The influence of physical training on glucose tolerance, insulin sensitivity, and lipid and lipoprotein concentrations in middle-aged hypertriglyceridaemic, carbohydrate intolerant men.
The effects of 9 weeks of moderate intensity exercise training while on a weight-maintaining diet were studied in 19 untrained middle-aged, hypertriglyceridaemic, carbohydrate intolerant men. Initial mean maximum oxygen consumption was low (29.7 +/- 1.0 ml.min-1.kg-1; mean +/- SEM) and improved (34.2 +/- 1.4 ml.min-1.kg-1, p less than 0.01) with exercise training. Fasting glucose, insulin, lipid and lipoprotein concentrations did not change. While the abnormal glucose response to oral glucose did not change with training, insulin concentrations were significantly (p less than 0.05) lower at 90 and 120 min during the final oral glucose tolerance test. Insulin mediated glucose uptake did not change, indicating that the degree of exercise training failed to improve in vivo insulin sensitivity. Significant associations were found between the following parameters measured: fasting concentrations of triglycerides and insulin, very low density lipoprotein-triglycerides and glucose, and measures of in vivo insulin resistance and fasting insulin levels, suggesting that insulin resistance in these glucose intolerant subjects may play a role in their hypertriglyceridaemia. These data indicate that moderate increases in physical training alone are not sufficient to improve the carbohydrate, insulin and lipid metabolism of hypertriglyceridaemic, glucose intolerant men.