the losses of strength and physical function accompanying sarcopenia.
KW - Ageing
KW - Carbohydrate oxidation
KW - Exercise
KW - Fat oxidation
KW - Metabolic flexibility
KW - Metabolism
KW - Sarcopenia
UR - http://www.scopus.com/inward/record.url?scp=85124725564&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85124725564&partnerID=8YFLogxK
U2 - 10.1002/jcsm.12932
DO - 10.1002/jcsm.12932
M3 - Article
C2 - 35178889
AN - SCOPUS:85124725564
SN - 2190-5991
VL - 13
SP - 1224
EP - 1237
JO - Journal of Cachexia, Sarcopenia and Muscle
JF - Journal of Cachexia, Sarcopenia and Muscle
IS - 2
ER -