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

Abstract

BACKGROUND CONTEXTModic changes (MCs) have long been suspected as a pathologic cause of back pain. Although 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. PURPOSETo investigate associations between MCs and lifestyle and lifetime occupational exposures using a general population sample. STUDY DESIGNCross-sectional study. PATIENT SAMPLEThe 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 MEASURESThe presence and type of MCs in the lumbosacral spine were evaluated on sagittal magnetic resonance images. Demographics, lifestyle factors, and occupational exposures were measured using a structured interview. METHODSUnivariate and multivariate logistic regressions were used to examine the associations of MCs with various environmental exposures. RESULTSAmong the 644 subjects (52.6±13.9 years; range 20–88 years) included in this study, 44.7% had MCs. In univariate regression analyses, the presence of MCs was associated with greater age, higher BMI, greater cigarette smoking, regular exercise, and absence of daily vehicle vibration. Modic changes 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. CONCLUSIONSAge 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.