Background:
Lumbar spondylolisthesis (LS) is a disease that adversely affects low back pain (LBP) and lower extremity symptoms in the elderly and contributes to locomotive syndrome. However, the epidemiology of this condition remains unclear. This study aims to elucidate the distribution of the cumulative incidence of LS on radiographic lumbar spine in the general population through a 10-year longitudinal survey in the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study.
Methods:
From the cohort of 1551 participants involved in the 2nd survey of the ROAD study (2008-2010), comprising 735 individuals from mountainous areas and 816 from coastal communities, a total of 799 also participated in the 5th survey a decade later (2018-19) and all of them underwent lumbar X-ray in both surveys. A diagnosis of LS was established when slip was ≧3mm in the lateral views of lumbar X-rays. Among these, 681 individuals (226 males and 455 females, with a mean age of 59.2±11.1 years) who showed no LS in the 2nd survey were categorized into the non-LS group. We investigated the incidence of LS in the non-LS group in the 5th survey 10 years later.
Results:
The 10-year follow-up survey, out of the 681 participants who did not have LS in the 2nd survey, 138 individuals (41 males, 97 females) were occurrence with LS, resulting in a cumulative incidence rate of 20.3%. When stratified by gender, the incidence rate was 18.1% for males and 21.3% for females, with no significant difference observed. (Student t-test, P=0.36) The average age of the LS incidence group was 70.2±9.5 years, while that of the non-incidence group was 68.9±11.4 years, and no significant difference was found. (Student t-test, P=0.18) Looking at the age-specific cumulative incidence rates in the 2nd survey, in males, the rates were 0%, 7.7%, 17.1%, 20.9%, and 25.0% for the 40s, 50s, 60s, 70s, and 80s age groups, respectively. Similarly, in females, the rates were 5.9%, 22.7%, 22.8%, 24.7%, and 14.9% for the same age groups. In males, the 80s age group had the highest incidence of LS, while in females, it was the 70s age group. When comparing the cumulative incidence rates over 10 years between mountainous (23.0%) and coastal communities (18.5%), no significant difference was observed. (Chi-Square test, P=0.17)
Conclusion:
The cumulative incidence of LS in the general population over 10 years was 20.3% (18.1% for males, 21.3% for females), and no significant associations were observed with gender, age, or region. We plan to further investigate the risk factors for LS in the future.