Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function

Andrew Murton, Kanagaraj Marimuthu, Joanne E. Mallinson, Anna L. Selby, Kenneth Smith, Michael J. Rennie, Paul L. Greenhaff

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Obesity is increasing, yet despite the necessity of maintaining muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ± 1.1 kg $ m-2) and 15 healthy-weight (BMI 23.4 ± 0.3 kg $ m-2) oldermen (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under postabsorptive (hypoinsulinemic-euglycemic clamp) and postprandial (hyperinsulinemic hyperaminoacidemiceuglycemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whereas leg lean mass, strength, and work done during maximal exercise were no different. Under postabsorptive conditions, MPS and LPB were equivalent between groups, whereas insulin and amino acid administration increased MPS in only healthy-weight subjects and was associated with lower leg glucose disposal (LGD) (63%) in obese men. Blunting of MPS in the obese men was offset by an apparent decline in LPB, which was absent in healthy-weight subjects. Lower postprandial LGD in obese subjects and blunting of MPS responses to amino acids suggest that obesity in older adults is associated with diminished muscle metabolic quality. This does not, however, appear to be associated with lower leg lean mass or strength.

Original languageEnglish (US)
Pages (from-to)3160-3171
Number of pages12
JournalDiabetes
Volume64
Issue number9
DOIs
StatePublished - Sep 1 2015
Externally publishedYes

Fingerprint

Muscle Proteins
Leg
Obesity
Food
Muscles
Weights and Measures
Healthy Volunteers
Amino Acids
Glucose
Proteins
Glucose Clamp Technique
Fats
Exercise
Insulin
Inflammation
Messenger RNA

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism

Cite this

Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function. / Murton, Andrew; Marimuthu, Kanagaraj; Mallinson, Joanne E.; Selby, Anna L.; Smith, Kenneth; Rennie, Michael J.; Greenhaff, Paul L.

In: Diabetes, Vol. 64, No. 9, 01.09.2015, p. 3160-3171.

Research output: Contribution to journalArticle

Murton, Andrew ; Marimuthu, Kanagaraj ; Mallinson, Joanne E. ; Selby, Anna L. ; Smith, Kenneth ; Rennie, Michael J. ; Greenhaff, Paul L. / Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function. In: Diabetes. 2015 ; Vol. 64, No. 9. pp. 3160-3171.
@article{93a973c7988b4289b872806a7032bb39,
title = "Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function",
abstract = "Obesity is increasing, yet despite the necessity of maintaining muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ± 1.1 kg $ m-2) and 15 healthy-weight (BMI 23.4 ± 0.3 kg $ m-2) oldermen (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under postabsorptive (hypoinsulinemic-euglycemic clamp) and postprandial (hyperinsulinemic hyperaminoacidemiceuglycemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whereas leg lean mass, strength, and work done during maximal exercise were no different. Under postabsorptive conditions, MPS and LPB were equivalent between groups, whereas insulin and amino acid administration increased MPS in only healthy-weight subjects and was associated with lower leg glucose disposal (LGD) (63{\%}) in obese men. Blunting of MPS in the obese men was offset by an apparent decline in LPB, which was absent in healthy-weight subjects. Lower postprandial LGD in obese subjects and blunting of MPS responses to amino acids suggest that obesity in older adults is associated with diminished muscle metabolic quality. This does not, however, appear to be associated with lower leg lean mass or strength.",
author = "Andrew Murton and Kanagaraj Marimuthu and Mallinson, {Joanne E.} and Selby, {Anna L.} and Kenneth Smith and Rennie, {Michael J.} and Greenhaff, {Paul L.}",
year = "2015",
month = "9",
day = "1",
doi = "10.2337/db15-0021",
language = "English (US)",
volume = "64",
pages = "3160--3171",
journal = "Diabetes",
issn = "0012-1797",
publisher = "American Diabetes Association Inc.",
number = "9",

}

TY - JOUR

T1 - Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function

AU - Murton, Andrew

AU - Marimuthu, Kanagaraj

AU - Mallinson, Joanne E.

AU - Selby, Anna L.

AU - Smith, Kenneth

AU - Rennie, Michael J.

AU - Greenhaff, Paul L.

PY - 2015/9/1

Y1 - 2015/9/1

N2 - Obesity is increasing, yet despite the necessity of maintaining muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ± 1.1 kg $ m-2) and 15 healthy-weight (BMI 23.4 ± 0.3 kg $ m-2) oldermen (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under postabsorptive (hypoinsulinemic-euglycemic clamp) and postprandial (hyperinsulinemic hyperaminoacidemiceuglycemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whereas leg lean mass, strength, and work done during maximal exercise were no different. Under postabsorptive conditions, MPS and LPB were equivalent between groups, whereas insulin and amino acid administration increased MPS in only healthy-weight subjects and was associated with lower leg glucose disposal (LGD) (63%) in obese men. Blunting of MPS in the obese men was offset by an apparent decline in LPB, which was absent in healthy-weight subjects. Lower postprandial LGD in obese subjects and blunting of MPS responses to amino acids suggest that obesity in older adults is associated with diminished muscle metabolic quality. This does not, however, appear to be associated with lower leg lean mass or strength.

AB - Obesity is increasing, yet despite the necessity of maintaining muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ± 1.1 kg $ m-2) and 15 healthy-weight (BMI 23.4 ± 0.3 kg $ m-2) oldermen (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under postabsorptive (hypoinsulinemic-euglycemic clamp) and postprandial (hyperinsulinemic hyperaminoacidemiceuglycemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whereas leg lean mass, strength, and work done during maximal exercise were no different. Under postabsorptive conditions, MPS and LPB were equivalent between groups, whereas insulin and amino acid administration increased MPS in only healthy-weight subjects and was associated with lower leg glucose disposal (LGD) (63%) in obese men. Blunting of MPS in the obese men was offset by an apparent decline in LPB, which was absent in healthy-weight subjects. Lower postprandial LGD in obese subjects and blunting of MPS responses to amino acids suggest that obesity in older adults is associated with diminished muscle metabolic quality. This does not, however, appear to be associated with lower leg lean mass or strength.

UR - http://www.scopus.com/inward/record.url?scp=84947297754&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84947297754&partnerID=8YFLogxK

U2 - 10.2337/db15-0021

DO - 10.2337/db15-0021

M3 - Article

VL - 64

SP - 3160

EP - 3171

JO - Diabetes

JF - Diabetes

SN - 0012-1797

IS - 9

ER -