Short-term PTT supplementation has no effect on platelet aggregation in metabolic syndrome
Short-term supplementation of palm-based tocotrienols and tocopherol (PTT) does not significantly impact platelet aggregation and activation, coagulation and inflammation in patients with metabolic syndrome, a new randomized controlled trial reveals.
“Our results implied the lack of clinically significant effect on platelet homeostasis with acute supplementation of PTT mixture,” said researchers.
In the study cohort of 32 metabolic syndrome patients, body weight remained relatively stable and no adverse events were reported over the study period. Fasting plasma tocotrienol was higher in the PTT group (n=16; 0.58±0.50 µg/mL) than in the placebo control group (n=16; 0.03±0.06 µg/mL; p<0.001). [Sci Rep 2017;7:11542]
After 14 days of PTT supplementation, there was no significant difference in adenosine diphosphate (ADP)-induced platelet aggregation reactivity between the PTT and placebo groups (290±50 vs 295±48 P2Y reactivity units [PRU] respectively; p=0.393) as measured by the VerifyNow P2Y12 assay.
Similarly, platelet aggregation reactivity induced by arachidonic acid was not significantly different between the PTT and placebo groups (p=0.763), yielding respective aspirin reactivity units (ARU) of 631±33 and 628±36, respectively.
In terms of acute response following supplementation, there were also no significant differences in postprandial ADP-induced (1.77±31.59 vs -4.79±26.11 PRU; p=0.408) and arachidonic acid-induced (-1.29±37.77 vs 0.45±35.63; p=0.776) platelet aggregation between the PTT and placebo groups.
In terms of secondary outcomes, there were no significant between-group differences in terms of levels of fibrinogen (p=0.865), activated glycoproteins (p=0.602), soluble E-selectin (p=0.715) and P-selectin (p=0.224), D-dimer (p=0.505) and high-sensitivity C-reactive protein (p=0.795).
Levels of plasminogen activator inhibitor type 1 (p=0.551), undercarboxylated osteocalcin (p=0.196) and soluble intracellular (p=0.629) and soluble vascular (p=0.210) cellular adhesion molecules 1 were also comparable between the two groups.
The current literature provides conflicting reports on the effect of tocotrienol supplements on the platelet aggregation induced by ADP. Some have shown significant inhibitory effects on aggregation, while others have shown no substantial effects. According to the authors, these discrepancies may have stemmed from the differences in methods and measurements used.
Researchers employed the VerifyNow P2Y12 cartridge system, which uses fibrinogen-coated beads, and a specific agonist to measure the platelet aggregation reactivity.
“Unlike previous studies, VerifyNow instrument, a fully automated cartridge-based instrument that measures platelet aggregation at a standardised condition with its cartridge-based design and at a fixed concentration of ADP, was used in current trial,” they said.
The study has several limitations. Among these are the short supplementation period and the potential interactions between tocopherol and tocotrienols, both of which could have confounded the findings.
“Information from this study would add value to health practitioners and this cohort intending to consume PTT mixture as supplements for a short period of time,” said researchers. “Nevertheless, their long-term effects on platelet function remained uncertain and should be warranted in future studies.”