Physiologic responses of juvenile-onset diabetic boys to muscular work.

The cardiorespiratory and metabolic responses of juvenile-onset diabetic (Dia) and nondiabetic (Con) boys to light, moderate, and maximal treadmill work were investigated. No significant differences were observed between the Dia and Con subjects in cardiorespiratory responses to maximal and submaximal work. The mean values for the Dia boys during maximal treadmill work for ventilatory volume, oxygen uptake, heart rate, and lactic acid were 91.5 L/min, 54.9 ml/kg . min, rate, and lactic acid were 91.5 L/nin, 54.9 ml/kg . min, 198 beats/min, and 7.0 mM/L, respectively. In the Dia boys, maximal-, light-, and moderate-intensity work produced significant plasma glucose decreases (P less than 0.05) of 1.64, 3.23, and 7.2 mM/L, respectively. In the Con boys, the submaximal work bouts were performed without significant change in plasma glucose levels, but glucose levels after maximal work were elevated 1.58 mM/L. Light and moderate work in both groups produced no changes in plasma triglycerides, free fatty acids, or lactic acid. However, for the Dia boys, maximal work was associated with a significant increase of 0.36 mM/L in triglycerides.