glycogen and Lung-Diseases--Obstructive

Skeletal muscle metabolite depletion exists in advanced chronic obstructive pulmonary disease (COPD) patients with chronic hypoxaemia. The purpose of this study was to investigate if long-term oxygen therapy (LTOT) can improve skeletal muscle energy metabolism. Eight patients with advanced COPD, four with chronic hypoxaemia, were investigated using muscle biopsy specimens from the quadriceps femoris muscle applying the needle biopsy technique. The investigation was performed twice, before and after approximately 8 months of LTOT in the hypoxaemic patients. Eight healthy controls of similar age were also investigated. In the COPD patients, muscle glycogen, ATP and creatine phosphate (CrP) concentrations, were 42% (P < 0.01), 18% (P < 0.05) and 21% (P = n.s.) lower than in the healthy controls, respectively, while creatine (Cr) and lactate concentrations were 21% and 90% higher, respectively in the COPD patients compared to the healthy control subjects (P < 0.05). After LTOT, the 'energy index' CrP/(CrP + Cr) ratio increased by 0.12 in the LTOT patients but decreased by 0.12 in the control COPD patients (P < 0.05). The results indicate an improvement in skeletal muscle energy metabolism during LTOT in COPD patients with chronic hypoxaemia.

Topics: Adenosine Triphosphate; Aged; Creatine; Energy Metabolism; Female; Glycogen; Humans; Hypoxia; Lactates; Long-Term Care; Lung Diseases, Obstructive; Male; Middle Aged; Muscle, Skeletal; Oxygen Inhalation Therapy; Phosphocreatine

We have previously reported increased blood glucose concentrations and skeletal muscle glycogen depletion in severe COPD patients with chronic respiratory failure. In order to see if insulin resistance exists in severe COPD, we investigated nine patients with advanced COPD with chronic hypoxaemia and seven healthy control subjects of similar age, using the euglycaemic hyperinsulinaemic glucose clamp technique. We could not demonstrate a subnormal intravenous glucose requirement in response to insulin when maintaining euglycaemia in the COPD patients with chronic hypoxaemia. This indicates that the net metabolism of glucose in COPD patients with chronic hypoxaemia is not resistant to insulin.

Topics: Blood Gas Analysis; Blood Glucose; Female; Glucose Clamp Technique; Glycogen; Humans; Insulin; Insulin Resistance; Lung Diseases, Obstructive; Male; Middle Aged; Muscle, Skeletal; Respiratory Function Tests

Early lactic acidosis has been suggested as negatively influencing the exercise capacity of patients with chronic obstructive pulmonary disease (COPD). We conducted a study to investigate whether the early lactate (La) response to exercise in COPD is related to alterations in exercise-related substrate levels in resting muscle, associated with physical inactivity. Twenty-seven COPD patients and 22 controls (physically inactive [PI] subjects, n = 15; and physically active [PA] subjects, n = 7) performed an incremental cycle test. Venous blood was sampled for La analyses, and the oxygen uptake at which the La level began to rise (La threshold) was calculated. Vastus lateralis biopsy specimens were obtained at rest. In the PA group, muscle glutamate (GLU) and glycogen were higher, but muscle La, pyruvate, and glucose were not different than in the PI group. Moreover, the La threshold was higher in the PA group. The COPD group had lower values for La threshold and muscle GLU, and higher values for muscle La and pyruvate levels than did the PI group. Stratification of patients into those with and without macroscopic emphysema (EMPH+, EMPH-, respectively), with comparable physical activity levels on the basis of previous observations, revealed lower values for La threshold and GLU in EMPH+ patients. Diffusing capacity for carbon monoxide (DL(CO)) and arterial oxygen tension (Pa(O(2))) in the four study groups were positively related to GLU and La threshold. Moreover, La threshold was positively related to GLU. This study illustrates that the early lactic acidosis during exercise in patients with COPD is associated with the physical inactivity-related reduction in these patient's muscle GLU. However, factors other than physical inactivity, such as Pa(O(2)) or DL(CO), play a role in the different La responses during exercise in subjects with different subtypes of COPD.

Topics: Aged; Exercise Tolerance; Female; Glucose; Glutamic Acid; Glycogen; Humans; Lactic Acid; Leg; Lung Diseases, Obstructive; Male; Middle Aged; Muscle, Skeletal; Oxygen Consumption; Physical Exertion; Pulmonary Diffusing Capacity; Pulmonary Emphysema; Pyruvic Acid; Respiratory Mechanics

Eighteen patients with advanced COPD, 8 with chronic respiratory failure (RF) and 10 without (nonRF, NRF) were investigated using spirometry, arterial blood gas analysis and biopsies taken from the quadriceps femorls muscle. The biopsies were analysed for ATP, creatine phosphate (CrP), creatine (Cr), lactate and glycogen content. Muscle fibre composition was also studied. Low concentrations of ATP, glycogen and CrP were found in the RF patients. Significant correlations were found between muscle metabolites and arterial blood gas values with the strongest correlation between muscle glycogen and arterial PO2 (r = 0.70; p less than 0.001). A very low percentage of "oxidative" type I muscle fibres was found in both groups. Possible mechanisms causing depletion of muscle metabolites are discussed.

Topics: Adenosine Triphosphate; Biopsy; Creatine; Female; Glycogen; Humans; Lactates; Lactic Acid; Lung Diseases, Obstructive; Male; Middle Aged; Muscles; Phosphocreatine; Respiratory Insufficiency

Topics: Diagnosis, Differential; Glycogen; Humans; Lipids; Lung Diseases, Obstructive; Lung Neoplasms; Neutrophils; Oxidoreductases; Peroxidases; Phagocytosis

1. The concentration of metabolites in intercostal and quadriceps muscle, and pulmonary function, were studied in twelve patients with chronic obstructive lung disease and acute respiratory failure before, during and after standardized treatment at an intensive care unit. The findings were compared with those obtained in hospitalized patients of comparable age with non-pulmonary diseases. 2. On admission, when the patients had marked hypoxaemia, hypercapnia and acidosis, the concentrations of ATP and creatine phosphate were low in both intercostal and quadriceps muscle, particularly the latter. The lactate concentration was increased in relation to control values but glycogen did not differ significantly. 3. In response to therapy, the Pa,CO2 and the patient's acidosis decreased, the vital capacity increased and lung mechanics improved along with the clinical condition. At the same time there were significant increases in the concentrations of ATP, creatine phosphate and glycogen in intercostal and quadriceps muscles, to values similar to, and for glycogen in excess of, those found in control subjects. Lactate concentration fell significantly during treatment. 4. In view of the low initial muscle concentrations of ATP and creatine phosphate in the patients, it is suggested that dysfunction of the respiratory muscles may be an important component of respiratory failure. Moreover, the concentration of energy-rich compounds in muscle rose significantly as the patients responded to treatment, which emphasizes the importance of adequate nutritional therapy in this disorder.

Topics: Acute Disease; Adenosine Triphosphate; Aged; Chronic Disease; Female; Glycogen; Humans; Intercostal Muscles; Lactates; Lung Diseases, Obstructive; Male; Middle Aged; Muscles; Phosphocreatine; Respiratory Function Tests; Respiratory Insufficiency

Topics: Aged; Chronic Disease; Exercise Therapy; Glycogen; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Respiratory Function Tests