Factors associated with lumbar intervertebral disc degeneration in the elderly.
BACKGROUND
Lumbar intervertebral disc degeneration (DD) precedes degenerative diseases of the lumbar spine. Various factors in addition to normal aging are reported to be associated with DD, and recently atherosclerosis and risk factors for cardiovascular diseases (cardiovascular risk factors) have received much attention; however, the links between these risk factors and DD are unclear.


OBJECTIVE
By correlating magnetic resonance images (MRI) with suspected degenerative disc risk factors such as obesity, cardiovascular risk factors, and atherosclerosis, we hope to clarify the factors associated with DD.


METHODS
An observational study.


METHODS
Two hundred seventy adults (51-86 years old) who participated in a health promotion program.


METHODS
DD evaluated based on the signal intensity of MR T2-weighted mid-sagittal images of the lumbar spine.


METHODS
Age, gender, body mass index (BMI), low-density lipoprotein cholesterol (LDLc), triglyceride (TG), glycosylated hemoglobin (HbA(1c)), brachial-ankle pulse wave velocity (baPWV) as an index of atherosclerosis, osteo-sono-assessment index (OSI) calculated from quantitative ultrasound assessment of the calcaneus as an index of bone mineral density (BMD), history of low back pain (LBP), smoking and drinking habits, and physical loading related to occupations and sports were assessed. The univariate relationships between DD and the variables were evaluated, and finally, odds ratios (OR) and 95% confidence intervals (CI) for the associations of each factor with DD were calculated using logistic regression at each disc level.


RESULTS
Aging correlated significantly with DD of L1/2 (OR, 2.14), L2/3 (OR, 3.56), L3/4 (OR, 2.84), and L4/5 (OR, 3.05); high BMI, with L2/3 (OR, 2.98), L3/4 (OR, 3.58), L4/5 (OR, 2.32), and L5/S1 (OR, 3.34); high LDLc, with L4/5 (OR, 2.65); occupational lifting, with L1/2 (OR, 4.25); and sports activities, with L5/S1 (OR, 3.36).


CONCLUSIONS
Aging, high BMI, high LDLc, occupational lifting, and sports activities are associated with DD. The results of this study raise our index of suspicion that cardiovascular risk factors and particular physical loading may contribute to DD; however additional studies are required to further investigate associations between DD and these factors.
Hangai
Mika
M
Department of Orthopaedic Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki, 305-8575, Japan.
Kaneoka
Koji
K
Kuno
Shinya
S
Hinotsu
Shiro
S
Sakane
Masataka
M
Mamizuka
Naotaka
N
Sakai
Shinsuke
S
Ochiai
Naoyuki
N
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D050197:Atherosclerosis / Q000150:complications; D015992:Body Mass Index; D015519:Bone Density; D002318:Cardiovascular Diseases / Q000150:complications; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D017770:Lifting / Q000009:adverse effects; D008055:Lipids / Q000097:blood; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009765:Obesity / Q000150:complications; D016273:Occupational Exposure; D012307:Risk Factors; D013122:Spinal Diseases / Q000150:complications* / Q000473:pathology
D008055:Lipids