Persistent lumbar radicular and low back pain; impact of genetic variability versus emotional distress.
OBJECTIVE
Earlier studies documenting the effect of candidate genes on recovery have seldom taken into consideration the impact of emotional distress. Thus, we aimed to assess the modifying effect of emotional distress on genetic variability as a predictor for pain recovery in lumbar radicular (LRP) and low back pain (LBP).


RESULTS
The study population comprised 201 patients and mean age was 41.7 years. The significant association between MMP9 rs17576 (B = 0.71, 95% CI 0.18 to 1.24, p = 0.009) and pain recovery remained statistically significant after adjusting for pain intensity at baseline, age, gender, smoking, body mass index, pain localization and emotional distress (B = 0.68, 95% CI 0.18 to 1.18, p = 0.008). In contrast, the association between OPRM1 (B = - 0.85, 95% CI - 1.66 to - 0.05, p = 0.038) and pain recovery was abolished in the multivariate analysis (B = - 0.72, 95% CI - 1.46 to 0.02, p = 0.058). Hence, MMP9 rs17576 and emotional distress independently seem to predict persistent back pain. The predictive effect of OPRM1 rs179971 with regard to the same outcome is probably dependent on other factors including emotional processing. Trial registration The Regional Committee for Medical Research and Ethics reference number 2014/1754.
['Bjorland|Siri|S|', 'Gjerstad|Johannes|J|', 'Schistad|Elina|E|', 'Swanson|David M|DM|', 'Røe|Cecilie|C|']
D000328:Adult D001416:Back Pain D004644:Emotions D005260:Female D020022:Genetic Predisposition to Disease D006801:Humans D017116:Low Back Pain D008159:Lumbar Vertebrae D008297:Male D020780:Matrix Metalloproteinase 9 D008875:Middle Aged D010147:Pain Measurement D020641:Polymorphism, Single Nucleotide D011446:Prospective Studies D000079225:Psychological Distress D012307:Risk Factors
Low back pain Genetic variability Emotional distress Lumbar radicular pain