Occupational and genetic risk factors associated with intervertebral disc disease.
METHODS
Cross-sectional epidemiologic study.


OBJECTIVE
To evaluate the interaction between known genetic risk factors and whole-body vibration for symptomatic intervertebral disc disease (IDD) in an occupational sample.


BACKGROUND
Risk factors of IDD include, among others, whole-body vibration and heredity. In this study, the importance of a set of known genetic risk factors and whole-body vibration was evaluated in an occupational sample of train engineers and sedentary controls.


METHODS
Eleven variations in 8 genes (COL9A2, COL9A3, COL11A2, IL1A, IL1B, IL6, MMP-3, and VDR) were genotyped in 150 male train engineers with an average of 21-year exposure to whole-body vibration and 61 male paper mill workers with no exposure to vibration. Subjects were classified into IDD-phenotype and asymptomatic groups, based on the latent class analysis.


RESULTS
The number of individuals belonging to the IDD-phenotype was significantly higher among train engineers (42% of train engineers vs. 17.5% of sedentary workers; P = 0.005). IL1A -889T allele represented a significant risk factor for the IDD-phenotype both in the single marker allelic association test (P = 0.043) and in the logistic regression analysis (P = 0.01). None of the other allele markers was significantly associated with symptoms when analyzed independently. However, for all the SNP markers considered, whole-body vibration represents a nominally significant risk factor.


CONCLUSIONS
The results suggest that whole-body vibration is a risk factor for symptomatic IDD. Moreover, whole-body vibration had an additive effect with genetic risk factors increasing the likelihood of belonging to the IDD-phenotype group. Of the independent genetic markers, IL1A -889T allele had strongest association with IDD-phenotype.
Virtanen
Iita M
IM
Collagen Research Unit, Biocenter and Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland.
Karppinen
Jaro
J
Taimela
Simo
S
Ott
Jürg
J
Barral
Sandra
S
Kaikkonen
Kaisu
K
Heikkilä
Olli
O
Mutanen
Pertti
P
Noponen
Noora
N
Männikkö
Minna
M
Tervonen
Osmo
O
Natri
Antero
A
Ala-Kokko
Leena
L
D000328:Adult; D024081:Collagen Type IX / Q000235:genetics; D024161:Collagen Type XI / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D053582:Interleukin-1alpha / Q000235:genetics; D053583:Interleukin-1beta / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics; D007405:Intervertebral Disc Displacement / Q000453:epidemiology* / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D019278:Matrix Metalloproteinase 3 / Q000235:genetics; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000235:genetics*; D016273:Occupational Exposure; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011890:Railroads; D018167:Receptors, Calcitriol / Q000235:genetics; D012307:Risk Factors; D014732:Vibration
C499319:COL11A2 protein, human; C120282:COL9A2 protein, human; C120768:COL9A3 protein, human; D024081:Collagen Type IX; D024161:Collagen Type XI; C508584:IL1A protein, human; C508585:IL1B protein, human; C508600:IL6 protein, human; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D015850:Interleukin-6; D018167:Receptors, Calcitriol; D019278:Matrix Metalloproteinase 3