RESUMO
A cross-sectional study method combined with two types of traditional Chinese medicine(TCM) syndrome differentiation methods was adopted to investigate the clinical symptoms and distribution characteristics of TCM syndromes in patients with pulmonary nodules from the perspectives of number, size, nature, and stability of pulmonary nodules by using the χ~2 test, systematic clustering and Apriori algorithm correlation analysis. The common clinical symptoms of pulmonary nodules were fatigue(77.35%) and irritability(75.40%), and 40 symptoms were clustered into 3 groups(digestive system symptoms, respiratory system symptoms, and emotional and systemic symptoms) and 8 major symptom categories. The proportion of cold and heat in complexity syndrome(63.43%) was higher based on cold-heat syndrome differentiation. The top two syndromes were Qi deficiency syndrome(88.03%) and Qi depression syndrome(83.17%) based on disease syndrome differentiation. Yang deficiency syndrome(60.52%) was more than Yin deficiency syndrome(50.16%). There were higher proportions of phlegm syndrome(78.67%) and Yang deficiency syndrome(69.33%) of so-litary pulmonary nodules in terms of the number of pulmonary nodules. In terms of size, the proportion of phlegm syndrome decreased as the mean diameter of pulmonary nodules increased, while the proportions of Yang deficiency syndrome and blood stasis syndrome increased. The distribution of Qi depression syndrome was more in those with mean diameter<10 mm(85.02%, P=0.044) and cold syndrome was more in those with mean diameter ≥10 mm(16.67%, P=0.024). In terms of the nature of pulmonary nodules, the proportions of Qi depression syndrome and heat syndrome decreased with the increase in solid components of pulmonary nodules, while the proportions of Yin deficiency syndrome and cold and heat in complexity syndrome increased. The blood stasis syndrome accounted for a higher proportion of pulmonary nodules with solid components. In terms of the stability of pulmonary nodules, dampness syndrome(72.97%), blood stasis syndrome(37.84%), and cold and heat in complexity syndrome(70.27%) accounted for higher proportions. In addition, patients with new nodules presented higher proportions in Qi inversion syndrome(52.00%, P=0.007) and cold and heat in complexity syndrome(66.00%, P=0.008). Meanwhile, 11 syndromes were associated and 4 common compound syndromes were obtained(Qi deficiency and depression syndrome, Qi depression and phlegm coagulation syndrome, Qi deficiency and phlegm coagulation syndrome, and Qi deficiency and dampness obstruction syndrome). Qi deficiency syndrome and Qi depression syndrome could be associated with other syndromes. The results show that the main clinical symptoms of pulmonary nodules are fatigue and irritability. The main TCM syndromes of pulmonary nodules are Qi deficiency syndrome, Qi depression syndrome, Yang deficiency syndrome, and cold and heat in complexity syndrome. The distribution of TCM syndromes is significantly correlated with the size of pulmonary nodules and the presence or absence of new nodules. The common compound syndromes are Qi deficiency and depression syndrome, Qi depression and phlegm coagulation syndrome, Qi deficiency and phlegm coagulation syndrome, and Qi deficiency and dampness obstruction syndrome.