Low levels of human serum glucosamine after ingestion of glucosamine sulphate relative to capability for peripheral effectiveness

• Published in: Annals of the rheumatic diseases Vol. 65; no. 2; pp. 222 - 226
• Main Authors: Biggee, B A, Blinn, C M, McAlindon, T E, Nuite, M, Silbert, J E
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and European League Against Rheumatism 01.02.2006; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Accuracy; Administration, Oral; Adult; Aged; Arthritis; Automation; Biological and medical sciences; BMI; body mass index; Bones, joints and connective tissue. Antiinflammatory agents; cartilage; Chromatography, High Pressure Liquid - instrumentation; Chromatography, High Pressure Liquid - methods; Dietary supplements; Diseases of the osteoarticular system; Drug Administration Schedule; Drug dosages; Extended Report; Female; glucosamine; Glucosamine - administration & dosage; Glucosamine - blood; Glucosamine - pharmacokinetics; Glucosamine - urine; Heart attacks; high performance liquid chromatography; HPLC; human; Humans; interleukin; Male; Medical sciences; Middle Aged; osteoarthritis; Osteoarthritis - blood; Osteoarthritis - drug therapy; Osteoarthritis - urine; Pharmacology. Drug treatments; Rheumatology; Sensitivity and Specificity; serum; Time Factors; Human; Serum; Glucosamine; Antirheumatic agent; Rheumatology
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/ard.2005.036368

Background: Oral glucosamine preparations are widely used as a treatment for osteoarthritis, purportedly functioning by a variety of mechanisms suggested by results of in vitro experiments, and generally using glucosamine concentrations well in excess of 100 μmol/l. Objective: To use high performance liquid chromatography with a high sensitivity Metrohm-Peak instrument for pulsed amperometric measurement of human serum glucosamine; a detection limit of 0.5 μmol/l at 1:10 serum dilution allowed measurement of low levels of glucosamine in human serum, which previously has not been possible. Methods: Eighteen subjects with osteoarthritis were given 1500 mg of commercial glucosamine sulphate after an overnight fast, and serum was then obtained at baseline and every 15–30 minutes over 3 hours, and additionally, from two subjects at 5 and 8 hours. Urine samples were collected at baseline and 3 hours after ingestion from three subjects. Results: Baseline glucosamine was below the detection limit of 0.5 μmol/l for all subjects, but after ingestion, glucosamine was detected in 17/18 subjects, beginning to rise at 30–45 minutes to a maximum at 90–180 minutes, with a range of 1.9–11.5 μmol/l (0.34–2 μg/ml). Conclusion: This maximum concentration of 11.5 μmol/l has previously been shown to contribute less than 2% of the galactosamine incorporated into chondroitin sulphate in incubations of glucosamine with cultured human chondrocytes, and is a much lower concentration than the glucosamine concentrations claimed by other investigators to have various significant in vitro effects. This raises questions about current biological rationales for glucosamine use that were based on in vitro effects of glucosamine at much higher concentrations.