Gender, race and diet affect platelet function tests in normal subjects, contributing to a high rate of abnormal results

Abstract

Summary To assess sources of variability in platelet function tests in normal subjects, 64 healthy young adults were tested on 2–6 occasions at 2 week intervals using 4 methods: platelet aggregation (AGG) in platelet-rich plasma (PRP) in the Bio/Data PAP-4 Aggregometer (BD) and Chrono-Log Lumi-Aggregometer (CL); and AGG in whole blood (WB) in the CL and Multiplate Platelet Function Analyzer (MP), with ATP release (REL) in CL-PRP and CL-WB. Food and medication exposures were recorded prospectively for 2 weeks prior to each blood draw. At least one AGG abnormality was seen in 21% of 81 drug-free specimens with CL-PRP, 15% with CL-WB, 13% with BD-PRP, and 6% with MP-WB, increasing with inclusion of REL to 28% for CL-PRP and 30% for CL-WB. Epinephrine AGG and REL were significantly reduced in males (P<0.0001). Ristocetin AGG and collagen and thrombin REL were significantly reduced in Blacks (P<0.0001). One-third of specimens drawn following flavonoid-rich food exposures had aberrant results, compared to 8.5% of specimens without such exposures (P=0.0035). PRP tests had less intra-individual variation than WB tests. Gender, race, diet, and test system affected results of platelet function testing in healthy subjects, suggesting caution when interpreting the results of platelet function testing in patients.

Cytokine, chemokine, and growth factor profile of platelet-rich plasma

“…Interestingly, from the data analysis, the only difference concerning possible gender variability dealt with the concentration of PDGF, which was higher in males, independently of the platelet count. This result may be partially discordant with the data published by Gomez et al [43], but it is certainly consistent with Miller and colleagues [44], who pointed out that gender, diet, and test system affected the results of platelet function in healthy subjects. It is noteworthy that the values of PDGF-BB here described are quite similar to those reported previously [6], while the content of PDGF was respectively higher in serum [45] and lower in plasma [46] according to other studies.…”

Oleocanthal-rich extra virgin olive oil demonstrates acute anti-platelet effects in healthy men in a randomized trial

“…Subjects were also asked to refrain from consumption of foods previously described to affect platelet function for at least 24 hours prior to each study visit. A list of these foods was provided to the subjects during recruitment, and included phenolic- and polyphenol-rich foods, such as, cocoa products, coffee, tea, wine, other grape products and other colourful fruits and vegetables (Holt, Heiss, Kelm, & Keen, 2012; Miller, Rice, Garrett, & Stein, 2014). Dietary compliance was confirmed via questioning of the individual participants upon their arrival to the facility.…”

Population pharmacodynamics of cilostazol in healthy Korean subjects

“…This result was consistent with previous reports; caffeine inhibited platelet aggregation by up-regulating adenosine A 2A receptor, [19] and chronic coffee drinking decreased platelet aggregation. [20] For the influence of sex, previous studies in Caucasians reported that baseline platelet aggregation in females was higher than that in males, [21][22][23] whereas in a study conducted in a healthy Korean population CTs were reported to be significantly longer in females. [17] Although one possible reason for this inconsistency would be a race difference (Caucasian versus Asian), more studies will be needed to better understand the influence of sex on CT.…”

“…After first dosing on Day 8, blood samples were collected at 0 (predose), 1,2,3,4,6,8,10,12,13,14,15,16,18,20,22,24,36,48, and 72 hours for PK. In the case of PD, blood samples were collected at 0 hour (baseline) on Day 1 and 0 (predose), 3,6,8,10,12,15,18,20,22,24,36, 48 and 72 hours after first dosing on Day 8. Among the 40 subjects who participated in the study, 29 completed sampling, and their PD data up to 24 hours for the reference drug was used in this analysis.…”