Lifestyle and lifetime occupational exposures may not play a role in the pathogenesis of Modic changes on the lumbar spine MR images

Abstract Background Context Modic changes (MCs) have long been suspected as a pathological cause of back pain. While much attention has been focused on clinical perspectives, the etiology of MCs remains unclear. Although some studies have reported that sex, body mass index (BMI), cigarette smoking, and physical loading may associate with MCs, the observed associations are inconsistent among studies. Purpose To investigate associations between MCs and lifestyle and lifetime occupational exposures using a general population sample. Study Design Cross-sectional study. Patient Sample The study was an extension of the Hangzhou Lumbar Spine Study, a population-based study of mainland Chinese focusing on lumbar degenerative changes. A total of 644 randomly selected subjects from a typical community in Hangzhou, Eastern China participated. Outcome Measures The presence and type of MCs in the lumbosacral spine were evaluated on sagittal MRIs. Demographics, lifestyle factors, and occupational exposures were measured using a structured interview. Methods Univariate and multivariate logistic regressions were used to examine the associations of MCs with various environmental exposures. The study was supported by the National Natural Science Foundation of China and Key Platform Project of the Health Department of Zhejiang Province. There is no conflict to disclose. Results Among the 644 subjects (52.6±13.9 yrs; range, 20-88 yrs) included in this study, 44.7% had MCs. In univariate regression analyses, the presence of MCs was associated with greater age, higher body mass index (BMI), greater cigarette smoking, regular exercise, and absence of daily vehicle vibration. MCs were not univariately associated with sex or alcohol consumption. In addition, all occupational loading measurements were associated with the occurrence of MCs in univariate analyses, except work time spent in vehicles and work-related back injuries. However, in multivariate regression analyses, no statistically significant associations between the occurrence of MCs and lifestyle or lifetime occupational exposures were observed after adjusting for age, sex and BMI. Conclusions Age is an important determinant of MCs, with BMI and sex also playing a role. Lifestyle and occupational factors appear to have minor effects, if any, on the pathogenesis of MCs in the lumbar spine.