Glucosamine and Chondroitin Limit Cartilage Loss in Knee OA

Long-term use of glucosamine and chondroitin sulfate (Glu/CS) in patients with knee osteoarthritis (OA) is beneficial in limiting knee damage due to delayed cartilage loss, according to a study published in Arthritis Care and Research.

Johanne Martel-Pelletier, PhD, director of the Osteoarthritis Research Unit at the University of Montréal Hospital Research Center, and colleagues used data obtained from the Osteoarthritis Initiative (OAI) database — a longitudinal observational cohort — to assess long-term effects of structure-modifying agents on knee OA.

Researchers combined the OAI progression subcohort and incidence subcohort to create a study cohort (n=1593). Participants underwent 6 years of follow-up, had available radiographic and magnetic resonance imaging (MRI) data for baseline and 6 years, had a joint space width of >1 mm, and had complete information available on Glu/CS use.

The main outcome of the study was to evaluate structural changes within the symptomatic knee, assessed by cartilage volume loss and measured using automated, quantitative MRI technology.

Participants were divided into 2 groups, based on medial meniscal extrusion at baseline. Those with meniscal extrusion (n=429) were further divided into subgroups based on non-exposure (n=183), 1 year (n=96), 2 to 3 years (n=38), and 4 to 6 years (n=112) of exposure to Glu/CS.

After ≥2 years of Glu/CS exposure, participants were found to have less cartilage volume loss in the lateral compartment. In the control group (not exposed), mean loss was –8.85±4.45%; loss at 1 year was –8.21±4.81%, –6.66±4.11% at 2 to 3 years (P =.006), and –6.90±5.33% at 4 to 6 years (P =.002). Additionally, a protective factor was noted for the global knee (not exposed: –10.03±4.04% vs 4 to 6 years: –8.83±4.38% (P =.048).

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) self-administered questionnaire was used to determine patient’s pain scores at the start of the study. Scores from 3 domains — pain, stiffness, and function — are combined into a total score, on a scale of 0 to 96, with higher values indicating more pain and functional impairment. No symptom improvement, as measured by the WOMAC questionnaire, was noted in the nonexposed group vs the 1-, 2- to 3-, or 4- to 6-year groups.

Summary and Clinical Applicability

“Our results support the long-term (6-year) structure-modifying effects of the combination of [glucosamine and chondroitin sulfate] on cartilage volume,” the researchers wrote. “The Glu/CS long-term effect was found to prevent cartilage loss in the lateral compartment of the knee.” 

They added, “The structural impact of 6 years of Glu/CS is relatively small…and represents an ‘absolute protection’ of 1.20%, which is statistically significant (P =.048).”

Clinically, this demonstrated that protective effect can be linked to a reduction in the need for total knee replacements in this patient population.

Study Limitations 

• The study included fewer participants due to the requirement of available MRI and meniscal damage data from baseline and at 6-year follow-up
• Researchers had no information about the dose or quality of the medication taken by patients
• Results should be viewed in the context of “stringent” patient selection from the OAI cohort
• Radiography measurement data were only provided for the first 4 years, which may have limited assessment of long-term impact of Glu/CS

Disclosures 

Dr Raynauld has received consulting fees from ArthroLab, Inc. Drs Pelletier and Martel-Pelletier have received consultant fees from Bioibérica and are shareholders in ArthroLab, Inc. Drs Abram, Dodin, and Delorme are employees of ArthroLab, Inc.

Reference

Raynauld J-P, Pelletier J-P, Abram F, et al. Long-term effects of glucosamine and chondroitin sulfate on the progression of structural changes in knee osteoarthritis: six-year follow-up data from the Osteoarthritis Initiative. Arthrit Care Res.  2016;68(10):1560-1566. doi:10.1002/acr.22866 

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