A comparative study on the use of glucosamine sulfate versus placebo in the management of osteoarthritis

ABSTRACT

OBJECTIVE: To compare glucosamine sulfate with placebo in the management of osteoarthritis. DESIGN: Therapeutic Controlled Trial-Single Blind. SETTING: Out Patient Department of Quezon City General Hospital. STUDY SUBJECTS: Patients aged 50 years old and above who satisfied the clinical criteria for idiopathic knee osteoarthritis. INTERVENTIONS: Subjects were randomly assigned to receive either Glucosamine sulfate (Viartril-S) 500 mg/cap taken three times a day for four weeks or a piacebo taken three times also for four weeks upon admission to the study. MEASUREMENTS: Thorough history taking was done giving particular attention on the knee pain plus the clinical criteria for idiopathic osteoarthritis of the knee. They were randomly assigned to receive either glucosamine sulfate 500 mg/cap or placebo. They were allowed to use their current analgesic for rescue analgesia and continue any form of alternative therapy currently being practiced. Scheduled follow-ups were done after 2 weeks and after 4 weeks from the start of the study period. Visual Analog Scale (VAS) was used to assess for global pain and Western Ontario McMaster Universities (WOMAC) Osteoarthritis Index to assess for pain, stiffness and physical function during the study period. These were done on the first and second follow-up. Subject clinical progress was recorded on the same checklist or data collection forms based on the two scheduled follow-ups. Adverse events were also noted on each follow-up, though study subjects were instructed to have a check-up any day from the start of treatment for instances of occurrence of adverse reactions. RESULTS: A total of 42 patients were screened for eligibility to the study. Six (14.28 percent) were excluded from the study, 4 (9.5 percent) did not fulfill the inclusion criteria and 2 (4.76 percent) declined to be included. From this, 36 (85.71 percent) subjects were enrolled in the study, 18 (50 percent) were placed in Group A (Glucosamine sulfate) and 18 (50 percent) were placed in Group B (Placebo). The prototype of the study subjects with knee osteoarthritis is belonging to age group 51-60 years (Group A = 72.2 percent; Group B = 83.3 percent). Both groups have 9 (50 percent) females and 9 (50 percent) males. Majority of the study subjects are overweight with a BM1 = 25-29.9 kg/m2, (Group A = 66.7 percent; Group B = 66.7 percent), with blue-collar jobs previously (Group A = 100 percent; Group B = 85.3 percent), presently unemployed or housewives (Group A = 77.8 percent; Group B = 66.7 percent) and reached high school (Group A = 88.9 percent; Group B = 50 percent). Most of the subjects in Group A have less than 1 year history of knee osteoarthritis, while in Group B, most of the subjects have history of knee osteoarthritis for 2 years. For both groups, 18 (100 percent) in Group A and 18 (100 percent) in Group B came for their scheduled follow-ups. A total of 36 participants completed the trial. After 4 weeks of the study period, subjects in Group A had a 40 percent decrease from the baseline on VAS scores in contrast to Group B which only has 17.15 percent decrease from the baseline score. The pain dimension on WOMAC in Group A had a decrease from baseline of 57.8 percent, while in Group B there was a decrease of only 12.41 percent from the baseline score. At 4 weeks after treatment, though not statistically significant, Group A had a greater decrease from its baseline stiffness and physical function scores (51 percent) and (58 percent), respectively than Group B (17.07 percent) and (8.4 percent), respectively. Both modes of treatment were well tolerated, with Group A having 22.2 percent occurrence of adverse effects and Group B having 27.8 percent. Adverse events experienced by the study subjects in Group A are cold, headache, constipation and diarrhea. While in Group B, two experienced colds and 1 developed abdominal pain. All adverse events for both groups occurred on the first day of treatment and lasted for only one day. No management was required for these adverse events because all were spontaneously resolved. CONCLUSION: Despite the greater decrease of scores in VAS and WOMAC in group A, glucosamine sulfate use may not be cost-effective.