Table 3.

Platelet-rich plasma serotonin levels in the three study groups, stratified by the G681C HTR1B polymorphism.

	G681C HTR1BPolymorphismGenotype	Mean (ng/ml) ±Standard Deviation (%)	N
NR	C C	74.68±49.13	5
	C G	121.73±79.37	11
	G G	184.39±162.59	14
	Total	143.13±127.12	30
RP	C G	163.26±128.90	13
	G G	175.36±124.81	12
	Total	169.07±124.44	25
CN	C C	558.01±80.12	2
	C G	540.52±220.26	12
	G G	390.63±117.03	15
	Total	464.20*±179.33	29
Total	C C	212.78±241.45	7
	C G	276.32±242.76	36
	G G	257.20±167.96	41
	Total	261.69±207.28	84

Note: RP = Responders; NR = Non-responders; CN = Control. The platelet-rich plasma level of serotonin was statistically higher in the CN (*p<0.001; F = 14.63) than in the other two groups. A significant interaction between the groups and the G681C HTR1B polymorphism was observed (p = 0.022; F = 3.383), with the highest serotonin level observed among the CC homozygous of the CN and the lowest among the NR group with the same genotype.