Steve Messier, at left, works with a research patient in the J.B Snow Biomechanics Laboratory.
Addressing an 'epidemic'
Researcher Steve Messier devotes his career to improving the lives of older adults suffering with osteoarthritis
Stephen Messier is a health and exercise science professor, and the director of the J.B Snow Biomechanics Laboratory. A faculty member since 1981, he has spent over 20 years researching knee osteoarthritis. He is also the director of the Wake Forest Runners' Clinic, which uses the skills of physical therapists, orthopedic surgeons and biomechanists to determine the causes of overuse injuries in runners.
How prevalent is arthritis?
Over 70 million Americans are afflicted with some form of arthritis. With nearly 1 out of every 4 people afflicted with arthritis, I would suggest we are in the midst of an epidemic.
Our knees are particularly vulnerable as we age, correct?
Osteoarthritis is said to be the inevitable consequence of aging and is widely considered the leading cause of disability in the elderly. The knee is the most often affected weight-bearing joint. Knee osteoarthritis causes a decrease in physical function that is associated with mobility impairment and with mobility impairment comes an accelerated decline from independent living to disability and assisted living.
What is the goal of your research?
To slow the progression of the disease and provide older adults with more years of independent living and a good quality of life.
How do you incorporate your research into your classes?
My research on osteoarthritis in older adults and overuse injuries in runners fit very nicely into the two courses I teach, Human Gross Anatomy and Biomechanics of Human Motion. I often use examples from my research when discussing the effects of aging on physical function.
When did you begin exploring knee osteoarthritis?
Our first major clinical trial began in 1991 and was called the Fitness Arthritis and Seniors Trial or FAST. The study was designed to determine whether aerobic and weight-training exercise improved function and mobility in older adults with knee osteoarthritis.
We had a group that performed aerobic exercise, a group that performed resistance training and a control group that did neither. Both intervention groups were significantly less disabled than the control group after 18 months. The weight-training group performed the best on the balance measures but both exercise groups had better balance than the control group.
Balance is important for older people. Falls are the leading cause of death and injury in adults over 65. Only one half of older adults hospitalized due to a fall are alive after one year.
Can exercise help delay or avoid knee osteoarthritis?
Yes, but exercise can also alleviate the pain associated with the disease once it has begun. Exercise is a safe and effective therapy that slows the decline in physical function due to knee osteoarthritis and it should be part of the treatment regime for older adults with this disease.
Have you researched the role of weight in contributing to knee osteoarthritis?
The results from our first clinical trial led us to develop the Arthritis Diet and Activity Promotion Trial or ADAPT. In ADAPT, we examined the effects of exercise and diet, both separately and in combination, on physical function in older overweight and obese adults with knee osteoarthritis. The subjects were randomized to one of four groups: exercise, diet, exercise and diet, and a health education control group.
Both weight-loss groups-diet and exercise and diet-lost significantly more weight relative to the healthy lifestyle control group. In addition, we found that each pound of weight lost resulted in a 4-fold reduction in the load exerted on the knee per step during daily activities. Accumulated over thousands of steps per day, a reduction of this magnitude might be clinically meaningful.
So weight loss and exercise are keys to less knee pain?
Yes. Weight loss is the most modifiable risk factor for knee osteoarthritis. So, based on our findings, diet plus exercise should be an integral part of any treatment program for older overweight and obese adults with symptomatic knee osteoarthritis.
Weight loss is easy to recommend but difficult to accomplish. With gastric bypass surgery becoming increasingly common, many question whether natural weight loss is too difficult. But the answer seems partially to be that doctors do not discuss weight loss with their patients. According to previously published studies, only 42% of older obese adults who visit a doctor are advised to lose weight, and only 42 seconds of the office visit are spent discussing diet and exercise. People need regular attention to succeed.
What is the next step in your research?
We suspect that weight loss will not only reduce knee joint loads but will improve gait mechanics. This, in turn, will decrease subchondral tissue damage and reduce cartilage loss. Weight loss will also impact the inflammatory pathway by decreasing pro-inflammatory cytokines resulting in less joint destruction.
And you have started a new clinical trial?
Intensive Diet and Exercise for Arthritis (IDEA) consists of three intervention groups of 150 per group. There is an exercise only control group consisting of two- to 15-minute exercise periods separated by a 20-minute resistance-training period; a diet-only group whose weight loss goal is 10% to 14% of body weight; and a combination of diet plus exercise group.
What do you hope to discover in this clinical trial?
We hope to impact both of the biomechanical and inflammatory disease pathways. IDEA will determine whether intensive weight loss reduces joint loads, improves inflammation, and most importantly slows disease progression compared to an exercise only control group and a combination of intensive weight loss plus exercise.
How do students help with your research?
Last year we had 18 undergraduate students volunteer with the IDEA program. They perform a variety of duties ranging from assisting in biomechanics gait analysis, nutrition intervention, exercise intervention, data entry, and accompanying patients for tests conducted at the medical school. We could not run our program without their help, and in return they get valuable experience working on a major clinical trial.