The following is a summary of “Familial effects account for association between chronic pain and past month smoking,” published in the February 2024 issue of Pain by Rader et al.
Researchers conducted a retrospective study to leverage a twin design and directly assess the impact of smoking on chronic pain, independent of familial factors while exploring whether cortico-striatal connectivity mediates this association.
They conducted a study with 692 twins (average age was 28.83 years). Examined smoking habits in the past month (132 reported smoking), current pain episodes (179 reported having pain), and the connectivity between the nucleus accumbens and medial prefrontal cortex (NAc-mPFC).
The results showed smoking had a significant association with pain, yet NAc-mPFC connectivity didn’t significantly mediate this association. In a co-twin control model, smoking predicted pain frequency within families but couldn’t differentiate between family members. Pain risk was 43% attributable to additive genetic (A) factors and 57% due to non-shared environmental (E) influences. Past-month smoking frequency was 71% influenced by genetics and 29% by the non-shared environment. Smoking and pain were strongly correlated genetically (rg = 0.51, P<0.001) and phenotypically (r = 0.21, P=0.001) but not environmentally (re = -0.18, =0.339).
Investigators concluded that while smoking and pain co-occurred, the study suggests familial factors, not smoking itself, likely explain the link and the reward pathway’s connectivity held no bearing on the association.
Source: onlinelibrary.wiley.com/doi/abs/10.1002/ejp.2247
