Increased subsarcolemmal lipids in type 2 diabetes: effect of training on localization of lipids, mitochondria, and glycogen in sedentary human skeletal muscle
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Increased subsarcolemmal lipids in type 2 diabetes: effect of training on localization of lipids, mitochondria, and glycogen in sedentary human skeletal muscle. / Nielsen, Joachim; Hey-Mogensen, Martin; Vind, Birgitte F; Sahlin, Kent; Højlund, Kurt; Schrøder, Henrik D; Ortenblad, Niels.
In: American Journal of Physiology: Endocrinology and Metabolism, Vol. 298, No. 3, 01.03.2010, p. E706-13.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Increased subsarcolemmal lipids in type 2 diabetes: effect of training on localization of lipids, mitochondria, and glycogen in sedentary human skeletal muscle
AU - Nielsen, Joachim
AU - Hey-Mogensen, Martin
AU - Vind, Birgitte F
AU - Sahlin, Kent
AU - Højlund, Kurt
AU - Schrøder, Henrik D
AU - Ortenblad, Niels
PY - 2010/3/1
Y1 - 2010/3/1
N2 - The purpose of the study was to investigate the effect of aerobic training and type 2 diabetes on intramyocellular localization of lipids, mitochondria, and glycogen. Obese type 2 diabetic patients (n = 12) and matched obese controls (n = 12) participated in aerobic cycling training for 10 wk. Endurance-trained athletes (n = 15) were included for comparison. Insulin action was determined by euglycemic-hyperinsulinemic clamp. Intramyocellular contents of lipids, mitochondria, and glycogen at different subcellular compartments were assessed by transmission electron microscopy in biopsies obtained from vastus lateralis muscle. Type 2 diabetic patients were more insulin resistant than obese controls and had threefold higher volume of subsarcolemmal (SS) lipids compared with obese controls and endurance-trained subjects. No difference was found in intermyofibrillar lipids. Importantly, following aerobic training, this excess SS lipid volume was lowered by approximately 50%, approaching the levels observed in the nondiabetic subjects. A strong inverse association between insulin sensitivity and SS lipid volume was found (r(2)=0.62, P = 0.002). The volume density and localization of mitochondria and glycogen were the same in type 2 diabetic patients and control subjects, and showed in parallel with improved insulin sensitivity a similar increase in response to training, however, with a more pronounced increase in SS mitochondria and SS glycogen than in other localizations. In conclusion, this study, estimating intramyocellular localization of lipids, mitochondria, and glycogen, indicates that type 2 diabetic patients may be exposed to increased levels of SS lipids. Thus consideration of cell compartmentation may advance the understanding of the role of lipids in muscle function and type 2 diabetes.
AB - The purpose of the study was to investigate the effect of aerobic training and type 2 diabetes on intramyocellular localization of lipids, mitochondria, and glycogen. Obese type 2 diabetic patients (n = 12) and matched obese controls (n = 12) participated in aerobic cycling training for 10 wk. Endurance-trained athletes (n = 15) were included for comparison. Insulin action was determined by euglycemic-hyperinsulinemic clamp. Intramyocellular contents of lipids, mitochondria, and glycogen at different subcellular compartments were assessed by transmission electron microscopy in biopsies obtained from vastus lateralis muscle. Type 2 diabetic patients were more insulin resistant than obese controls and had threefold higher volume of subsarcolemmal (SS) lipids compared with obese controls and endurance-trained subjects. No difference was found in intermyofibrillar lipids. Importantly, following aerobic training, this excess SS lipid volume was lowered by approximately 50%, approaching the levels observed in the nondiabetic subjects. A strong inverse association between insulin sensitivity and SS lipid volume was found (r(2)=0.62, P = 0.002). The volume density and localization of mitochondria and glycogen were the same in type 2 diabetic patients and control subjects, and showed in parallel with improved insulin sensitivity a similar increase in response to training, however, with a more pronounced increase in SS mitochondria and SS glycogen than in other localizations. In conclusion, this study, estimating intramyocellular localization of lipids, mitochondria, and glycogen, indicates that type 2 diabetic patients may be exposed to increased levels of SS lipids. Thus consideration of cell compartmentation may advance the understanding of the role of lipids in muscle function and type 2 diabetes.
KW - Diabetes Mellitus, Type 2
KW - Exercise Therapy
KW - Glycogen
KW - Humans
KW - Lipid Metabolism
KW - Male
KW - Middle Aged
KW - Mitochondria
KW - Muscle, Skeletal
KW - Physical Endurance
KW - Physical Fitness
KW - Rest
KW - Sarcolemma
KW - Tissue Distribution
KW - Treatment Outcome
U2 - 10.1152/ajpendo.00692.2009
DO - 10.1152/ajpendo.00692.2009
M3 - Journal article
C2 - 20028967
VL - 298
SP - E706-13
JO - American Journal of Physiology - Endocrinology and Metabolism
JF - American Journal of Physiology - Endocrinology and Metabolism
SN - 0193-1849
IS - 3
ER -
ID: 33836895