[A study on relation between active pulmonary tuberculosis and underlying diseases]

A study was made on the relation between active pulmonary tuberculosis and underlying diseases in 119 tuberculosis patients. Out of total 119 patients, 87 patients (73.1%) had underlying diseases. The most common underlying disease was diabetes mellitus in 34 patients (39.1%), followed by HCV (+) chronic hepatitis, sequela of cerebral infarction, hypertension and gastric ulcer. In patients who had underlying diseases, the mean age was higher, proportion of sputum smear positive cases was higher, albumin was lower, and period until sputum culture negative conversion was longer. In patients who had diabetes mellitus, proportion of cases with cavity on chest X-P was higher, and in patients who had sequela of cerebral infarction or hypertension, mean age was higher. In patients who had diabetes mellitus and whose HbA1C was > or = 9%, proportion of smear positive cases was higher, albumin was lower and period until culture negative conversion was longer than in patients who had diabetes mellitus and whose HbA1c was < 9%, suggesting that control of blood sugar in diabetes mellitus related to severity of pulmonary tuberculosis. In patients who had diabetes mellitus and whose albumin was < 3 g/dl, period until culture negative conversion was longer than in patients who had diabetes mellitus and whose albumin was > or = 3 g/dl. In patients who had underlying diseases, these diseases caused decline of tuberculous immunity and nutritional disturbance represented by lower albumin also promoted decline of tuberculous immunity. It is suggested that the underlying diseases affected the onset and progression of pulmonary tuberculosis.