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Would Reducing Obesity Save Thousands of Knees?



On most days, our obesity clinic could easily be confused with an orthopedic clinic given the sheer number of patients who present with severe pains in their backs, knees, hips, and ankles – often to the point of immobility.

It turns out (perhaps not surprisingly) that today, obesity and knee osteoarthritis are among the most frequent chronic conditions affecting Americans aged 50 to 84 years – my guess is that these conditions are no less frequent among Canadians.

Given the high prevalence of both obesity and knee osteoarthritis and their very significant impact on quality of life, Losina and a team of researchers from Harvard, Boston University, Chapel Hill, Yale and the University of Sydney undertook the rather momentous task of estimating the impact of these conditions on morbidity and mortality in older Americans. Their results were now published in the Annals of Internal Medicine.

The researchers based their analyses on U.S. Census and national obesity data with estimated prevalence of symptomatic knee osteoarthritis, whereby they assigned the US population aged 50 to 84 years to four subpopulations: nonobese without knee osteoarthritis (reference group), nonobese with knee osteoarthritis, obese without knee osteoarthritis, and obese with knee osteoarthritis.

They then used a computer simulation model (The Osteoarthritis Policy Model) to estimate quality-adjusted life-year losses due to knee osteoarthritis and obesity and to determine health benefits of reducing obesity prevalence to levels observed a decade ago.

It turns out that the estimated total losses of per-person quality-adjusted life-years ranged from around 2 years in nonobese persons with knee osteoarthritis to about 3.5 years for persons affected by both conditions. Although these numbers may not sound shocking, they actually represent 10% to 25% of the remaining quality-adjusted survival of persons aged 50 to 84 years.

When calculated for the entire US population in that age range, this amounts to a staggering 86 million quality-adjusted lost to these conditions.

The researchers also calculate that reversing obesity prevalence to levels seen 10 years ago would avert just over 110,000 total knee replacements – so reducing obesity (even to where it was just 10 years ago) could indeed save a substantial number of knees.

What the paper of course does not disclose is how exactly such a reversal in obesity rates could possibly be achieved.

Clearly, the impact of weight loss on knee (and other) pain that we see in our clinic is often dramatic, but achieving weight loss for someone who is already immobilised by knee (or other) pain is definitely a challenge.

I’d certainly love to hear from my readers on how knee (or other) pain has affected their weight and whether or not they have experienced improvement in their knee (or other) pain with weight loss.

AMS
Edmonton, Alberta

Losina E, Walensky RP, Reichmann WM, Holt HL, Gerlovin H, Solomon DH, Jordan JM, Hunter DJ, Suter LG, Weinstein AM, Paltiel AD, & Katz JN (2011). Impact of obesity and knee osteoarthritis on morbidity and mortality in older americans. Annals of internal medicine, 154 (4), 217-26 PMID: 21320937

12 Comments

  1. I have had a weight problem my entire life. I am now 48. I had my first knee surgery at age 13. My knee cap continually slipped from the joint. I had repeated injuries over many years. At age 37 I was diagnosed with arthritis in that knee and 4 years later I was diagnosed with arthritis in the hip on the same side. Because of my weight problems walking was painful, even short distances, and just sitting would cause aching. In addition, waking up in the morning and getting out of bed was extremely painful to the point whereby I could barely walk.Over the past 3.5 years I lost over 100 pounds and am close to “normal” in terms of weight. I am happy to report that all symptoms of my arthritis have completely disappeared and I can even jog now. How exciting is that! It is really amazing to be truthful.

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  2. I’m certainly hoping that weight reduction is going to improve my mobility (still recovering from a meniscus tear in one of my knees).

    One comment though. I’m on a crusade calling out places where I see obesity blamed for a particular disease/condition where it may be correlation, not causation. That said, I’ve been willing to grant that when it comes to joint issues, you have to look at excess weight as largely *the* cause.

    That said, I thought this post over at Dr. Davis’ Heart Scan blog on “wheat hip” (http://www.heartscanblog.org/2010/08/wheat-hip.html) was interesting. It may not be as simple as excess weight wrt joints; diet may play a big role here as well as elsewhere.

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  3. “What the paper of course does not disclose is how exactly such a reversal in obesity rates could possibly be achieved.” — right.

    I would argue for a radically different approach toward prevention that focused on strategies to achieve the best possible weight in children/young people who have a propensity for weight gain. A focus away from weight, and on developing strength, psychological well-being, balance, eating healthfully, with the idea of trying to avoid unnecessary weight gain but not in an obsessive way. This would certainly require altering our food environment as well.

    For people who are already suffering from pain that is exacerbated by excess weight — doing whatever is possible to regain mobility and have the best life possible, and if losing weight contributes to that aim, that’s the individual’s own decision to make about quality of life, and how best to get there. But for many who are carrying excess weight — losing long-term may be extremely difficult — or it may be extremely difficult to lose sufficient weight and maintain that loss to make a big difference. Hats off to those who do achieve it — I’m sure that the increase in mobility is a positive reward that keeps them on track. Weight stigma is probably part of what keeps people away from seeing doctors who may be able to help earlier in the disease process. So addressing that could go a long way in terms of seeing people at risk for these sorts of problems earlier on — when they might be able to see benefits of a sustainable 10% weight loss — and with increased mobility at that point, may be able to move more and not continue to gain weight.

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  4. I have been in the WeightWise program for 2 years now and have lost over 100 lbs. due to injuring both of my knees in falls in the previous 5 years, I have arthritis in both of them. I have noticed a significant decrease in my knee pain and increase in mobility in my legs since my weight loss. I can definately say that my weight loss has had a huge impact on that.

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  5. As a younger man, I was quite athletic. Like many athletic and active people, I could eat pretty much as many calories as I wished. An injury to my knee, however, changed everything. My activity level dropped off as I recovered from the injury, but my food consumption did not. I gained 75lbs in less than a year, and have been at that weight, or higher, ever since.

    The increased weight has been cited as an aggravating factor for my knee pain. The weight and the injury has made it impossible to engage in my preferred exercise, running, but I have been able to walk, cycle, swim and do resistance training. These have never resulted inn significant weight loss, but has allowed me to maintain with little attention to diet. Now, with some additional health issues arising with age (high blood pressure, high triglycerides, and diabetes), I am hoping that a new focus on nutrition, combined with my continued exercise, will result in some weight loss and, hopefully, some relief for my knee pain.

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  6. An important corollary to this problem is when an obese patient has advanced arthritis and is told by the orthopedic surgeon that they cannot have surgery UNLESS they lose weight. This is resonably done to lower any surgical risk. Many times the amount of weight loss requested is completely random and unrealistic. When these patients are sent to our clinic, it gives us a real and attainable goal to achieve and in many instances, the 10% sustained weight loss objective improves their pain and function without having to have surgery. Any comments?

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  7. A few years ago I began a walking program and ended up pulling some muscles in my leg. I used rest, ice, elevation, and continued walking a few days later. I injured myself again. After a few months I could barely walk on my right knee. X-rays showed I had some slight arthritis in both knees, but mostly in the left one — the one without pain. I ended up in physical therapy and now walk a mile a day. I also continue with the strength training (squats, a variety of leg lifts, etc) that I began in physical therapy.

    I don’t think that exercise would work for everyone, but so far it’s working fine for me.

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  8. In my late teens and early twenties I was quite athletic and did competition sports (Judo). I then injured my left knee when I slipped on a piece of meat working at a butcher shop and hitting a treshold with my knee cap. From that point on I didn’t do any sports anymore as it was just too painful even after months of physical therapy and I ended up gaining lb by lb year after year. In 2006 I got my referral into weight wise weighing in at 440lbs and I waited for 18 months to get accepted into the program barely able to walk from the parking lot to the clinic and I couldn’t stand more then 2 – 3 minutes. I had sleeve surgery in Oct 2008 and my life changed completely. As I lost weight I gained mobility and the pain in my (mainly) left knee got less and less and after about a year I even had some painfree days !!! What a change !! I started with swimming & Tai Chi back in Jan 2009 (3 months after surgery) and added weight, resistance & cardio with a personal trainer about a year ago. Ever since I started that I have hardly ever any pain in my knees …. they sometimes “pop” or “block” but only for a split second and then it’s fine again and not painful. I have lost 225lbs and counting …. I know the weight loss combined with exercise (low impact) did the trick for me and I hope I do not need any knee surgery after all as I am painfree now (and if I need at some point I have at least delayed by many years).

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  9. My immobility due to knee problems is what motivated me to undergo gastric band surgery. It was either that or a walker. Considerable improvement in mobility and quality of life started with only 10% weight loss.

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  10. I weigh about 300 lbs on a 6 ft frame (think female linebacker) and have structural birth defects in my knees, ankles, and feet. My doctor forbade me to run from a very early age due to the birth defects, but I was allowed to walk and to engage in other forms of exercise — such walking, tai chi, and upper-body weightlifting — that didn’t stress my knees, lower legs, or feet. I’ve walked a lot for my entire life, including having lived for the past 8 years in small towns where I walk everywhere. I don’t drive or own a car.

    For me, the key to good mobility and lack of pain has always been exercise. When I injured my weaker ankle about 7 years ago, I had to stop walking for a while until the injury healed. I had a lot of pain after I resumed walking. I found that slow, careful exercises designed to build up the strength and elasticity of the muscles of that foot and ankle helped a lot. Over about two or three months, I was able to resume normal walking (2 to 4 miles a day) and the pain went away.

    When I wrenched my knee last winter clambering over a snowbank, I had the exact same experience: pain and muscle weakness in the affected leg when I resumed walking, cut down to an endurable level by gentle exercise and cured entirely by continued effort. This time I had another factor, too; I now live in a two-story house so I have to climb stairs several times a day whether I want to or not. I practiced slowly, carefully going up and down stairs, with crutches or a cane at first, and then unsupported. I found that mindful attention to how I was placing my foot and shifitng my weight made a positive difference in how well I was able to climb the stairs and how much or little pain I suffered. (Thank you tai chi training for teaching me that!)

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  11. I’ve been “obese” (BMI of 30-37) since I reached my adult height at 11 or 12. However I was an active kid, an active teenager, and pretty active all my life. When I was 19, I was in a car accident. My left hip was dislocated and broken in two places at the joint. I went on to do a lot of walking, dance exercise, backpacking, skiing and rollerblading in my twenties and thirties, having decided in my early twenties to try to eat a healthy diet and stay active while letting my weight take care of itself (I stayed in my high school weight range – “type 1 obese”). In my late thirties, I developed severe trauma induced osteoarthritis in my left hip.

    I understand from my web based research that, considering my injuries, the same thing would likely have happened if I’d been thin. In the two years leading up to and following the hip replacement (I was 40), I gained around 20 pounds. Now, a year and a half after the hip replacement, I feel almost normal again and am ramping up my activity level. Maybe my weight will go back to normal, and maybe it won’t. My weight might have aggregated the joint issue. I don’t know – my right hip was fine when the problems with my left hip started. Frankly, I’m not convinced. Maybe being heavy put extra strain on the joint, but if I was undernourished, would I have mended as well as I did after the car accident and after the hip replacement?

    One thing that comes up again and again in medical studies is that fat people are resilient, and I certainly am.

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  12. I’ve been “obese” (BMI of 30-37) since I reached my adult height at 11 or 12. However I was an active kid, an active teenager, and pretty active all my life. When I was 19, I was in a car accident. My left hip was dislocated and broken in two places at the joint. I went on to do a lot of walking, dance exercise, backpacking, skiing and rollerblading in my twenties and thirties, having decided in my early twenties to try to eat a healthy diet and stay active while letting my weight take care of itself (I stayed in my high school weight range – “type 1 obese”). In my late thirties, I developed severe trauma induced osteoarthritis in my left hip.

    I understand from my web based research that, considering my injuries, the same thing would likely have happened if I’d been thin. In the two years leading up to and following the hip replacement (I was 40), I gained around 20 pounds. Now, a year and a half after the hip replacement, I feel almost normal again and am ramping up my activity level. Maybe my weight will go back to normal, and maybe it won’t. My weight might have aggregated the joint issue. I don’t know – my right hip was fine when the problems with my left hip started. Frankly, I’m not convinced. Maybe being heavy put extra strain on the joint, but if I was undernourished, would I have mended as well as I did after the car accident and after the hip replacement?

    One thing that comes up again and again in medical studies is that fat people are resilient, and I certainly am.

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