Tuberculous pleural effusion (n=20) Malignant pleural effusion (n=20) Transudative pleural effusion (n=18) F P value L-Alanine 89.51±19.67† 108.21±16.04 105.90±16.78 3.369 0.049* Citric acid 19.42±7.20† 26.80±6.89 24.26±4.73 4.165 0.027* Betaine 110.51±19.86 130.20±20.40 130.22±28.99 2.351 0.114 Creatine 3.95±1.22† 7.67±3.36 7.45±3.21 5.647 0.009** LDL 37.21±4.00 37.56±12.25 23.11±5.15† 10.577 0.000** Aspartate 0.77±0.70 1.56±1.40 1.55±1.19 1.599 0.221 Pyruvic acid 21.88±6.60 25.18±7.86 26.46±9.08 0.893 0.421 Glutamine 37.41±11.96 45.38±11.36 43.90±15.60 1.049 0.364 L-glutamine 38.23±13.00 47.23±12.14 44.75±16.88 1.078 0.354 Succinate 5.34±1.72 7.45±3.86 8.47±2.92 2.895 0.073 Acetate 2.94±0.70 3.26±1.43 3.77±1.08 1.397 0.265 Putrescine 13.81±5.67 14.88±5.11 17.34±5.63 1.094 0.349 L-lactic acid 0.09±0.16 0.68±0.57† 0.17±0.24 7.567 0.002**

ANOVA showed *P < 0.05 ** P < 0.01.Data are presented as mean ± SD. SNK-q showed †p < 0.05 compared with each of the other two groups. The comparisons were determined by one-way analysis of variance

Table 4: Statistical results of ANOVA and SNK-q.