Dataset Information

Lipid in skeletal muscle myotubes is associated to the donors' insulin sensitivity and physical activity phenotypes.

ABSTRACT:

Objective

This study investigated the relationship between in vitro lipid content in myotubes and in vivo whole body phenotypes of the donors such as insulin sensitivity, intramyocellular lipids (IMCL), physical activity, and oxidative capacity.

Design and methods

Six physically active donors were compared to six sedentary lean and six T2DM. Lipid content was measured in tissues and myotubes by immunohistochemistry. Ceramides, triacylglycerols, and diacylglycerols (DAGs) were measured by LC-MS-MS and GC-FID. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp (80 mU min⁻¹ m⁻²), maximal mitochondrial capacity (ATPmax) by ³¹P-MRS, physical fitness by VO₂max and physical activity level (PAL) by accelerometers.

Results

Myotubes cultured from physically active donors had higher lipid content (0.047 ± 0.003 vs. 0.032 ± 0.001 and 0.033 ± 0.001AU; P < 0.001) than myotubes from lean and T2DM donors. Lipid content in myotubes was not associated with IMCL in muscle tissue but importantly, correlated with in vivo measures of ATPmax (r = 0.74; P < 0.001), insulin sensitivity (r = 0.54; P < 0.05), type-I fibers (r = 0.50; P < 0.05), and PAL (r = 0.92; P < 0.0001). DAGs and ceramides in myotubes were inversely associated with insulin sensitivity (r = -0.55, r = -0.73; P < 0.05) and ATPmax (r = -0.74, r = -0.85; P < 0.01).

Conclusions

These results indicate that cultured human myotubes can be used in mechanistic studies to study the in vitro impact of interventions on phenotypes such as mitochondrial capacity, insulin sensitivity, and physical activity.

SUBMITTER: Bajpeyi S

PROVIDER: S-EPMC3883809 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

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Publications

Lipid in skeletal muscle myotubes is associated to the donors' insulin sensitivity and physical activity phenotypes.

Bajpeyi Sudip S Myrland Cassandra K CK Covington Jeffrey D JD Obanda Diana D Cefalu William T WT Smith Steven R SR Rustan Arild C AC Ravussin Eric E

Obesity (Silver Spring, Md.) 20130910 2

<h4>Objective</h4>This study investigated the relationship between in vitro lipid content in myotubes and in vivo whole body phenotypes of the donors such as insulin sensitivity, intramyocellular lipids (IMCL), physical activity, and oxidative capacity.<h4>Design and methods</h4>Six physically active donors were compared to six sedentary lean and six T2DM. Lipid content was measured in tissues and myotubes by immunohistochemistry. Ceramides, triacylglycerols, and diacylglycerols (DAGs) were meas ...[more]

PMID: 23818429

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Project description:PurposeBariatric surgery is considered as an effective therapeutic strategy for weight loss in severe obesity. Remission of type 2 diabetes is often achieved after the surgery. We investigated whether increase in self-reported habitual physical activity associates with improved skeletal muscle insulin sensitivity and reduction of fat depots after bariatric surgery.MethodsWe assessed self-reported habitual physical activity using Baecke questionnaire in 18 diabetic and 28 nondiabetic patients with morbid obesity (median age, 46 yr; body mass index, 42.0 kg·m) before and 6 months after bariatric surgery operation. Insulin-stimulated femoral muscle glucose uptake was measured using fluorodeoxyglucose positron emission tomography method during hyperinsulinemia. In addition, abdominal subcutaneous and visceral fat masses were quantified using magnetic resonance imaging and liver fat content using magnetic resonance spectroscopy. Also, serum proinflammatory cytokines were measured.ResultsPatients lost on average 22.9% of weight during the follow-up period of 6 months (P < 0.001). Self-reported habitual physical activity level increased (P = 0.017). Improvement in skeletal muscle insulin sensitivity was observed only in those patients who reported increase in their physical activity postoperatively (P = 0.018). The increase in self-reported physical activity associated with the loss of visceral fat mass (P = 0.029). Postoperative self-reported physical activity correlated also positively with postoperative hepatic insulin clearance (P = 0.02) and tended to correlate negatively with liver fat content (P = 0.076). Postoperative self-reported physical activity also correlated negatively with serum TNFα, methyl-accepting chemotaxis protein and interleukin 6 levels.ConclusionsSelf-reported physical activity is associated with reversal of skeletal muscle insulin resistance after bariatric surgery as well as with the loss of visceral fat content and improved postoperative metabolism in bariatric surgery patients.Trial registrationClinicaltrials.gov, NCT00793143 (SLEEVEPASS), NCT01373892 (SLEEVEPET2).

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Dataset Information

Lipid in skeletal muscle myotubes is associated to the donors' insulin sensitivity and physical activity phenotypes.

Objective

Design and methods

Results

Conclusions

Publications

Lipid in skeletal muscle myotubes is associated to the donors' insulin sensitivity and physical activity phenotypes.

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