Effect of long-term physical training on physical fitness, glucose tolerance, and plasma lipids in maturity onset diabetes

The effect of long-term physical training on physical fitness, glucose metabolism, and plasma lipids was examined in 17 patients with abnormal glucose tolerance (7 had mild non insulin dependent diabetes mellitus, and 10 had impaired glucose tolerance). The training program was consisted of a walking exercise for 40-60 min in daily life and an aerobic -muscle training once a month at community center. The subjects in exercise group were trained for more than 4 years (6.6±2.4 years). Seventeen patients matched for sex, age, fasting blood glucose, and observation period in exercise group were participated as untrained control subjects. They were all instructed to follow individualized diet during the study. The long-term physical training significantly increased (P<0.01) physical fitness scores in size steps, zigzag dribble, and step test, and maintained the initial level in vertical jamp, but a significant decrease (P<0.01) in grip strength was observed. Fasting blood glucose concentration showed no significant change in either group, but a significant relationship (P<0.05) was observed between the changes in fasting blood glucose and step test score in exercise group. Blood glucose concentration at 120 min in an oral glucose tolerance test (OGTT) significantly decreased (P<0.05) after the physical training in exercise group, but did not change in control group. Sum of blood glucose concentration in the OGTT tended to decrease (P<0.1) in response to physical training in exercise group, but did not change in control group. There were significant relationships (P<0.05) between the change in step test score and the change in blood glucose at 60 min or sum of blood glucose in the OGTT. HbA1 showed no significant change in exercise group, but a significant increase (P<0.05) in control group. HDL cholesterol was significantly increased (P<0.05) after the physical training in exercise group, but no significant changes in plasma lipids were observed in control group. These results provide evidence that regularly performed, long-term habitual physical exercise under diet control can be effective in improving physical fitness and glucose metabolism in some patients with mild non-insulin dependent diabetes mellitus and with impaired glucose tolerance.