According to a significant study, losing weight and reducing BMI may help you postpone, slow down, or even stop the worsening of degenerative knee arthritis.
In an interview, senior study author Amanda Sainsbury, PhD, professor of obesity research at the University of Western Australia in Perth, explains that her team’s findings “showed that the more weight that is lost, the greater the apparent benefit for preventing or delaying degradation of knee joints in osteoarthritis.”
A person who weighs 220 pounds and loses 22 pounds, for instance, “is likely to get double the benefit” compared to someone who loses 11 pounds, according to Sainsbury.
The study was released in the “Arthritis & Rheumatology” publication.
Knee osteoarthritis, also known as wear-and-tear arthritis, is characterised by the loss of shock-absorbing cartilage cushioning between the joints. As a result, the bones in the joints rub more closely against one another, resulting in stiffness, swelling, and pain that can impair mobility and result in disability.
The most prevalent kind of arthritis, osteoarthritis, typically affects the hands, hips, and knees, according to the CDC. More than 32.5 million persons in the United States are affected by the illness, which mostly affects people over 50 but can sometimes strike younger people. Since there is no known treatment for osteoarthritis, doctors treat its symptoms with physical therapy, medications, crutches or canes, surgery, and by advising patients to lose weight and follow a healthy diet to relieve pain, reduce pressure on the joints, and slow joint degeneration.
Sainsbury’s research team examined X-rays of the knees of adult participants in three separate trials conducted in the Netherlands and the United States to investigate how changes in BMI may affect knee osteoarthritis.
The “incidence cohort,” which consisted of 9,683 knees from 5,774 people who did not have structural osteoarthritis at the beginning of the trial, and the “progression cohort,” which consisted of 6,075 knees from 3,988 people who did, were separated into two groups.
The participants in both groups were roughly 60 years old on average, over 60% of them were female, and more than 80% were white. However, the prevalence of obesity varied between the groups: almost one-third of those in the incidence group and almost half of those in the progression group were obese (classified as having a BMI of 30 or more).
Researchers analysed data from the three studies and discovered a favourable correlation between changes in BMI over a 4- to 5-year period and the onset and progression of structural abnormalities associated with knee osteoarthritis, particularly in the inner joints.
People with normal weight also experienced benefits.
Losing 1 BMI unit decreased a person’s risk of knee osteoarthritis structural abnormalities by 4.76%. Losing 5 BMI units, which can move a person from one category to another, such as from being overweight to normal, decreased a person’s chances by 21.65%.
According to lead study author Zübeyir Salis, BEng, a PhD candidate in Public Health at the University of New South Wales in Kensington, “Weight loss is emerging as a promising therapy for potentially avoiding and delaying osteoarthritic deterioration of knee joints.”
Two experts who were not involved in the study applaud its findings.
Strengths of the study, according to Eduardo Grunvald, MD, FACP, professor of medicine at UC San Diego and medical director of the weight management programme, include the sizeable sample size drawn from three databases, the lengthy follow-up period, and statistical analysis.
However, he is curious as to whether the alterations in BMI caused the knee changes or vice versa. “A person’s developing knee pain may cause them to engage in less physical activity and possibly gain weight.
“Maintaining weight loss over the long term is quite difficult, and for best results, health care providers who treat joint illness should collaborate with specialists trained to manage obesity,” he says.
This study is significant because it disproves the idea that once you have “bone on bone,” a knee replacement is your only option, according to Caroline M. Apovian, MD, co-director of the Center for Weight Management and Wellness at Brigham and Women’s Hospital in Boston.
According to her, “Providers can now safely advise weight loss as a method to avoid knee replacement in some individuals.” Weight loss is beneficial at every stage.
To increase the applicability of the findings, Apovian would want to see comparable studies in minority groups.
The authors intend to do additional related study. This study, which was not a randomised controlled trial, found a correlation between lower BMI and better outcomes but not causation. They must carry out a randomised controlled trial to demonstrate that.