B-aminoisobutyric Acid Relates to Favorable Glucose Metabolism and Adiponectin in Adults with Metabolic Syndrome

poste

Early Chronotype Favors Appetite and Reduced Later Day Caloric Intake Among Adults with Metabolic Syndrome

poiste

Role of Chronotype on Vascular Insulin Sensitivity in Adults with Obesity

poste

Nocturnal Blood Pressure Dipping Relates to Insulin Sensitivity but not Vascular Function in Metabolic Syndrome

Click the PDF icon to download the abstrac

Roel of Morning versus Evening Chronotype on Insulin Sensitivity and Central Hemodynamics in Adults with Metabolic Syndrome

Click the PDF icon to download the abstrac

Impact of short-term exercise training intensity on β-cell function in older obese adults with prediabetes

The effect of work-matched exercise intensity on β-cell function is unknown in people with prediabetes before clinical weight loss. We determined if short-term moderate continuous (CONT) vs. high-intensity interval (INT) exercise increased β-cell function. Thirty-one subjects (age: 61.4 ± 2.5 yr; body mass index: 32.1 ± 1.0 kg/m2) with prediabetes [American Diabetes Association criteria, 75-g oral glucose tolerance test (OGTT)] were randomized to work-matched CONT (70% HRpeak) or INT (3 min 90% HRpeak and 3 min 50% HRpeak) exercise for 60 min/day over 2 wk. A 75-g 2-h OGTT was conducted after an overnight fast, and plasma glucose, insulin, C-peptide, and free fatty acids were determined for calculations of skeletal muscle [oral minimal model (OMM)], hepatic (homeostatic model of insulin resistance), and adipose (Adipose-IR) insulin sensitivity. β-Cell function was defined from glucose-stimulated insulin secretion (GSIS, deconvolution modeling) and the disposition index (DI). Glucagon-like polypeptide-1 [GLP-1(active)] and glucose-dependent insulinotropic polypeptide (GIP) were also measured during the OGTT, along with peak oxygen consumption and body composition. CONT and INT increased skeletal muscle- but not hepatic- or adipose-derived DI (P \u3c 0.05). Although both treatments tended to reduce fasting GLP-1(active) (P = 0.08), early phase GLP-1(active) increased post-CONT and INT training (P \u3c 0.001). Interestingly, CONT exercise increased fasting GIP compared with decreases in INT (P = 0.02). Early and total-phase skeletal muscle DI correlated with decreased total glucose area under the curve (r = −0.52, P = 0.002 and r = −0.50, P = 0.003, respectively). Independent of intensity, short-term training increased pancreatic function adjusted to skeletal muscle in relation to improved glucose tolerance in adults with prediabetes. Exercise also uniquely affected GIP and GLP-1(active). Further work is needed to elucidate the dose-dependent mechanism(s) by which exercise impacts glycemia. NEW & NOTEWORTHY Exercise is cornerstone for reducing blood glucose, but whether high-intensity interval training is better than moderate continuous exercise is unclear in people with prediabetes before weight loss. We show that 2 wk of exercise training, independent of intensity, increased pancreatic function in relation to elevated glucagon-like polypeptide-1 secretion. Furthermore, β-cell function, but not insulin sensitivity, was also correlated with improved glucose tolerance. These data suggest that β-cell function is a strong predictor of glycemia regardless of exercise intensity

Reduced Aortic Waveform Responses to Insulin in Late Chronotype with Metabolic Syndrome

See Attached Abstrac

Combining short-term interval training with caloric restriction improves ß-cell function in obese adults

Although low-calorie diets (LCD) improve glucose regulation, it is unclear if interval exercise (INT) is additive. We examined the impact of an LCD versus LCD + INT training on ß-cell function in relation to glucose tolerance in obese adults. Twenty-six adults (Age: 46 ± 12 year; BMI 38 ± 6 kg/m2) were randomized to 2-week of LCD (~1200 kcal/day) or energy-matched LCD + INT (60 min/day alternating 3 min at 90 and 50% HRpeak). A 2 h 75 g oral glucose tolerance test (OGTT) was performed. Insulin secretion rates (ISR) were determined by deconvolution modeling to assess glucose-stimulated insulin secretion ([GSIS: ISR/glucose total area under the curve (tAUC)]) and ß-cell function (Disposition Index [DI: GSIS/IR]) relative to skeletal muscle (Matsuda Index), hepatic (HOMA-IR) and adipose (Adipose-IRfasting) insulin resistance (IR). LCD + INT, but not LCD alone, reduced glucose and total-phase ISR tAUC (Interactions: p = 0.04 and p = 0.05, respectively). Both interventions improved skeletal muscle IR by 16% (p = 0.04) and skeletal muscle and hepatic DI (Time: p \u3c 0.05). Improved skeletal muscle DI was associated with lower glucose tAUC (r = −0.57, p \u3c 0.01). Thus, LCD + INT improved glucose tolerance more than LCD in obese adults, and these findings relate to ß-cell function. These data support LCD + INT for preserving pancreatic function for type 2 diabetes prevention

Effect of Late versus Early Chronotype on Fuel Metabolism During Exercise

See Attached Abstrac

Aortic waveform responses to insulin in late versus early chronotype with metabolic syndrome

Abstract Late chronotype (LC) correlates with reduced metabolic insulin sensitivity and cardiovascular disease. It is unclear if insulin action on aortic waveforms and inflammation is altered in LC versus early chronotype (EC). Adults with metabolic syndrome (n = 39, MetS) were classified as either EC (Morning‐Eveningness Questionnaire [MEQ] = 63.5 ± 1.2) or LC (MEQ = 45.5 ± 1.3). A 120 min euglycemic clamp (40 mU/m2/min, 90 mg/dL) with indirect calorimetry was used to determine metabolic insulin sensitivity (glucose infusion rate [GIR]) and nonoxidative glucose disposal (NOGD). Aortic waveforms via applanation tonometry and inflammation by blood biochemistries were assessed at 0 and 120 min of the clamp. LC had higher fat‐free mass and lower VO2max, GIR, and NOGD (between groups, all p ≤ 0.05) than EC. Despite no difference in 0 min waveforms, both groups had insulin‐stimulated elevations in pulse pressure amplification with reduced AIx75 and augmentation pressure (AP; time effect, p ≤ 0.05). However, EC had decreased forward pressure (Pf; interaction effect, p = 0.007) with insulin versus rises in LC. Although LC had higher tumor necrosis factor‐α (TNF‐α; group effect, p ≤ 0.01) than EC, both LC and EC had insulin‐stimulated increases in TNF‐α and decreases in hs‐CRP (time effect, both p ≤ 0.01). Higher MEQ scores related to greater insulin‐stimulated reductions in AP (r = −0.42, p = 0.016) and Pf (r = −0.41, p = 0.02). VO2max correlated with insulin‐mediated reductions in AIx75 (r = −0.56, p < 0.01) and AP (r = −0.49, p < 0.01). NOGD related to decreased AP (r = −0.44, p = 0.03) and Pf (r = −0.43, p = 0.04) during insulin infusion. LC was depicted by blunted forward pressure waveform responses to insulin and higher TNF‐α in MetS. More work is needed to assess endothelial function across chronotypes