In this study we tested the hypothesis that hypoalgesia
in individuals at risk for hypertension is related to enhanced
activation of supraspinal pain modulation systems. Supraspinal
inhibition of pain signals was assessed using a diffuse
noxious inhibitory control paradigm, in which a noxious
conditioning stimulus was used to suppress pain in response
to a noxious test stimulus applied to a remote area of
the body. Specifically, the nociceptive flexion reflex
(NFR) was assessed in 113 healthy young adults before,
during, and after exposure to forearm tourniquet ischemia.
Consistent with previous evidence of hypoalgesia in individuals
at risk for hypertension, offspring of hypertensive individuals
exhibited significantly higher NFR thresholds than offspring
of normotensive persons. Although NFR activity was significantly
decreased in all participants during concomitant application
of forearm ischemia, the degree of attenuation of NFR activity
was not significantly different as a function of risk for
hypertension.