Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The impact of body weight on the progression of knee osteoarthritis

02.12.2004


Benefits of weight loss may depend on alignment of affected leg, study suggests



A painful and sometimes crippling disease characterized by progressive cartilage loss, osteoarthritis (OA) of the knee affects an estimated 6 percent of adults over age 30. AT present, no treatments are available that have been shown to impede the destructive course of this disease, apart from knee replacement surgery. Numerous studies have shown that being overweight increases the risk of developing knee OA, whose sufferers, on average, tend to be heavy. While doctors routinely advise patients to lose weight, researchers have yet to affirm the benefits of weight loss to prevent ongoing joint deterioration.

To better understand the effect of body weight on the course of knee OA, researchers at Boston University focused on an important predictor of disease progression: limb malalignment, defined by joint space loss at the point where the thigh and shin bones connect to the knee. Featured in the December 2004 issue of Arthritis & Rheumatism, their findings suggest that the benefits of weight loss for knee OA patients depend on the degree of alignment in the affected leg.


The researchers recruited their subjects from two studies on quality of life conducted by the Veterans Administration of the Boston Health Care System. 228 individuals with knee OA were selected; all but one completed a 30-month period of follow-up. 41 percent were women and the mean age was 66 years. Among the subjects, the diagnosis of OA was confirmed by radiographs in 394 knees. At the first follow-up examination, each subject was assessed for degree of alignment in the affected leg, which was then categorized as moderate, severe, or neutral. Malaligned limbs could be either varus (bowlegged) or valgus (knock-kneed). The body mass index (BMI) of each subject was also computed.

Of the total 394 knees studied, 90 showed disease progression. Weight gain did have a significant impact. For each 2-unit increase in BMI, researchers found an 8 percent increase in the risk of disease progression. However, this effect was limited to knees in the moderately malaligned legs. In neutrally aligned legs on the one end of the spectrum and severely maligned legs on the other, body weight had no measurable effect on the risk of OA progression. "The effect of BMI on progression was different at different levels of alignment, with the risk being much greater for limbs with moderate malalignment," affirms the study’s author, David T. Felson, M.D.

Why would the impact of body weight on knee OA be restricted to legs where malalignment was moderate? Dr. Felson offers possible reasons. In patients with severe malalignment, the extreme stress already placed on local cartilage may be the only risk factor required for continued structural deterioration. In patients with neutrally aligned limbs, the increased joint loading that accompanies increased body weight would be distributed across much of the joint surface, thus protecting against further damage. Since moderate alignment increases the stress on cartilage, the addition of excess weight effectively works to aggravate the cartilage damage. For these patients, losing weight might relieve the stress and considerably slow disease progression.

"Our findings, which need to be confirmed in other studies, suggest that prevention and treatment efforts for obesity and knee OA could be efficiently targeted to those subjects with moderate malalignment," Dr. Felson concludes. "These findings may have broad implications not just for the effect of body weight on OA, but for other risk factors that affect joint loading."

Amy Molnar | EurekAlert!
Further information:
http://www.interscience.wiley.com/journal/arthritis
http://www.wiley.com

More articles from Health and Medicine:

nachricht Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku

nachricht Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>