MUSCLE ENERGY-METABOLISM AND NUTRITIONAL-STATUS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE - A P-31 MAGNETIC-RESONANCE STUDY

We investigated the relationship between nutritional status and muscle energy metabolism during exercise in 18 male patients with chronic ob structive pulmonary disease (COPD) and 15 male control subjects using P-31 nuclear magnetic resonance spectroscopy (P-31-MRS). The patients and control subjects were further categorized as in either a well-nour ished (% ideal body weight, % IBW greater than or equal to 90) or maln ourished (% IBW < 90) state. Muscle energy metabolism was evaluated by determining the ratios PCr/(PCr + Pi) (PCr, phosphocreatine; Pi, inor ganic phosphate), and ATP/(PCr + Pi + ATP). The exercise consisted of repetitive hand grips performed against a load. The work rate was norm alized for the individual's lean muscle mass by dividing work performe d by the forearm fat-free cross-sectional area, which was calculated u sing H-1-MRS. The PCr/(PCr + Pi) values during exercise did not correl ate with the % IBW in any of the groups of control subjects or COPD pa tients. Furthermore, the PCr/(PCr + Pi) did not correlate with the nor malized work rate in either the well-nourished or malnourished subject groups. However, there were correlations within the groups of control subjects and COPD patients. The PCr/(PCr + Pi) values for the normali zed work rate were consistently lower in the COPD patients than in the central subjects. These findings suggest that the altered muscle meta bolism in COPD patients is not affected by their nutritional status.