Delayed gadolinium-enhanced magnetic resonance imaging of cartilage: clinical associations in obese adults.
OBJECTIVE
Delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) is used to assess cartilage glycosaminoglycan distribution. Our aim was to determine the relationships between self-reported pain and disability, clinical variables, and serum leptin, and dGEMRIC indices in obese subjects with and without clinical knee osteoarthritis (OA).


METHODS
Seventy-seven subjects were recruited from laparoscopic adjustable gastric banding or exercise and diet-weight loss programs. The dGEMRIC index was assessed on MRI according to established protocol. Regression analysis adjusted for age, sex, body mass index (BMI), and presence of clinical knee OA.


RESULTS
Mean age and BMI were 51 +/- 12.7 years and 39.6 +/- 6.2 kg/m(2). Twenty-three subjects (30%) had clinical knee OA (American College of Rheumatology criteria). The medial and lateral dGEMRIC indices were 538 +/- 80 ms and 539 +/- 86 ms. Age correlated negatively with medial (r = -0.40, p < 0.001) and lateral (r = -0.29, p = 0.012) dGEMRIC index. Subjects with clinical knee OA had significantly lower medial dGEMRIC index; however, no association was found for BMI. Varus alignment correlated with lower medial dGEMRIC index (r = -0.43, p < 0.006), while quadriceps strength correlated positively with lateral dGEMRIC index (r = 0.32, p = 0.008). There was also a negative correlation between serum leptin and lateral dGEMRIC index in women (r = -0.39, p = 0.035), with a trend in men (r = -0.52, p = 0.08). There were weak associations with physical disability, as self-reported on the WOMAC questionnaire.


CONCLUSIONS
In obese subjects, knee dGEMRIC index was associated with age, clinical knee OA, abnormal tibiofemoral alignment, and quadriceps strength. Longitudinal studies are required to assess the potential for improvement in dGEMRIC index with interventions such as strength training.
Department of Rheumatology, Institute of Bone and Joint Research, Kolling Institute, University of Sydney, Royal North Shore Hospital, Sydney, Australia.
Ananthila
A
Anandacoomarasamy
Bruno M
BM
Giuffre
Steven
S
Leibman
Ian D
ID
Caterson
Garett S
GS
Smith
Marlene
M
Fransen
Philip N
PN
Sambrook
Lyn M
LM
March
D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D015390:Gastric Bypass; D006304:Health Status; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D010535:Laparoscopy; D020738:Leptin / Q000097:blood; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000473:pathology* / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D011859:Radiography; D016059:Range of Motion, Articular; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
D003287:Contrast Media; D020738:Leptin; D019786:Gadolinium DTPA