title: Pain intensity the first year after lumbar disc herniation is associated with the A118G polymorphism in the opioid receptor mu 1 gene: evidence of a sex and genotype interaction.
abstract: Earlier studies have shown that the single nucleotide polymorphism (SNP) A118G (rs1799971) in the opioid receptor mu 1 (OPRM1) gene may affect pain sensitivity. In the present study we investigated whether the A118G SNP could predict clinical outcome regarding progression of pain intensity and disability in patients with low back pain and sciatica after lumbar disc herniation. Patients (n = 258) with lumbar disc herniation and sciatic pain, all European-Caucasian, were recruited from two hospitals in Norway. Pain and disability were rated on a visual analog scale (VAS), by McGill Sensory Questionnaire and by Oswestry Disability Index (ODI) over a 12 months period. The data revealed a significant interaction between sex and A118G genotype regarding the pain intensity during the 12 months (VAS, p = 0.002; McGill, p = 0.021; ODI, p = 0.205, repeated-measures ANOVA). We found that */G women had a slower recovery rate than the */G men. Actually, the */G women had 2.3 times as much pain as the */G men 12 months after the disc herniation (VAS, p = 0.043, one-way ANOVA; p = 0.035, Tukey HSD). In contrast, the A/A women and A/A men seemed to have almost exactly the same recovery rate. The present data suggest that OPRM1 G allele increases the pain intensity in women, but has a protective effect in men the first year after disc herniation.
authors: National Institute of Occupational Health, 0033 Oslo, Norway. maria.b.olsen@stami.no
authors: Maria Belland
authors: MB
authors: Olsen
authors: Line Melå
authors: LM
authors: Jacobsen
authors: Elina Iordanova
authors: EI
authors: Schistad
authors: Linda Margareth
authors: LM
authors: Pedersen
authors: Lars Jørgen
authors: LJ
authors: Rygh
authors: Cecilie
authors: C
authors: Røe
authors: Johannes
authors: J
authors: Gjerstad
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000235:genetics* / Q000601:surgery; D017116:Low Back Pain / Q000209:etiology / Q000235:genetics* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D020641:Polymorphism, Single Nucleotide; D017450:Receptors, Opioid, mu / Q000235:genetics*; D012585:Sciatica / Q000209:etiology / Q000235:genetics* / Q000601:surgery; D012737:Sex Factors; D011795:Surveys and Questionnaires
chemical_list: C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu