Obesity speeds up cartilage loss


Boston: Obesity, among other factors, is strongly associated with an increased risk of rapid cartilage loss, according to a study published in the August issue of the magazine Radiology.

“We have isolated demographic and MRI-based risk factors for progressive cartilage loss,” said the study’s lead author, Frank W. Roemer, M.D., adjunct associate professor at Boston University and co-director of the Quantitative Imaging Center at the Department of Radiology at Boston University School of Medicine.

“Increased baseline body mass index (BMI) was the only non-MRI-based predictor identified.”

As obesity is one of the few established risk factors for osteoarthritis, it is not surprising that obesity may also precede and predict rapid cartilage loss. Weight loss is probably the most important factor to slow disease progression.
Risk Factors for MRI-detected Rapid Cartilage Loss of the Tibio-femoral Joint over a 30-month Period: the MOST Study.

Tibio-femoral cartilage is a flexible connective tissue that covers and protects the bones of the knee. Cartilage damage can occur due to excessive wear and tear, injury, misalignment of the joint or other factors, including osteoarthritis.

Osteoarthritis is the most common form of arthritis, affecting 27 million Americans, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. In osteoarthritis, the cartilage breaks down and, in severe cases, can completely wear away, leaving the joint without a cushion. The bones rub together, causing further damage, significant pain and loss of mobility.

The best way to prevent or slow cartilage loss and subsequent disability is to identify risk factors early.

“Osteoarthritis is a slowly progressive disorder, but a minority of patients with hardly any osteoarthritis at first diagnosis exhibit fast disease progression,”

Dr. Roemer said. “So we set out to identify baseline risk factors that might predict rapid cartilage loss in patients with early knee osteoarthritis or at high risk for the disease.”

The researchers recruited patients from the Multicenter Osteoarthritis (MOST) Study, a prospective study of 3,026 people, age 50 – 79, at risk for osteoarthritis or with early x-ray evidence of the disease. The study is funded by the National Institute on Aging.

Dr. Roemer’s study consisted of 347 knees in 336 patients. The patient group was comprised of 65.2 percent women, mean age 61.2, with a mean BMI of 29.5, which is classified as overweight. Recommended BMI typically ranges from 18.5 to 25. Only knees with minimal or no baseline cartilage damage were included. Of 347 knees selected for the study, 20.2 percent exhibited slow cartilage loss over the 30-month follow-up period and 5.8 percent showed rapid cartilage loss. Rapid cartilage loss was defined by a whole organ magnetic imaging score of at least 5, indicating a large full thickness loss of 75 percent in any subregion of the knee during the follow-up period.

The results showed that the top risk factors contributing to rapid cartilage loss were baseline cartilage damage, high BMI, tears or other injury to the meniscus (the cartilage cushion at the knee joint) and severe lesions seen on MRI at the initial exam. Other predictors were synovitis (inflammation of the membrane that lines the joints) and effusion (abnormal build-up of joint fluid).

Excess weight was significantly associated with an increased risk of rapid cartilage loss. For a one-unit increase in BMI, the odds of rapid cartilage loss increased by 11 percent. No other demographic factors–including age, sex and ethnicity–were associated with rapid cartilage loss.

“As obesity is one of the few established risk factors for osteoarthritis, it is not surprising that obesity may also precede and predict rapid cartilage loss,” Dr. Roemer said. “Weight loss is probably the most important factor to slow disease progression.”


* Researchers using MRI have identified risk factors for rapid cartilage loss in the knee.
* People with a high body mass index (BMI) may be at increased risk for rapid cartilage loss and osteoarthritis.
* Osteoarthritis affects 27 million Americans.

“Risk Factors for MRI-detected Rapid Cartilage Loss of the Tibio-femoral Joint over a 30-month Period: the MOST Study.” Collaborating with Dr. Roemer were Yuqing Zhang, D.Sc., Jingbo Niu, M.D., John A. Lynch, Ph.D., Michel D. Crema, M.D., Monica D. Marra, M.D., Michael C. Nevitt, Ph.D., David T. Felson, M.D., M.P.H., Laura Hughes, Georges El-Khoury, M.D., Martin Englund, M.D., Ph.D., and Ali Guermazi, M.D., for MOST study investigators.

Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsnajnls.org/)

RSNA is an association of more than 43,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. www.RSNA.org

For patient-friendly information on MRI, visit www.RadiologyInfo.org

Knee arthritis may be sign of lung cancer in smokers

Rome: Arthritis of the knee may be the first sign of a type of lung cancer that is hard to treat in heavy smokers, suggests research published ahead of print in the Annals of the Rheumatic Diseases.

The Italian researchers reviewed the case notes of all patients with rheumatic disorders, diagnosed at one tertiary referral centre over six years.

Between 2000 and 2005, more than 6500 new patients attended the clinic. Of these, 296 (4.4%) were cases of monoarthritis—inflammation in just one joint—of the knee.

Among this group of patients, the knee arthritis, which was very mild, was the first sign of as yet undiagnosed non-small cell lung cancer in just under 2%.

All the patients were middle aged men, who had been heavy smokers for most of their lives.

But in every case, the lung cancer was operable, and once the cancerous tissue had been removed, the knee symptoms subsided.

Non-small cell lung cancer is linked to other conditions, which feature abnormal growths, in up to 20 per cent of cases, say the authors. And spread to the bones occurs in around one in five cases.

But the authors note that it has not so far been linked to arthritis.

Non-small cell lung cancer is particularly difficult to treat unless caught early, and in over half the cases diagnosed, the disease is already advanced.

Features that could act as early warning signs are therefore especially important, say the authors.

Glucosamine kills pain, says new research

London: The natural supplement Glucosamine is just as effective as powerful as painkilling drugs in the treatment of osteoarthritis (OA) of the knee, according to new research[1] published today in a leading scientific journal.

Data from the European Guide [2] trial, published today in Arthritis and Rheumatism, reveals that Glucosamine, a naturally occurring amino sugar derived from shellfish, is as efficacious as paracetamol (acetaminophen) in the control of moderately severe OA symptoms and clearly superior when compared to placebo.

Significantly, Glucosamine also raises none of the safety concerns commonly associated with drugs such as Paracetamol, which has been linked to various side effects including liver disease.

The results from the 318 person GUIDE trial were based on multi-centre, randomised, placebo-controlled, double-blind trials and led by Prof. Gabriel Herrero-Beaumont, University of Madrid.

For the trial, patients received 1500 mg of Glucosamine, the equivalent to levels in commonly-available supplements such as Seven Seas JointCare Max, which also contains Chondroitin and Cod Liver Oil to relieve painful joints.

Dr Sarah Jarvis, GP, stated, “This study is extremely exciting and shows there is now powerful academic research demonstrating that the natural supplement Glucosamine is as effective as painkillers like paracetamol in managing OA. In addition, Glucosamine is very important when treating OA as it is one of the few products that can be used in association with other pain medications.”

Professor Olivier Bruyere, of the University of Liège in Belgium, and a world authority on the efficacy of Glucosamine stated, “The results of this study support existing research and highlight the importance of Glucosamine as a treatment for osteoarthritis. There is no doubt that Glucosamine has proved its worth in the treatment of this debilitating condition.”

This new evidence adds increasing weight to the argument for natural supplements to be used in the maintenance of healthy joints. In 2004, the results from the 1258 person GAIT trial[3], also a multi-centre, placebo-controlled double blind trial showed that 79% of patients who took the combination of Glucosamine and Chondroitin, experienced relief from the pain caused by osteoarthritis, compared to 69% of those who took the prescription drug, celecoxib (Celebrex).

Seven Seas JointCare is a range of natural, evidence-based Glucosamine health supplements, to help provide the essential elements that the body needs to maintain healthy joints and connective tissue. In particular, Seven Seas JointCare Max combines 1500mg of Glucosamine sulphate, the dose used in the GUIDE trial, with maximum strength Cod Liver Oil. In addition, the range also includes Seven Seas JointCare Projoint Formula, and JointCare Glucosamine plus Chondroitin, which combines Glucosamine with chondroitin as in the GAIT trial, along with Cod Liver Oil (Omega-3s).