RESUMO
<p><b>OBJECTIVE</b>To explore the synergistic interaction between MMP-3,VDR gene polymorphisms and occupational risk factors on lumbar disc degeneration.</p><p><b>METHODS</b>A case-control study including 178 cases of lumbar disc degeneration and 284 controls was carried out through questionnaire and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Additive model was used to analyze the synergistic interaction between gene polymorphisms and occupational risk factors.</p><p><b>RESULTS</b>The non-conditional logistic regression analysis showed that bending/twisting, whole-body vibration, heavy physical workload, alleles 5A of MMP-3 (6A5A/5A5A) and A of VDR-Apa (AA/Aa) were significantly associated with lumbar disc degeneration(OR = 4.06, 8.96, 5.46, 1.96 and 1.70, respectively, P < 0.05). There were synergistic interactions between the mutation genotype 5A of MMP-3 and whole-body vibration exposure, between the mutation genotype 5A of MMP-3 and bending/twisting, and between the mutation genotype A of VDR-Apa and whole-body vibration exposure (SI: 13.27, 2.91 and 2.35 respectively, P < 0.05).</p><p><b>CONCLUSION</b>People with the mutation genotypes 5A of MMP-3 and/or A of VDR-Apa may have the increased risk of developing lumbar disc degeneration if they are exposed to whole-body vibration and/or bending/twisting.</p>