Muscles in obesity have problems choosing fuel
(3 July 2005: VIDYYA MEDICAL NEWS SERVICE) -- In obese and diabetic people, fat and carbohydrate oxidation by skeletal muscle is disrupted, contributing to insulin resistance. In a new study appearing in the July 1 print issue of The Journal of Clinical Investigation, Barbara Ukropcova and colleagues from Pennington Biomedical Research Center examine whether the ability of skeletal muscle to oxidize fat in vitro is representative of the donor's metabolic characteristics.
The authors find that skeletal muscle cells, cultured in a controlled environment for up to 5 weeks, isolated from the endocrine and nutritional influences of their donor, retained their donor's metabolic characteristics. This suggests that defects in switching between fat oxidation and carbohydrate oxidation, possibly due to genetic defects in skeletal muscle, contribute to obesity and insulin resistance. The authors show that fuel preference in muscle cells is abnormal in young healthy obese individuals.
In an accompanying commentary, David Kelley writes, "these findings support the concept that the capacity of skeletal muscle to oxidize fat under appropriate physiological conditions is related to leanness, aerobic fitness, and insulin sensitivity."
TITLE: Dynamic Changes in Fat Oxidation in Human Primary Myocytes Mirror Metabolic Characteristics of the Donor
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