Study design: Cross-sectional cohort study of elderly people.
Objectives: To examine the factors influencing osteophyte formation without lumbar disc degeneration and to estimate the implications of osteophytes from the viewpoint of low back pain and gene polymorphisms.
Summary of background data: The degenerative changes that occur in the intervertebral discs are the point of departure of osteophyte formation. Several studies on factors associated with genetic susceptibility to spinal osteophyte formation, such as VDR and TGF-beta1. However, there are no detailed studies concerning osteophytes not accompanied with disc degeneration.
Methods: A total of 387 elderly persons were recruited, and disc degeneration and osteophyte formation were evaluated. The cases with osteophyte formation were classified into 3 groups: osteophyte formation with disc height narrowing (n = 217), osteophyte formation without disc height narrowing (n = 99), and control group defined as the cases without osteophyte formation (n = 71). Twelve genotypes were characterized. Correlations between these degenerative factors and the polymorphisms were analyzed.
Results: The prevalence of low back pain was significantly greater in the group of osteophyte formation with disc height narrowing than the other 2 groups. In the polymorphism of alcohol dehydrogenase (ADH2), prevalence of osteophyte formation without disc height narrowing was less in His/Arg (odds ratio = 0.57, P = 0.041) and Arg/Arg (odds ratio = 0.41, P = 0.18) than His/His.
Conclusions: Patients with osteophyte formation preceding intervertebral disc narrowing had a lower risk of low back pain compared with those without osteophytes. The 47Arg polymorphism in the ADH2 may act to suppress osteophyte formation unaffected by disc degeneration.