A randomised placebo-controlled trial of the efficacy of beta-sitosterol and its glucoside as adjuvants in the treatment of pulmonary tuberculosis
OBJECTIVE: To evaluate the adjuvant effect of betasitosterol and its glucoside in the treatment of culture proven pulmonary tuberculosis (PTB). DESIGN: A blinded randomised placebo-controlled trial in culture proven drug sensitive PTB. Patients were hospitalised for the duration of treatment and evaluated at monthly intervals with regard to sputum culture positivity, chest radiography, weight gain, Mantoux test response, routine haematology and liver functions. STATISTICAL EVALUATION: General linear models for repeated measures (SAS GLM package) compared the interaction effects, group effects and time effects of findings in 19 patients receiving sitosterols with those in 18 patients receiving a placebo (talcum powder). Absolute values and change from baseline values were evaluated, although only the latter are reported. RESULTS: Weight gain was significantly greater in the sitosterol group (mean weight gain 8.9 kg) than the placebo group (mean gain 6.1 kg) (P = 0.0023 group effects; P = 0.0001 for time effects). Speed of achieving culture negativity, radiological improvement and induration on Mantoux testing was similar in the two groups. Change in lymphocyte counts from baseline was significantly higher in the sitosterol group (P = 0.0001 and P = 0.0001 for group and time effects) as was the increase in eosinophil counts (P = 0.0001 and P = 0.0137 for group and time effects). CONCLUSION: The study has shown significantly improved weight gain and higher lymphocyte and eosinophil counts in PTB patients receiving sitosterols in addition to an efficacious antituberculosis regimen. Sitosterols and their possible mode of action should now be evaluated in larger numbers of tuberculosis patients and in diseases with a similar immunopathogenesis.