scholarly journals Skeletal Muscle Lipid Peroxidation and Insulin Resistance in Humans

2012 ◽  
Vol 97 (7) ◽  
pp. E1182-E1186 ◽  
Author(s):  
Katherine H. Ingram ◽  
Helliner Hill ◽  
Douglas R. Moellering ◽  
Bradford G. Hill ◽  
Cristina Lara-Castro ◽  
...  

Abstract Objective: The relationships among skeletal muscle lipid peroxidation, intramyocellular lipid content (IMCL), and insulin sensitivity were evaluated in nine insulin-sensitive (IS), 13 insulin-resistant (IR), and 10 adults with type 2 diabetes (T2DM). Design: Insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp [glucose disposal rate (GDR)]. Lipid peroxidation was assessed by 4-hydroxynonenal (HNE)-protein adducts and general oxidative stress by protein carbonyl content. All patients were sedentary. Results: Protein-HNE adducts were elevated 1.6-fold in T2DM compared with IS adults, whereas IR showed intermediate levels of HNE-modified proteins. Protein-HNE adducts correlated with GDR, waist circumference, and body mass index. IMCL was increased by 4.0- and 1.9-fold in T2DM and IR patients, respectively, compared with IS, and was correlated with GDR and waist circumference but not BMI. Protein carbonyls were not different among groups and did not correlate with any of the measured variables. Correlations were detected between IMCL and protein-HNE. Conclusion: Our data show for the first time that skeletal muscle protein-HNE adducts are related to the severity of insulin resistance in sedentary adults. These results suggest that muscle lipid peroxidation could be involved in the development of insulin resistance.

Author(s):  
Claire Laurens ◽  
Cedric Moro

AbstractOver the past decades, obesity and its metabolic co-morbidities such as type 2 diabetes (T2D) developed to reach an endemic scale. However, the mechanisms leading to the development of T2D are still poorly understood. One main predictor for T2D seems to be lipid accumulation in “non-adipose” tissues, best known as ectopic lipid storage. A growing body of data suggests that these lipids may play a role in impairing insulin action in metabolic tissues, such as liver and skeletal muscle. This review aims to discuss recent literature linking ectopic lipid storage and insulin resistance, with emphasis on lipid deposition in skeletal muscle. The link between skeletal muscle lipid content and insulin sensitivity, as well as the mechanisms of lipid-induced insulin resistance and potential therapeutic strategies to alleviate lipotoxic lipid pressure in skeletal muscle will be discussed.


2003 ◽  
Vol 35 (Supplement 1) ◽  
pp. S10
Author(s):  
C R. Bruce ◽  
M J. Anderson ◽  
A L. Carey ◽  
D G. Newman ◽  
A Bonen ◽  
...  

2013 ◽  
Vol 38 (5) ◽  
pp. 512-519 ◽  
Author(s):  
Andrea S. Cornford ◽  
Alexander Hinko ◽  
Rachael K. Nelson ◽  
Ariel L. Barkan ◽  
Jeffrey F. Horowitz

Prolonged overeating and the resultant weight gain are clearly linked with the development of insulin resistance and other cardiometabolic abnormalities, but adaptations that occur after relatively short periods of overeating are not completely understood. The purpose of this study was to characterize metabolic adaptations that may accompany the development of insulin resistance after 2 weeks of overeating. Healthy, nonobese subjects (n = 9) were admitted to the hospital for 2 weeks, during which time they ate ∼4000 kcals·day−1 (70 kcal·kg−1 fat free mass·day−1). Insulin sensitivity was estimated during a meal tolerance test, and a muscle biopsy was obtained to assess muscle lipid accumulation and protein markers associated with insulin resistance, inflammation, and the regulation of lipid metabolism. Whole-body insulin sensitivity declined markedly after 2 weeks of overeating (Matsuda composite index: 8.3 ± 1.3 vs. 4.6 ± 0.7, p < 0.05). However, muscle markers of insulin resistance and inflammation (i.e., phosphorylation of IRS-1-Ser312, Akt-Ser473, and c-Jun N-terminal kinase) were not altered by overeating. Intramyocellular lipids tended to increase after 2 weeks of overeating (triacylglyceride: 7.6 ± 1.6 vs. 10.0 ± 1.8 nmol·mg−1 wet weight; diacylglyceride: 104 ± 10 vs. 142 ± 23 pmol·mg−1 wet weight) but these changes did not reach statistical significance. Overeating induced a 2-fold increase in 24-h insulin response (area under the curve (AUC); p < 0.05), with a resultant ∼35% reduction in 24-h plasma fatty acid AUC (p < 0.05). This chronic reduction in circulating fatty acids may help explain the lack of a robust increase in muscle lipid accumulation. In summary, our findings suggest alterations in skeletal muscle metabolism may not contribute meaningfully to the marked whole-body insulin resistance observed after 2 weeks of overeating.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1748-P ◽  
Author(s):  
FENGYUAN HUANG ◽  
KEVIN YANG ◽  
KAMALAMMA SAJA ◽  
YICHENG HUANG ◽  
QINGQIANG LONG ◽  
...  

2015 ◽  
Vol 225 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sandra Pereira ◽  
Anu Shah ◽  
I George Fantus ◽  
Jamie W Joseph ◽  
Adria Giacca

Circulating free fatty acids (FFAs) are elevated in obesity and cause insulin resistance. The objective of the current study was to determine whether the antioxidantN-acetyl-l-cysteine (NAC) prevented hepatic and peripheral insulin resistance caused by prolonged elevation of plasma FFAs. Chronically cannulated Wistar rats received saline (SAL), Intralipid plus heparin (IH), IH plus NAC, or NAC i.v. infusion for 48 h. Insulin sensitivity was determined using the hyperinsulinemic–euglycemic clamp with tritiated glucose tracer. IH induced hepatic and peripheral insulin resistance (P<0.05). NAC co-infusion did not prevent insulin resistance in the liver, although it was able to prevent peripheral insulin resistance. Prolonged IH infusion did not appear to induce oxidative stress in the liver because hepatic content of protein carbonyl, malondialdehyde, and reduced to oxidized glutathione ratio did not differ across treatment groups. In alignment with our insulin sensitivity results, IH augmented skeletal muscle protein carbonyl content and this was prevented by NAC co-infusion. Taken together, our results indicate that oxidative stress mediates peripheral, but not hepatic, insulin resistance resulting from prolonged plasma FFA elevation. Thus, in states of chronic plasma FFA elevation, such as obesity, antioxidants may protect against peripheral but not hepatic insulin resistance.


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