Increased intramuscular lipid synthesis and low saturation relate to insulin sensitivity in endurance-trained athletes.

Intramuscular triglyceride (IMTG) has received considerable attention as a potential mechanism promoting insulin resistance. Endurance-trained athletes have high amounts of IMTG but are insulin sensitive, suggesting IMTG content alone does not change insulin action. Recent data suggest increased muscle lipid synthesis protects against fat-induced insulin resistance.

Intramuscular lipid metabolism in the insulin resistance of smoking.

Objective: Smoking decreases insulin action and increases the risk of type 2 diabetes in humans. Mechanisms responsible for smoking-induced insulin resistance are unclear. We hypothesized smokers would have increased intramuscular triglyceride (IMTG) and diacylglycerol (DAG) concentration and decreased fractional synthesis rate (FSR) compared with nonsmokers.