scholarly journals The Effect of Acute Exercise on Undercarboxylated Osteocalcin and Insulin Sensitivity in Obese Men

2014 ◽  
Vol 29 (12) ◽  
pp. 2571-2576 ◽  
Author(s):  
Itamar Levinger ◽  
George Jerums ◽  
Nigel K Stepto ◽  
Lewan Parker ◽  
Fabio R Serpiello ◽  
...  
2013 ◽  
Vol 305 (4) ◽  
pp. E557-E566 ◽  
Author(s):  
Michele Schiavon ◽  
Ling Hinshaw ◽  
Ashwini Mallad ◽  
Chiara Dalla Man ◽  
Giovanni Sparacino ◽  
...  

Quantifying the effect size of acute exercise on insulin sensitivity (SIexercise) and simultaneous measurement of glucose disappearance (Rd), endogenous glucose production (EGP), and meal glucose appearance in the postprandial state has not been developed in humans. To do so, we studied 12 healthy subjects [5 men, age 37.1 ± 3.1 yr, body mass index 24.1 ± 1.1 kg/m2, fat-free mass (FFM) 50.9 ± 3.9 kg] during moderate exercise at 50% V̇o2max for 75 min, 120–195 min after a triple-tracer mixed meal consumed at time 0. Tracer infusion rates were adjusted to achieve constant tracer-to-tracee ratio and minimize non-steady-state errors. Glucose turnover was estimated by accounting for the nonstationary kinetics introduced by exercise. Insulin sensitivity index was calculated in each subject both in the absence [time ( t) = 0–120 min, SIrest] and presence ( t = 0–360 min, SIexercise) of physical activity. EGP at t = 0 min (13.4 ± 1.1 μM·kg FFM−1·min−1) fell at t = 120 min (2.4 ± 0.4 μM·kg FFM−1·min−1) and then rapidly rose almost eightfold at t = 180 min (18.2 ± 2.6 μM·kg FFM−1·min−1) before gradually falling at t = 360 min (10.6 ± 0.9 μM·kg FFM−1·min−1). Rd rapidly peaked at t = 120 min at the start of exercise (89.5 ± 11.6 μM·kg FFM−1·min−1) and then gradually declined at t = 195 min (26.4 ± 3.3 μM·kg FFM−1·min−1) before returning to baseline at t = 360 min. SIexercise was significantly higher than SIrest (21.6 ± 3.7 vs. 12.5 ± 2.0 10−4 dl·kg−1·min−1 per μU/ml, P < 0.0005). Glucose turnover was estimated for the first time during exercise with the triple-tracer technique. Our results, applying state-of-the-art techniques, show that moderate exercise almost doubles postprandial insulin sensitivity index in healthy subjects.


1986 ◽  
Vol 250 (2) ◽  
pp. E137-E143 ◽  
Author(s):  
T. A. Davis ◽  
S. Klahr ◽  
E. D. Tegtmeyer ◽  
D. F. Osborne ◽  
T. L. Howard ◽  
...  

Effects of insulin on glycogen synthesis (GS), glycolytic utilization (GU), and glucose uptake (GT) were studied in isolated epitrochlearis muscles from exercise-trained or sedentary rats during recovery from acute exercise or at rest. During the 1st h after acute exercise, the enhanced basal and insulin-stimulated GT was directed mainly toward replenishment of glycogen but basal GU was also increased. During the second through third hours after exercise, basal GS decreased but remained greater than rest and basal GU and GT returned to normal. Insulin sensitivity of these parameters was enhanced. Training alone reduced basal GS but enhanced insulin sensitivity of GT and GU. Training reduced the acute exercise-stimulated increase in basal and insulin sensitivity of GS during recovery from acute exercise, probably due to elevated glycogen stores. Thus recovery from acute exercise or training, either alone or in combination, enhances insulin stimulated GT in muscle; however, the increased glucose is primarily channeled toward GS after acute exercise, which is reduced by prior training and is directed to GU in trained animals either at rest or after acute exercise.


1994 ◽  
Vol 77 (2) ◽  
pp. 534-541 ◽  
Author(s):  
J. Gao ◽  
W. M. Sherman ◽  
S. A. McCune ◽  
K. Osei

This study utilized the obese male spontaneously hypertensive heart failure rat (SHHF/Mcc-facp), which has metabolic features very similar to human non-insulin-dependent diabetes mellitus. The purpose of this study was to assess the insulin sensitivity and responsiveness of whole body glucose disposal and insulin suppressability of hepatic glucose production with use of the euglycemic-hyperinsulinemic clamp procedure in 12- to 15-wk-old SHHF/Mcc-facp rats at rest (OS) and 2.5 h after a single session of acute exercise (OE). Lean male SHHF/Mcc-facp rats were sedentary (LS) control animals. At least three clamps producing different insulin-stimulated responses were performed on each animal in a randomized order. At this age the obese animals are normotensive and have not developed congestive heart failure. Compared with LS, OS were significantly hyperglycemic and hyperinsulinemic and insulin sensitivity and responsiveness of whole body glucose uptake and insulin suppressability of hepatic glucose production were significantly decreased. Compared with LS and OS, acute exercise significantly decreased resting plasma glucose but did not alter plasma insulin. Compared with OS, acute exercise significantly increased the insulin responsiveness of whole body glucose disposal but did not affect the sensitivity of whole body glucose disposal or insulin suppressability of hepatic glucose production. Compared with LS, however, acute exercise did not “normalize” the insulin responsiveness of whole body glucose disposal. Thus a single acute exercise session improves but does not normalize whole body insulin resistance in the SHHF/Mcc-facp rat.


2016 ◽  
Vol 120 (11) ◽  
pp. 1355-1363 ◽  
Author(s):  
Sean A. Newsom ◽  
Joseph T. Brozinick ◽  
Katja Kiseljak-Vassiliades ◽  
Allison N. Strauss ◽  
Samantha D. Bacon ◽  
...  

Several recent reports indicate that the balance of skeletal muscle phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is a key determinant of muscle contractile function and metabolism. The purpose of this study was to determine relationships between skeletal muscle PC, PE and insulin sensitivity, and whether PC and PE are dynamically regulated in response to acute exercise in humans. Insulin sensitivity was measured via intravenous glucose tolerance in sedentary obese adults (OB; n = 14), individuals with type 2 diabetes (T2D; n = 15), and endurance-trained athletes (ATH; n = 15). Vastus lateralis muscle biopsies were obtained at rest, immediately after 90 min of cycle ergometry at 50% maximal oxygen consumption (V̇o2 max), and 2-h postexercise (recovery). Skeletal muscle PC and PE were measured via infusion-based mass spectrometry/mass spectrometry analysis. ATH had greater levels of muscle PC and PE compared with OB and T2D ( P < 0.05), with total PC and PE positively relating to insulin sensitivity (both P < 0.05). Skeletal muscle PC:PE ratio was elevated in T2D compared with OB and ATH ( P < 0.05), tended to be elevated in OB vs. ATH ( P = 0.07), and was inversely related to insulin sensitivity among the entire cohort ( r = −0.43, P = 0.01). Muscle PC and PE were altered by exercise, particularly after 2 h of recovery, in a highly group-specific manner. However, muscle PC:PE ratio remained unchanged in all groups. In summary, total muscle PC and PE are positively related to insulin sensitivity while PC:PE ratio is inversely related to insulin sensitivity in humans. A single session of exercise significantly alters skeletal muscle PC and PE levels, but not PC:PE ratio.


1985 ◽  
Vol 17 (2) ◽  
pp. 242 ◽  
Author(s):  
K. J. Mikines ◽  
B. Sonne ◽  
P. A. Farrell ◽  
H. Galbo

2018 ◽  
Vol 314 (2) ◽  
pp. E152-E164 ◽  
Author(s):  
Bryan C. Bergman ◽  
Leigh Perreault ◽  
Allison Strauss ◽  
Samantha Bacon ◽  
Anna Kerege ◽  
...  

Intramuscular triglyceride (IMTG) concentration is elevated in insulin-resistant individuals and was once thought to promote insulin resistance. However, endurance-trained athletes have equivalent concentration of IMTG compared with individuals with type 2 diabetes, and have very low risk of diabetes, termed the “athlete’s paradox.” We now know that IMTG synthesis is positively related to insulin sensitivity, but the exact mechanisms for this are unclear. To understand the relationship between IMTG synthesis and insulin sensitivity, we measured IMTG synthesis in obese control subjects, endurance-trained athletes, and individuals with type 2 diabetes during rest, exercise, and recovery. IMTG synthesis rates were positively related to insulin sensitivity, cytosolic accumulation of DAG, and decreased accumulation of C18:0 ceramide and glucosylceramide. Greater rates of IMTG synthesis in athletes were not explained by alterations in FFA concentration, DGAT1 mRNA expression, or protein content. IMTG synthesis during exercise in Ob and T2D indicate utilization as a fuel despite unchanged content, whereas IMTG concentration decreased during exercise in athletes. mRNA expression for genes involved in lipid desaturation and IMTG synthesis were increased after exercise and recovery. Further, in a subset of individuals, exercise decreased cytosolic and membrane di-saturated DAG content, which may help explain insulin sensitization after acute exercise. These data suggest IMTG synthesis rates may influence insulin sensitivity by altering intracellular lipid localization, and decreasing specific ceramide species that promote insulin resistance.


1983 ◽  
Vol 55 (6) ◽  
pp. 1660-1664 ◽  
Author(s):  
D. E. James ◽  
K. M. Burleigh ◽  
E. W. Kraegen ◽  
D. J. Chisholm

Physical training causes hypoinsulinemia and enhanced insulin sensitivity. Insulin sensitivity is also enhanced by a single bout of exercise. However, changes in beta-cell responsiveness with acute exercise are ill defined. To clarify these relationships intravenous glucose tolerance tests were performed in 1) physically trained rats (3 different levels), 48 h after the last bout of exercise; 2) untrained rats, 0.5, 4, and 24 h after a single bout of exercise; or 3) sedentary control rats. The total area under the glucose-stimulated insulin response curve (GSIR) was negatively correlated with total distance run during training (r = -0.45, P less than 0.05), whereas glucose tolerance was improved (P less than 0.005 vs. controls) with intensive training. GSIR was suppressed by 38% (P less than 0.01 vs. controls) 0.5 h after a single bout of exercise. This effect persisted for 4 h but was not present after 24 h. These results indicate that a single bout of exercise induces suppression of GSIR which lasts less than 24 h. In contrast, physical training induces prolonged suppression (for at least 48 h) of GSIR, proportional to the intensity of training, and improved glucose tolerance.


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