According to data from the World Health Organization, more than 1.6 billion people are overweight worldwide and over 400 million people are obese, making obesity one of the leading causes of health problems and mortality in the world. Several studies have indicated a direct link between obesity and osteoarthritis as well as other musculoskeletal problems.
Osteoarthritis (OA) affects more than two-thirds of the population aged 65 years or
above. In America, this translates to 12.1% of the adult demographic, which is a staggering 27 million people. Currently, OA is the world’s most widely prevalent bone-joint ailment. Naturally, OA has a significant economic impact with millions of dollars in medical expenses every year to manage the condition [1].
OA is the most frequently appearing form of arthritis. The two biggest factors causing an increased OA risk are aging and obesity. It mainly occurs in hands, hips and knees. Joint pain is the most obvious symptom of this ailment. Deterioration and loss of articular cartilage is the cause of this pain, which initially occurs only when the affected joint is used. As OA progresses pain is constant even while sleeping or resting.
OA involves several methods of treatment of varying effectiveness, in both conventional and non-conventional systems of medicine. People can delay the onset of OA, or ameliorate symptoms with non-surgical procedures. These include medication, dietary and lifestyle changes, and acupuncture. In severe cases, where these methods do not provide adequate pain relief, surgery is an effective method of treatment.
Analgesics or non-steroidal anti-inflammatory medication are typically used in the pharmacological approach. However, many of these substances are known to have serious side-effects and particularly cause negative gastrointestinal reactions.
Consequently, pain relief medication is increasingly focusing on natural remedies and anti-inflammatory formulations, such as Eazol, as opposed to synthetic drugs. The successful Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) is an example of one such effort. Unsurprisingly, the positive results of the GAIT program now see over 5 million users in the U.S. alone, taking dietary supplements with glucosamine or chondroitin sulphate, such as the Joint Kote articular pain relief formula.
Excess Weight: Is It The Cause Of OA?
While being overweight is not necessarily the sole cause of arthritis, research has established a correlation between the two. Several studies across different geographic regions have found evidence indicating increased incidence of arthritis in overweight people.
A Scottish study with 858 people aged 58 and above found that the prevalence of joint pain was twice as high in overweight people. Another independent Australian study involving 7500 subjects also found that overweight adults are twice as likely to be diagnosed with arthritis [2].
OA Of The Knee and Excess Weight
Analyses of demographic patterns have indicated that people with a higher than normal body mass index (BMI) have a strong tendency to develop OA. For example, a study in Australia that followed 224 postmenopausal healthy women for a number of years found that the weight of these women at the beginning of the study was a good predictor of development of knee OA 11 years later [3].
Another study of 830 women compared the risk of developing OA for people of different BMI. Over a four-year period, the risk for OA was found to be twice as high for women with greater BMI. This may illustrate the significance of weight to OA risk, with a large increase in weight correlating with higher OA risk.
OA Of The Hip and Excess Weight
Unlike the knees, which have a greater ratio of weight to joint area, hips are subjected to relatively lighter loads, owing to increased area for distribution of weight. Common sense would, therefore, reason that excess weight may not have as strong an impact on hips as it does on knees. Such reasoning has been verified by some studies, although many others present contradictory information.
A cross-sectional study with a large test base of more than 2000 people over 55 years of age, found no link between obesity and hip OA. As previously mentioned, other studies have found conflicting evidence. A Norwegian study of 1.2 million people, for example, demonstrated a 3.4 fold higher risk of undergoing hip arthroplasty among men with a BMI greater than 32, as opposed to those with BMI less than 21 [4].
Another independent study comparing individuals aged 18, found a massive five-fold increase in risk for hip replacement at a later age, for those with high BMI.
OA of the Hand and Excess Weight
As discussed in the previous section, one may reason that the reduction of load on a joint may make the joint less susceptible to weight or obesity induced OA. Clearly, several studies have shown that this line of reasoning is incorrect.
A good case in point would be to study OA risk correlated to weight, for hand joints. Hands are not weight-bearing joints, in the conventional sense of the term. The amount of body load imposed on hand joints is nowhere comparable to that experienced by hip or knee joints.
Thus, studies indicating an increased OA risk for hand joints in overweight people may demonstrate that load imposed on a joint is not necessarily the sole factor influencing OA risk. Interestingly enough, quite a few studies have demonstrated this. Yet, while mechanical stress may not be the culprit, there is still a definite correlation between obesity and increased OA risk for hand joints.
OA And Obesity: Which Causes Which?
Research data may demonstrate a relationship between obesity and OA. In statistics, however, correlation may not necessarily imply causality. This raises the important question – does obesity lead to OA, or is it the other way round? The question isn’t as light as it may seem at first sight. After all, it may be the case that individuals have gained excess weight as a result of lifestyle limitations imposed by painful OA.
Several studies have attempted to resolve this question. One such study assessed a group of 1420 healthy subjects over an extensive period of 36 years. Subjects in the study, who were overweight but otherwise healthy at age 37, were found to be more likely of developing OA, later in life.
Such a finding does indeed show that overweight individuals are at greater risk of developing OA. This strongly suggests that OA might be caused by obesity, although it does not eliminate the possibility that once OA develops, it may contribute to weight increase.
Conclusion
Excess weight and obesity, best gauged through a measure of high BMI, are important factors influencing OA. Marked and dramatic increases in knee OA risk have been associated with obesity. In comparison, a lesser yet positive correlation has been established between obesity and increased OA risk for hand and hip joints.
While establishing unidirectional causality is tedious, from the perspective of well-being, weight reduction is recommended as an important aspect of OA prevention and treatment. This is particularly true for OA of the knees.
About The Author
Matthew Dinnos, PhD, is a writer and researcher. His articles focus on obesity and its co-morbidities. Matthew finds particularly encouraging and worthy of further investigation the fact that weight loss can alleviate joint pain. Matthew offers a Bistro MD coupon code and a promotion code for Diet To Go, two meal replacement diet programs in the US, considered by many as best rated weight loss programs.
References
1. Insurer and out-of-pocket costs of osteoarthritis in the US: evidence from national survey data.Kotlarz H, Gunnarsson CL, Fang H, Rizzo JA.Arthritis Rheum. 2009 Dec;60(12):3546-53
2. Role of age, sex, and obesity in the higher prevalence of arthritis among lower socioeconomic groups: a population-based survey. Busija L, Hollingsworth B, Buchbinder R, Osborne RH. The University of Melbourne, Melbourne, Victoria, Australia.
3. Szoeke C, Dennerstein L, Guthrie J, Clark M, Cicuttini F. The relationship between prospectively assessed body weight and physical activity and prevalence of radiological knee osteoarthritis in postmenopausal women. J Rheumatol 2006;33:1835–40
4. The impact of body mass index on later total hip arthroplasty for primary osteoarthritis: a cohort study in 1.2 million persons. Flugsrud GB, Nordsletten L, Espehaug B, Havelin LI, Engeland A, Meyer HE. Arthritis Rheum. 2006 Mar;54(3):802-7.
Obesity And Osteoarthritis
obesity, osteoarthritis