The synergistic effect of taurine and caffeine on platelet activity and hemostatic function

Several studies have shown the deleterious effects of energy drinks, containing taurine and caffeine, on cardiac health. This study aimed to examine synergistic effect of taurine and caffeine on platelets and haemostasis because platelet hyperactivity is a known predictor of cardiovascular diseases. Blood from twelve healthy volunteers aged 18 – 60 years was incubated with 500 µM taurine and 700 µM caffeine individually or together. Platelet activity was evaluated using platelet aggregation assays induced by ADP and collagen, and, haemostatic function by coagulation profile testing, glucose, lipid profile and inflammation marker C- reactive protein assessment (CRP). The optimal time and doses of taurine and caffeine required to inhibit platelet hyperactivity in vitro were established. A combined action of lower doses of taurine and caffeine (T+C) inhibited platelet aggregation, induced by ADP and collagen, greater than taurine or caffeine individually (p < 0.05). Taurine and T+C increased prothrombin clotting time (PT) significantly (p < 0.05), while caffeine alone decreased PT (p <0.05). Caffeine alone increased CRP (p < 0.05). No significant change was observed in lipid parameters. These data support our hypothesis that, synergistically lower concentrations of taurine and caffeine, found in much higher concentrations in energy drinks, may be instrumental in reducing platelet activity and prolongation of clot formation

Estimation of annual risk of tuberculosis infection (ARTI) among children aged 1–9 years in the south zone of India

OBJECTIVE: To estimate the annual risk of tuberculosis infection (ARTI) among children aged 1–9 years in the south zone of India. SETTING: The survey was carried out in a representative sample of villages and census enumeration blocks of towns in four south Indian states, as a part of a nationwide tuberculin survey. DESIGN: Six districts were selected through systematic random sampling. Four hundred and twenty rural clusters and 180 urban clusters were selected from these districts on the basis of the rural–urban ratio in the entire zone. To obtain the required sample of 12 000 children without bacille Calmette-Guérin (BCG) vaccination, 51 000 had to be covered. Eighty-five children from each cluster were tuberculin tested and read for reaction sizes. The ARTI was computed from the estimated prevalence of TB infection among children without a BCG scar. RESULT: Among 52 951 children registered for the study, 50 846 (96%) had a tuberculin test result. The BCG coverage for the study population was about 65%. Among 17 811 children without a BCG scar, the prevalence of infection was 5.9% (95%CI 4.0–7.7%); the corresponding ARTI was 1.7% (95%CI 0.7–1.4%). CONCLUSION: The estimated ARTI for the south zone is 1.0%, as compared to the national average of 1.7% used for programme evaluation. This baseline information should be useful for the assessment of future trends