From: Combined analysis of circulating β-endorphin with gene polymorphisms in OPRM1, CACNAD2 and ABCB1 reveals correlation with pain, opioid sensitivity and opioid-related side effects
Patients
Controls
n=80
n=56
High responder
16
Normal responder
44
Non-responder
20
Sex M/F
39/41
25/31
Mean age (range)
46.2 (25-66)
40.5 (27-61)