BACKGROUNDEstablishing cardiovascular safety of new therapies for type 2 diabetes is important. Safety data are available for the subcutaneous form of the glucagon-like peptide-1 receptor agonist semaglutide but are needed for oral semaglutide. METHODSWe assessed cardiovascular outcomes of once-daily oral semaglutide in an event-driven, randomized, double-blind, placebo-controlled trial involving patients at high cardiovascular risk (age of ≥50 years with established cardiovascular or chronic kidney disease, or age of ≥60 years with cardiovascular risk factors only). The primary outcome in a timeto-event analysis was the first occurrence of a major adverse cardiovascular event (death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke). The trial was designed to rule out 80% excess cardiovascular risk as compared with placebo (noninferiority margin of 1.8 for the upper boundary of the 95% confidence interval for the hazard ratio for the primary outcome). RESULTSA total of 3183 patients were randomly assigned to receive oral semaglutide or placebo. The mean age of the patients was 66 years; 2695 patients (84.7%) were 50 years of age or older and had cardiovascular or chronic kidney disease. The median time in the trial was 15.9 months. Major adverse cardiovascular events occurred in 61 of 1591 patients (3.8%) in the oral semaglutide group and 76 of 1592 (4.8%) in the placebo group (hazard ratio, 0.79; 95% confidence interval [CI], 0.57 to 1.11; P<0.001 for noninferiority). Results for components of the primary outcome were as follows: death from cardiovascular causes, 15 of 1591 patients (0.9%) in the oral semaglutide group and 30 of 1592 (1.9%) in the placebo group (hazard ratio, 0.49; 95% CI, 0.27 to 0.92); nonfatal myocardial infarction, 37 of 1591 patients (2.3%) and 31 of 1592 (1.9%), respectively (hazard ratio, 1.18; 95% CI, 0.73 to 1.90); and nonfatal stroke, 12 of 1591 patients (0.8%) and 16 of 1592 (1.0%), respectively (hazard ratio, 0.74; 95% CI, 0.35 to 1.57). Death from any cause occurred in 23 of 1591 patients (1.4%) in the oral semaglutide group and 45 of 1592 (2.8%) in the placebo group (hazard ratio, 0.51; 95% CI, 0.31 to 0.84). Gastrointestinal adverse events leading to discontinuation of oral semaglutide or placebo were more common with oral semaglutide. CONCLUSIONSIn this trial involving patients with type 2 diabetes, the cardiovascular risk profile of oral semaglutide was not inferior to that of placebo. (Funded by Novo Nordisk; PIONEER 6 ClinicalTrials.gov number, NCT02692716.

A better understanding of skeletal muscle lipid metabolism is needed to identify the molecular mechanisms relating intramuscular triglyceride (IMTG) to muscle metabolism and insulin sensitivity. An increasing number of proteins have been reported to be associated with intracellular triglyceride (TG), among them the PAT family members: perilipin, ADRP (for adipocyte differentiation-related protein), and TIP47 (for tail-interacting protein of 47 kDa). Hormone-sensitive lipase (HSL) is thought to be the major enzyme responsible for IMTG hydrolysis in skeletal muscle. In adipocytes, regulation of HSL by intracellular redistribution has been demonstrated. The existence of such regulatory mechanisms in skeletal muscle has long been hypothesized but has never been demonstrated. The aim of this study was to characterize the PAT family proteins associated with IMTG and to investigate the effect of epinephrine stimulation or muscle contraction on skeletal muscle TG content and HSL intracellular distribution. Rat soleus muscles were either incubated with epinephrine or electrically stimulated for 15 min. Single muscle fibers were used for morphological analysis by confocal and transmission electron microscopy. We show a decrease in IMTG in response to both lipolytic stimuli. Furthermore, we identify two PAT family proteins, ADRP and TIP47, associated with IMTG. Finally, we demonstrate HSL translocation to IMTG and ADRP after stimulation with epinephrine or contraction. Interest in skeletal muscle lipid metabolism has increased exponentially during the last decades. One of the reasons is the repeatedly reported inverse relation between intramuscular triglyceride (IMTG) concentrations and insulin sensitivity (1-5). Paradoxically, endurance training is well known to increase insulin sensitivity, whereas it has been shown to increase IMTG content (6, 7). Thus, it seems that IMTG content may not directly determine insulin sensitivity. A better understanding of skeletal muscle lipid metabolism is required to identify the molecular mechanisms involved in the effect of IMTG content on muscle metabolism and insulin sensitivity.For many years, it has been debated whether IMTGs are used during exercise, but today this question remains unresolved. The most likely explanation for the discrepancy between previous studies is that, in most of them, chemical methods to measure triglyceride (TG) were used. Such methods cannot distinguish between IMTG and TG contained in adipocytes surrounding muscle fibers. Illustrating the problem, Donsmark et al. (8) showed that the TG content of a single adipocyte (z0.3 nmol) corresponds to z5% of the TG content of a 2 mg soleus muscle sample, but the adipocyte volume makes up only 0.01% of the sample. Therefore, decreases in IMTG may have been undetected, being masked by contaminating TG from adipocytes (9).IMTG is stored within intracellular lipid droplets (LDs). LDs were initially considered to be relatively static

Background Oral semaglutide is a novel tablet containing the human glucagon-like peptide-1 (GLP-1) analogue semaglutide, co-formulated with the absorption enhancer sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). The safety and pharmacokinetics of oral semaglutide were investigated in two randomised, double-blind, placebo-controlled trials. Methods In a single-dose, first-inhuman trial, 135 healthy males received oral semaglutide (2-20 mg semaglutide coformulated with 150-600 mg SNAC) or placebo with SNAC. In a 10-week, once-daily, multiple-dose trial, 84 healthy males received 20 or 40 mg oral semaglutide (with 300 mg SNAC), placebo, or placebo with SNAC, and 23 males with type 2 diabetes (T2D) received 40 mg oral semaglutide (with 300 mg SNAC), placebo, or placebo with SNAC. Results Oral semaglutide was safe and well-tolerated in both trials. The majority of adverse events (AEs) were mild, with the most common AEs being gastrointestinal disorders. In the single-dose trial, semaglutide exposure was highest when coformulated with 300 mg SNAC. In the multiple-dose trial, semaglutide exposure was approximately twofold higher with 40 versus 20 mg oral semaglutide in healthy males, in accordance with dose proportionality, and was similar between healthy males and males with T2D. The half-life of semaglutide was approximately 1 week in all groups. Conclusion The safety profile of oral semaglutide was as expected for the GLP-1 receptor agonist drug class. Oral semaglutide co-formulated with 300 mg SNAC was chosen for further clinical development. The pharmacokinetic results supported that oral semaglutide is suitable for once-daily dosing. ClinicalTrials.gov identifiers NCT01037582, NCT01686945.

To investigate whether this could be due to sex-specific regulation of hormone-sensitive lipase (HSL) and to use sex comparison as a model to gain further insight into HSL regulation, nine women and eight men performed bicycle exercise (90 min, 60% V O2 peak), and skeletal muscle HSL expression, phosphorylation, and activity were determined. Supporting previous findings, basal IMTG content (P Ͻ 0.001) and net IMTG decrease during exercise (P Ͻ 0.01) were higher in women than in men and correlated significantly (r ϭ 0.72, P ϭ 0.001). Muscle HSL mRNA (80%, P ϭ 0.11) and protein content (50%, P Ͻ 0.05) were higher in women than in men. HSL total activity increased during exercise (47%, P Ͻ 0.05) but did not differ between sexes. Accordingly, HSL specific activity (HSL activity per HSL protein content) increased during exercise (62%, P Ͻ 0.05) and was generally higher in men than in women (82%, P Ͻ 0.05). A similar pattern was observed for HSL Ser 659 phosphorylation, suggesting a role in regulation of HSL activity. Likewise, plasma epinephrine increased during exercise (P Ͻ 0.05) and was higher in men than in women during the end of the exercise bout (P Ͻ 0.05). We conclude that, although HSL expression and Ser 659 phosphorylation in skeletal muscle during exercise is sex specific, total muscle HSL activity measured in vitro was similar between sexes. The higher basal IMTG content in women compared with men is therefore the best candidate to explain the higher IMTG net hydrolysis during exercise in women. intramuscular triacylglycerol; epinephrine; extracellular signal-regulated kinase TRIACYLGLYCEROL STORED IN skeletal muscle fibers (intramuscular triacylglycerol, IMTG) represents a large source of energy that may be used for muscle contraction during exercise. In men, it is still controversial to what extent IMTG is utilized during exercise (18,29,40). This is probably so because methodological limitations in measuring IMTG content have made it difficult to detect the relatively small net hydrolysis of IMTG that appears to occur during submaximal exercise in men (13,29,40,46). On the other hand, in women it has been shown that IMTG content is reduced by ϳ25% during 90-min bicycle exercise at 60% peak oxygen uptake (V O 2 peak ) (33), and it can be estimated that IMTG covers a large fraction (ϳ25%) of oxidative energy production in such an exercise bout in women (27). Therefore, the degree of IMTG hydrolysis during submaximal exercise appears to depend on sex, being higher in women than in men. It is presently unknown what may be the cause underlying this sex difference in IMTG hydrolysis during exercise.Hormone-sensitive lipase (HSL) is thought to catalyze the hydrolysis of IMTG in skeletal muscle as it does in adipose tissue (14,21). In rodent as well as in human skeletal muscle, neutral lipase activity increases during contraction (22,28,41), and it has been shown that the increase in neutral lipase activity elicited by contraction is completely accounted for by HSL activation both in rats and in man (22,28,45)...

Hormone-sensitive lipase (HSL) catalyses the hydrolysis of myocellular triacylglycerol (MCTG), which is a potential energy source during exercise. Therefore, it is important to elucidate the regulation of HSL activity in human skeletal muscle during exercise. The main purpose of the present study was to investigate the role of 5 AMP-activated protein kinase (AMPK) in the regulation of muscle HSL activity and Ser 565 phosphorylation (the presumed AMPK target site) in healthy, moderately trained men during 60 min bicycling (65%V O 2 peak ). α 2 AMPK activity during exercise was manipulated by studying subjects with either low (LG) or high (HG) muscle glycogen content. HSL activity was distinguished from the activity of other neutral lipases by immunoinhibition of HSL using an anti-HSL antibody. During exercise a 62% higher (P < 0.01) α 2 AMPK activity in LG than in HG was paralleled by a similar difference (61%, P < 0.01) in HSL Ser 565 phosphorylation but without any difference between trials in HSL activity or MCTG hydrolysis. HSL activity was increased (117%, P < 0.05) at 30 min of exercise but not at 60 min of exercise. In both trials, HSL phosphorylation on Ser 563 (a presumed PKA target site) was not increased by exercise despite a fourfold increase (P < 0.001) in plasma adrenaline. ERK1/2 phosphorylation was increased by exercise in both trials (P < 0.001) and was higher in LG than in HG both at rest and during exercise (P = 0.06). In conclusion, the present study suggests that AMPK phosphorylates HSL on Ser 565 in human skeletal muscle during exercise with reduced muscle glycogen. Apparently, HSL Ser 565 phosphorylation by AMPK during exercise had no effect on HSL activity. Alternatively, other factors including ERK may have counterbalanced any effect of AMPK on HSL activity.