Role of Comorbid Military-Relevant Stressors in Osteoarthritis
Abstract
This proposal addresses FY21 PRMRP Topic Area: Arthritis in the Areas of Encouragement: a) Determine factors that lead to accelerated degeneration (post-traumatic osteoarthritis within 3 years) following military-relevant joint injuries. b) Research quantifying the impacts of obesity, weight loss, physical fitness (all components, e.g., cardiovascular, strength, flexibility, balance), and dietary factors on the development of or prevention/risk reduction of arthritis. The clinical problem: Twice as many military personnel have osteoarthritis than in civilian populations, and female Veterans are impacted to the greatest extent. In the knee, osteoarthritis is inevitable following combat knee injury, but develops following knee injury in only 23%-44% of civilians. In addition, the rate of progression of knee osteoarthritis is far more rapid in military and Veteran populations than in civilian populations. Arthritis is diagnosed in military personnel in many cases only 3-5 years after knee injury, with knee replacement being performed 10 years earlier in life in military and Veteran populations following knee injury, compared to civilians. The reason for the accelerated rate of development of knee osteoarthritis in military populations is unknown, but severity of injury is not the only factor associated with this accelerated development of knee osteoarthritis. Military occupations are stressful for a number of reasons: Osteoarthritis and post-traumatic stress disorder (PTSD) are among the most common conditions affecting Veterans, but the interactions between these conditions and the impact of other stressors relevant to military occupations have not been studied. Combat stress and post-traumatic stress disorder substantially change how pain is experienced, but there are a multitude of other stressors that up to half of military personnel experience. These other work-related stressors include length of deployment, unexpected deployment, exposure to adverse living conditions, unit morale, barriers to effective management of stress, low autonomy, change in work hours, long work hours, humanitarian deployments, periodic permanent change of station, and tendency for supervisor-employee conflict to be resolved in favor of supervisors. Military-relevant factors modulate pain thresholds. Just the experience of basic military training on entering the military increases pain thresholds, particularly in those with low pain thresholds initially. High levels of physical fitness are required for military readiness, and physical activity is generally beneficial in reducing the severity of diseases related to stress, and in increasing pain thresholds, but this is only true for physical activity that occurs in leisure time. Occupational physical activity is a stressor in military occupations, suggesting that the context of the physical activity is important for stress reduction and in maintaining normal pain thresholds. While high pain thresholds, or reduced ability to feel pain, are beneficial for survival in potentially life-threatening situations, sustained increases in pain thresholds could be detrimental over a military career and over the long term, because normal ability to feel pain in injured tissues is protective against further injury. There is some evidence to support this concept directly from combat Veterans with PTSD compared to civilian populations. PTSD is associated with chronic pain and increased pain sensitivity in most Veterans seeking treatment for PTSD, many of whom have osteoarthritis. However, in combat Veterans with PTSD but who do not have chronic pain, these Veterans are less sensitive to pain than would be expected, as are combat Veterans without PTSD, suggesting that other military factors could also be important in reduced pain perception in military personnel. These data potentially have important implications for progression of knee injury to osteoarthritis in active military personnel. If military p
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 28, 2022
- Source ID
- W81XWH2210885
Entities
People
- Dianne Little
Organizations
- Purdue University
- United States Army