Concerned about weight gain knee pain? It’s not often you see a study with almost a quarter million people, but one was just published showing an association between knee replacement risk and weight gain in young women and men. The issue of weight and knee arthritis has gone back and forth for a while. Most studies now show that it’s not necessarily only the mechanical impact of more weight on a knee that leads to arthritis, but also the impact of the metabolic syndrome that goes with all of that weight. Metabolic syndrome is the blood sugar instability that leads to type 2 diabetes. This blood sugar instability ultimately impacts the chemical environment of the joint-causing more bad chemicals that break it down.
This new study looked at 225,908 patients who were followed for more than 12 years. During that time, almost sixteen hundred patients had knee replacements. The researchers queried whether weight gain over that time was associated with a higher risk of needing knee replacement surgery. There was a strong association when the patients were younger, with young women having a 43% increased risk for every 11 pounds gained, which amounts to about a doubling of risk for every 22 pounds gained. Young men fared better, with a 26% increased risk for the same weight gain. The association was lost in older patients, so weight gain didn’t seem to impact the risk of a knee replacement in the elderly. Why? It’s likely that the “die is cast” by the time patients are older (i.e. they are either heading towards a certain knee replacement or not) and gaining weight doesn’t increase an already elevated risk.
The upshot? Weight gain is a significant issue that increases the likelihood of a joint replacement. Based at least on this huge registry study, it may be more important to take action when you’re younger, as shedding pounds when you’re older and once joint arthritis has set in, seems unlikely to impact your knee replacement risk.