title: Risk factors for lumbar intervertebral disc herniation in Chinese population: a case-control study.
abstract: METHODS
  A case-control study of 4180 subjects was carried.
  
  
  OBJECTIVE
  To explore the risk factors of lumbar disc herniation in China.
  
  
  BACKGROUND
  In China, along with the economic development, people's living environment and working conditions have undergone some tremendous changes, such as the accelerating life pace and competition. In this situation, it is important to know whether the risk factors of lumbar disc herniation have changed or not. This case-control study, including the possible social and psychological factors based on the literature, attempted to search the new risk factor, therefore provide better prevention measures for lumbar disc herniation.
  
  
  METHODS
  A total of 2010 hospitalized patients, diagnosed with lumbar disc protrusion by CT and/or MRI were selected as cases. A total of 2070 people from communities and hospitals, without history of low back pain and sciatica, were selected as controls. All patients and controls were investigated for their family history, occupational characters' smoking status, working psychosocial factors, etc. The risk factors were analyzed by multiple nonconditional logistic regression method.
  
  
  RESULTS
  Family history (OR = 3.6) was the most important risk factor for lumbar disc protrusion in this study, followed by lumbar load (OR = 2.1), hard-working (OR = 1.8), and time urgency (OR = 1.1). Additionally, physical exercises (OR = 0.5) and bed characteristics (OR = 0.4) appeared to be the protective factors for lumbar disc protrusion. After stratified by age, family history (OR = 14.5), occupational character (OR = 5.2), and physical exercises (OR = 0.2) stronger association with lumbar disc protrusion was seen in subjects younger than 30 years. In subjects from 30 to 55 years, family history (OR = 5.1), lumbar load (OR = 1.91), hard-working (1.9), physical exercises (OR = 0.5), time urgency (OR = 1. 3), bed characteristics (OR = 0.4) were significantly important. In subjects older than 55 years, lumbar load (OR = 2.9) and bed characteristics (OR = 0.4) were closely related to lumbar disc protrusion.
  
  
  CONCLUSIONS
  Family history, lumbar load, hard-working, and time urgency are the major risk factors for lumbar disc herniation, and physical exercises and sleeping on the hard bed might be the protective factors.
authors: Department of Orthopaedics, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Shanxi, People's Republic of China. zyingang@mail.xjtu.edu.cn
authors: Yin-gang
authors: YG
authors: Zhang
authors: Zhengming
authors: Z
authors: Sun
authors: Zhi
authors: Z
authors: Zhang
authors: Jian
authors: J
authors: Liu
authors: Xiong
authors: X
authors: Guo
mesh_terms: D000328:Adult; D001513:Beds; D016022:Case-Control Studies; D002681:China; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000453:epidemiology* / Q000208:ethnology* / Q000517:prevention & control; D016015:Logistic Models; D008159:Lumbar Vertebrae / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D011584:Psychology; D012307:Risk Factors; D012959:Socioeconomic Factors; D016474:Weight-Bearing; D016526:Workload