A short-term study led by C. Kent Kwoh, MD, director of the University of Arizona Arthritis Center, and a collaborative team of researchers has found that oral glucosamine supplementation is not associated with a lessening of knee cartilage deterioration among individuals with chronic knee pain.
The study was conducted by researchers at the University of Pittsburgh, VA Pittsburgh Healthcare System, Boston University, Texas Woman’s University in Houston and Klinikum Augsburg in Augsburg, Germany. Dr. Kwoh, who previously was with the University of Pittsburgh and VA Pittsburgh Healthcare System, is corresponding author of the study.
“Our study found no evidence that drinking a glucosamine supplement reduced knee cartilage damage, relieved pain or improved function in individuals with chronic knee pain,” said Dr. Kwoh. An internationally recognized expert in osteoarthritis, rheumatoid arthritis and other joint diseases, he also is UA professor of medicine and medical imaging, The Charles A.L. and Suzanne M. Stephens Chair of Rheumatology, and chief of the Division of Rheumatology and Clinical Immunology at the UA College of Medicine – Tucson.
The findings, published online March 11 in Arthritis & Rheumatology, a journal of the American College of Rheumatology (ACR), indicate that glucosamine does not decrease pain or improve knee bone marrow lesions—more commonly known as bone bruises and thought to be a source of pain in those with osteoarthritis (OA).
According to the ACR, 27 million Americans over age 25 are diagnosed with OA—the most common form of arthritis and primary cause of disability in the elderly. Patients may seek alternative therapies to treat joint pain and arthritis, with prior research showing glucosamine as the second-most commonly used natural product. A 2007 Gallup poll reported that 10 percent of individuals over the age of 18 in the United States use glucosamine. According to the website www.nutraingredients-usa.com, global sales of the supplement in 2010 totaled more than $2.1 billion.
“The Joints on Glucosamine (Jog) Study: The Effect of Oral Glucosamine on Joint Structure, A Randomized Trial” is the first study to investigate whether the supplement prevents the worsening of cartilage damage or bone marrow lesions.
For the double-blind, placebo-controlled clinical trial, Dr. Kwoh and colleagues enrolled 201 participants with mild-to-moderate pain in one or both knees. Participants were randomized and treated daily for 24 weeks with 1,500 mg of glucosamine hydrochloride in a 16-ounce bottle of diet lemonade or a placebo. Magnetic resonance imaging (MRI) was used to assess cartilage damage.
Trial results showed no decrease in cartilage damage in participants in the glucosamine group, compared to the placebo group. Researchers report no change in bone marrow lesions in 70 percent of knees, 18 percent of knees worsened and 10 percent improved.
The control group had greater improvement in bone marrow lesions compared to treated participants, with neither group displaying a worsening of bone marrow lesions. Glucosamine was not found to decrease urinary excretion of C-telopeptides of type II collagen (CTX-II)—a predictor of cartilage destruction.
In addition to Dr. Kwoh, researchers who contributed to the study included Ali Guermazi, MD, Boston University; Frank W. Roemer, MD, Boston University, Mass., and Klinikum Augsburg, Augsburg, Germany; Michael J. Hannon, John M. Jakicic, MD, Stephanie M. Green, Rhobert W. Evans, PhD, and Robert Boudreau, PhD, University of Pittsburgh; and Carolyn E. Moore, PhD, Texas Woman’s University, Houston.
The study was funded by the Beverage Institute for Health & Wellness, The Coca-Cola Company and the National Institute of Arthritis, Musculoskeletal and Skin Diseases (P60 AR054731).