Yoshihide Asanuma

Characteristics of pulmonary function in patients with diabetes mellitus

The incidence of pulmonary diseases among diabetics in Japan has been found to be more than 50% at death. This suggests the existence of some pulmonary risk factors. We analyzed pulmonary functions in 50 diabetics (31 males and 19 females) without overt lung disease, compared to 21 healthy male subjects of the same age (around 50 years old). Forced vital capacity and timed vital capacity were lower in diabetics (P less than 0.005). Diffusing capacity was also decreased in male diabetics (P less than 0.05). Among diabetics, a decrease in the diffusing capacity was dominant in patients with diabetic retinopathy, which correlated with an increasing duration of their diabetes. Analysis by the partial correlation method which accounts for the smoking index showed that standardized indices for peripheral airflow in male diabetics decreased significantly as the patients age increased (P less than 0.005); the rate of decrement was greater than that of the control subjects. Diabetic patients showed abnormal lung function in the peripheral airways which increased with age and gas transfer was also affected by diabetic microangiopathy as well as the duration of diabetes. These changes seemed to deteriorate progressively, possibly combining and contributing to respiratory insufficiency in critical pathological conditions.

Improvement of respiratory resistance by hot water immersing exercise in adult asthmatic patients

Acute effect of hot water immersing exercise on respiratory resistance (RR) was investigated in 12 adult asthmatics and six healthy males. They underwent mild exercise with comparable heart rates (HR = 120) in a hot water pool (water temp. 38°C) for 10 minutes. RRs were measured before and until 40 minutes after the exercise. Mean RRs of the patients before exercise (0.36 Kpa/l/s) reduced to less than 0.32 during 15 to 30 minutes after exercise (p<0.05). RRs of healthy subjects (0.19 Kpa/l/s) did not decrease significantly. Analysis of humoral factors relating to exercise metabolism and autonomic nervous system function of the patients suggested that the influence of sympathetic nervous activation persisted until 20 minutes after exercise. This physiotherapy had a specific feasibility for adult asthmatics in preventing exercise-induced wheezing.

Genetic Aspects of Serum Immunoglobulins and Respiratory Chemosensitivity

The role of genetics and environmental factors determining serum concentrations of immunoglobulins (IgA, IgG, and IgM,) were analyzed in 20 pairs of monozygotic (MZ) and 11 pairs of dizygotic (DZ) twins. Respiratory chemosensitivity to hypoxia and hypercapnia was also measured. Intrapair variances for alpha 2-, beta-, and gamma-globulins, IgG, IgA, and IgM were significantly smaller than interpair variances in MZ, indicating that these variables are more similar between pairs than among pairs in MZ. In DZ, intrapair variance for IgM was significantly smaller than interpair variance. Intrapair variance in MZ for gamma-globulin, IgG, IgA, hypoxic ventilatory response, and hypercapnic ventilatory response were significantly smaller than those in DZ, indicating that these variables are genetically controlled. Subjects with low IgA showed a blunted hypoxic ventilatory response, and subjects with high IgA, a vigorous ventilatory response. These results indicate that while IgM is controlled predominantly by environmental factors, IgA and IgG are genetically determined in young healthy subjects. Serum IgA levels and hypoxic ventilatory response are interrelated in young healthy subjects.

Role of Chemosensitivity during Exercise in Normal Subjects and Patients with Pulmonary Emphysema

In 11 normal subjects (mean age = 22.8 years) and 8 patients with pulmonary emphysema (mean age = 70.4 years), the role of chemosensitivity in determining ventilation, cardiac output, lactic acid, and cyclic AMP and GMP was evaluated quantitatively during 150 or 30 W exercise and simulated exercise. Simulated exercise was done while the subjects took a rest by regulating arterial blood gases at exercise levels in patients and at PaO2 = 65 mm Hg and PaCO2 = 48 mm Hg in normal subjects. In normal subjects, the role of arterial blood gases in determining exercise ventilation, cardiac output, cyclic AMP and GMP are large, while those contributed much less to lactic acid. In patients, PaO2 contributed only half of the exercise ventilation. It accounted for a negligibly small portion of exercise cardiac output, lactic acid, and cyclic GMP. These results indicate, by deduction, that either augmentation of chemosensitivity, pH, or humoral factors is responsible for about half of the changes of exercise ventilation in patients with pulmonary emphysema. These factors seem to influence cardiac output, lactic acid, and cyclic AMP and GMP more strongly than PaO2 alone in exercising patients.