Maximal Fat Oxidation Rate during Exercise in Korean Women with Type 2 Diabetes Mellitus

BACKGROUND: The purpose of this study was to determine the appropriate exercise intensity associated with maximum fat oxidation, improvement of body composition, and metabolic status in Korean women with type 2 diabetes mellitus (T2DM). METHODS: The study included a T2DM group (12 women) and a control group (12 women). The groups were matched in age and body mass index. The subjects performed a graded exercise test on a cycle ergometer to measure their maximal fat oxidation (Fatmax). We also measured their body composition, metabolic profiles, and mitochondrial DNA (mtDNA). RESULTS: The exercise intensity for Fatmax was significantly lower in the T2DM group (34.19% maximal oxygen uptake [VO2 max]) than the control group (51.80% VO2 max). Additionally, the rate of fat oxidation during exercise (P<0.05) and mtDNA (P<0.05) were significantly lower in the T2DM group than the control group. The VO2 max level (P<0.001) and the insulin level (P<0.05) were positively correlated with the rate of fat oxidation. CONCLUSION: The results of this study suggest lower exercise intensity that achieves Fatmax is recommended for improving fat oxidation and enhancing fitness levels in Korean women with T2DM. Our data could be useful when considering an exercise regimen to improve health and fitness.

Effects of Acute Aerobic Exercise on Circulating Adiponectin and Inflammatory Makers in Obese Middle-Aged Women

BACKGROUND: Exercise intensity may induce changes in inflammatory markers and adipocytokines. However, it is not clear whether acute exercise-induced change to adiponenctin is associated with inflammatory markers and other adipocytokines in obese middle-aged individuals. The aim of this study was to investigate the effects of acute aerobic exercise on circulating adipocytokines and inflammatory markers in obese middle-aged women. METHODS: Using a crossover design, 10 obese middle-aged women (aged 48.4+/-5.1 years; body mass index 29.6+/-2.9 kg/m2) exercised on the treadmill at different durations and velocities at 60% and 80% maximum oxygen consumption (VO2max) in order to equalize energy expenditure (400 kcal). Blood samples were drawn to measure glucose, insulin, fibrinogen, high-sensitive C-reactive protein, leptin, tumor necrosis factor-alpha (TNF-alpha), and adiponectin concentrations. RESULTS: Glucose, fibrinogen, and hsCRP increased significantly (P<0.05) after exercise whereas homeostasis model assessment-insulin resistance decreased significantly (P<0.05). Adiponectin, leptin, and TNF-alpha levels did not change significantly at immediate postexercise, and there were also no significant time x intensity interactions for all variables. The percentage change in adiponectin concentration from baseline to the end of exercise correlated with the percentage change in leptin concentration (r=-0.642, P<0.05) with 60% VO2max exercise. CONCLUSIONS: Our results indicated that, in obese middle-aged women, neither 60% nor 80% VO2max exercise alters adiponectin concentration, in spite of the changes to insulin resistance and inflammatory markers. However, after acute moderate exercise, adiponectin concentration may be associated with the change in leptin levels.