Knee osteoarthritis has doubled in prevalence since the mid-20th century
Knee osteoarthritis (OA) is believed to be highly prevalent today because of recent increases in life expectancy and body mass index (BMI), but this assumption has not been tested using long-term historical or evolutionary data. We analyzed long-term trends in knee OA prevalence in the United States using cadaver-derived skeletons of people aged ≥50 y whose BMI at death was documented and who lived during the early industrial era (1800s to early 1900s; n = 1,581) and the modern postindustrial era (late 1900s to early 2000s; n = 819). Our results indicate that increases in longevity and BMI are insufficient to explain the approximate doubling of knee OA prevalence that has occurred in the United States since the mid-20th century. Knee OA is thus more preventable than is commonly assumed, but prevention will require research on additional independent risk factors that either arose or have become amplified in the postindustrial era.
Wallace, Ian J., Steven Worthington, David T. Felson, Robert D. Jurmain, Kimberly T. Wren, Heli Maijanen, Robert J. Woods, and Daniel E. Lieberman. “Knee Osteoarthritis Has Doubled in Prevalence since the Mid-20th Century.” Proceedings of the National Academy of Sciences 114, no. 35 (August 29, 2017): 9332–36. https://doi.org/10.1073/pnas.1703856114.
The link between metabolic syndrome and certain forms of osteoarthritis:
MetS have a cumulative and negative effect on forms of osteoarthritis occurrence, independent of weight.
Courties, Alice, Jérémie Sellam, and Francis Berenbaum. “Metabolic Syndrome-Associated Osteoarthritis:” Current Opinion in Rheumatology 29, no. 2 (March 2017): 214–22. https://doi.org/10.1097/BOR.0000000000000373.