Expression of inducible nitric oxide synthase (iNOS) is a marker of vascular inflammation which c... more Expression of inducible nitric oxide synthase (iNOS) is a marker of vascular inflammation which can result in thrombosis and atherosclerosis. This study was undertaken to examine the difference in iNOS expression in the internal mammary artery (IMA) and saphenous veins (SVs) of patients with diabetes mellitus undergoing coronary artery bypass graft (CABG) surgery using both qualitative and quantitative methodology. Segments of IMA and SV harvested in 100 diabetic patients with diabetes mellitus undergoing CABG surgery were fixed in formalin and immunostained to detect the presence of iNOS. Sections were graded using a qualitative score (0 = absence of iNOS expression to 3 = extensive expression of iNOS) and a quantitative computer-aided image analysis (area of staining/area of endothelium). Linear regression analyses were performed to assess the association of the degree of iNOS expression in both the IMA and SV with the type of diabetes control (insulin, oral, diet), and the serum levels of HbAlc, glucose, free fatty acids (ffa), C-reactive protein (CRP), and low-density liproprotein (LDL) at the time of conduit harvest. The degree of iNOS expression was significantly lower in the IMA compared to the SV by both qualitative (0.88 +/- 0.74 SD IMA vs. 1.38 +/- 0.68 SV; p < 0.0001) and quantitative (11.76 +/- 3.34% IMA vs. 17.10 +/- 2.54% SV; p = 0.01) methods. The Spearman rank correlation analysis showed a highly statistically significant association between the two methodologies (p < 0.0001). There was no correlation between iNOS expression in either the IMA or SV and the type of diabetes control, or levels of HA1c, glucose, ffa, and CRP. However, there was a significant (p = 0.04) correlation between LDL and iNOS expression in the SV graft, but not the IMA. iNOS expression is significantly decreased in the IMA compared to the SV in patients with diabetes mellitus undergoing CABG surgery. The degree of iNOS expression is unrelated to the level of glycemic control at the time of conduit harvest, but is associated with serum LDL levels in the SV, but not in the IMA grafts.
OBJECTIVEdPhysical activity or metformin enhances insulin sensitivity and opposes the progression... more OBJECTIVEdPhysical activity or metformin enhances insulin sensitivity and opposes the progression from prediabetes to type 2 diabetes. The combination may be more effective because each treatment stimulates AMP-activated protein kinase activity in skeletal muscle. We evaluated the effects of exercise training plus metformin on insulin sensitivity in men and women with prediabetes, compared with each treatment alone. RESEARCH DESIGN AND METHODSdFor 12 weeks, men and women with prediabetes were assigned to the following groups: placebo (P), 2,000 mg/day metformin (M), exercise training with placebo (EP), or exercise training with metformin (EM) (n = 8 per group). Before and after the intervention, insulin sensitivity was measured by euglycemic hyperinsulinemic (80 mU/m 2 /min) clamp enriched with [6,6-2 H]glucose. Changes due to intervention were compared across groups by repeated-measures ANOVA. RESULTSdAll three interventions increased insulin sensitivity (P , 0.05) relative to the control group. The mean rise was 25-30% higher after EP than after either EM or M, but this difference was not significant. CONCLUSIONSdInsulin sensitivity was considerably higher after 12 weeks of exercise training and/or metformin in men and women with prediabetes. Subtle differences among condition means suggest that adding metformin blunted the full effect of exercise training.
Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a can... more Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a candidate heuristic cadence threshold for 6 METs.
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a can... more Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a candidate heuristic cadence threshold for 6 METs.
Journal for the Measurement of Physical Behaviour, 2021
Step-based metrics provide simple measures of ambulatory activity, yet device software either inc... more Step-based metrics provide simple measures of ambulatory activity, yet device software either includes undisclosed proprietary step detection algorithms or simply does not compute step-based metrics. We aimed to develop and validate a simple algorithm to accurately detect steps across various ambulatory and nonambulatory activities. Seventy-five adults (21–39 years) completed seven simulated activities of daily living (e.g., sitting, vacuuming, folding laundry) and an incremental treadmill protocol from 0.22 to 2.2 m/s. Directly observed steps were hand-tallied. Participants wore GENEActiv and ActiGraph accelerometers, one of each on their waist and on their nondominant wrist. Raw acceleration (g) signals from the anterior–posterior, medial–lateral, vertical, and vector magnitude directions were assessed separately for each device. Signals were demeaned across all activities and band-pass filtered (0.25, 2.5 Hz). Steps were detected via peak picking, with optimal thresholds (i.e., m...
American Journal of Physiology-Endocrinology and Metabolism, 1996
Tissue-specific changes in GLUT-4 were compared in the following three different rat models by in... more Tissue-specific changes in GLUT-4 were compared in the following three different rat models by inducing varying degrees of hyperinsulinemia with or without hyperglycemia and hypertriglyceridemia: 1) sucrose feeding (Suc), 2) subcutaneous dexamethasone administration (Dex), and 3) a combination of both treatments (Dex/Suc). Suc raised circulatory insulin and triglyceride levels without affecting plasma glucose, whereas both Dex and Dex/Suc induced significant hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. In adipocytes and skeletal muscle, Suc feeding was not associated with any change in total cellular GLUT-4 levels. However, Suc induced a sevenfold increase in fat cell plasma membrane GLUT-4 levels in the basal state and inhibited GLUT-4 translocation in response to insulin. Administration of Dex or Dex/Suc diminished GLUT-4 expression in fat cells, increased it in skeletal muscle, but did not induce any change in heart. Similar to Suc feeding, Dex and Dex/Suc also incr...
Medicine and science in sports and exercise, Jan 20, 2015
Statin therapy can result in muscle pain, cramps, and weakness that may limit physical activity a... more Statin therapy can result in muscle pain, cramps, and weakness that may limit physical activity although reports are mixed. We conducted a randomized control trial to examine the effect of atorvastatin on habitual physical activity levels among a large sample of healthy adults. Participants (n=418) were statin-naïve adults [44.0±16.1yr (X±SD)] that were randomized and double-blinded to 80mg per day of atorvastatin or placebo for 6 months. Accelerometers were worn for 96hr before and after drug treatment. Repeated measures analysis tested physical activity levels after versus before drug treatment among groups with age and VO2max as covariates. Among the total sample, sedentary behavior increased (19.5±5.1min•d), while light (9.1±3.0min•d) and moderate intensity (9.7±2.8min•d) physical activity decreased, as did total activity counts (17.8±6.3•dx10) over 6 months (P<0.01), with no differences between groups. The atorvastatin group increased sedentary behavior (19.8±7.4min•d), and ...
Adipocytes are physiological targets for GH in both growing and nongrowing individuals. In adipoc... more Adipocytes are physiological targets for GH in both growing and nongrowing individuals. In adipocytes that have been deprived of GH for at least 3 h, GH initially produces a response that is characterized by increased metabolism of glucose and inhibition of the lipolytic effects of catecholamines. This insulin-like effect disappears within 2-3 h despite continued stimulation and cannot be elicited again unless cells are deprived of GH for at least 3 h. Despite refractoriness to the insulin-like action of GH, the lipolytic effect of GH is evident at this time. Although termination of the insulin-like response and induction of both refractoriness and lipolysis all depend upon synthesis of RNA and proteins, these 3 effects of GH appear to be neither temporally nor causally related. Scatchard analysis of ligand binding data suggests that these various effects are produced by interaction of GH with a single class of receptors. However, since modification of either the hormone or the carb...
Expression of inducible nitric oxide synthase (iNOS) is a marker of vascular inflammation which c... more Expression of inducible nitric oxide synthase (iNOS) is a marker of vascular inflammation which can result in thrombosis and atherosclerosis. This study was undertaken to examine the difference in iNOS expression in the internal mammary artery (IMA) and saphenous veins (SVs) of patients with diabetes mellitus undergoing coronary artery bypass graft (CABG) surgery using both qualitative and quantitative methodology. Segments of IMA and SV harvested in 100 diabetic patients with diabetes mellitus undergoing CABG surgery were fixed in formalin and immunostained to detect the presence of iNOS. Sections were graded using a qualitative score (0 = absence of iNOS expression to 3 = extensive expression of iNOS) and a quantitative computer-aided image analysis (area of staining/area of endothelium). Linear regression analyses were performed to assess the association of the degree of iNOS expression in both the IMA and SV with the type of diabetes control (insulin, oral, diet), and the serum levels of HbAlc, glucose, free fatty acids (ffa), C-reactive protein (CRP), and low-density liproprotein (LDL) at the time of conduit harvest. The degree of iNOS expression was significantly lower in the IMA compared to the SV by both qualitative (0.88 +/- 0.74 SD IMA vs. 1.38 +/- 0.68 SV; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001) and quantitative (11.76 +/- 3.34% IMA vs. 17.10 +/- 2.54% SV; p = 0.01) methods. The Spearman rank correlation analysis showed a highly statistically significant association between the two methodologies (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). There was no correlation between iNOS expression in either the IMA or SV and the type of diabetes control, or levels of HA1c, glucose, ffa, and CRP. However, there was a significant (p = 0.04) correlation between LDL and iNOS expression in the SV graft, but not the IMA. iNOS expression is significantly decreased in the IMA compared to the SV in patients with diabetes mellitus undergoing CABG surgery. The degree of iNOS expression is unrelated to the level of glycemic control at the time of conduit harvest, but is associated with serum LDL levels in the SV, but not in the IMA grafts.
OBJECTIVEdPhysical activity or metformin enhances insulin sensitivity and opposes the progression... more OBJECTIVEdPhysical activity or metformin enhances insulin sensitivity and opposes the progression from prediabetes to type 2 diabetes. The combination may be more effective because each treatment stimulates AMP-activated protein kinase activity in skeletal muscle. We evaluated the effects of exercise training plus metformin on insulin sensitivity in men and women with prediabetes, compared with each treatment alone. RESEARCH DESIGN AND METHODSdFor 12 weeks, men and women with prediabetes were assigned to the following groups: placebo (P), 2,000 mg/day metformin (M), exercise training with placebo (EP), or exercise training with metformin (EM) (n = 8 per group). Before and after the intervention, insulin sensitivity was measured by euglycemic hyperinsulinemic (80 mU/m 2 /min) clamp enriched with [6,6-2 H]glucose. Changes due to intervention were compared across groups by repeated-measures ANOVA. RESULTSdAll three interventions increased insulin sensitivity (P , 0.05) relative to the control group. The mean rise was 25-30% higher after EP than after either EM or M, but this difference was not significant. CONCLUSIONSdInsulin sensitivity was considerably higher after 12 weeks of exercise training and/or metformin in men and women with prediabetes. Subtle differences among condition means suggest that adding metformin blunted the full effect of exercise training.
Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a can... more Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a candidate heuristic cadence threshold for 6 METs.
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a can... more Additional file 3. Table displaying a classification accuracy analysis for 125 steps/min as a candidate heuristic cadence threshold for 6 METs.
Journal for the Measurement of Physical Behaviour, 2021
Step-based metrics provide simple measures of ambulatory activity, yet device software either inc... more Step-based metrics provide simple measures of ambulatory activity, yet device software either includes undisclosed proprietary step detection algorithms or simply does not compute step-based metrics. We aimed to develop and validate a simple algorithm to accurately detect steps across various ambulatory and nonambulatory activities. Seventy-five adults (21–39 years) completed seven simulated activities of daily living (e.g., sitting, vacuuming, folding laundry) and an incremental treadmill protocol from 0.22 to 2.2 m/s. Directly observed steps were hand-tallied. Participants wore GENEActiv and ActiGraph accelerometers, one of each on their waist and on their nondominant wrist. Raw acceleration (g) signals from the anterior–posterior, medial–lateral, vertical, and vector magnitude directions were assessed separately for each device. Signals were demeaned across all activities and band-pass filtered (0.25, 2.5 Hz). Steps were detected via peak picking, with optimal thresholds (i.e., m...
American Journal of Physiology-Endocrinology and Metabolism, 1996
Tissue-specific changes in GLUT-4 were compared in the following three different rat models by in... more Tissue-specific changes in GLUT-4 were compared in the following three different rat models by inducing varying degrees of hyperinsulinemia with or without hyperglycemia and hypertriglyceridemia: 1) sucrose feeding (Suc), 2) subcutaneous dexamethasone administration (Dex), and 3) a combination of both treatments (Dex/Suc). Suc raised circulatory insulin and triglyceride levels without affecting plasma glucose, whereas both Dex and Dex/Suc induced significant hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. In adipocytes and skeletal muscle, Suc feeding was not associated with any change in total cellular GLUT-4 levels. However, Suc induced a sevenfold increase in fat cell plasma membrane GLUT-4 levels in the basal state and inhibited GLUT-4 translocation in response to insulin. Administration of Dex or Dex/Suc diminished GLUT-4 expression in fat cells, increased it in skeletal muscle, but did not induce any change in heart. Similar to Suc feeding, Dex and Dex/Suc also incr...
Medicine and science in sports and exercise, Jan 20, 2015
Statin therapy can result in muscle pain, cramps, and weakness that may limit physical activity a... more Statin therapy can result in muscle pain, cramps, and weakness that may limit physical activity although reports are mixed. We conducted a randomized control trial to examine the effect of atorvastatin on habitual physical activity levels among a large sample of healthy adults. Participants (n=418) were statin-naïve adults [44.0±16.1yr (X±SD)] that were randomized and double-blinded to 80mg per day of atorvastatin or placebo for 6 months. Accelerometers were worn for 96hr before and after drug treatment. Repeated measures analysis tested physical activity levels after versus before drug treatment among groups with age and VO2max as covariates. Among the total sample, sedentary behavior increased (19.5±5.1min•d), while light (9.1±3.0min•d) and moderate intensity (9.7±2.8min•d) physical activity decreased, as did total activity counts (17.8±6.3•dx10) over 6 months (P<0.01), with no differences between groups. The atorvastatin group increased sedentary behavior (19.8±7.4min•d), and ...
Adipocytes are physiological targets for GH in both growing and nongrowing individuals. In adipoc... more Adipocytes are physiological targets for GH in both growing and nongrowing individuals. In adipocytes that have been deprived of GH for at least 3 h, GH initially produces a response that is characterized by increased metabolism of glucose and inhibition of the lipolytic effects of catecholamines. This insulin-like effect disappears within 2-3 h despite continued stimulation and cannot be elicited again unless cells are deprived of GH for at least 3 h. Despite refractoriness to the insulin-like action of GH, the lipolytic effect of GH is evident at this time. Although termination of the insulin-like response and induction of both refractoriness and lipolysis all depend upon synthesis of RNA and proteins, these 3 effects of GH appear to be neither temporally nor causally related. Scatchard analysis of ligand binding data suggests that these various effects are produced by interaction of GH with a single class of receptors. However, since modification of either the hormone or the carb...
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