When Environment Meets Genetics: A Clinical Review of the Epigenetics of Pain, Psychological Factors, and Physical Activity.

Epigenetic mechanisms represent a link between the environment and gene function. Recent research shows how early life stress, inflammation, and physical activity can influence gene expression through epigenetic mechanisms. Epigenetic changes-such as DNA methylation and microRNA interference-can be measured in humans and might soon become important biological markers. Epigenetic marks can accompany clinical assessment to measure the effectiveness of various interventions, such as exercise therapy. In addition, epigenetics is improving the understanding of important underlying mechanisms related to the central nervous system, the opioidergic system, and stress responses. Epigenetics is closing a gap in our explanatory abilities and should be implemented to broaden the field of rehabilitation sciences, promote a mechanism-based clinical reasoning, and develop new treatments. In the present review, we focused on epigenetic mechanisms related to pain, psychological factors (such as fear and anxiety), and physical activity, translating relevant findings from these 3 different, yet related, areas of cardinal importance for clinicians.