Predictors of symptomatic response to glucosamine in knee osteoarthritis: an exploratory study.
OBJECTIVE
To evaluate whether patient characteristics and/or radiographic disease patterns predict symptomatic response to treatment with glucosamine in osteoarthritis (OA) of the knee.


METHODS
Exploratory prospective correlational study.


METHODS
Institutional.


METHODS
39 participants with chronic knee pain from the local community.


METHODS
Glucosamine sulphate (1.5 g/day) for 12 weeks.


METHODS
Pain and physical function were assessed with visual analogue scales (VASs) and participant-perceived global change scores (GCSs). Regression modelling evaluated the relationship between treatment outcome and age, body mass index (BMI), pain and function self-efficacy and presence/absence of osteophytes in the medial and lateral tibiofemoral joint (TFJ) and patellofemoral joint (PFJ) compartments.


RESULTS
13 (33%) participants were men. The mean (SD) age and BMI were 53.6 (13.1) years and 27.9 (4.6) kg/m(2), respectively. 13 (33%), 19 (49%) and 24 (62%) participants had medial TFJ, lateral TFJ and PFJ osteophytes, respectively. Glucosamine significantly improved pain (mean change on VAS = -1.4, 95% CI -0.6 to -2.2; p = 0.002) and activity restriction (-1.9, 95% CI -1.0 to -2.8; p<0.001). At 12 weeks, 30 (77%) and 27 (69%) participants reported improvement in pain and physical function, respectively. Regression modelling showed that no evaluated variables predicted change in pain on VAS. Decreased function self-efficacy, presence of PFJ osteophytes and absence of medial TFJ osteophytes predicted functional improvement on VAS. BMI, pain self-efficacy and function self-efficacy predicted improvement in pain by GCS.


CONCLUSIONS
Although glucosamine significantly improved symptoms, most of the variance in outcome at 12 weeks was unexplained by the predictors evaluated. However, glucosamine may be more effective at improving symptoms in patients with knee OA who have a lower BMI, PFJ osteophytes and lower functional self-efficacy.
Bennett
Alexander N
AN
Centre for Health Exercise and Sports Medicine, University of Melbourne, Melbourne, Victoria, Australia. alexander.n.bennett@btinternet.com
Crossley
Kay M
KM
Brukner
Peter D
PD
Hinman
Rana S
RS
D000203:Activities of Daily Living; D015992:Body Mass Index; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D005944:Glucosamine / Q000627:therapeutic use*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D011446:Prospective Studies; D011859:Radiography; D016896:Treatment Outcome
D005944:Glucosamine